#filter substitution
// -*- Mode: js2; tab-width: 2; indent-tabs-mode: nil; js2-basic-offset: 2; js2-skip-preprocessor-directives: t; -*-
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";

let Cc = Components.classes;
let Ci = Components.interfaces;
let Cu = Components.utils;
let Cr = Components.results;

Cu.import("resource://gre/modules/XPCOMUtils.jsm");
Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/AddonManager.jsm");
Cu.import("resource://gre/modules/FileUtils.jsm");
Cu.import("resource://gre/modules/JNI.jsm");

#ifdef ACCESSIBILITY
Cu.import("resource://gre/modules/accessibility/AccessFu.jsm");
#endif

XPCOMUtils.defineLazyGetter(this, "PluralForm", function() {
  Cu.import("resource://gre/modules/PluralForm.jsm");
  return PluralForm;
});

XPCOMUtils.defineLazyGetter(this, "DebuggerServer", function() {
  Cu.import("resource://gre/modules/devtools/dbg-server.jsm");
  return DebuggerServer;
});

XPCOMUtils.defineLazyGetter(this, "NetUtil", function() {
  Cu.import("resource://gre/modules/NetUtil.jsm");
  return NetUtil;
});

#ifdef MOZ_SAFE_BROWSING
XPCOMUtils.defineLazyGetter(this, "SafeBrowsing", function() {
  let tmp = {};
 Cu.import("resource://gre/modules/SafeBrowsing.jsm", tmp);
  return tmp.SafeBrowsing;
});
#endif

XPCOMUtils.defineLazyGetter(this, "PrivateBrowsingUtils", function() {
  Cu.import("resource://gre/modules/PrivateBrowsingUtils.jsm");
  return PrivateBrowsingUtils;
});

// Lazily-loaded browser scripts:
[
  ["HelperApps", "chrome://browser/content/HelperApps.js"],
  ["SelectHelper", "chrome://browser/content/SelectHelper.js"],
  ["InputWidgetHelper", "chrome://browser/content/InputWidgetHelper.js"],
  ["AboutReader", "chrome://browser/content/aboutReader.js"],
  ["WebAppRT", "chrome://browser/content/WebAppRT.js"],
].forEach(function (aScript) {
  let [name, script] = aScript;
  XPCOMUtils.defineLazyGetter(window, name, function() {
    let sandbox = {};
    Services.scriptloader.loadSubScript(script, sandbox);
    return sandbox[name];
  });
});

XPCOMUtils.defineLazyServiceGetter(this, "Haptic",
  "@mozilla.org/widget/hapticfeedback;1", "nsIHapticFeedback");

XPCOMUtils.defineLazyServiceGetter(this, "DOMUtils",
  "@mozilla.org/inspector/dom-utils;1", "inIDOMUtils");

XPCOMUtils.defineLazyServiceGetter(window, "URIFixup",
  "@mozilla.org/docshell/urifixup;1", "nsIURIFixup");

#ifdef MOZ_WEBRTC
XPCOMUtils.defineLazyServiceGetter(this, "MediaManagerService",
  "@mozilla.org/mediaManagerService;1", "nsIMediaManagerService");
#endif

const kStateActive = 0x00000001; // :active pseudoclass for elements

const kXLinkNamespace = "http://www.w3.org/1999/xlink";

// The element tag names that are considered to receive input. Mouse-down
// events directed to one of these are allowed to go through.
const kElementsReceivingInput = {
    applet: true,
    audio: true,
    button: true,
    embed: true,
    input: true,
    map: true,
    select: true,
    textarea: true,
    video: true
};

const kDefaultCSSViewportWidth = 980;
const kDefaultCSSViewportHeight = 480;

function dump(a) {
  Cc["@mozilla.org/consoleservice;1"].getService(Ci.nsIConsoleService).logStringMessage(a);
}

function getBridge() {
  return Cc["@mozilla.org/android/bridge;1"].getService(Ci.nsIAndroidBridge);
}

function sendMessageToJava(aMessage) {
  return getBridge().handleGeckoMessage(JSON.stringify(aMessage));
}

#ifdef MOZ_CRASHREPORTER
Cu.import("resource://gre/modules/XPCOMUtils.jsm");
XPCOMUtils.defineLazyServiceGetter(this, "CrashReporter",
  "@mozilla.org/xre/app-info;1", "nsICrashReporter");
#endif

XPCOMUtils.defineLazyGetter(this, "ContentAreaUtils", function() {
  let ContentAreaUtils = {};
  Services.scriptloader.loadSubScript("chrome://global/content/contentAreaUtils.js", ContentAreaUtils);
  return ContentAreaUtils;
});

XPCOMUtils.defineLazyGetter(this, "Rect", function() {
  Cu.import("resource://gre/modules/Geometry.jsm");
  return Rect;
});

function resolveGeckoURI(aURI) {
  if (aURI.indexOf("chrome://") == 0) {
    let registry = Cc['@mozilla.org/chrome/chrome-registry;1'].getService(Ci["nsIChromeRegistry"]);
    return registry.convertChromeURL(Services.io.newURI(aURI, null, null)).spec;
  } else if (aURI.indexOf("resource://") == 0) {
    let handler = Services.io.getProtocolHandler("resource").QueryInterface(Ci.nsIResProtocolHandler);
    return handler.resolveURI(Services.io.newURI(aURI, null, null));
  }
  return aURI;
}

function shouldShowProgress(url) {
  return (url != "about:home" && !/^about:reader/.test(url));
}

/**
 * Cache of commonly used string bundles.
 */
var Strings = {};
[
  ["brand",      "chrome://branding/locale/brand.properties"],
  ["browser",    "chrome://browser/locale/browser.properties"],
  ["charset",    "chrome://global/locale/charsetTitles.properties"]
].forEach(function (aStringBundle) {
  let [name, bundle] = aStringBundle;
  XPCOMUtils.defineLazyGetter(Strings, name, function() {
    return Services.strings.createBundle(bundle);
  });
});

var BrowserApp = {
  _tabs: [],
  _selectedTab: null,

  deck: null,

  startup: function startup() {
    window.QueryInterface(Ci.nsIDOMChromeWindow).browserDOMWindow = new nsBrowserAccess();
    dump("zerdatime " + Date.now() + " - browser chrome startup finished.");

    this.deck = document.getElementById("browsers");
    BrowserEventHandler.init();
    ViewportHandler.init();

    getBridge().browserApp = this;

    Services.obs.addObserver(this, "Tab:Load", false);
    Services.obs.addObserver(this, "Tab:Selected", false);
    Services.obs.addObserver(this, "Tab:Closed", false);
    Services.obs.addObserver(this, "Session:Back", false);
    Services.obs.addObserver(this, "Session:Forward", false);
    Services.obs.addObserver(this, "Session:Reload", false);
    Services.obs.addObserver(this, "Session:Stop", false);
    Services.obs.addObserver(this, "SaveAs:PDF", false);
    Services.obs.addObserver(this, "Browser:Quit", false);
    Services.obs.addObserver(this, "Preferences:Get", false);
    Services.obs.addObserver(this, "Preferences:Set", false);
    Services.obs.addObserver(this, "ScrollTo:FocusedInput", false);
    Services.obs.addObserver(this, "Sanitize:ClearData", false);
    Services.obs.addObserver(this, "FullScreen:Exit", false);
    Services.obs.addObserver(this, "Viewport:Change", false);
    Services.obs.addObserver(this, "Viewport:Flush", false);
    Services.obs.addObserver(this, "Passwords:Init", false);
    Services.obs.addObserver(this, "FormHistory:Init", false);
    Services.obs.addObserver(this, "ToggleProfiling", false);
    Services.obs.addObserver(this, "gather-telemetry", false);

    Services.obs.addObserver(this, "sessionstore-state-purge-complete", false);

    function showFullScreenWarning() {
      NativeWindow.toast.show(Strings.browser.GetStringFromName("alertFullScreenToast"), "short");
    }

    window.addEventListener("fullscreen", function() {
      sendMessageToJava({
        gecko: {
          type: window.fullScreen ? "ToggleChrome:Show" : "ToggleChrome:Hide"
        }
      });
    }, false);

    window.addEventListener("mozfullscreenchange", function() {
      sendMessageToJava({
        gecko: {
          type: document.mozFullScreen ? "DOMFullScreen:Start" : "DOMFullScreen:Stop"
        }
      });

      if (document.mozFullScreen)
        showFullScreenWarning();
    }, false);

    // When a restricted key is pressed in DOM full-screen mode, we should display
    // the "Press ESC to exit" warning message.
    window.addEventListener("MozShowFullScreenWarning", showFullScreenWarning, true);

    NativeWindow.init();
    SelectionHandler.init();
    LightWeightThemeWebInstaller.init();
    Downloads.init();
    FindHelper.init();
    FormAssistant.init();
    OfflineApps.init();
    IndexedDB.init();
    XPInstallObserver.init();
    ConsoleAPI.init();
    ClipboardHelper.init();
    PermissionsHelper.init();
    CharacterEncoding.init();
    ActivityObserver.init();
    WebappsUI.init();
    RemoteDebugger.init();
    Reader.init();
    UserAgent.init();
    ExternalApps.init();
    MemoryObserver.init();
    Distribution.init();
    Tabs.init();
#ifdef MOZ_TELEMETRY_REPORTING
    Telemetry.init();
#endif
#ifdef ACCESSIBILITY
    AccessFu.attach(window);
#endif
#ifdef MOZ_WEBRTC
    WebrtcUI.init();
#endif

    // Init LoginManager
    Cc["@mozilla.org/login-manager;1"].getService(Ci.nsILoginManager);
    // Init FormHistory
    Cc["@mozilla.org/satchel/form-history;1"].getService(Ci.nsIFormHistory2);

    let url = null;
    let pinned = false;
    if ("arguments" in window) {
      if (window.arguments[0])
        url = window.arguments[0];
      if (window.arguments[1])
        gScreenWidth = window.arguments[1];
      if (window.arguments[2])
        gScreenHeight = window.arguments[2];
      if (window.arguments[3])
        pinned = window.arguments[3];
    }

    let updated = this.isAppUpdated();
    if (pinned) {
      WebAppRT.init(updated, url).then(function(aUrl) {
        BrowserApp.addTab(aUrl);
      }, function() {
        let uri = Services.io.newURI(url, null, null);
        if (!uri)
          return;
        Cc["@mozilla.org/uriloader/external-protocol-service;1"].getService(Ci.nsIExternalProtocolService).getProtocolHandlerInfo(uri.scheme).launchWithURI(uri);
        BrowserApp.quit();
      });
    } else {
      SearchEngines.init();
      this.initContextMenu();
    }

    // XXX maybe we don't do this if the launch was kicked off from external
    Services.io.offline = false;

    // Broadcast a UIReady message so add-ons know we are finished with startup
    let event = document.createEvent("Events");
    event.initEvent("UIReady", true, false);
    window.dispatchEvent(event);

    if (updated)
      this.onAppUpdated();

    // Store the low-precision buffer pref
    this.gUseLowPrecision = Services.prefs.getBoolPref("layers.low-precision-buffer");

    // notify java that gecko has loaded
    sendMessageToJava({
      gecko: {
        type: "Gecko:Ready"
      }
    });

#ifdef MOZ_SAFE_BROWSING
    // Bug 778855 - Perf regression if we do this here. To be addressed in bug 779008.
    setTimeout(function() { SafeBrowsing.init(); }, 5000);
#endif
  },

  isAppUpdated: function() {
    let savedmstone = null;
    try {
      savedmstone = Services.prefs.getCharPref("browser.startup.homepage_override.mstone");
    } catch (e) {
    }
#expand    let ourmstone = "__MOZ_APP_VERSION__";
    if (ourmstone != savedmstone) {
      Services.prefs.setCharPref("browser.startup.homepage_override.mstone", ourmstone);
      return savedmstone ? "upgrade" : "new";
    }
    return "";
  },

  initContextMenu: function ba_initContextMenu() {
    // TODO: These should eventually move into more appropriate classes
    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.openInNewTab"),
      NativeWindow.contextmenus.linkOpenableNonPrivateContext,
      function(aTarget) {
        let url = NativeWindow.contextmenus._getLinkURL(aTarget);
        BrowserApp.addTab(url, { selected: false, parentId: BrowserApp.selectedTab.id });

        let newtabStrings = Strings.browser.GetStringFromName("newtabpopup.opened");
        let label = PluralForm.get(1, newtabStrings).replace("#1", 1);
        NativeWindow.toast.show(label, "short");
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.openInPrivateTab"),
      NativeWindow.contextmenus.linkOpenableContext,
      function(aTarget) {
        let url = NativeWindow.contextmenus._getLinkURL(aTarget);
        BrowserApp.addTab(url, { selected: false, parentId: BrowserApp.selectedTab.id, isPrivate: true });

        let newtabStrings = Strings.browser.GetStringFromName("newprivatetabpopup.opened");
        let label = PluralForm.get(1, newtabStrings).replace("#1", 1);
        NativeWindow.toast.show(label, "short");
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.copyLink"),
      NativeWindow.contextmenus.linkCopyableContext,
      function(aTarget) {
        let url = NativeWindow.contextmenus._getLinkURL(aTarget);
        NativeWindow.contextmenus._copyStringToDefaultClipboard(url);
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.copyEmailAddress"),
      NativeWindow.contextmenus.emailLinkContext,
      function(aTarget) {
        let url = NativeWindow.contextmenus._getLinkURL(aTarget);
        let emailAddr = NativeWindow.contextmenus._stripScheme(url);
        NativeWindow.contextmenus._copyStringToDefaultClipboard(emailAddr);
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.copyPhoneNumber"),
      NativeWindow.contextmenus.phoneNumberLinkContext,
      function(aTarget) {
        let url = NativeWindow.contextmenus._getLinkURL(aTarget);
        let phoneNumber = NativeWindow.contextmenus._stripScheme(url);
        NativeWindow.contextmenus._copyStringToDefaultClipboard(phoneNumber);
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.shareLink"),
      NativeWindow.contextmenus.linkShareableContext,
      function(aTarget) {
        let url = NativeWindow.contextmenus._getLinkURL(aTarget);
        let title = aTarget.textContent || aTarget.title;
        NativeWindow.contextmenus._shareStringWithDefault(url, title);
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.shareEmailAddress"),
      NativeWindow.contextmenus.emailLinkContext,
      function(aTarget) {
        let url = NativeWindow.contextmenus._getLinkURL(aTarget);
        let emailAddr = NativeWindow.contextmenus._stripScheme(url);
        let title = aTarget.textContent || aTarget.title;
        NativeWindow.contextmenus._shareStringWithDefault(emailAddr, title);
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.sharePhoneNumber"),
      NativeWindow.contextmenus.phoneNumberLinkContext,
      function(aTarget) {
        let url = NativeWindow.contextmenus._getLinkURL(aTarget);
        let phoneNumber = NativeWindow.contextmenus._stripScheme(url);
        let title = aTarget.textContent || aTarget.title;
        NativeWindow.contextmenus._shareStringWithDefault(phoneNumber, title);
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.bookmarkLink"),
      NativeWindow.contextmenus.linkBookmarkableContext,
      function(aTarget) {
        let url = NativeWindow.contextmenus._getLinkURL(aTarget);
        let title = aTarget.textContent || aTarget.title || url;
        sendMessageToJava({
          gecko: {
            type: "Bookmark:Insert",
            url: url,
            title: title
          }
        });
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.playMedia"),
      NativeWindow.contextmenus.mediaContext("media-paused"),
      function(aTarget) {
        aTarget.play();
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.pauseMedia"),
      NativeWindow.contextmenus.mediaContext("media-playing"),
      function(aTarget) {
        aTarget.pause();
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.showControls2"),
      NativeWindow.contextmenus.mediaContext("media-hidingcontrols"),
      function(aTarget) {
        aTarget.setAttribute("controls", true);
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.shareMedia"),
      NativeWindow.contextmenus.SelectorContext("video"),
      function(aTarget) {
        let url = (aTarget.currentSrc || aTarget.src);
        let title = aTarget.textContent || aTarget.title;
        NativeWindow.contextmenus._shareStringWithDefault(url, title);
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.fullScreen"),
      NativeWindow.contextmenus.SelectorContext("video:not(:-moz-full-screen)"),
      function(aTarget) {
        aTarget.mozRequestFullScreen();
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.copyImageLocation"),
      NativeWindow.contextmenus.imageLocationCopyableContext,
      function(aTarget) {
        let url = aTarget.src;
        NativeWindow.contextmenus._copyStringToDefaultClipboard(url);
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.shareImage"),
      NativeWindow.contextmenus.imageSaveableContext,
      function(aTarget) {
        let doc = aTarget.ownerDocument;
        let imageCache = Cc["@mozilla.org/image/tools;1"].getService(Ci.imgITools)
                                                         .getImgCacheForDocument(doc);
        let props = imageCache.findEntryProperties(aTarget.currentURI, doc.characterSet);
        let src = aTarget.src;
        let type = "";
        try {
           type = String(props.get("type", Ci.nsISupportsCString));
        } catch(ex) {
           type = "";
        }
        sendMessageToJava({
          gecko: {
            type: "Share:Image",
            url: src,
            mime: type,
          }
        });
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.saveImage"),
      NativeWindow.contextmenus.imageSaveableContext,
      function(aTarget) {
        ContentAreaUtils.saveImageURL(aTarget.currentURI.spec, null, "SaveImageTitle",
                                      false, true, aTarget.ownerDocument.documentURIObject,
                                      aTarget.ownerDocument);
      });

    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.setWallpaper"),
      NativeWindow.contextmenus.imageSaveableContext,
      function(aTarget) {
        let src = aTarget.src;
        sendMessageToJava({
          gecko: {
            type: "Wallpaper:Set",
            url: src
          }
        });
      });

    NativeWindow.contextmenus.add(
      function(aTarget) {
        if (aTarget instanceof HTMLVideoElement) {
          // If a video element is zero width or height, its essentially
          // an HTMLAudioElement.
          if (aTarget.videoWidth == 0 || aTarget.videoHeight == 0 )
            return Strings.browser.GetStringFromName("contextmenu.saveAudio");
          return Strings.browser.GetStringFromName("contextmenu.saveVideo");
        } else if (aTarget instanceof HTMLAudioElement) {
          return Strings.browser.GetStringFromName("contextmenu.saveAudio");
        }
        return Strings.browser.GetStringFromName("contextmenu.saveVideo");
      }, NativeWindow.contextmenus.mediaSaveableContext,
      function(aTarget) {
        let url = aTarget.currentSrc || aTarget.src;
        let filePickerTitleKey = (aTarget instanceof HTMLVideoElement &&
                                  (aTarget.videoWidth != 0 && aTarget.videoHeight != 0))
                                  ? "SaveVideoTitle" : "SaveAudioTitle";
        // Skipped trying to pull MIME type out of cache for now
        ContentAreaUtils.internalSave(url, null, null, null, null, false,
                                      filePickerTitleKey, null, aTarget.ownerDocument.documentURIObject,
                                      aTarget.ownerDocument, true, null);
      });
  },

  onAppUpdated: function() {
    // initialize the form history and passwords databases on upgrades
    Services.obs.notifyObservers(null, "FormHistory:Init", "");
    Services.obs.notifyObservers(null, "Passwords:Init", "");
  },

  shutdown: function shutdown() {
    NativeWindow.uninit();
    SelectionHandler.uninit();
    LightWeightThemeWebInstaller.uninit();
    FormAssistant.uninit();
    FindHelper.uninit();
    OfflineApps.uninit();
    IndexedDB.uninit();
    ViewportHandler.uninit();
    XPInstallObserver.uninit();
    ConsoleAPI.uninit();
    CharacterEncoding.uninit();
    SearchEngines.uninit();
    WebappsUI.uninit();
    RemoteDebugger.uninit();
    Reader.uninit();
    UserAgent.uninit();
    ExternalApps.uninit();
    MemoryObserver.uninit();
    Distribution.uninit();
    Tabs.uninit();
#ifdef MOZ_TELEMETRY_REPORTING
    Telemetry.uninit();
#endif
#ifdef MOZ_WEBRTC
    WebrtcUi.uninit();
#endif
  },

  // This function returns false during periods where the browser displayed document is
  // different from the browser content document, so user actions and some kinds of viewport
  // updates should be ignored. This period starts when we start loading a new page or
  // switch tabs, and ends when the new browser content document has been drawn and handed
  // off to the compositor.
  isBrowserContentDocumentDisplayed: function() {
    try {
      if (window.top.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils).isFirstPaint)
        return false;
    } catch (e) {
      return false;
    }

    let tab = this.selectedTab;
    if (!tab)
      return true;
    return tab.contentDocumentIsDisplayed;
  },

  displayedDocumentChanged: function() {
    window.top.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils).isFirstPaint = true;
  },

  get tabs() {
    return this._tabs;
  },

  get selectedTab() {
    return this._selectedTab;
  },

  set selectedTab(aTab) {
    if (this._selectedTab == aTab)
      return;

    if (this._selectedTab) {
      Tabs.touch(this._selectedTab);
      this._selectedTab.setActive(false);
    }

    this._selectedTab = aTab;
    if (!aTab)
      return;

    Tabs.touch(aTab);
    aTab.setActive(true);
    aTab.setResolution(aTab._zoom, true);
    this.displayedDocumentChanged();
    this.deck.selectedPanel = aTab.browser;
  },

  get selectedBrowser() {
    if (this._selectedTab)
      return this._selectedTab.browser;
    return null;
  },

  getTabForId: function getTabForId(aId) {
    let tabs = this._tabs;
    for (let i=0; i < tabs.length; i++) {
       if (tabs[i].id == aId)
         return tabs[i];
    }
    return null;
  },

  getTabForBrowser: function getTabForBrowser(aBrowser) {
    let tabs = this._tabs;
    for (let i = 0; i < tabs.length; i++) {
      if (tabs[i].browser == aBrowser)
        return tabs[i];
    }
    return null;
  },

  getTabForWindow: function getTabForWindow(aWindow) {
    let tabs = this._tabs;
    for (let i = 0; i < tabs.length; i++) {
      if (tabs[i].browser.contentWindow == aWindow)
        return tabs[i];
    }
    return null; 
  },

  getBrowserForWindow: function getBrowserForWindow(aWindow) {
    let tabs = this._tabs;
    for (let i = 0; i < tabs.length; i++) {
      if (tabs[i].browser.contentWindow == aWindow)
        return tabs[i].browser;
    }
    return null;
  },

  getBrowserForDocument: function getBrowserForDocument(aDocument) {
    let tabs = this._tabs;
    for (let i = 0; i < tabs.length; i++) {
      if (tabs[i].browser.contentDocument == aDocument)
        return tabs[i].browser;
    }
    return null;
  },

  loadURI: function loadURI(aURI, aBrowser, aParams) {
    aBrowser = aBrowser || this.selectedBrowser;
    if (!aBrowser)
      return;

    aParams = aParams || {};

    let flags = "flags" in aParams ? aParams.flags : Ci.nsIWebNavigation.LOAD_FLAGS_NONE;
    let postData = ("postData" in aParams && aParams.postData) ? aParams.postData : null;
    let referrerURI = "referrerURI" in aParams ? aParams.referrerURI : null;
    let charset = "charset" in aParams ? aParams.charset : null;

    if ("showProgress" in aParams) {
      let tab = this.getTabForBrowser(aBrowser);
      if (tab)
        tab.showProgress = aParams.showProgress;
    }

    try {
      aBrowser.loadURIWithFlags(aURI, flags, referrerURI, charset, postData);
    } catch(e) {
      let tab = this.getTabForBrowser(aBrowser);
      if (tab) {
        let message = {
          gecko: {
            type: "Content:LoadError",
            tabID: tab.id,
            uri: aBrowser.currentURI.spec,
            title: aBrowser.contentTitle
          }
        };
        sendMessageToJava(message);
        dump("Handled load error: " + e)
      }
    }
  },

  addTab: function addTab(aURI, aParams) {
    aParams = aParams || {};

    let newTab = new Tab(aURI, aParams);
    this._tabs.push(newTab);

    let selected = "selected" in aParams ? aParams.selected : true;
    if (selected)
      this.selectedTab = newTab;

    let pinned = "pinned" in aParams ? aParams.pinned : false;
    if (pinned) {
      let ss = Cc["@mozilla.org/browser/sessionstore;1"].getService(Ci.nsISessionStore);
      ss.setTabValue(newTab, "appOrigin", aURI);
    }

    let evt = document.createEvent("UIEvents");
    evt.initUIEvent("TabOpen", true, false, window, null);
    newTab.browser.dispatchEvent(evt);

    Tabs.expireLruTab();

    return newTab;
  },

  // Use this method to close a tab from JS. This method sends a message
  // to Java to close the tab in the Java UI (we'll get a Tab:Closed message
  // back from Java when that happens).
  closeTab: function closeTab(aTab) {
    if (!aTab) {
      Cu.reportError("Error trying to close tab (tab doesn't exist)");
      return;
    }

    let message = {
      gecko: {
        type: "Tab:Close",
        tabID: aTab.id
      }
    };
    sendMessageToJava(message);
  },

  // Calling this will update the state in BrowserApp after a tab has been
  // closed in the Java UI.
  _handleTabClosed: function _handleTabClosed(aTab) {
    if (aTab == this.selectedTab)
      this.selectedTab = null;

    let evt = document.createEvent("UIEvents");
    evt.initUIEvent("TabClose", true, false, window, null);
    aTab.browser.dispatchEvent(evt);

    aTab.destroy();
    this._tabs.splice(this._tabs.indexOf(aTab), 1);
  },

  // Use this method to select a tab from JS. This method sends a message
  // to Java to select the tab in the Java UI (we'll get a Tab:Selected message
  // back from Java when that happens).
  selectTab: function selectTab(aTab) {
    if (!aTab) {
      Cu.reportError("Error trying to select tab (tab doesn't exist)");
      return;
    }

    // There's nothing to do if the tab is already selected
    if (aTab == this.selectedTab)
      return;

    let message = {
      gecko: {
        type: "Tab:Select",
        tabID: aTab.id
      }
    };
    sendMessageToJava(message);
  },

  /**
   * Gets an open tab with the given URL.
   *
   * @param  aURL URL to look for
   * @return the tab with the given URL, or null if no such tab exists
   */
  getTabWithURL: function getTabWithURL(aURL) {
    let uri = Services.io.newURI(aURL, null, null);
    for (let i = 0; i < this._tabs.length; ++i) {
      let tab = this._tabs[i];
      if (tab.browser.currentURI.equals(uri)) {
        return tab;
      }
    }
    return null;
  },

  /**
   * If a tab with the given URL already exists, that tab is selected.
   * Otherwise, a new tab is opened with the given URL.
   *
   * @param aURL URL to open
   */
  selectOrOpenTab: function selectOrOpenTab(aURL) {
    let tab = this.getTabWithURL(aURL);
    if (tab == null) {
      this.addTab(aURL);
    } else {
      this.selectTab(tab);
    }
  },

  // This method updates the state in BrowserApp after a tab has been selected
  // in the Java UI.
  _handleTabSelected: function _handleTabSelected(aTab) {
    this.selectedTab = aTab;

    let evt = document.createEvent("UIEvents");
    evt.initUIEvent("TabSelect", true, false, window, null);
    aTab.browser.dispatchEvent(evt);
  },

  quit: function quit() {
    // Figure out if there's at least one other browser window around.
    let lastBrowser = true;
    let e = Services.wm.getEnumerator("navigator:browser");
    while (e.hasMoreElements() && lastBrowser) {
      let win = e.getNext();
      if (win != window)
        lastBrowser = false;
    }

    if (lastBrowser) {
      // Let everyone know we are closing the last browser window
      let closingCanceled = Cc["@mozilla.org/supports-PRBool;1"].createInstance(Ci.nsISupportsPRBool);
      Services.obs.notifyObservers(closingCanceled, "browser-lastwindow-close-requested", null);
      if (closingCanceled.data)
        return;

      Services.obs.notifyObservers(null, "browser-lastwindow-close-granted", null);
    }

    window.QueryInterface(Ci.nsIDOMChromeWindow).minimize();
    window.close();
  },

  saveAsPDF: function saveAsPDF(aBrowser) {
    // Create the final destination file location
    let fileName = ContentAreaUtils.getDefaultFileName(aBrowser.contentTitle, aBrowser.currentURI, null, null);
    fileName = fileName.trim() + ".pdf";

    let dm = Cc["@mozilla.org/download-manager;1"].getService(Ci.nsIDownloadManager);
    let downloadsDir = dm.defaultDownloadsDirectory;

    let file = downloadsDir.clone();
    file.append(fileName);
    file.createUnique(file.NORMAL_FILE_TYPE, parseInt("666", 8));

    let printSettings = Cc["@mozilla.org/gfx/printsettings-service;1"].getService(Ci.nsIPrintSettingsService).newPrintSettings;
    printSettings.printSilent = true;
    printSettings.showPrintProgress = false;
    printSettings.printBGImages = true;
    printSettings.printBGColors = true;
    printSettings.printToFile = true;
    printSettings.toFileName = file.path;
    printSettings.printFrameType = Ci.nsIPrintSettings.kFramesAsIs;
    printSettings.outputFormat = Ci.nsIPrintSettings.kOutputFormatPDF;

    //XXX we probably need a preference here, the header can be useful
    printSettings.footerStrCenter = "";
    printSettings.footerStrLeft   = "";
    printSettings.footerStrRight  = "";
    printSettings.headerStrCenter = "";
    printSettings.headerStrLeft   = "";
    printSettings.headerStrRight  = "";

    // Create a valid mimeInfo for the PDF
    let ms = Cc["@mozilla.org/mime;1"].getService(Ci.nsIMIMEService);
    let mimeInfo = ms.getFromTypeAndExtension("application/pdf", "pdf");

    let webBrowserPrint = aBrowser.contentWindow.QueryInterface(Ci.nsIInterfaceRequestor)
                                                .getInterface(Ci.nsIWebBrowserPrint);

    let cancelable = {
      cancel: function (aReason) {
        webBrowserPrint.cancel();
      }
    }
    let isPrivate = PrivateBrowsingUtils.isWindowPrivate(aBrowser.contentWindow);
    let download = dm.addDownload(Ci.nsIDownloadManager.DOWNLOAD_TYPE_DOWNLOAD,
                                  aBrowser.currentURI,
                                  Services.io.newFileURI(file), "", mimeInfo,
                                  Date.now() * 1000, null, cancelable, isPrivate);

    webBrowserPrint.print(printSettings, download);
  },

  getPreferences: function getPreferences(aPrefNames) {
    try {
      let json = JSON.parse(aPrefNames);
      let prefs = [];

      for each (let prefName in json.preferences) {
        let pref = {
          name: prefName
        };

        // The plugin pref is actually two separate prefs, so
        // we need to handle it differently
        if (prefName == "plugin.enable") {
          // Use a string type for java's ListPreference
          pref.type = "string";
          pref.value = PluginHelper.getPluginPreference();
          prefs.push(pref);
          continue;
        } else if (prefName == MasterPassword.pref) {
          // Master password is not a "real" pref
          pref.type = "bool";
          pref.value = MasterPassword.enabled;
          prefs.push(pref);
          continue;
        }

        try {
          switch (Services.prefs.getPrefType(prefName)) {
            case Ci.nsIPrefBranch.PREF_BOOL:
              pref.type = "bool";
              pref.value = Services.prefs.getBoolPref(prefName);
              break;
            case Ci.nsIPrefBranch.PREF_INT:
              pref.type = "int";
              pref.value = Services.prefs.getIntPref(prefName);
              break;
            case Ci.nsIPrefBranch.PREF_STRING:
            default:
              pref.type = "string";
              try {
                // Try in case it's a localized string (will throw an exception if not)
                pref.value = Services.prefs.getComplexValue(prefName, Ci.nsIPrefLocalizedString).data;
              } catch (e) {
                pref.value = Services.prefs.getCharPref(prefName);
              }
              break;
          }
        } catch (e) {
          dump("Error reading pref [" + prefName + "]: " + e);
          // preference does not exist; do not send it
          continue;
        }

        // some preferences use integers or strings instead of booleans for
        // indicating enabled/disabled. since the java ui uses the type to
        // determine which ui elements to show, we need to normalize these
        // preferences to be actual booleans.
        switch (prefName) {
          case "network.cookie.cookieBehavior":
            pref.type = "string";
            pref.value = pref.value.toString();
            break;
          case "font.size.inflation.minTwips":
            pref.type = "string";
            pref.value = pref.value.toString();
            break;
        }

        prefs.push(pref);
      }

      sendMessageToJava({
        gecko: {
          type: "Preferences:Data",
          requestId: json.requestId,    // opaque request identifier, can be any string/int/whatever
          preferences: prefs
        }
      });
    } catch (e) {}
  },

  setPreferences: function setPreferences(aPref) {
    let json = JSON.parse(aPref);

    if (json.name == "plugin.enable") {
      // The plugin pref is actually two separate prefs, so
      // we need to handle it differently
      PluginHelper.setPluginPreference(json.value);
      return;
    } else if (json.name == MasterPassword.pref) {
      // MasterPassword pref is not real, we just need take action and leave
      if (MasterPassword.enabled)
        MasterPassword.removePassword(json.value);
      else
        MasterPassword.setPassword(json.value);
      return;
    } else if (json.name == SearchEngines.PREF_SUGGEST_ENABLED) {
      // Enabling or disabling suggestions will prevent future prompts
      Services.prefs.setBoolPref(SearchEngines.PREF_SUGGEST_PROMPTED, true);
    }

    // when sending to java, we normalized special preferences that use
    // integers and strings to represent booleans.  here, we convert them back
    // to their actual types so we can store them.
    switch (json.name) {
      case "network.cookie.cookieBehavior":
        json.type = "int";
        json.value = parseInt(json.value);
        break;
      case "font.size.inflation.minTwips":
        json.type = "int";
        json.value = parseInt(json.value);
        break;
    }

    if (json.type == "bool") {
      Services.prefs.setBoolPref(json.name, json.value);
    } else if (json.type == "int") {
      Services.prefs.setIntPref(json.name, json.value);
    } else {
      let pref = Cc["@mozilla.org/pref-localizedstring;1"].createInstance(Ci.nsIPrefLocalizedString);
      pref.data = json.value;
      Services.prefs.setComplexValue(json.name, Ci.nsISupportsString, pref);
    }
  },

  sanitize: function (aItems) {
    let sanitizer = new Sanitizer();
    let json = JSON.parse(aItems);
    let success = true;

    for (let key in json) {
      if (!json[key])
        continue;

      try {
        switch (key) {
          case "history_downloads":
            sanitizer.clearItem("history");
            sanitizer.clearItem("downloads");
            break;
          case "cookies_sessions":
            sanitizer.clearItem("cookies");
            sanitizer.clearItem("sessions");
            break;
          default:
            sanitizer.clearItem(key);
        }
      } catch (e) {
        dump("sanitize error: " + e);
        success = false;
      }
    }

    sendMessageToJava({
      gecko: {
        type: "Sanitize:Finished",
        success: success
      }
    });
  },

  getFocusedInput: function(aBrowser, aOnlyInputElements = false) {
    if (!aBrowser)
      return null;

    let doc = aBrowser.contentDocument;
    if (!doc)
      return null;

    let focused = doc.activeElement;
    while (focused instanceof HTMLFrameElement || focused instanceof HTMLIFrameElement) {
      doc = focused.contentDocument;
      focused = doc.activeElement;
    }

    if (focused instanceof HTMLInputElement && focused.mozIsTextField(false))
      return focused;

    if (aOnlyInputElements)
      return null;

    if  (focused instanceof HTMLTextAreaElement || focused.isContentEditable) {

      if (focused instanceof HTMLBodyElement) {
        // we are putting focus into a contentEditable frame. scroll the frame into
        // view instead of the contentEditable document contained within, because that
        // results in a better user experience
        focused = focused.ownerDocument.defaultView.frameElement;
      }
      return focused;
    }
    return null;
  },

  scrollToFocusedInput: function(aBrowser, aAllowZoom = true) {
    let focused = this.getFocusedInput(aBrowser);
    if (focused) {
      // _zoomToElement will handle not sending any message if this input is already mostly filling the screen
      BrowserEventHandler._zoomToElement(focused, -1, false, aAllowZoom);
    }
  },

  observe: function(aSubject, aTopic, aData) {
    let browser = this.selectedBrowser;

    switch (aTopic) {

      case "Session:Back":
        browser.goBack();
        break;

      case "Session:Forward":
        browser.goForward();
        break;

      case "Session:Reload":
        // Try to use the session history to reload so that framesets are
        // handled properly. If the window has no session history, fall back
        // to using the web navigation's reload method.
        let flags = Ci.nsIWebNavigation.LOAD_FLAGS_BYPASS_PROXY | Ci.nsIWebNavigation.LOAD_FLAGS_BYPASS_CACHE;
        let webNav = browser.webNavigation;
        try {
          let sh = webNav.sessionHistory;
          if (sh)
            webNav = sh.QueryInterface(Ci.nsIWebNavigation);
        } catch (e) {}
        webNav.reload(flags);
        break;

      case "Session:Stop":
        browser.stop();
        break;

      case "Tab:Load": {
        let data = JSON.parse(aData);

        // Pass LOAD_FLAGS_DISALLOW_INHERIT_OWNER to prevent any loads from
        // inheriting the currently loaded document's principal.
        let flags = Ci.nsIWebNavigation.LOAD_FLAGS_ALLOW_THIRD_PARTY_FIXUP;
        if (data.userEntered) {
          flags |= Ci.nsIWebNavigation.LOAD_FLAGS_DISALLOW_INHERIT_OWNER;
        }

        let delayLoad = ("delayLoad" in data) ? data.delayLoad : false;
        let params = {
          selected: !delayLoad,
          parentId: ("parentId" in data) ? data.parentId : -1,
          flags: flags,
          tabID: data.tabID,
          isPrivate: (data.isPrivate === true),
          pinned: (data.pinned === true),
          delayLoad: (delayLoad === true),
          desktopMode: (data.desktopMode === true)
        };

        let url = data.url;
        if (data.engine) {
          let engine = Services.search.getEngineByName(data.engine);
          if (engine) {
            let submission = engine.getSubmission(url);
            url = submission.uri.spec;
            params.postData = submission.postData;
          }
        }

        // Don't show progress throbber for about:home or about:reader
        if (!shouldShowProgress(url))
          params.showProgress = false;

        if (data.newTab)
          this.addTab(url, params);
        else
          this.loadURI(url, browser, params);
        break;
      }

      case "Tab:Selected":
        this._handleTabSelected(this.getTabForId(parseInt(aData)));
        break;

      case "Tab:Closed":
        this._handleTabClosed(this.getTabForId(parseInt(aData)));
        break;

      case "Browser:Quit":
        this.quit();
        break;

      case "SaveAs:PDF":
        this.saveAsPDF(browser);
        break;

      case "Preferences:Get":
        this.getPreferences(aData);
        break;

      case "Preferences:Set":
        this.setPreferences(aData);
        break;

      case "ScrollTo:FocusedInput":
        // these messages come from a change in the viewable area and not user interaction
        // we allow scrolling to the selected input, but not zooming the page
        this.scrollToFocusedInput(browser, false);
        break;

      case "Sanitize:ClearData":
        this.sanitize(aData);
        break;

      case "FullScreen:Exit":
        browser.contentDocument.mozCancelFullScreen();
        break;

      case "Viewport:Change":
        if (this.isBrowserContentDocumentDisplayed())
          this.selectedTab.setViewport(JSON.parse(aData));
        break;

      case "Viewport:Flush":
        this.displayedDocumentChanged();
        break;

      case "Passwords:Init": {
        let storage = Cc["@mozilla.org/login-manager/storage/mozStorage;1"].
                      getService(Ci.nsILoginManagerStorage);
        storage.init();

        sendMessageToJava({gecko: { type: "Passwords:Init:Return" }});
        Services.obs.removeObserver(this, "Passwords:Init", false);
        break;
      }

      case "FormHistory:Init": {
        let fh = Cc["@mozilla.org/satchel/form-history;1"].getService(Ci.nsIFormHistory2);
        // Force creation/upgrade of formhistory.sqlite
        let db = fh.DBConnection;
        sendMessageToJava({gecko: { type: "FormHistory:Init:Return" }});
        Services.obs.removeObserver(this, "FormHistory:Init", false);
        break;
      }

      case "sessionstore-state-purge-complete":
        sendMessageToJava({ gecko: { type: "Session:StatePurged" }});
        break;

      case "ToggleProfiling": {
        let profiler = Cc["@mozilla.org/tools/profiler;1"].
                       getService(Ci.nsIProfiler);
        if (profiler.IsActive()) {
          profiler.StopProfiler();
        } else {
          profiler.StartProfiler(100000, 25, ["stackwalk"], 1);
        }
        break;
      }

      case "gather-telemetry":
        sendMessageToJava({ gecko: { type: "Telemetry:Gather" }});
        break;

      default:
        dump('BrowserApp.observe: unexpected topic "' + aTopic + '"\n');
        break;

    }
  },

  get defaultBrowserWidth() {
    delete this.defaultBrowserWidth;
    let width = Services.prefs.getIntPref("browser.viewport.desktopWidth");
    return this.defaultBrowserWidth = width;
  },

  // nsIAndroidBrowserApp
  getBrowserTab: function(tabId) {
    return this.getTabForId(tabId);
  },
};

var NativeWindow = {
  init: function() {
    Services.obs.addObserver(this, "Menu:Clicked", false);
    Services.obs.addObserver(this, "Doorhanger:Reply", false);
    this.contextmenus.init();
  },

  uninit: function() {
    Services.obs.removeObserver(this, "Menu:Clicked");
    Services.obs.removeObserver(this, "Doorhanger:Reply");
    this.contextmenus.uninit();
  },

  loadDex: function(zipFile, implClass) {
    sendMessageToJava({
      gecko: {
        type: "Dex:Load",
        zipfile: zipFile,
        impl: implClass || "Main"
      }
    });
  },

  toast: {
    show: function(aMessage, aDuration) {
      sendMessageToJava({
        gecko: {
          type: "Toast:Show",
          message: aMessage,
          duration: aDuration
        }
      });
    }
  },

  menu: {
    _callbacks: [],
    _menuId: 0,
    add: function() {
      let options;
      if (arguments.length == 1) {
        options = arguments[0];
      } else if (arguments.length == 3) {
          options = {
            name: arguments[0],
            icon: arguments[1],
            callback: arguments[2]
          };
      } else {
         throw "Incorrect number of parameters";
      }

      options.type = "Menu:Add";
      options.id = this._menuId;

      sendMessageToJava({ gecko: options });
      this._callbacks[this._menuId] = options.callback;
      this._menuId++;
      return this._menuId - 1;
    },

    remove: function(aId) {
      sendMessageToJava({ gecko: {type: "Menu:Remove", id: aId }});
    },

    update: function(aId, aOptions) {
      if (!aOptions)
        return;

      sendMessageToJava({
        gecko: {
          type: "Menu:Update", 
          id: aId,
          options: aOptions
        }
      });
    }
  },

  doorhanger: {
    _callbacks: {},
    _callbacksId: 0,
    _promptId: 0,

  /**
   * @param aOptions
   *        An options JavaScript object holding additional properties for the
   *        notification. The following properties are currently supported:
   *        persistence: An integer. The notification will not automatically
   *                     dismiss for this many page loads. If persistence is set
   *                     to -1, the doorhanger will never automatically dismiss.
   *        persistWhileVisible:
   *                     A boolean. If true, a visible notification will always
   *                     persist across location changes.
   *        timeout:     A time in milliseconds. The notification will not
   *                     automatically dismiss before this time.
   *        checkbox:    A string to appear next to a checkbox under the notification
   *                     message. The button callback functions will be called with
   *                     the checked state as an argument.                   
   */
    show: function(aMessage, aValue, aButtons, aTabID, aOptions) {
      aButtons.forEach((function(aButton) {
        this._callbacks[this._callbacksId] = { cb: aButton.callback, prompt: this._promptId };
        aButton.callback = this._callbacksId;
        this._callbacksId++;
      }).bind(this));

      this._promptId++;
      let json = {
        gecko: {
          type: "Doorhanger:Add",
          message: aMessage,
          value: aValue,
          buttons: aButtons,
          // use the current tab if none is provided
          tabID: aTabID || BrowserApp.selectedTab.id,
          options: aOptions || {}
        }
      };
      sendMessageToJava(json);
    },

    hide: function(aValue, aTabID) {
      sendMessageToJava({ gecko: {
        type: "Doorhanger:Remove",
        value: aValue,
        tabID: aTabID
      }});
    }
  },

  observe: function(aSubject, aTopic, aData) {
    if (aTopic == "Menu:Clicked") {
      if (this.menu._callbacks[aData])
        this.menu._callbacks[aData]();
    } else if (aTopic == "Doorhanger:Reply") {
      let data = JSON.parse(aData);
      let reply_id = data["callback"];

      if (this.doorhanger._callbacks[reply_id]) {
        // Pass the value of the optional checkbox to the callback
        let checked = data["checked"];
        this.doorhanger._callbacks[reply_id].cb(checked);

        let prompt = this.doorhanger._callbacks[reply_id].prompt;
        for (let id in this.doorhanger._callbacks) {
          if (this.doorhanger._callbacks[id].prompt == prompt) {
            delete this.doorhanger._callbacks[id];
          }
        }
      }
    }
  },
  contextmenus: {
    items: {}, //  a list of context menu items that we may show
    _nativeItemsSeparator: 0, // the index to insert native context menu items at
    _contextId: 0, // id to assign to new context menu items if they are added

    init: function() {
      Services.obs.addObserver(this, "Gesture:LongPress", false);
    },

    uninit: function() {
      Services.obs.removeObserver(this, "Gesture:LongPress");
    },

    add: function(aName, aSelector, aCallback) {
      if (!aName)
        throw "Menu items must have a name";

      let item = {
        name: aName,
        context: aSelector,
        callback: aCallback,
        matches: function(aElt, aX, aY) {
          return this.context.matches(aElt, aX, aY);
        },
        getValue: function(aElt) {
          return {
            label: (typeof this.name == "function") ? this.name(aElt) : this.name,
            id: this.id
          }
        }
      };
      item.id = this._contextId++;
      this.items[item.id] = item;
      return item.id;
    },

    remove: function(aId) {
      delete this.items[aId];
    },

    SelectorContext: function(aSelector) {
      return {
        matches: function(aElt) {
          if (aElt.mozMatchesSelector)
            return aElt.mozMatchesSelector(aSelector);
          return false;
        }
      }
    },

    linkOpenableNonPrivateContext: {
      matches: function linkOpenableNonPrivateContextMatches(aElement) {
        let doc = aElement.ownerDocument;
        if (!doc || PrivateBrowsingUtils.isWindowPrivate(doc.defaultView)) {
          return false;
        }

        return NativeWindow.contextmenus.linkOpenableContext.matches(aElement);
      }
    },

    linkOpenableContext: {
      matches: function linkOpenableContextMatches(aElement) {
        let uri = NativeWindow.contextmenus._getLink(aElement);
        if (uri) {
          let scheme = uri.scheme;
          let dontOpen = /^(javascript|mailto|news|snews|tel)$/;
          return (scheme && !dontOpen.test(scheme));
        }
        return false;
      }
    },

    linkCopyableContext: {
      matches: function linkCopyableContextMatches(aElement) {
        let uri = NativeWindow.contextmenus._getLink(aElement);
        if (uri) {
          let scheme = uri.scheme;
          let dontCopy = /^(mailto|tel)$/;
          return (scheme && !dontCopy.test(scheme));
        }
        return false;
      }
    },

    linkShareableContext: {
      matches: function linkShareableContextMatches(aElement) {
        let uri = NativeWindow.contextmenus._getLink(aElement);
        if (uri) {
          let scheme = uri.scheme;
          let dontShare = /^(about|chrome|file|javascript|mailto|resource|tel)$/;
          return (scheme && !dontShare.test(scheme));
        }
        return false;
      }
    },

    linkBookmarkableContext: {
      matches: function linkBookmarkableContextMatches(aElement) {
        let uri = NativeWindow.contextmenus._getLink(aElement);
        if (uri) {
          let scheme = uri.scheme;
          let dontBookmark = /^(mailto|tel)$/;
          return (scheme && !dontBookmark.test(scheme));
        }
        return false;
      }
    },

    emailLinkContext: {
      matches: function emailLinkContextMatches(aElement) {
        let uri = NativeWindow.contextmenus._getLink(aElement);
        if (uri)
          return uri.schemeIs("mailto");
        return false;
      }
    },

    phoneNumberLinkContext: {
      matches: function phoneNumberLinkContextMatches(aElement) {
        let uri = NativeWindow.contextmenus._getLink(aElement);
        if (uri)
          return uri.schemeIs("tel");
        return false;
      }
    },

    textContext: {
      matches: function textContext(aElement) {
        return ((aElement instanceof Ci.nsIDOMHTMLInputElement && aElement.mozIsTextField(false))
                || aElement instanceof Ci.nsIDOMHTMLTextAreaElement);
      }
    },

    imageLocationCopyableContext: {
      matches: function imageLinkCopyableContextMatches(aElement) {
        return (aElement instanceof Ci.nsIImageLoadingContent && aElement.currentURI);
      }
    },

    imageSaveableContext: {
      matches: function imageSaveableContextMatches(aElement) {
        if (aElement instanceof Ci.nsIImageLoadingContent && aElement.currentURI) {
          // The image must be loaded to allow saving
          let request = aElement.getRequest(Ci.nsIImageLoadingContent.CURRENT_REQUEST);
          return (request && (request.imageStatus & request.STATUS_SIZE_AVAILABLE));
        }
        return false;
      }
    },

    mediaSaveableContext: {
      matches: function mediaSaveableContextMatches(aElement) {
        return (aElement instanceof HTMLVideoElement ||
               aElement instanceof HTMLAudioElement);
      }
    },

    mediaContext: function(aMode) {
      return {
        matches: function(aElt) {
          if (aElt instanceof Ci.nsIDOMHTMLMediaElement) {
            let hasError = aElt.error != null || aElt.networkState == aElt.NETWORK_NO_SOURCE;
            if (hasError)
              return false;

            let paused = aElt.paused || aElt.ended;
            if (paused && aMode == "media-paused")
              return true;
            if (!paused && aMode == "media-playing")
              return true;
            let controls = aElt.controls;
            if (!controls && aMode == "media-hidingcontrols")
              return true;
          }
          return false;
        }
      }
    },

    get _target() {
      if (this._targetRef)
        return this._targetRef.get();
      return null;
    },
  
    set _target(aTarget) {
      if (aTarget)
        this._targetRef = Cu.getWeakReference(aTarget);
      else this._targetRef = null;
    },

    _addHTMLContextMenuItems: function cm_addContextMenuItems(aMenu, aParent) {
      for (let i = 0; i < aMenu.childNodes.length; i++) {
        let item = aMenu.childNodes[i];
        if (!item.label)
          continue;

        let id = this._contextId++;
        let menuitem = {
          id: id,
          isGroup: false,
          callback: (function(aTarget, aX, aY) {
            // If this is a menu item, show a new context menu with the submenu in it
            if (item instanceof Ci.nsIDOMHTMLMenuElement) {
              this.menuitems = [];
              this._nativeItemsSeparator = 0;

              this._addHTMLContextMenuItems(item, id);
              this._innerShow(aTarget, aX, aY);
            } else {
              // oltherwise just click the item
              item.click();
            }
          }).bind(this),

          getValue: function(aElt) {
            if (item.hasAttribute("hidden"))
              return null;

            return {
              icon: item.icon,
              label: item.label,
              id: id,
              isGroup: false,
              inGroup: false,
              disabled: item.disabled,
              isParent: item instanceof Ci.nsIDOMHTMLMenuElement
            }
          }
        };

        this.menuitems.splice(this._nativeItemsSeparator, 0, menuitem);
        this._nativeItemsSeparator++;
      }
    },

    _getMenuItemForId: function(aId) {
      if (!this.menuitems)
        return null;

      for (let i = 0; i < this.menuitems.length; i++) {
        if (this.menuitems[i].id == aId)
          return this.menuitems[i];
      }
      return null;
    },

    // Checks if there are context menu items to show, and if it finds them
    // sends a contextmenu event to content. We also send showing events to
    // any html5 context menus we are about to show
    _sendToContent: function(aX, aY) {
      // find and store the top most element this context menu is being shown for
      // use the highlighted element if possible, otherwise look for nearby clickable elements
      // If we still don't find one we fall back to using anything
      let target = BrowserEventHandler._highlightElement || ElementTouchHelper.elementFromPoint(aX, aY);
      if (!target)
        target = ElementTouchHelper.anyElementFromPoint(aX, aY);

      if (!target)
        return;

      // store a weakref to the target to be used when the context menu event returns
      this._target = target;

      this.menuitems = [];
      let menuitemsSet = false;

      // now walk up the tree and for each node look for any context menu items that apply
      let element = target;
      this._nativeItemsSeparator = 0;
      while (element) {
        // first check for any html5 context menus that might exist
        let contextmenu = element.contextMenu;
        if (contextmenu) {
          // send this before we build the list to make sure the site can update the menu
          contextmenu.QueryInterface(Components.interfaces.nsIHTMLMenu);
          contextmenu.sendShowEvent();
          this._addHTMLContextMenuItems(contextmenu, null);
        }

        // then check for any context menu items registered in the ui
         for each (let item in this.items) {
          if (!this._getMenuItemForId(item.id) && item.matches(element, aX, aY)) {
            this.menuitems.push(item);
          }
        }

        element = element.parentNode;
      }

      // only send the contextmenu event to content if we are planning to show a context menu (i.e. not on every long tap)
      if (this.menuitems.length > 0) {
        let event = target.ownerDocument.createEvent("MouseEvent");
        event.initMouseEvent("contextmenu", true, true, content,
                             0, aX, aY, aX, aY, false, false, false, false,
                             0, null);
        target.ownerDocument.defaultView.addEventListener("contextmenu", this, false);
        target.dispatchEvent(event);
      } else {
        this._target = null;
        BrowserEventHandler._cancelTapHighlight();

        if (SelectionHandler.canSelect(target))
          SelectionHandler.startSelection(target, aX, aY);
      }
    },

    // Actually shows the native context menu by passing a list of context menu items to
    // show to the Java.
    _show: function(aEvent) {
      let popupNode = this._target;
      this._target = null;
      if (aEvent.defaultPrevented || !popupNode) {
        return;
      }
      this._innerShow(popupNode, aEvent.clientX, aEvent.clientY);
    },

    _innerShow: function(aTarget, aX, aY) {
      Haptic.performSimpleAction(Haptic.LongPress);

      // spin through the tree looking for a title for this context menu
      let node = aTarget;
      let title ="";
      while(node && !title) {
        if (node.hasAttribute && node.hasAttribute("title")) {
          title = node.getAttribute("title");
        } else if ((node instanceof Ci.nsIDOMHTMLAnchorElement && node.href) ||
                (node instanceof Ci.nsIDOMHTMLAreaElement && node.href)) {
          title = this._getLinkURL(node);
        } else if (node instanceof Ci.nsIImageLoadingContent && node.currentURI) {
          title = node.currentURI.spec;
        } else if (node instanceof Ci.nsIDOMHTMLMediaElement) {
          title = (node.currentSrc || node.src);
        }
        node = node.parentNode;
      }

      // convert this.menuitems object to an array for sending to native code
      let itemArray = [];
      for (let i = 0; i < this.menuitems.length; i++) {
        let val = this.menuitems[i].getValue(aTarget);

        // hidden menu items will return null from getValue
        if (val)
          itemArray.push(val);
      }

      if (itemArray.length == 0)
        return;

      let msg = {
        gecko: {
          type: "Prompt:Show",
          title: title,
          listitems: itemArray
        }
      };
      let data = JSON.parse(sendMessageToJava(msg));
      if (data.button == -1) {
        // prompt was cancelled
        return;
      }

      let selectedId = itemArray[data.button].id;
      let selectedItem = this._getMenuItemForId(selectedId);

      this.menuitems = null;
      if (selectedItem && selectedItem.callback) {
        if (selectedItem.matches) {
          // for menuitems added using the native UI, pass the dom element that matched that item to the callback
          while (aTarget) {
            if (selectedItem.matches(aTarget, aX, aY)) {
              selectedItem.callback.call(selectedItem, aTarget, aX, aY);
              break;
            }
            aTarget = aTarget.parentNode;
          }
        } else {
          // if this was added using the html5 context menu api, just click on the context menu item
          selectedItem.callback.call(selectedItem, aTarget, aX, aY);
        }
      }
    },

    handleEvent: function(aEvent) {
      BrowserEventHandler._cancelTapHighlight();
      aEvent.target.ownerDocument.defaultView.removeEventListener("contextmenu", this, false);
      this._show(aEvent);
    },

    observe: function(aSubject, aTopic, aData) {
      let data = JSON.parse(aData);
      // content gets first crack at cancelling context menus
      this._sendToContent(data.x, data.y);
    },

    // XXX - These are stolen from Util.js, we should remove them if we bring it back
    makeURLAbsolute: function makeURLAbsolute(base, url) {
      // Note:  makeURI() will throw if url is not a valid URI
      return this.makeURI(url, null, this.makeURI(base)).spec;
    },

    makeURI: function makeURI(aURL, aOriginCharset, aBaseURI) {
      return Services.io.newURI(aURL, aOriginCharset, aBaseURI);
    },

    _getLink: function(aElement) {
      if (aElement.nodeType == Ci.nsIDOMNode.ELEMENT_NODE &&
          ((aElement instanceof Ci.nsIDOMHTMLAnchorElement && aElement.href) ||
          (aElement instanceof Ci.nsIDOMHTMLAreaElement && aElement.href) ||
          aElement instanceof Ci.nsIDOMHTMLLinkElement ||
          aElement.getAttributeNS(kXLinkNamespace, "type") == "simple")) {
        try {
          let url = NativeWindow.contextmenus._getLinkURL(aElement);
          return Services.io.newURI(url, null, null);
        } catch (e) {}
      }
      return null;
    },

    _getLinkURL: function ch_getLinkURL(aLink) {
      let href = aLink.href;
      if (href)
        return href;

      href = aLink.getAttributeNS(kXLinkNamespace, "href");
      if (!href || !href.match(/\S/)) {
        // Without this we try to save as the current doc,
        // for example, HTML case also throws if empty
        throw "Empty href";
      }

      return this.makeURLAbsolute(aLink.baseURI, href);
    },

    _copyStringToDefaultClipboard: function(aString) {
      let clipboard = Cc["@mozilla.org/widget/clipboardhelper;1"].getService(Ci.nsIClipboardHelper);
      clipboard.copyString(aString);
    },

    _shareStringWithDefault: function(aSharedString, aTitle) {
      let sharing = Cc["@mozilla.org/uriloader/external-sharing-app-service;1"].getService(Ci.nsIExternalSharingAppService);
      sharing.shareWithDefault(aSharedString, "text/plain", aTitle);
    },

    _stripScheme: function(aString) {
      return aString.slice(aString.indexOf(":") + 1);
    }
  }
};

var SelectionHandler = {
  HANDLE_TYPE_START: "START",
  HANDLE_TYPE_MIDDLE: "MIDDLE",
  HANDLE_TYPE_END: "END",

  TYPE_NONE: 0,
  TYPE_CURSOR: 1,
  TYPE_SELECTION: 2,

  // Keeps track of data about the dimensions of the selection. Coordinates
  // stored here are relative to the _view window.
  cache: null,
  _activeType: 0, // TYPE_NONE

  // The window that holds the selection (can be a sub-frame)
  get _view() {
    if (this._viewRef)
      return this._viewRef.get();
    return null;
  },

  set _view(aView) {
    this._viewRef = Cu.getWeakReference(aView);
  },

  // The target can be a window or an input element
  get _target() {
    if (this._targetRef)
      return this._targetRef.get();
    return null;
  },

  set _target(aTarget) {
    this._targetRef = Cu.getWeakReference(aTarget);
  },

  get _cwu() {
    return BrowserApp.selectedBrowser.contentWindow.QueryInterface(Ci.nsIInterfaceRequestor).
                                                    getInterface(Ci.nsIDOMWindowUtils);
  },

  _isRTL: false,

  init: function sh_init() {
    Services.obs.addObserver(this, "Gesture:SingleTap", false);
    Services.obs.addObserver(this, "Window:Resize", false);
    Services.obs.addObserver(this, "Tab:Selected", false);
    Services.obs.addObserver(this, "after-viewport-change", false);
    Services.obs.addObserver(this, "TextSelection:Move", false);
    Services.obs.addObserver(this, "TextSelection:Position", false);
  },

  uninit: function sh_uninit() {
    Services.obs.removeObserver(this, "Gesture:SingleTap");
    Services.obs.removeObserver(this, "Window:Resize");
    Services.obs.removeObserver(this, "Tab:Selected");
    Services.obs.removeObserver(this, "after-viewport-change");
    Services.obs.removeObserver(this, "TextSelection:Move");
    Services.obs.removeObserver(this, "TextSelection:Position");
  },

  observe: function sh_observe(aSubject, aTopic, aData) {
    switch (aTopic) {
      case "Gesture:SingleTap": {
        if (this._activeType == this.TYPE_SELECTION) {
          let data = JSON.parse(aData);
          this.endSelection(data.x, data.y);
        }
        break;
      }
      case "Tab:Selected":
        if (this._activeType == this.TYPE_CURSOR) {
          this.hideThumb();
        }
        // fall through
      case "Window:Resize": {
        if (this._activeType == this.TYPE_SELECTION) {
          // Knowing when the page is done drawing is hard, so let's just cancel
          // the selection when the window changes. We should fix this later.
          this.endSelection();
        }
        break;
      }
      case "after-viewport-change": {
        if (this._activeType == this.TYPE_SELECTION) {
          // Update the cache after the viewport changes (e.g. panning, zooming).
          this.updateCacheForSelection();
        }
        break;
      }
      case "TextSelection:Move": {
        let data = JSON.parse(aData);
        if (this._activeType == this.TYPE_SELECTION)
          this.moveSelection(data.handleType == this.HANDLE_TYPE_START, data.x, data.y);
        else if (this._activeType == this.TYPE_CURSOR) {
          // Send a click event to the text box, which positions the caret
          this._sendMouseEvents(data.x, data.y);

          // Move the handle directly under the caret
          this.positionHandles();
        }
        break;
      }
      case "TextSelection:Position": {
        if (this._activeType == this.TYPE_SELECTION) {
          let data = JSON.parse(aData);

          // Reverse the handles if necessary.
          let selectionReversed = this.updateCacheForSelection(data.handleType == this.HANDLE_TYPE_START);
          if (selectionReversed) {
            // Re-send mouse events to update the selection corresponding to the new handles.
            if (this._isRTL) {
              this._sendMouseEvents(this.cache.end.x, this.cache.end.y, false);
              this._sendMouseEvents(this.cache.start.x, this.cache.start.y, true);
            } else {
              this._sendMouseEvents(this.cache.start.x, this.cache.start.y, false);
              this._sendMouseEvents(this.cache.end.x, this.cache.end.y, true);
            }
          }

          // Position the handles to align with the edges of the selection.
          this.positionHandles();
        } else if (this._activeType == this.TYPE_CURSOR) {
          this.positionHandles();
        }
        break;
      }
    }
  },

  handleEvent: function sh_handleEvent(aEvent) {
    switch (aEvent.type) {
      case "pagehide":
        if (this._activeType == this.TYPE_SELECTION)
          this.endSelection();
        else
          this.hideThumb();
        break;

      case "keydown":
      case "blur":
        if (this._activeType == this.TYPE_CURSOR)
          this.hideThumb();
        break;
    }
  },

  _ignoreCollapsedSelection: false,

  notifySelectionChanged: function sh_notifySelectionChanged(aDoc, aSel, aReason) {
    if (aSel.isCollapsed) {
      // Bail if we're ignoring events for a collapsed selection.
      if (this._ignoreCollapsedSelection)
        return;

      // If the selection is collapsed because of one of the mouse events we 
      // sent while moving the handle, don't get rid of the selection handles.
      if (aReason & Ci.nsISelectionListener.MOUSEDOWN_REASON) {
        this._ignoreCollapsedSelection = true;
        return;
      }

      // Otherwise, we do want to end the selection.
      this.endSelection();
    }

    this._ignoreCollapsedSelection = false;
  },

  /** Returns true if the provided element can be selected in text selection, false otherwise. */
  canSelect: function sh_canSelect(aElement) {
    return !(aElement instanceof Ci.nsIDOMHTMLButtonElement ||
             aElement instanceof Ci.nsIDOMHTMLEmbedElement ||
             aElement instanceof Ci.nsIDOMHTMLImageElement ||
             aElement instanceof Ci.nsIDOMHTMLMediaElement) &&
             aElement.style.MozUserSelect != 'none';
  },

  // aX/aY are in top-level window browser coordinates
  startSelection: function sh_startSelection(aElement, aX, aY) {
    // Clear out any existing selection
    if (this._activeType == this.TYPE_SELECTION) {
      this.endSelection();
    } else if (this._activeType == this.TYPE_CURSOR) {
      // Hide the cursor handles.
      this.hideThumb();
    }

    // Get the element's view
    this._view = aElement.ownerDocument.defaultView;

    if (aElement instanceof Ci.nsIDOMNSEditableElement)
      this._target = aElement;
    else
      this._target = this._view;

    this._view.addEventListener("pagehide", this, false);
    this._isRTL = (this._view.getComputedStyle(aElement, "").direction == "rtl");

    // Remove any previous selected or created ranges. Tapping anywhere on a
    // page will create an empty range.
    let selection = this.getSelection();
    selection.removeAllRanges();

    // Position the caret using a fake mouse click sent to the top-level window
    this._sendMouseEvents(aX, aY, false);

    try {
      let selectionController = this.getSelectionController();

      // Select the word nearest the caret
      selectionController.wordMove(false, false);

      // Move forward in LTR, backward in RTL
      selectionController.wordMove(!this._isRTL, true);
    } catch(e) {
      // If we couldn't select the word at the given point, bail
      this._cleanUp();
      return;
    }

    // If there isn't an appropriate selection, bail
    if (!selection.rangeCount || !selection.getRangeAt(0) || !selection.toString().trim().length) {
      selection.collapseToStart();
      this._cleanUp();
      return;
    }

    // Add a listener to end the selection if it's removed programatically
    selection.QueryInterface(Ci.nsISelectionPrivate).addSelectionListener(this);

    // Initialize the cache
    this.cache = { start: {}, end: {}};
    this.updateCacheForSelection();

    this._activeType = this.TYPE_SELECTION;
    this.positionHandles();

    sendMessageToJava({
      gecko: {
        type: "TextSelection:ShowHandles",
        handles: [this.HANDLE_TYPE_START, this.HANDLE_TYPE_END]
      }
    });

    if (aElement instanceof Ci.nsIDOMNSEditableElement)
      aElement.focus();
  },

  getSelection: function sh_getSelection() {
    if (this._target instanceof Ci.nsIDOMNSEditableElement)
      return this._target.QueryInterface(Ci.nsIDOMNSEditableElement).editor.selection;
    else
      return this._target.getSelection();
  },

  getSelectionController: function sh_getSelectionController() {
    if (this._target instanceof Ci.nsIDOMNSEditableElement)
      return this._target.QueryInterface(Ci.nsIDOMNSEditableElement).editor.selectionController;
    else
      return this._target.QueryInterface(Ci.nsIInterfaceRequestor).
                          getInterface(Ci.nsIWebNavigation).
                          QueryInterface(Ci.nsIInterfaceRequestor).
                          getInterface(Ci.nsISelectionDisplay).
                          QueryInterface(Ci.nsISelectionController);
  },

  // Used by the contextmenu "matches" functions in ClipboardHelper
  shouldShowContextMenu: function sh_shouldShowContextMenu(aX, aY) {
    return (this._activeType == this.TYPE_SELECTION) && this._pointInSelection(aX, aY);
  },

  selectAll: function sh_selectAll(aElement, aX, aY) {
    if (this._activeType != this.TYPE_SELECTION)
      this.startSelection(aElement, aX, aY);

    let selectionController = this.getSelectionController();
    selectionController.selectAll();
    this.updateCacheForSelection();
    this.positionHandles();
  },

  // Moves the ends of the selection in the page. aX/aY are in top-level window
  // browser coordinates.
  moveSelection: function sh_moveSelection(aIsStartHandle, aX, aY) {
    // Update the handle position as it's dragged.
    if (aIsStartHandle) {
      this.cache.start.x = aX;
      this.cache.start.y = aY;
    } else {
      this.cache.end.x = aX;
      this.cache.end.y = aY;
    }

    // The handles work the same on both LTR and RTL pages, but the underlying selection
    // works differently, so we need to reverse how we send mouse events on RTL pages.
    if (this._isRTL) {
      // Position the caret at the end handle using a fake mouse click
      if (!aIsStartHandle)
        this._sendMouseEvents(this.cache.end.x, this.cache.end.y, false);

      // Selects text between the carat and the start handle using a fake shift+click
      this._sendMouseEvents(this.cache.start.x, this.cache.start.y, true);
    } else {
      // Position the caret at the start handle using a fake mouse click
      if (aIsStartHandle)
        this._sendMouseEvents(this.cache.start.x, this.cache.start.y, false);

      // Selects text between the carat and the end handle using a fake shift+click
      this._sendMouseEvents( this.cache.end.x, this.cache.end.y, true);
    }
  },

  _sendMouseEvents: function sh_sendMouseEvents(aX, aY, useShift) {
    // If we're positioning a cursor in an input field, make sure the handle
    // stays within the bounds of the field
    if (this._activeType == this.TYPE_CURSOR) {
      // Get rect of text inside element
      let range = document.createRange();
      range.selectNodeContents(this._target.QueryInterface(Ci.nsIDOMNSEditableElement).editor.rootElement);
      let textBounds = range.getBoundingClientRect();

      // Get rect of editor
      let editorBounds = this._cwu.sendQueryContentEvent(this._cwu.QUERY_EDITOR_RECT, 0, 0, 0, 0);
      let editorRect = new Rect(editorBounds.left, editorBounds.top, editorBounds.width, editorBounds.height);

      // Use intersection of the text rect and the editor rect
      let rect = new Rect(textBounds.left, textBounds.top, textBounds.width, textBounds.height);
      rect.restrictTo(editorRect);

      // Clamp vertically and scroll if handle is at bounds. The top and bottom
      // must be restricted by an additional pixel since clicking on the top
      // edge of an input field moves the cursor to the beginning of that
      // field's text (and clicking the bottom moves the cursor to the end).
      if (aY < rect.y + 1) {
        aY = rect.y + 1;
        this.getSelectionController().scrollLine(false);
      } else if (aY > rect.y + rect.height - 1) {
        aY = rect.y + rect.height - 1;
        this.getSelectionController().scrollLine(true);
      }

      // Clamp horizontally and scroll if handle is at bounds
      if (aX < rect.x) {
        aX = rect.x;
        this.getSelectionController().scrollCharacter(false);
      } else if (aX > rect.x + rect.width) {
        aX = rect.x + rect.width;
        this.getSelectionController().scrollCharacter(true);
      }
    } else if (this._activeType == this.TYPE_SELECTION) {
      // Send mouse event 1px too high to prevent selection from entering the line below where it should be
      aY -= 1;
    }

    this._cwu.sendMouseEventToWindow("mousedown", aX, aY, 0, 0, useShift ? Ci.nsIDOMNSEvent.SHIFT_MASK : 0, true);
    this._cwu.sendMouseEventToWindow("mouseup", aX, aY, 0, 0, useShift ? Ci.nsIDOMNSEvent.SHIFT_MASK : 0, true);
  },

  // aX/aY are in top-level window browser coordinates
  endSelection: function sh_endSelection(aX, aY) {
    if (this._activeType != this.TYPE_SELECTION)
      return "";
 
    this._activeType = this.TYPE_NONE;
    sendMessageToJava({
      gecko: {
        type: "TextSelection:HideHandles",
        handles: [this.HANDLE_TYPE_START, this.HANDLE_TYPE_END]
      }
    });


    let selectedText = "";
    let pointInSelection = false;
    if (this._view) {
      let selection = this.getSelection();
      if (selection) {
        // Get the text before we clear the selection!
        selectedText = selection.toString().trim();

        // Also figure out if the point is in the selection before we clear it.
        if (arguments.length == 2 && this._pointInSelection(aX, aY))
          pointInSelection = true;

        selection.removeAllRanges();
        selection.QueryInterface(Ci.nsISelectionPrivate).removeSelectionListener(this);
      }
    }

    // Only try copying text if there's text to copy!
    if (pointInSelection && selectedText.length) {
      let element = ElementTouchHelper.anyElementFromPoint(aX, aY);
      // Only try copying text if the tap happens in the same view
      if (element.ownerDocument.defaultView == this._view) {
        let clipboard = Cc["@mozilla.org/widget/clipboardhelper;1"].getService(Ci.nsIClipboardHelper);
        clipboard.copyString(selectedText, element.ownerDocument);
        NativeWindow.toast.show(Strings.browser.GetStringFromName("selectionHelper.textCopied"), "short");
      }
    }

    this._cleanUp();

    return selectedText;
  },

  _cleanUp: function sh_cleanUp() {
    this._view.removeEventListener("pagehide", this, false);
    this._view.removeEventListener("keydown", this, false);
    this._view.removeEventListener("blur", this, true);
    this._activeType = this.TYPE_NONE;
    this._view = null;
    this._target = null;
    this._isRTL = false;
    this.cache = null;
  },

  _getViewOffset: function sh_getViewOffset() {
    let offset = { x: 0, y: 0 };
    let win = this._view;

    // Recursively look through frames to compute the total position offset.
    while (win.frameElement) {
      let rect = win.frameElement.getBoundingClientRect();
      offset.x += rect.left;
      offset.y += rect.top;

      win = win.parent;
    }

    return offset;
  },

  _pointInSelection: function sh_pointInSelection(aX, aY) {
    let offset = this._getViewOffset();
    let rangeRect = this.getSelection().getRangeAt(0).getBoundingClientRect();
    let radius = ElementTouchHelper.getTouchRadius();
    return (aX - offset.x > rangeRect.left - radius.left &&
            aX - offset.x < rangeRect.right + radius.right &&
            aY - offset.y > rangeRect.top - radius.top &&
            aY - offset.y < rangeRect.bottom + radius.bottom);
  },

  // Returns true if the selection has been reversed. Takes optional aIsStartHandle
  // param to decide whether the selection has been reversed.
  updateCacheForSelection: function sh_updateCacheForSelection(aIsStartHandle) {
    let selection = this.getSelection();
    let rects = selection.getRangeAt(0).getClientRects();
    let start = { x: this._isRTL ? rects[0].right : rects[0].left, y: rects[0].bottom };
    let end = { x: this._isRTL ? rects[rects.length - 1].left : rects[rects.length - 1].right, y: rects[rects.length - 1].bottom };

    let selectionReversed = false;
    if (this.cache.start) {
      // If the end moved past the old end, but we're dragging the start handle, then that handle should become the end handle (and vice versa)
      selectionReversed = (aIsStartHandle && (end.y > this.cache.end.y || (end.y == this.cache.end.y && end.x > this.cache.end.x))) ||
                          (!aIsStartHandle && (start.y < this.cache.start.y || (start.y == this.cache.start.y && start.x < this.cache.start.x)));
    }

    this.cache.start = start;
    this.cache.end = end;

    return selectionReversed;
  },

  showThumb: function sh_showThumb(aElement) {
    if (!aElement)
      return;

    // Get the element's view
    this._view = aElement.ownerDocument.defaultView;
    this._target = aElement;

    this._view.addEventListener("pagehide", this, false);
    this._view.addEventListener("keydown", this, false);
    this._view.addEventListener("blur", this, true);

    this._activeType = this.TYPE_CURSOR;
    this.positionHandles();

    sendMessageToJava({
      gecko: {
        type: "TextSelection:ShowHandles",
        handles: [this.HANDLE_TYPE_MIDDLE]
      }
    });
  },

  hideThumb: function sh_hideThumb() {
    this._activeType = this.TYPE_NONE;
    this._cleanUp();

    sendMessageToJava({
      gecko: {
        type: "TextSelection:HideHandles",
        handles: [this.HANDLE_TYPE_MIDDLE]
      }
    });
  },

  positionHandles: function sh_positionHandles() {
    // Translate coordinates to account for selections in sub-frames. We can't cache
    // this because the top-level page may have scrolled since selection started.
    let offset = this._getViewOffset();
    let scrollX = {}, scrollY = {};
    this._view.top.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils).getScrollXY(false, scrollX, scrollY);

    // the checkHidden function tests to see if the given point is hidden inside an
    // iframe/subdocument. this is so that if we select some text inside an iframe and
    // scroll the iframe so the selection is out of view, we hide the handles rather
    // than having them float on top of the main page content.
    let checkHidden = function(x, y) {
      return false;
    };
    if (this._view.frameElement) {
      let bounds = this._view.frameElement.getBoundingClientRect();
      checkHidden = function(x, y) {
        return x < 0 || y < 0 || x > bounds.width || y > bounds.height;
      }
    }

    let positions = null;
    if (this._activeType == this.TYPE_CURSOR) {
      let cursor = this._cwu.sendQueryContentEvent(this._cwu.QUERY_CARET_RECT, this._target.selectionEnd, 0, 0, 0);
      let x = cursor.left;
      let y = cursor.top + cursor.height;
      positions = [ { handle: this.HANDLE_TYPE_MIDDLE,
                     left: x + offset.x + scrollX.value,
                     top: y + offset.y + scrollY.value,
                     hidden: checkHidden(x, y) } ];
    } else {
      let sx = this.cache.start.x;
      let sy = this.cache.start.y;
      let ex = this.cache.end.x;
      let ey = this.cache.end.y;
      positions = [ { handle: this.HANDLE_TYPE_START,
                     left: sx + offset.x + scrollX.value,
                     top: sy + offset.y + scrollY.value,
                     hidden: checkHidden(sx, sy) },
                   { handle: this.HANDLE_TYPE_END,
                     left: ex + offset.x + scrollX.value,
                     top: ey + offset.y + scrollY.value,
                     hidden: checkHidden(ex, ey) } ];
    }

    sendMessageToJava({
      gecko: {
        type: "TextSelection:PositionHandles",
        positions: positions,
        rtl: this._isRTL
      }
    });
  },

  subdocumentScrolled: function sh_subdocumentScrolled(aElement) {
    if (this._activeType == this.TYPE_NONE) {
      return;
    }
    let scrollView = aElement.ownerDocument.defaultView;
    let view = this._view;
    while (true) {
      if (view == scrollView) {
        // The selection is in a view (or sub-view) of the view that scrolled.
        // So we need to reposition the handles.
        if (this._activeType == this.TYPE_SELECTION) {
          this.updateCacheForSelection();
        }
        this.positionHandles();
        break;
      }
      if (view == view.parent) {
        break;
      }
      view = view.parent;
    }
  }
};

var LightWeightThemeWebInstaller = {
  init: function sh_init() {
    let temp = {};
    Cu.import("resource://gre/modules/LightweightThemeConsumer.jsm", temp);
    let theme = new temp.LightweightThemeConsumer(document);
    BrowserApp.deck.addEventListener("InstallBrowserTheme", this, false, true);
    BrowserApp.deck.addEventListener("PreviewBrowserTheme", this, false, true);
    BrowserApp.deck.addEventListener("ResetBrowserThemePreview", this, false, true);
  },

  uninit: function() {
    BrowserApp.deck.addEventListener("InstallBrowserTheme", this, false, true);
    BrowserApp.deck.addEventListener("PreviewBrowserTheme", this, false, true);
    BrowserApp.deck.addEventListener("ResetBrowserThemePreview", this, false, true);
  },

  handleEvent: function (event) {
    switch (event.type) {
      case "InstallBrowserTheme":
      case "PreviewBrowserTheme":
      case "ResetBrowserThemePreview":
        // ignore requests from background tabs
        if (event.target.ownerDocument.defaultView.top != content)
          return;
    }

    switch (event.type) {
      case "InstallBrowserTheme":
        this._installRequest(event);
        break;
      case "PreviewBrowserTheme":
        this._preview(event);
        break;
      case "ResetBrowserThemePreview":
        this._resetPreview(event);
        break;
      case "pagehide":
      case "TabSelect":
        this._resetPreview();
        break;
    }
  },

  get _manager () {
    let temp = {};
    Cu.import("resource://gre/modules/LightweightThemeManager.jsm", temp);
    delete this._manager;
    return this._manager = temp.LightweightThemeManager;
  },

  _installRequest: function (event) {
    let node = event.target;
    let data = this._getThemeFromNode(node);
    if (!data)
      return;

    if (this._isAllowed(node)) {
      this._install(data);
      return;
    }

    let allowButtonText = Strings.browser.GetStringFromName("lwthemeInstallRequest.allowButton");
    let message = Strings.browser.formatStringFromName("lwthemeInstallRequest.message", [node.ownerDocument.location.hostname], 1);
    let buttons = [{
      label: allowButtonText,
      callback: function () {
        LightWeightThemeWebInstaller._install(data);
      }
    }];

    NativeWindow.doorhanger.show(message, "Personas", buttons, BrowserApp.selectedTab.id);
  },

  _install: function (newLWTheme) {
    this._manager.currentTheme = newLWTheme;
  },

  _previewWindow: null,
  _preview: function (event) {
    if (!this._isAllowed(event.target))
      return;
    let data = this._getThemeFromNode(event.target);
    if (!data)
      return;
    this._resetPreview();

    this._previewWindow = event.target.ownerDocument.defaultView;
    this._previewWindow.addEventListener("pagehide", this, true);
    BrowserApp.deck.addEventListener("TabSelect", this, false);
    this._manager.previewTheme(data);
  },

  _resetPreview: function (event) {
    if (!this._previewWindow ||
        event && !this._isAllowed(event.target))
      return;

    this._previewWindow.removeEventListener("pagehide", this, true);
    this._previewWindow = null;
    BrowserApp.deck.removeEventListener("TabSelect", this, false);

    this._manager.resetPreview();
  },

  _isAllowed: function (node) {
    let pm = Services.perms;

    let uri = node.ownerDocument.documentURIObject;
    return pm.testPermission(uri, "install") == pm.ALLOW_ACTION;
  },

  _getThemeFromNode: function (node) {
    return this._manager.parseTheme(node.getAttribute("data-browsertheme"), node.baseURI);
  }
};

var UserAgent = {
  DESKTOP_UA: null,
  YOUTUBE_DOMAIN: /\.?youtube\.com$/,

  init: function ua_init() {
    Services.obs.addObserver(this, "DesktopMode:Change", false);
    Services.obs.addObserver(this, "http-on-modify-request", false);

    // See https://developer.mozilla.org/en/Gecko_user_agent_string_reference
    this.DESKTOP_UA = Cc["@mozilla.org/network/protocol;1?name=http"]
                        .getService(Ci.nsIHttpProtocolHandler).userAgent
                        .replace(/Android; [a-zA-Z]+/, "X11; Linux x86_64")
                        .replace(/Gecko\/[0-9\.]+/, "Gecko/20100101");
  },

  uninit: function ua_uninit() {
    Services.obs.removeObserver(this, "DesktopMode:Change");
    Services.obs.removeObserver(this, "http-on-modify-request");
  },

  _getRequestLoadContext: function ua_getRequestLoadContext(aRequest) {
    if (aRequest && aRequest.notificationCallbacks) {
      try {
        return aRequest.notificationCallbacks.getInterface(Ci.nsILoadContext);
      } catch (ex) { }
    }

    if (aRequest && aRequest.loadGroup && aRequest.loadGroup.notificationCallbacks) {
      try {
        return aRequest.loadGroup.notificationCallbacks.getInterface(Ci.nsILoadContext);
      } catch (ex) { }
    }

    return null;
  },

  _getWindowForRequest: function ua_getWindowForRequest(aRequest) {
    let loadContext = this._getRequestLoadContext(aRequest);
    if (loadContext)
      return loadContext.associatedWindow;
    return null;
  },

  observe: function ua_observe(aSubject, aTopic, aData) {
    switch (aTopic) {
      case "DesktopMode:Change": {
        let args = JSON.parse(aData);
        let tab = BrowserApp.getTabForId(args.tabId);
        if (tab != null)
          tab.reloadWithMode(args.desktopMode);
        break;
      }
      case "http-on-modify-request": {
        let channel = aSubject.QueryInterface(Ci.nsIHttpChannel);
        let channelWindow = this._getWindowForRequest(channel);
        let tab = BrowserApp.getTabForWindow(channelWindow);
        if (tab == null)
          break;

        if (this.YOUTUBE_DOMAIN.test(channel.URI.host)) {
          let ua = Cc["@mozilla.org/network/protocol;1?name=http"].getService(Ci.nsIHttpProtocolHandler).userAgent;
          // Send the phone UA to youtube if this is a tablet
          if (ua.indexOf("Android; Mobile;") === -1) {
            ua = ua.replace("Android;", "Android; Mobile;");
            channel.setRequestHeader("User-Agent", ua, false);
          }
        }

        // Send desktop UA if "Request Desktop Site" is enabled
        if (tab.desktopMode)
          channel.setRequestHeader("User-Agent", this.DESKTOP_UA, false);

        break;
      }
    }
  }
};


function nsBrowserAccess() {
}

nsBrowserAccess.prototype = {
  QueryInterface: XPCOMUtils.generateQI([Ci.nsIBrowserDOMWindow]),

  _getBrowser: function _getBrowser(aURI, aOpener, aWhere, aContext) {
    let isExternal = (aContext == Ci.nsIBrowserDOMWindow.OPEN_EXTERNAL);
    if (isExternal && aURI && aURI.schemeIs("chrome"))
      return null;

    let loadflags = isExternal ?
                      Ci.nsIWebNavigation.LOAD_FLAGS_FROM_EXTERNAL :
                      Ci.nsIWebNavigation.LOAD_FLAGS_NONE;
    if (aWhere == Ci.nsIBrowserDOMWindow.OPEN_DEFAULTWINDOW) {
      switch (aContext) {
        case Ci.nsIBrowserDOMWindow.OPEN_EXTERNAL:
          aWhere = Services.prefs.getIntPref("browser.link.open_external");
          break;
        default: // OPEN_NEW or an illegal value
          aWhere = Services.prefs.getIntPref("browser.link.open_newwindow");
      }
    }

    Services.io.offline = false;

    let referrer;
    if (aOpener) {
      try {
        let location = aOpener.location;
        referrer = Services.io.newURI(location, null, null);
      } catch(e) { }
    }

    let ss = Cc["@mozilla.org/browser/sessionstore;1"].getService(Ci.nsISessionStore);
    let pinned = false;

    if (aURI && aWhere == Ci.nsIBrowserDOMWindow.OPEN_SWITCHTAB) {
      pinned = true;
      let spec = aURI.spec;
      let tabs = BrowserApp.tabs;
      for (let i = 0; i < tabs.length; i++) {
        let appOrigin = ss.getTabValue(tabs[i], "appOrigin");
        if (appOrigin == spec) {
          let tab = tabs[i];
          BrowserApp.selectTab(tab);
          return tab.browser;
        }
      }
    }

    let newTab = (aWhere == Ci.nsIBrowserDOMWindow.OPEN_NEWWINDOW ||
                  aWhere == Ci.nsIBrowserDOMWindow.OPEN_NEWTAB ||
                  aWhere == Ci.nsIBrowserDOMWindow.OPEN_SWITCHTAB);
    let isPrivate = false;

    if (newTab) {
      let parentId = -1;
      if (!isExternal && aOpener) {
        let parent = BrowserApp.getTabForWindow(aOpener.top);
        if (parent) {
          parentId = parent.id;
          isPrivate = PrivateBrowsingUtils.isWindowPrivate(parent.browser.contentWindow);
        }
      }

      // BrowserApp.addTab calls loadURIWithFlags with the appropriate params
      let tab = BrowserApp.addTab(aURI ? aURI.spec : "about:blank", { flags: loadflags,
                                                                      referrerURI: referrer,
                                                                      external: isExternal,
                                                                      parentId: parentId,
                                                                      selected: true,
                                                                      isPrivate: isPrivate,
                                                                      pinned: pinned });

      return tab.browser;
    }

    // OPEN_CURRENTWINDOW and illegal values
    let browser = BrowserApp.selectedBrowser;
    if (aURI && browser)
      browser.loadURIWithFlags(aURI.spec, loadflags, referrer, null, null);

    return browser;
  },

  openURI: function browser_openURI(aURI, aOpener, aWhere, aContext) {
    let browser = this._getBrowser(aURI, aOpener, aWhere, aContext);
    return browser ? browser.contentWindow : null;
  },

  openURIInFrame: function browser_openURIInFrame(aURI, aOpener, aWhere, aContext) {
    let browser = this._getBrowser(aURI, aOpener, aWhere, aContext);
    return browser ? browser.QueryInterface(Ci.nsIFrameLoaderOwner) : null;
  },

  isTabContentWindow: function(aWindow) {
    return BrowserApp.getBrowserForWindow(aWindow) != null;
  }
};


// track the last known screen size so that new tabs
// get created with the right size rather than being 1x1
let gScreenWidth = 1;
let gScreenHeight = 1;

function Tab(aURL, aParams) {
  this.browser = null;
  this.id = 0;
  this.lastTouchedAt = Date.now();
  this.showProgress = true;
  this._zoom = 1.0;
  this._drawZoom = 1.0;
  this.userScrollPos = { x: 0, y: 0 };
  this.contentDocumentIsDisplayed = true;
  this.pluginDoorhangerTimeout = null;
  this.shouldShowPluginDoorhanger = true;
  this.clickToPlayPluginsActivated = false;
  this.desktopMode = false;
  this.originalURI = null;
  this.savedArticle = null;
  this.hasTouchListener = false;

  this.create(aURL, aParams);
}

Tab.prototype = {
  create: function(aURL, aParams) {
    if (this.browser)
      return;

    aParams = aParams || {};

    this.browser = document.createElement("browser");
    this.browser.setAttribute("type", "content-targetable");
    this.setBrowserSize(kDefaultCSSViewportWidth, kDefaultCSSViewportHeight);

    // Make sure the previously selected panel remains selected. The selected panel of a deck is
    // not stable when panels are added.
    let selectedPanel = BrowserApp.deck.selectedPanel;
    BrowserApp.deck.insertBefore(this.browser, aParams.sibling || null);
    BrowserApp.deck.selectedPanel = selectedPanel;

    if (BrowserApp.manifestUrl) {
      let appsService = Cc["@mozilla.org/AppsService;1"].getService(Ci.nsIAppsService);
      let manifest = appsService.getAppByManifestURL(BrowserApp.manifestUrl);
      if (manifest) {
        let app = manifest.QueryInterface(Ci.mozIApplication);
        this.browser.docShell.setIsApp(app.localId);
      }
    }

    // Must be called after appendChild so the docshell has been created.
    this.setActive(false);

    let isPrivate = ("isPrivate" in aParams) && aParams.isPrivate;
    if (isPrivate) {
      this.browser.docShell.QueryInterface(Ci.nsILoadContext).usePrivateBrowsing = true;
    }

    this.browser.stop();

    let frameLoader = this.browser.QueryInterface(Ci.nsIFrameLoaderOwner).frameLoader;
    frameLoader.renderMode = Ci.nsIFrameLoader.RENDER_MODE_ASYNC_SCROLL;

    // only set tab uri if uri is valid
    let uri = null;
    let title = aParams.title || aURL;
    try {
      uri = Services.io.newURI(aURL, null, null).spec;
    } catch (e) {}

    if (!aParams.zombifying) {
      if ("tabID" in aParams) {
        this.id = aParams.tabID;
      } else {
        let jni = new JNI();
        let cls = jni.findClass("org/mozilla/gecko/Tabs");
        let method = jni.getStaticMethodID(cls, "getNextTabId", "()I");
        this.id = jni.callStaticIntMethod(cls, method);
        jni.close();
      }

      this.desktopMode = ("desktopMode" in aParams) ? aParams.desktopMode : false;

      let message = {
        gecko: {
          type: "Tab:Added",
          tabID: this.id,
          uri: uri,
          parentId: ("parentId" in aParams) ? aParams.parentId : -1,
          external: ("external" in aParams) ? aParams.external : false,
          selected: ("selected" in aParams) ? aParams.selected : true,
          title: title,
          delayLoad: aParams.delayLoad || false,
          desktopMode: this.desktopMode,
          isPrivate: isPrivate
        }
      };
      sendMessageToJava(message);

      this.overscrollController = new OverscrollController(this);
    }

    this.browser.contentWindow.controllers.insertControllerAt(0, this.overscrollController);

    let flags = Ci.nsIWebProgress.NOTIFY_STATE_ALL |
                Ci.nsIWebProgress.NOTIFY_LOCATION |
                Ci.nsIWebProgress.NOTIFY_SECURITY;
    this.browser.addProgressListener(this, flags);
    this.browser.sessionHistory.addSHistoryListener(this);

    this.browser.addEventListener("DOMContentLoaded", this, true);
    this.browser.addEventListener("DOMLinkAdded", this, true);
    this.browser.addEventListener("DOMTitleChanged", this, true);
    this.browser.addEventListener("DOMWindowClose", this, true);
    this.browser.addEventListener("DOMWillOpenModalDialog", this, true);
    this.browser.addEventListener("scroll", this, true);
    this.browser.addEventListener("MozScrolledAreaChanged", this, true);
    // Note that the XBL binding is untrusted
    this.browser.addEventListener("PluginBindingAttached", this, true, true);
    this.browser.addEventListener("pageshow", this, true);

    Services.obs.addObserver(this, "before-first-paint", false);
    Services.prefs.addObserver("browser.ui.zoom.force-user-scalable", this, false);

    if (aParams.delayLoad) {
      // If this is a zombie tab, attach restore data so the tab will be
      // restored when selected
      this.browser.__SS_data = {
        entries: [{
          url: aURL,
          title: title
        }],
        index: 1
      };
      this.browser.__SS_restore = true;
    } else {
      let flags = "flags" in aParams ? aParams.flags : Ci.nsIWebNavigation.LOAD_FLAGS_NONE;
      let postData = ("postData" in aParams && aParams.postData) ? aParams.postData.value : null;
      let referrerURI = "referrerURI" in aParams ? aParams.referrerURI : null;
      let charset = "charset" in aParams ? aParams.charset : null;

      // This determines whether or not we show the progress throbber in the urlbar
      this.showProgress = "showProgress" in aParams ? aParams.showProgress : true;

      try {
        this.browser.loadURIWithFlags(aURL, flags, referrerURI, charset, postData);
      } catch(e) {
        let message = {
          gecko: {
            type: "Content:LoadError",
            tabID: this.id,
            uri: this.browser.currentURI.spec,
            title: this.browser.contentTitle
          }
        };
        sendMessageToJava(message);
        dump("Handled load error: " + e);
      }
    }
  },

  performReflowOnZoom: function(aViewport) {
      let webNav = this.window.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIWebNavigation);
      let docShell = webNav.QueryInterface(Ci.nsIDocShell);
      let docViewer = docShell.contentViewer.QueryInterface(Ci.nsIMarkupDocumentViewer);
      let viewportWidth = gScreenWidth / aViewport.zoom;

      // We add in a bit of fudge just so that the end characters don't accidentally
      // get clipped. 15px is an arbitrary choice.
      docViewer.changeMaxLineBoxWidth(viewportWidth - 15);
  },

  /** 
   * Reloads the tab with the desktop mode setting.
   */
  reloadWithMode: function (aDesktopMode) {
    // Set desktop mode for tab and send change to Java
    if (this.desktopMode != aDesktopMode) {
      this.desktopMode = aDesktopMode;
      sendMessageToJava({
        gecko: {
          type: "DesktopMode:Changed",
          desktopMode: aDesktopMode,
          tabId: this.id
        }
      });
    }

    // Only reload the page for http/https schemes
    let currentURI = this.browser.currentURI;
    if (!currentURI.schemeIs("http") && !currentURI.schemeIs("https"))
      return;

    let url = currentURI.spec;
    let flags = Ci.nsIWebNavigation.LOAD_FLAGS_BYPASS_CACHE;
    if (this.originalURI && !this.originalURI.equals(currentURI)) {
      // We were redirected; reload the original URL
      url = this.originalURI.spec;
      flags |= Ci.nsIWebNavigation.LOAD_FLAGS_REPLACE_HISTORY;
    } else {
      // Many sites use mobile-specific URLs, such as:
      //   http://m.yahoo.com
      //   http://www.google.com/m
      // If the user clicks "Request Desktop Site" while on a mobile site, it
      // will appear to do nothing since the mobile URL is still being
      // requested. To address this, we do the following:
      //   1) Remove the path from the URL (http://www.google.com/m?q=query -> http://www.google.com)
      //   2) If a host subdomain is "m", remove it (http://en.m.wikipedia.org -> http://en.wikipedia.org)
      // This means the user is sent to site's home page, but this is better
      // than the setting having no effect at all.
      if (aDesktopMode)
        url = currentURI.prePath.replace(/([\/\.])m\./g, "$1");
      else
        flags |= Ci.nsIWebNavigation.LOAD_FLAGS_REPLACE_HISTORY;
    }

    this.browser.docShell.loadURI(url, flags, null, null, null);
  },

  destroy: function() {
    if (!this.browser)
      return;

    this.browser.contentWindow.controllers.removeController(this.overscrollController);

    this.browser.removeProgressListener(this);
    this.browser.sessionHistory.removeSHistoryListener(this);

    this.browser.removeEventListener("DOMContentLoaded", this, true);
    this.browser.removeEventListener("DOMLinkAdded", this, true);
    this.browser.removeEventListener("DOMTitleChanged", this, true);
    this.browser.removeEventListener("DOMWindowClose", this, true);
    this.browser.removeEventListener("DOMWillOpenModalDialog", this, true);
    this.browser.removeEventListener("scroll", this, true);
    this.browser.removeEventListener("MozScrolledAreaChanged", this, true);
    this.browser.removeEventListener("PluginBindingAttached", this, true);
    this.browser.removeEventListener("pageshow", this, true);

    Services.obs.removeObserver(this, "before-first-paint");
    Services.prefs.removeObserver("browser.ui.zoom.force-user-scalable", this);

    // Make sure the previously selected panel remains selected. The selected panel of a deck is
    // not stable when panels are removed.
    let selectedPanel = BrowserApp.deck.selectedPanel;
    BrowserApp.deck.removeChild(this.browser);
    BrowserApp.deck.selectedPanel = selectedPanel;

    this.browser = null;
  },

  // This should be called to update the browser when the tab gets selected/unselected
  setActive: function setActive(aActive) {
    if (!this.browser || !this.browser.docShell)
      return;

    if (aActive) {
      this.browser.setAttribute("type", "content-primary");
      this.browser.focus();
      this.browser.docShellIsActive = true;
    } else {
      this.browser.setAttribute("type", "content-targetable");
      this.browser.docShellIsActive = false;
    }
  },

  getActive: function getActive() {
      return this.browser.docShellIsActive;
  },

  setDisplayPort: function(aDisplayPort) {
    let zoom = this._zoom;
    let resolution = aDisplayPort.resolution;
    if (zoom <= 0 || resolution <= 0)
      return;

    // "zoom" is the user-visible zoom of the "this" tab
    // "resolution" is the zoom at which we wish gecko to render "this" tab at
    // these two may be different if we are, for example, trying to render a
    // large area of the page at low resolution because the user is panning real
    // fast.
    // The gecko scroll position is in CSS pixels. The display port rect
    // values (aDisplayPort), however, are in CSS pixels multiplied by the desired
    // rendering resolution. Therefore care must be taken when doing math with
    // these sets of values, to ensure that they are normalized to the same coordinate
    // space first.

    let element = this.browser.contentDocument.documentElement;
    if (!element)
      return;

    // we should never be drawing background tabs at resolutions other than the user-
    // visible zoom. for foreground tabs, however, if we are drawing at some other
    // resolution, we need to set the resolution as specified.
    let cwu = window.top.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
    if (BrowserApp.selectedTab == this) {
      if (resolution != this._drawZoom) {
        this._drawZoom = resolution;
        cwu.setResolution(resolution, resolution);
      }
    } else if (resolution != zoom) {
      dump("Warning: setDisplayPort resolution did not match zoom for background tab!");
    }

    // Finally, we set the display port, taking care to convert everything into the CSS-pixel
    // coordinate space, because that is what the function accepts. Also we have to fudge the
    // displayport somewhat to make sure it gets through all the conversions gecko will do on it
    // without deforming too much. See https://bugzilla.mozilla.org/show_bug.cgi?id=737510#c10
    // for details on what these operations are.
    let geckoScrollX = this.browser.contentWindow.scrollX;
    let geckoScrollY = this.browser.contentWindow.scrollY;
    aDisplayPort = this._dirtiestHackEverToWorkAroundGeckoRounding(aDisplayPort, geckoScrollX, geckoScrollY);

    cwu = this.browser.contentWindow.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);

    let displayPort = {
      x: (aDisplayPort.left / resolution) - geckoScrollX,
      y: (aDisplayPort.top / resolution) - geckoScrollY,
      width: (aDisplayPort.right - aDisplayPort.left) / resolution,
      height: (aDisplayPort.bottom - aDisplayPort.top) / resolution
    };

    let epsilon = 0.001;
    if (this._oldDisplayPort == null ||
        Math.abs(displayPort.x - this._oldDisplayPort.x) > epsilon ||
        Math.abs(displayPort.y - this._oldDisplayPort.y) > epsilon ||
        Math.abs(displayPort.width - this._oldDisplayPort.width) > epsilon ||
        Math.abs(displayPort.height - this._oldDisplayPort.height) > epsilon) {
      if (BrowserApp.gUseLowPrecision) {
        // Set the display-port to be 4x the size of the critical display-port,
        // on each dimension, giving us a 0.25x lower precision buffer around the
        // critical display-port. Spare area is *not* redistributed to the other
        // axis, as display-list building and invalidation cost scales with the
        // size of the display-port.
        let pageRect = cwu.getRootBounds();
        let pageXMost = pageRect.right - geckoScrollX;
        let pageYMost = pageRect.bottom - geckoScrollY;

        let dpW = Math.min(pageRect.right - pageRect.left, displayPort.width * 4);
        let dpH = Math.min(pageRect.bottom - pageRect.top, displayPort.height * 4);

        let dpX = Math.min(Math.max(displayPort.x - displayPort.width * 1.5,
                                    pageRect.left - geckoScrollX), pageXMost - dpW);
        let dpY = Math.min(Math.max(displayPort.y - displayPort.height * 1.5,
                                    pageRect.top - geckoScrollY), pageYMost - dpH);
        cwu.setDisplayPortForElement(dpX, dpY, dpW, dpH, element);
        cwu.setCriticalDisplayPortForElement(displayPort.x, displayPort.y,
                                             displayPort.width, displayPort.height,
                                             element);
      } else {
        cwu.setDisplayPortForElement(displayPort.x, displayPort.y,
                                     displayPort.width, displayPort.height,
                                     element);
      }
    }

    this._oldDisplayPort = displayPort;
  },

  /*
   * Yes, this is ugly. But it's currently the safest way to account for the rounding errors that occur
   * when we pump the displayport coordinates through gecko and they pop out in the compositor.
   *
   * In general, the values are converted from page-relative device pixels to viewport-relative app units,
   * and then back to page-relative device pixels (now as ints). The first half of this is only slightly
   * lossy, but it's enough to throw off the numbers a little. Because of this, when gecko calls
   * ScaleToOutsidePixels to generate the final rect, the rect may get expanded more than it should,
   * ending up a pixel larger than it started off. This is undesirable in general, but specifically
   * bad for tiling, because it means we means we end up painting one line of pixels from a tile,
   * causing an otherwise unnecessary upload of the whole tile.
   *
   * In order to counteract the rounding error, this code simulates the conversions that will happen
   * to the display port, and calculates whether or not that final ScaleToOutsidePixels is actually
   * expanding the rect more than it should. If so, it determines how much rounding error was introduced
   * up until that point, and adjusts the original values to compensate for that rounding error.
   */
  _dirtiestHackEverToWorkAroundGeckoRounding: function(aDisplayPort, aGeckoScrollX, aGeckoScrollY) {
    const APP_UNITS_PER_CSS_PIXEL = 60.0;
    const EXTRA_FUDGE = 0.04;

    let resolution = aDisplayPort.resolution;

    // Some helper functions that simulate conversion processes in gecko

    function cssPixelsToAppUnits(aVal) {
      return Math.floor((aVal * APP_UNITS_PER_CSS_PIXEL) + 0.5);
    }

    function appUnitsToDevicePixels(aVal) {
      return aVal / APP_UNITS_PER_CSS_PIXEL * resolution;
    }

    function devicePixelsToAppUnits(aVal) {
      return cssPixelsToAppUnits(aVal / resolution);
    }

    // Stash our original (desired) displayport width and height away, we need it
    // later and we might modify the displayport in between.
    let originalWidth = aDisplayPort.right - aDisplayPort.left;
    let originalHeight = aDisplayPort.bottom - aDisplayPort.top;

    // This is the first conversion the displayport goes through, going from page-relative
    // device pixels to viewport-relative app units.
    let appUnitDisplayPort = {
      x: cssPixelsToAppUnits((aDisplayPort.left / resolution) - aGeckoScrollX),
      y: cssPixelsToAppUnits((aDisplayPort.top / resolution) - aGeckoScrollY),
      w: cssPixelsToAppUnits((aDisplayPort.right - aDisplayPort.left) / resolution),
      h: cssPixelsToAppUnits((aDisplayPort.bottom - aDisplayPort.top) / resolution)
    };

    // This is the translation gecko applies when converting back from viewport-relative
    // device pixels to page-relative device pixels.
    let geckoTransformX = -Math.floor((-aGeckoScrollX * resolution) + 0.5);
    let geckoTransformY = -Math.floor((-aGeckoScrollY * resolution) + 0.5);

    // The final "left" value as calculated in gecko is:
    //    left = geckoTransformX + Math.floor(appUnitsToDevicePixels(appUnitDisplayPort.x))
    // In a perfect world, this value would be identical to aDisplayPort.left, which is what
    // we started with. However, this may not be the case if the value being floored has accumulated
    // enough error to drop below what it should be.
    // For example, assume geckoTransformX is 0, and aDisplayPort.left is 4, but
    // appUnitsToDevicePixels(appUnitsToDevicePixels.x) comes out as 3.9 because of rounding error.
    // That's bad, because the -0.1 error has caused it to floor to 3 instead of 4. (If it had errored
    // the other way and come out as 4.1, there's no problem). In this example, we need to increase the
    // "left" value by some amount so that the 3.9 actually comes out as >= 4, and it gets floored into
    // the expected value of 4. The delta values calculated below calculate that error amount (e.g. -0.1).
    let errorLeft = (geckoTransformX + appUnitsToDevicePixels(appUnitDisplayPort.x)) - aDisplayPort.left;
    let errorTop = (geckoTransformY + appUnitsToDevicePixels(appUnitDisplayPort.y)) - aDisplayPort.top;

    // If the error was negative, that means it will floor incorrectly, so we need to bump up the
    // original aDisplayPort.left and/or aDisplayPort.top values. The amount we bump it up by is
    // the error amount (increased by a small fudge factor to ensure it's sufficient), converted
    // backwards through the conversion process.
    if (errorLeft < 0) {
      aDisplayPort.left += appUnitsToDevicePixels(devicePixelsToAppUnits(EXTRA_FUDGE - errorLeft));
      // After we modify the left value, we need to re-simulate some values to take that into account
      appUnitDisplayPort.x = cssPixelsToAppUnits((aDisplayPort.left / resolution) - aGeckoScrollX);
      appUnitDisplayPort.w = cssPixelsToAppUnits((aDisplayPort.right - aDisplayPort.left) / resolution);
    }
    if (errorTop < 0) {
      aDisplayPort.top += appUnitsToDevicePixels(devicePixelsToAppUnits(EXTRA_FUDGE - errorTop));
      // After we modify the top value, we need to re-simulate some values to take that into account
      appUnitDisplayPort.y = cssPixelsToAppUnits((aDisplayPort.top / resolution) - aGeckoScrollY);
      appUnitDisplayPort.h = cssPixelsToAppUnits((aDisplayPort.bottom - aDisplayPort.top) / resolution);
    }

    // At this point, the aDisplayPort.left and aDisplayPort.top values have been corrected to account
    // for the error in conversion such that they end up where we want them. Now we need to also do the
    // same for the right/bottom values so that the width/height end up where we want them.

    // This is the final conversion that the displayport goes through before gecko spits it back to
    // us. Note that the width/height calculates are of the form "ceil(transform(right)) - floor(transform(left))"
    let scaledOutDevicePixels = {
      x: Math.floor(appUnitsToDevicePixels(appUnitDisplayPort.x)),
      y: Math.floor(appUnitsToDevicePixels(appUnitDisplayPort.y)),
      w: Math.ceil(appUnitsToDevicePixels(appUnitDisplayPort.x + appUnitDisplayPort.w)) - Math.floor(appUnitsToDevicePixels(appUnitDisplayPort.x)),
      h: Math.ceil(appUnitsToDevicePixels(appUnitDisplayPort.y + appUnitDisplayPort.h)) - Math.floor(appUnitsToDevicePixels(appUnitDisplayPort.y))
    };

    // The final "width" value as calculated in gecko is scaledOutDevicePixels.w.
    // In a perfect world, this would equal originalWidth. However, things are not perfect, and as before,
    // we need to calculate how much rounding error has been introduced. In this case the rounding error is causing
    // the Math.ceil call above to ceiling to the wrong final value. For example, 4 gets converted 4.1 and gets
    // ceiling'd to 5; in this case the error is 0.1.
    let errorRight = (appUnitsToDevicePixels(appUnitDisplayPort.x + appUnitDisplayPort.w) - scaledOutDevicePixels.x) - originalWidth;
    let errorBottom = (appUnitsToDevicePixels(appUnitDisplayPort.y + appUnitDisplayPort.h) - scaledOutDevicePixels.y) - originalHeight;

    // If the error was positive, that means it will ceiling incorrectly, so we need to bump down the
    // original aDisplayPort.right and/or aDisplayPort.bottom. Again, we back-convert the error amount
    // with a small fudge factor to figure out how much to adjust the original values.
    if (errorRight > 0) aDisplayPort.right -= appUnitsToDevicePixels(devicePixelsToAppUnits(errorRight + EXTRA_FUDGE));
    if (errorBottom > 0) aDisplayPort.bottom -= appUnitsToDevicePixels(devicePixelsToAppUnits(errorBottom + EXTRA_FUDGE));

    // Et voila!
    return aDisplayPort;
  },

  setScrollClampingSize: function(zoom) {
    let viewportWidth = gScreenWidth / zoom;
    let viewportHeight = gScreenHeight / zoom;
    let [pageWidth, pageHeight] = this.getPageSize(this.browser.contentDocument,
                                                   viewportWidth, viewportHeight);

    // Make sure the aspect ratio of the screen is maintained when setting
    // the clamping scroll-port size.
    let factor = Math.min(viewportWidth / gScreenWidth, pageWidth / gScreenWidth,
                          viewportHeight / gScreenHeight, pageHeight / gScreenHeight);
    let scrollPortWidth = gScreenWidth * factor;
    let scrollPortHeight = gScreenHeight * factor;

    let win = this.browser.contentWindow;
    win.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils).
        setScrollPositionClampingScrollPortSize(scrollPortWidth, scrollPortHeight);
  },

  setViewport: function(aViewport) {
    // Transform coordinates based on zoom
    let x = aViewport.x / aViewport.zoom;
    let y = aViewport.y / aViewport.zoom;

    this.setScrollClampingSize(aViewport.zoom);

    // Adjust the max line box width to be no more than the viewport width, but
    // only if the reflow-on-zoom preference is enabled.
    if (BrowserEventHandler.mReflozPref && BrowserEventHandler._mLastPinchData) {
      let webNav = window.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIWebNavigation);
      let docShell = webNav.QueryInterface(Ci.nsIDocShell);
      let docViewer = docShell.contentViewer.QueryInterface(Ci.nsIMarkupDocumentViewer);
      let viewportWidth = gScreenWidth / aViewport.zoom;
      // We add in a bit of fudge just so that the end characters don't accidentally
      // get clipped. 15px is an arbitrary choice.
      docViewer.changeMaxLineBoxWidth(viewportWidth - 15);
      BrowserEventHandler._mLastPinchData = null;
    }

    let win = this.browser.contentWindow;
    win.scrollTo(x, y);

    this.userScrollPos.x = win.scrollX;
    this.userScrollPos.y = win.scrollY;
    this.setResolution(aViewport.zoom, false);

    if (aViewport.displayPort)
      this.setDisplayPort(aViewport.displayPort);

    Services.obs.notifyObservers(null, "after-viewport-change", "");
  },

  setResolution: function(aZoom, aForce) {
    // Set zoom level
    if (aForce || Math.abs(aZoom - this._zoom) >= 1e-6) {
      this._zoom = aZoom;
      if (BrowserApp.selectedTab == this) {
        let cwu = window.top.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
        this._drawZoom = aZoom;
        cwu.setResolution(aZoom, aZoom);
      }
    }
  },

  getPageSize: function(aDocument, aDefaultWidth, aDefaultHeight) {
    let body = aDocument.body || { scrollWidth: aDefaultWidth, scrollHeight: aDefaultHeight };
    let html = aDocument.documentElement || { scrollWidth: aDefaultWidth, scrollHeight: aDefaultHeight };
    return [Math.max(body.scrollWidth, html.scrollWidth),
      Math.max(body.scrollHeight, html.scrollHeight)];
  },

  getViewport: function() {
    let viewport = {
      width: gScreenWidth,
      height: gScreenHeight,
      cssWidth: gScreenWidth / this._zoom,
      cssHeight: gScreenHeight / this._zoom,
      pageLeft: 0,
      pageTop: 0,
      pageRight: gScreenWidth,
      pageBottom: gScreenHeight,
      // We make up matching css page dimensions
      cssPageLeft: 0,
      cssPageTop: 0,
      cssPageRight: gScreenWidth / this._zoom,
      cssPageBottom: gScreenHeight / this._zoom,
      zoom: this._zoom,
    };

    // Set the viewport offset to current scroll offset
    viewport.cssX = this.browser.contentWindow.scrollX || 0;
    viewport.cssY = this.browser.contentWindow.scrollY || 0;

    // Transform coordinates based on zoom
    viewport.x = Math.round(viewport.cssX * viewport.zoom);
    viewport.y = Math.round(viewport.cssY * viewport.zoom);

    let doc = this.browser.contentDocument;
    if (doc != null) {
      let cwu = this.browser.contentWindow.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
      let cssPageRect = cwu.getRootBounds();

      /*
       * Avoid sending page sizes of less than screen size before we hit DOMContentLoaded, because
       * this causes the page size to jump around wildly during page load. After the page is loaded,
       * send updates regardless of page size; we'll zoom to fit the content as needed.
       *
       * In the check below, we floor the viewport size because there might be slight rounding errors
       * introduced in the CSS page size due to the conversion to and from app units in Gecko. The
       * error should be no more than one app unit so doing the floor is overkill, but safe in the
       * sense that the extra page size updates that get sent as a result will be mostly harmless.
       */
      let pageLargerThanScreen = (cssPageRect.width >= Math.floor(viewport.cssWidth))
                              && (cssPageRect.height >= Math.floor(viewport.cssHeight));
      if (doc.readyState === 'complete' || pageLargerThanScreen) {
        viewport.cssPageLeft = cssPageRect.left;
        viewport.cssPageTop = cssPageRect.top;
        viewport.cssPageRight = cssPageRect.right;
        viewport.cssPageBottom = cssPageRect.bottom;
        /* Transform the page width and height based on the zoom factor. */
        viewport.pageLeft = (viewport.cssPageLeft * viewport.zoom);
        viewport.pageTop = (viewport.cssPageTop * viewport.zoom);
        viewport.pageRight = (viewport.cssPageRight * viewport.zoom);
        viewport.pageBottom = (viewport.cssPageBottom * viewport.zoom);
      }
    }

    return viewport;
  },

  sendViewportUpdate: function(aPageSizeUpdate) {
    let viewport = this.getViewport();
    let displayPort = getBridge().getDisplayPort(aPageSizeUpdate, BrowserApp.isBrowserContentDocumentDisplayed(), this.id, viewport);
    if (displayPort != null)
      this.setDisplayPort(displayPort);
  },

  handleEvent: function(aEvent) {
    switch (aEvent.type) {
      case "DOMContentLoaded": {
        let target = aEvent.originalTarget;

        // ignore on frames and other documents
        if (target != this.browser.contentDocument)
          return;

        // Sample the background color of the page and pass it along. (This is used to draw the
        // checkerboard.) Right now we don't detect changes in the background color after this
        // event fires; it's not clear that doing so is worth the effort.
        var backgroundColor = null;
        try {
          let { contentDocument, contentWindow } = this.browser;
          let computedStyle = contentWindow.getComputedStyle(contentDocument.body);
          backgroundColor = computedStyle.backgroundColor;
        } catch (e) {
          // Ignore. Catching and ignoring exceptions here ensures that Talos succeeds.
        }

        sendMessageToJava({
          gecko: {
            type: "DOMContentLoaded",
            tabID: this.id,
            bgColor: backgroundColor
          }
        });

        // Attach a listener to watch for "click" events bubbling up from error
        // pages and other similar page. This lets us fix bugs like 401575 which
        // require error page UI to do privileged things, without letting error
        // pages have any privilege themselves.
        if (/^about:/.test(target.documentURI)) {
          this.browser.addEventListener("click", ErrorPageEventHandler, true);
          let listener = function() {
            this.browser.removeEventListener("click", ErrorPageEventHandler, true);
            this.browser.removeEventListener("pagehide", listener, true);
          }.bind(this);

          this.browser.addEventListener("pagehide", listener, true);
        }

        if (/^about:reader/.test(target.documentURI))
          new AboutReader(this.browser.contentDocument, this.browser.contentWindow);

        break;
      }

      case "DOMLinkAdded": {
        let target = aEvent.originalTarget;
        if (!target.href || target.disabled)
          return;

        // ignore on frames and other documents
        if (target.ownerDocument != this.browser.contentDocument)
          return;

        // sanitize the rel string
        let list = [];
        if (target.rel) {
          list = target.rel.toLowerCase().split(/\s+/);
          let hash = {};
          list.forEach(function(value) { hash[value] = true; });
          list = [];
          for (let rel in hash)
            list.push("[" + rel + "]");
        }

        // We want to get the largest icon size possible for our UI.
        let maxSize = 0;

        // We use the sizes attribute if available
        // see http://www.whatwg.org/specs/web-apps/current-work/multipage/links.html#rel-icon
        if (target.hasAttribute("sizes")) {
          let sizes = target.getAttribute("sizes").toLowerCase();

          if (sizes == "any") {
            // Since Java expects an integer, use -1 to represent icons with sizes="any"
            maxSize = -1; 
          } else {
            let tokens = sizes.split(" ");
            tokens.forEach(function(token) {
              // TODO: check for invalid tokens
              let [w, h] = token.split("x");
              maxSize = Math.max(maxSize, Math.max(w, h));
            });
          }
        }

        let json = {
          type: "DOMLinkAdded",
          tabID: this.id,
          href: resolveGeckoURI(target.href),
          charset: target.ownerDocument.characterSet,
          title: target.title,
          rel: list.join(" "),
          size: maxSize
        };

        sendMessageToJava({ gecko: json });
        break;
      }

      case "DOMTitleChanged": {
        if (!aEvent.isTrusted)
          return;

        // ignore on frames and other documents
        if (aEvent.originalTarget != this.browser.contentDocument)
          return;

        sendMessageToJava({
          gecko: {
            type: "DOMTitleChanged",
            tabID: this.id,
            title: aEvent.target.title.substring(0, 255)
          }
        });
        break;
      }

      case "DOMWindowClose": {
        if (!aEvent.isTrusted)
          return;

        // Find the relevant tab, and close it from Java
        if (this.browser.contentWindow == aEvent.target) {
          aEvent.preventDefault();

          sendMessageToJava({
            gecko: {
              type: "DOMWindowClose",
              tabID: this.id
            }
          });
        }
        break;
      }

      case "DOMWillOpenModalDialog": {
        if (!aEvent.isTrusted)
          return;

        // We're about to open a modal dialog, make sure the opening
        // tab is brought to the front.
        let tab = BrowserApp.getTabForWindow(aEvent.target.top);
        BrowserApp.selectTab(tab);
        break;
      }

      case "scroll": {
        let win = this.browser.contentWindow;
        if (this.userScrollPos.x != win.scrollX || this.userScrollPos.y != win.scrollY) {
          this.sendViewportUpdate();
        }
        break;
      }

      case "MozScrolledAreaChanged": {
        // This event is only fired for root scroll frames, and only when the
        // scrolled area has actually changed, so no need to check for that.
        // Just make sure it's the event for the correct root scroll frame.
        if (aEvent.originalTarget != this.browser.contentDocument)
          return;

        this.sendViewportUpdate(true);
        break;
      }

      case "PluginBindingAttached": {
        PluginHelper.handlePluginBindingAttached(this, aEvent);
        break;
      }

      case "pageshow": {
        // only send pageshow for the top-level document
        if (aEvent.originalTarget.defaultView != this.browser.contentWindow)
          return;

        sendMessageToJava({
          gecko: {
            type: "Content:PageShow",
            tabID: this.id
          }
        });

        // For low-memory devices, don't allow reader mode since it takes up a lot of memory.
        // See https://bugzilla.mozilla.org/show_bug.cgi?id=792603 for details.
        if (Cc["@mozilla.org/xpcom/memory-service;1"].getService(Ci.nsIMemory).isLowMemoryPlatform())
          return;

        // Once document is fully loaded, parse it
        Reader.parseDocumentFromTab(this.id, function (article) {
          // Do nothing if there's no article or the page in this tab has
          // changed
          let tabURL = this.browser.currentURI.specIgnoringRef;
          if (article == null || (article.url != tabURL)) {
            // Don't clear the article for about:reader pages since we want to
            // use the article from the previous page
            if (!/^about:reader/i.test(tabURL))
              this.savedArticle = null;

            return;
          }

          this.savedArticle = article;

          sendMessageToJava({
            gecko: {
              type: "Content:ReaderEnabled",
              tabID: this.id
            }
          });
        }.bind(this));
      }
    }
  },

  onStateChange: function(aWebProgress, aRequest, aStateFlags, aStatus) {
    let contentWin = aWebProgress.DOMWindow;
    if (contentWin != contentWin.top)
        return;

    // Filter optimization: Only really send NETWORK state changes to Java listener
    if (aStateFlags & Ci.nsIWebProgressListener.STATE_IS_NETWORK) {
      if ((aStateFlags & Ci.nsIWebProgressListener.STATE_STOP) && aWebProgress.isLoadingDocument) {
        // We may receive a document stop event while a document is still loading
        // (such as when doing URI fixup). Don't notify Java UI in these cases.
        return;
      }

      // Check to see if we restoring the content from a previous presentation (session)
      // since there should be no real network activity
      let restoring = aStateFlags & Ci.nsIWebProgressListener.STATE_RESTORING;
      let showProgress = restoring ? false : this.showProgress;

      // true if the page loaded successfully (i.e., no 404s or other errors)
      let success = false; 
      let uri = "";
      try {
        // Remember original URI for UA changes on redirected pages
        this.originalURI = aRequest.QueryInterface(Components.interfaces.nsIChannel).originalURI;

        if (this.originalURI != null)
          uri = this.originalURI.spec;
      } catch (e) { }
      try {
        success = aRequest.QueryInterface(Components.interfaces.nsIHttpChannel).requestSucceeded;
      } catch (e) { }

      let message = {
        gecko: {
          type: "Content:StateChange",
          tabID: this.id,
          uri: uri,
          state: aStateFlags,
          showProgress: showProgress,
          success: success
        }
      };
      sendMessageToJava(message);

      // Reset showProgress after state change
      this.showProgress = true;
    }
  },

  onLocationChange: function(aWebProgress, aRequest, aLocationURI, aFlags) {
    let contentWin = aWebProgress.DOMWindow;
    if (contentWin != contentWin.top)
        return;

    this._hostChanged = true;

    let fixedURI = aLocationURI;
    try {
      fixedURI = URIFixup.createExposableURI(aLocationURI);
    } catch (ex) { }

    let documentURI = contentWin.document.documentURIObject.spec;
    let contentType = contentWin.document.contentType;

    // If fixedURI matches browser.lastURI, we assume this isn't a real location
    // change but rather a spurious addition like a wyciwyg URI prefix. See Bug 747883.
    // Note that we have to ensure fixedURI is not the same as aLocationURI so we
    // don't false-positive page reloads as spurious additions.
    let sameDocument = (aFlags & Ci.nsIWebProgressListener.LOCATION_CHANGE_SAME_DOCUMENT) != 0 ||
                       ((this.browser.lastURI != null) && fixedURI.equals(this.browser.lastURI) && !fixedURI.equals(aLocationURI));
    this.browser.lastURI = fixedURI;

    // Reset state of click-to-play plugin notifications.
    clearTimeout(this.pluginDoorhangerTimeout);
    this.pluginDoorhangerTimeout = null;
    this.shouldShowPluginDoorhanger = true;
    this.clickToPlayPluginsActivated = false;

    let message = {
      gecko: {
        type: "Content:LocationChange",
        tabID: this.id,
        uri: fixedURI.spec,
        documentURI: documentURI,
        contentType: (contentType ? contentType : ""),
        sameDocument: sameDocument
      }
    };

    sendMessageToJava(message);

    if (!sameDocument) {
      // XXX This code assumes that this is the earliest hook we have at which
      // browser.contentDocument is changed to the new document we're loading
      this.contentDocumentIsDisplayed = false;
      this.hasTouchListener = false;
    } else {
      this.sendViewportUpdate();
    }
  },

  // Properties used to cache security state used to update the UI
  _state: null,
  _hostChanged: false, // onLocationChange will flip this bit

  onSecurityChange: function(aWebProgress, aRequest, aState) {
    // Don't need to do anything if the data we use to update the UI hasn't changed
    if (this._state == aState && !this._hostChanged)
      return;

    this._state = aState;
    this._hostChanged = false;

    let identity = IdentityHandler.checkIdentity(aState, this.browser);

    let message = {
      gecko: {
        type: "Content:SecurityChange",
        tabID: this.id,
        identity: identity
      }
    };

    sendMessageToJava(message);
  },

  onProgressChange: function(aWebProgress, aRequest, aCurSelfProgress, aMaxSelfProgress, aCurTotalProgress, aMaxTotalProgress) {
  },

  onStatusChange: function(aBrowser, aWebProgress, aRequest, aStatus, aMessage) {
  },

  _sendHistoryEvent: function(aMessage, aParams) {
    let message = {
      gecko: {
        type: "SessionHistory:" + aMessage,
        tabID: this.id,
      }
    };

    if (aParams) {
      if ("url" in aParams)
        message.gecko.url = aParams.url;
      if ("index" in aParams)
        message.gecko.index = aParams.index;
      if ("numEntries" in aParams)
        message.gecko.numEntries = aParams.numEntries;
    }

    sendMessageToJava(message);
  },

  OnHistoryNewEntry: function(aUri) {
    this._sendHistoryEvent("New", { url: aUri.spec });
  },

  OnHistoryGoBack: function(aUri) {
    this._sendHistoryEvent("Back");
    return true;
  },

  OnHistoryGoForward: function(aUri) {
    this._sendHistoryEvent("Forward");
    return true;
  },

  OnHistoryReload: function(aUri, aFlags) {
    // we don't do anything with this, so don't propagate it
    // for now anyway
    return true;
  },

  OnHistoryGotoIndex: function(aIndex, aUri) {
    this._sendHistoryEvent("Goto", { index: aIndex });
    return true;
  },

  OnHistoryPurge: function(aNumEntries) {
    this._sendHistoryEvent("Purge", { numEntries: aNumEntries });
    return true;
  },

  get metadata() {
    return ViewportHandler.getMetadataForDocument(this.browser.contentDocument);
  },

  /** Update viewport when the metadata changes. */
  updateViewportMetadata: function updateViewportMetadata(aMetadata, aInitialLoad) {
    if (Services.prefs.getBoolPref("browser.ui.zoom.force-user-scalable")) {
      aMetadata.allowZoom = true;
      aMetadata.minZoom = aMetadata.maxZoom = NaN;
    }

    let scaleRatio = aMetadata.scaleRatio = ViewportHandler.getScaleRatio();

    if ("defaultZoom" in aMetadata && aMetadata.defaultZoom > 0)
      aMetadata.defaultZoom *= scaleRatio;
    if ("minZoom" in aMetadata && aMetadata.minZoom > 0)
      aMetadata.minZoom *= scaleRatio;
    if ("maxZoom" in aMetadata && aMetadata.maxZoom > 0)
      aMetadata.maxZoom *= scaleRatio;

    ViewportHandler.setMetadataForDocument(this.browser.contentDocument, aMetadata);
    this.updateViewportSize(gScreenWidth, aInitialLoad);
    this.sendViewportMetadata();
  },

  /** Update viewport when the metadata or the window size changes. */
  updateViewportSize: function updateViewportSize(aOldScreenWidth, aInitialLoad) {
    // When this function gets called on window resize, we must execute
    // this.sendViewportUpdate() so that refreshDisplayPort is called.
    // Ensure that when making changes to this function that code path
    // is not accidentally removed (the call to sendViewportUpdate() is
    // at the very end).

    let browser = this.browser;
    if (!browser)
      return;

    let screenW = gScreenWidth;
    let screenH = gScreenHeight;
    let viewportW, viewportH;

    let metadata = this.metadata;
    if (metadata.autoSize) {
      if ("scaleRatio" in metadata) {
        viewportW = screenW / metadata.scaleRatio;
        viewportH = screenH / metadata.scaleRatio;
      } else {
        viewportW = screenW;
        viewportH = screenH;
      }
    } else {
      viewportW = metadata.width;
      viewportH = metadata.height;

      // If (scale * width) < device-width, increase the width (bug 561413).
      let maxInitialZoom = metadata.defaultZoom || metadata.maxZoom;
      if (maxInitialZoom && viewportW)
        viewportW = Math.max(viewportW, screenW / maxInitialZoom);

      let validW = viewportW > 0;
      let validH = viewportH > 0;

      if (!validW)
        viewportW = validH ? (viewportH * (screenW / screenH)) : BrowserApp.defaultBrowserWidth;
      if (!validH)
        viewportH = viewportW * (screenH / screenW);
    }

    // Make sure the viewport height is not shorter than the window when
    // the page is zoomed out to show its full width. Note that before
    // we set the viewport width, the "full width" of the page isn't properly
    // defined, so that's why we have to call setBrowserSize twice - once
    // to set the width, and the second time to figure out the height based
    // on the layout at that width.
    let oldBrowserWidth = this.browserWidth;
    this.setBrowserSize(viewportW, viewportH);

    // if this page has not been painted yet, then this must be getting run
    // because a meta-viewport element was added (via the DOMMetaAdded handler).
    // in this case, we should not do anything that forces a reflow (see bug 759678)
    // such as requesting the page size or sending a viewport update. this code
    // will get run again in the before-first-paint handler and that point we
    // will run though all of it. the reason we even bother executing up to this
    // point on the DOMMetaAdded handler is so that scripts that use window.innerWidth
    // before they are painted have a correct value (bug 771575).
    if (!this.contentDocumentIsDisplayed) {
      return;
    }

    let minScale = 1.0;
    if (this.browser.contentDocument) {
      // this may get run during a Viewport:Change message while the document
      // has not yet loaded, so need to guard against a null document.
      let [pageWidth, pageHeight] = this.getPageSize(this.browser.contentDocument, viewportW, viewportH);
      minScale = gScreenWidth / pageWidth;
    }
    minScale = this.clampZoom(minScale);
    viewportH = Math.max(viewportH, screenH / minScale);
    this.setBrowserSize(viewportW, viewportH);

    // Avoid having the scroll position jump around after device rotation.
    let win = this.browser.contentWindow;
    this.userScrollPos.x = win.scrollX;
    this.userScrollPos.y = win.scrollY;

    // This change to the zoom accounts for all types of changes I can conceive:
    // 1. screen size changes, CSS viewport does not (pages with no meta viewport
    //    or a fixed size viewport)
    // 2. screen size changes, CSS viewport also does (pages with a device-width
    //    viewport)
    // 3. screen size remains constant, but CSS viewport changes (meta viewport
    //    tag is added or removed)
    // 4. neither screen size nor CSS viewport changes
    //
    // In all of these cases, we maintain how much actual content is visible
    // within the screen width. Note that "actual content" may be different
    // with respect to CSS pixels because of the CSS viewport size changing.
    let zoomScale = (screenW * oldBrowserWidth) / (aOldScreenWidth * viewportW);
    let zoom = (aInitialLoad && metadata.defaultZoom) ? metadata.defaultZoom : this.clampZoom(this._zoom * zoomScale);
    this.setResolution(zoom, false);
    this.setScrollClampingSize(zoom);
    this.sendViewportUpdate();
  },

  sendViewportMetadata: function sendViewportMetadata() {
    sendMessageToJava({ gecko: {
      type: "Tab:ViewportMetadata",
      allowZoom: this.metadata.allowZoom,
      defaultZoom: this.metadata.defaultZoom || 0,
      minZoom: this.metadata.minZoom || 0,
      maxZoom: this.metadata.maxZoom || 0,
      tabID: this.id
    }});
  },

  setBrowserSize: function(aWidth, aHeight) {
    this.browserWidth = aWidth;

    if (!this.browser.contentWindow)
      return;
    let cwu = this.browser.contentWindow.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
    cwu.setCSSViewport(aWidth, aHeight);
  },

  /** Takes a scale and restricts it based on this tab's zoom limits. */
  clampZoom: function clampZoom(aZoom) {
    let zoom = ViewportHandler.clamp(aZoom, kViewportMinScale, kViewportMaxScale);

    let md = this.metadata;
    if (!md.allowZoom)
      return md.defaultZoom || zoom;

    if (md && md.minZoom)
      zoom = Math.max(zoom, md.minZoom);
    if (md && md.maxZoom)
      zoom = Math.min(zoom, md.maxZoom);
    return zoom;
  },

  observe: function(aSubject, aTopic, aData) {
    switch (aTopic) {
      case "before-first-paint":
        // Is it on the top level?
        let contentDocument = aSubject;
        if (contentDocument == this.browser.contentDocument) {
          BrowserApp.displayedDocumentChanged();
          this.contentDocumentIsDisplayed = true;

          // reset CSS viewport and zoom to default on new page, and then calculate
          // them properly using the actual metadata from the page. note that the
          // updateMetadata call takes into account the existing CSS viewport size
          // and zoom when calculating the new ones, so we need to reset these
          // things here before calling updateMetadata.
          this.setBrowserSize(kDefaultCSSViewportWidth, kDefaultCSSViewportHeight);
          this.setResolution(gScreenWidth / this.browserWidth, false);
          ViewportHandler.updateMetadata(this, true);

          // Note that if we draw without a display-port, things can go wrong. By the
          // time we execute this, it's almost certain a display-port has been set via
          // the MozScrolledAreaChanged event. If that didn't happen, the updateMetadata
          // call above does so at the end of the updateViewportSize function. As long
          // as that is happening, we don't need to do it again here.

          if (contentDocument.mozSyntheticDocument) {
            // for images, scale to fit width. this needs to happen *after* the call
            // to updateMetadata above, because that call sets the CSS viewport which
            // will affect the page size (i.e. contentDocument.body.scroll*) that we
            // use in this calculation. also we call sendViewportUpdate after changing
            // the resolution so that the display port gets recalculated appropriately.
            let fitZoom = Math.min(gScreenWidth / contentDocument.body.scrollWidth,
                                   gScreenHeight / contentDocument.body.scrollHeight);
            this.setResolution(fitZoom, false);
            this.sendViewportUpdate();
          }
        }

        // If the reflow-text-on-page-load pref is enabled, and reflow-on-zoom
        // is enabled, and our defaultZoom level is set, then we need to get
        // the default zoom and reflow the text according to the defaultZoom
        // level.
        let rzEnabled = BrowserEventHandler.mReflozPref;
        let rzPl = Services.prefs.getBoolPref("browser.zoom.reflowZoom.reflowTextOnPageLoad");

        if (rzEnabled && rzPl) {
          // Retrieve the viewport width and adjust the max line box width
          // accordingly.
          let vp = BrowserApp.selectedTab.getViewport();
          BrowserApp.selectedTab.performReflowOnZoom(vp);
        }
        break;
      case "nsPref:changed":
        if (aData == "browser.ui.zoom.force-user-scalable")
          ViewportHandler.updateMetadata(this, false);
        break;
    }
  },

  // nsIBrowserTab
  get window() {
    if (!this.browser)
      return null;
    return this.browser.contentWindow;
  },

  get scale() {
    return this._zoom;
  },

  QueryInterface: XPCOMUtils.generateQI([
    Ci.nsIWebProgressListener,
    Ci.nsISHistoryListener,
    Ci.nsIObserver,
    Ci.nsISupportsWeakReference,
    Ci.nsIBrowserTab
  ])
};

var BrowserEventHandler = {
  init: function init() {
    Services.obs.addObserver(this, "Gesture:SingleTap", false);
    Services.obs.addObserver(this, "Gesture:CancelTouch", false);
    Services.obs.addObserver(this, "Gesture:DoubleTap", false);
    Services.obs.addObserver(this, "Gesture:Scroll", false);
    Services.obs.addObserver(this, "dom-touch-listener-added", false);

    BrowserApp.deck.addEventListener("DOMUpdatePageReport", PopupBlockerObserver.onUpdatePageReport, false);
    BrowserApp.deck.addEventListener("touchstart", this, true);
    BrowserApp.deck.addEventListener("click", InputWidgetHelper, true);
    BrowserApp.deck.addEventListener("click", SelectHelper, true);
    document.addEventListener("MozMagnifyGestureStart", this, true);
    document.addEventListener("MozMagnifyGestureUpdate", this, true);
    document.addEventListener("MozMagnifyGesture", this, true);

    Services.prefs.addObserver("browser.zoom.reflowOnZoom", this, false);
    this.updateReflozPref();
  },

  resetMaxLineBoxWidth: function() {
    let webNav = window.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIWebNavigation);
    let docShell = webNav.QueryInterface(Ci.nsIDocShell);
    let docViewer = docShell.contentViewer.QueryInterface(Ci.nsIMarkupDocumentViewer);
    docViewer.changeMaxLineBoxWidth(0);
  },

  updateReflozPref: function() {
     this.mReflozPref = Services.prefs.getBoolPref("browser.zoom.reflowOnZoom");
  },

  handleEvent: function(aEvent) {
    switch (aEvent.type) {
      case 'touchstart':
        this._handleTouchStart(aEvent);
        break;
      case 'MozMagnifyGesture':
      case 'MozMagnifyGestureUpdate':
      case 'MozMagnifyGestureStart':
        this.observe(this, aEvent.type, JSON.stringify({x: aEvent.screenX, y: aEvent.screenY}));
        break;
    }
  },

  _handleTouchStart: function(aEvent) {
    if (!BrowserApp.isBrowserContentDocumentDisplayed() || aEvent.touches.length > 1 || aEvent.defaultPrevented)
      return;

    let closest = aEvent.target;

    if (closest) {
      // If we've pressed a scrollable element, let Java know that we may
      // want to override the scroll behaviour (for document sub-frames)
      this._scrollableElement = this._findScrollableElement(closest, true);
      this._firstScrollEvent = true;

      if (this._scrollableElement != null) {
        // Discard if it's the top-level scrollable, we let Java handle this
        let doc = BrowserApp.selectedBrowser.contentDocument;
        if (this._scrollableElement != doc.body && this._scrollableElement != doc.documentElement)
          sendMessageToJava({ gecko: { type: "Panning:Override" } });
      }
    }

    if (!ElementTouchHelper.isElementClickable(closest, null, false))
      closest = ElementTouchHelper.elementFromPoint(aEvent.changedTouches[0].screenX,
                                                    aEvent.changedTouches[0].screenY);
    if (!closest)
      closest = aEvent.target;

    if (closest) {
      let uri = this._getLinkURI(closest);
      if (uri) {
        Services.io.QueryInterface(Ci.nsISpeculativeConnect).speculativeConnect(uri, null);
      }
      this._doTapHighlight(closest);
    }
  },

  _getLinkURI: function(aElement) {
    if (aElement.nodeType == Ci.nsIDOMNode.ELEMENT_NODE &&
        ((aElement instanceof Ci.nsIDOMHTMLAnchorElement && aElement.href) ||
        (aElement instanceof Ci.nsIDOMHTMLAreaElement && aElement.href))) {
      try {
        return Services.io.newURI(aElement.href, null, null);
      } catch (e) {}
    }
    return null;
  },

  observe: function(aSubject, aTopic, aData) {
    if (aTopic == "dom-touch-listener-added") {
      let tab = BrowserApp.getTabForWindow(aSubject.top);
      if (!tab || tab.hasTouchListener)
        return;

      tab.hasTouchListener = true;
      sendMessageToJava({
        gecko: {
          type: "Tab:HasTouchListener",
          tabID: tab.id
        }
      });
      return;
    } else if (aTopic == "nsPref:changed") {
      if (aData == "browser.zoom.reflowOnZoom") {
        this.updateReflozPref();
      }
      return;
    }

    // the remaining events are all dependent on the browser content document being the
    // same as the browser displayed document. if they are not the same, we should ignore
    // the event.
    if (BrowserApp.isBrowserContentDocumentDisplayed()) {
      this.handleUserEvent(aTopic, aData);
    }
  },

  handleUserEvent: function(aTopic, aData) {
    switch (aTopic) {

      case "Gesture:Scroll": {
        // If we've lost our scrollable element, return. Don't cancel the
        // override, as we probably don't want Java to handle panning until the
        // user releases their finger.
        if (this._scrollableElement == null)
          return;

        // If this is the first scroll event and we can't scroll in the direction
        // the user wanted, and neither can any non-root sub-frame, cancel the
        // override so that Java can handle panning the main document.
        let data = JSON.parse(aData);

        // round the scroll amounts because they come in as floats and might be
        // subject to minor rounding errors because of zoom values. I've seen values
        // like 0.99 come in here and get truncated to 0; this avoids that problem.
        let zoom = BrowserApp.selectedTab._zoom;
        let x = Math.round(data.x / zoom);
        let y = Math.round(data.y / zoom);

        if (this._firstScrollEvent) {
          while (this._scrollableElement != null &&
                 !this._elementCanScroll(this._scrollableElement, x, y))
            this._scrollableElement = this._findScrollableElement(this._scrollableElement, false);

          let doc = BrowserApp.selectedBrowser.contentDocument;
          if (this._scrollableElement == null ||
              this._scrollableElement == doc.body ||
              this._scrollableElement == doc.documentElement) {
            sendMessageToJava({ gecko: { type: "Panning:CancelOverride" } });
            return;
          }

          this._firstScrollEvent = false;
        }

        // Scroll the scrollable element
        if (this._elementCanScroll(this._scrollableElement, x, y)) {
          this._scrollElementBy(this._scrollableElement, x, y);
          sendMessageToJava({ gecko: { type: "Gesture:ScrollAck", scrolled: true } });
          SelectionHandler.subdocumentScrolled(this._scrollableElement);
        } else {
          sendMessageToJava({ gecko: { type: "Gesture:ScrollAck", scrolled: false } });
        }

        break;
      }

      case "Gesture:CancelTouch":
        this._cancelTapHighlight();
        break;

      case "Gesture:SingleTap": {
        let element = this._highlightElement;
        if (element) {
          try {
            let data = JSON.parse(aData);
            let [x, y] = [data.x, data.y];
            if (ElementTouchHelper.isElementClickable(element)) {
              [x, y] = this._moveClickPoint(element, x, y);
              element = ElementTouchHelper.anyElementFromPoint(x, y);
            }

            this._sendMouseEvent("mousemove", element, x, y);
            this._sendMouseEvent("mousedown", element, x, y);
            this._sendMouseEvent("mouseup",   element, x, y);

            // See if its a input element
            if ((element instanceof HTMLInputElement && element.mozIsTextField(false)) ||
                (element instanceof HTMLTextAreaElement))
               SelectionHandler.showThumb(element);

            // scrollToFocusedInput does its own checks to find out if an element should be zoomed into
            BrowserApp.scrollToFocusedInput(BrowserApp.selectedBrowser);
          } catch(e) {
            Cu.reportError(e);
          }
        }
        this._cancelTapHighlight();
        break;
      }

      case"Gesture:DoubleTap":
        this._cancelTapHighlight();
        this.onDoubleTap(aData);
        break;

      case "MozMagnifyGestureStart":
      case "MozMagnifyGestureUpdate":
        this.onPinch(aData);
        break;

      case "MozMagnifyGesture":
        this.onPinchFinish(aData, this._mLastPinchPoint.x, this._mLastPinchPoint.y);
        break;

      default:
        dump('BrowserEventHandler.handleUserEvent: unexpected topic "' + aTopic + '"');
        break;
    }
  },

  _zoomOut: function() {
    BrowserEventHandler.resetMaxLineBoxWidth();
    sendMessageToJava({ gecko: { type: "Browser:ZoomToPageWidth"} });
  },

  _isRectZoomedIn: function(aRect, aViewport) {
    // This function checks to see if the area of the rect visible in the
    // viewport (i.e. the "overlapArea" variable below) is approximately
    // the max area of the rect we can show. It also checks that the rect
    // is actually on-screen by testing the left and right edges of the rect.
    // In effect, this tells us whether or not zooming in to this rect
    // will significantly change what the user is seeing.
    const minDifference = -20;
    const maxDifference = 20;
    const maxZoomAllowed = 4; // keep this in sync with mobile/android/base/ui/PanZoomController.MAX_ZOOM

    let vRect = new Rect(aViewport.cssX, aViewport.cssY, aViewport.cssWidth, aViewport.cssHeight);
    let overlap = vRect.intersect(aRect);
    let overlapArea = overlap.width * overlap.height;
    let availHeight = Math.min(aRect.width * vRect.height / vRect.width, aRect.height);
    let showing = overlapArea / (aRect.width * availHeight);
    let dw = (aRect.width - vRect.width);
    let dx = (aRect.x - vRect.x);

    if (Math.abs(aViewport.zoom - maxZoomAllowed) < 1e-6 && overlap.width / aRect.width > 0.9) {
      // we're already at the max zoom and the block is not spilling off the side of the screen so that even
      // if the block isn't taking up most of the viewport we can't pan/zoom in any more. return true so that we zoom out
      return true;
    }

    return (showing > 0.9 &&
            dx > minDifference && dx < maxDifference &&
            dw > minDifference && dw < maxDifference);
  },

  onDoubleTap: function(aData) {
    let data = JSON.parse(aData);

    let zoom = BrowserApp.selectedTab._zoom;
    let element = ElementTouchHelper.anyElementFromPoint(data.x, data.y);
    if (!element) {
      this._zoomOut();
      return;
    }

    while (element && !this._shouldZoomToElement(element))
      element = element.parentNode;

    if (!element) {
      this._zoomOut();
    } else {
      this._zoomToElement(element, data.y);
    }
  },

  /* Zoom to an element, optionally keeping a particular part of it
   * in view if it is really tall.
   */
  _zoomToElement: function(aElement, aClickY = -1, aCanZoomOut = true, aCanZoomIn = true) {
    const margin = 15;
    let rect = ElementTouchHelper.getBoundingContentRect(aElement);

    let viewport = BrowserApp.selectedTab.getViewport();
    let bRect = new Rect(aCanZoomIn ? Math.max(viewport.cssPageLeft, rect.x - margin) : viewport.cssPageLeft,
                         rect.y,
                         aCanZoomIn ? rect.w + 2 * margin : viewport.cssWidth,
                         rect.h);
    // constrict the rect to the screen's right edge
    bRect.width = Math.min(bRect.width, viewport.cssPageRight - bRect.x);

    // if the rect is already taking up most of the visible area and is stretching the
    // width of the page, then we want to zoom out instead.
    if (this._isRectZoomedIn(bRect, viewport)) {
      if (aCanZoomOut)
        this._zoomOut();
      return;
    }

    rect.type = "Browser:ZoomToRect";
    rect.x = bRect.x;
    rect.y = bRect.y;
    rect.w = bRect.width;
    rect.h = Math.min(bRect.width * viewport.cssHeight / viewport.cssWidth, bRect.height);

    if (aClickY >= 0) {
      // if the block we're zooming to is really tall, and we want to keep a particular
      // part of it in view, then adjust the y-coordinate of the target rect accordingly.
      // the 1.2 multiplier is just a little fuzz to compensate for bRect including horizontal
      // margins but not vertical ones.
      let cssTapY = viewport.cssY + aClickY;
      if ((bRect.height > rect.h) && (cssTapY > rect.y + (rect.h * 1.2))) {
        rect.y = cssTapY - (rect.h / 2);
      }
    }

    if (rect.w > viewport.cssWidth || rect.h > viewport.cssHeight) {
      BrowserEventHandler.resetMaxLineBoxWidth();
    }

    sendMessageToJava({ gecko: rect });
  },

  _zoomInAndSnapToElement: function(aX, aY, aElement) {
    let viewport = BrowserApp.selectedTab.getViewport();
    if (viewport.zoom < 1.0) {
      // We don't want to do this on zoom out.
      return;
    }

    let fudge = 15; // Add a bit of fudge.
    let win = BrowserApp.selectedBrowser.contentWindow;

    let rect = ElementTouchHelper.getBoundingContentRect(aElement);

    rect.type = "Browser:ZoomToRect";
    rect.x = Math.max(viewport.cssPageLeft, rect.x  - fudge);
    rect.y = viewport.cssY;
    rect.w = viewport.cssWidth;
    rect.h = viewport.cssHeight;

    sendMessageToJava({ gecko: rect });
   },

   onPinch: function(aData) {
     let data = JSON.parse(aData);
     this._mLastPinchPoint = {x: data.x, y: data.y};
   },

   onPinchFinish: function(aData, aX, aY) {
     if (this.mReflozPref) {
       let data = JSON.parse(aData);
       let pinchElement = ElementTouchHelper.anyElementFromPoint(aX, aY);
       data.element = pinchElement;
       BrowserApp.selectedTab._mLastPinchElement = pinchElement;
       this._mLastPinchData = data;
       this._zoomInAndSnapToElement(data.x, data.y, data.element);
     }
   },

  _shouldZoomToElement: function(aElement) {
    let win = aElement.ownerDocument.defaultView;
    if (win.getComputedStyle(aElement, null).display == "inline")
      return false;
    if (aElement instanceof Ci.nsIDOMHTMLLIElement)
      return false;
    if (aElement instanceof Ci.nsIDOMHTMLQuoteElement)
      return false;
    return true;
  },

  _firstScrollEvent: false,

  _scrollableElement: null,

  _highlightElement: null,

  _mLastPinchData: null,

  _doTapHighlight: function _doTapHighlight(aElement) {
    DOMUtils.setContentState(aElement, kStateActive);
    this._highlightElement = aElement;
  },

  _cancelTapHighlight: function _cancelTapHighlight() {
    if (!this._highlightElement)
      return;

    // If the active element is in a sub-frame, we need to make that frame's document
    // active to remove the element's active state.
    if (this._highlightElement.ownerDocument != BrowserApp.selectedBrowser.contentWindow.document)
      DOMUtils.setContentState(this._highlightElement.ownerDocument.documentElement, kStateActive);

    DOMUtils.setContentState(BrowserApp.selectedBrowser.contentWindow.document.documentElement, kStateActive);
    this._highlightElement = null;
  },

  _updateLastPosition: function(x, y, dx, dy) {
    this.lastX = x;
    this.lastY = y;
    this.lastTime = Date.now();

    this.motionBuffer.push({ dx: dx, dy: dy, time: this.lastTime });
  },

  _moveClickPoint: function(aElement, aX, aY) {
    // the element can be out of the aX/aY point because of the touch radius
    // if outside, we gracefully move the touch point to the edge of the element
    if (!(aElement instanceof HTMLHtmlElement)) {
      let isTouchClick = true;
      let rects = ElementTouchHelper.getContentClientRects(aElement);
      for (let i = 0; i < rects.length; i++) {
        let rect = rects[i];
        let inBounds =
          (aX > rect.left && aX < (rect.left + rect.width)) &&
          (aY > rect.top && aY < (rect.top + rect.height));
        if (inBounds) {
          isTouchClick = false;
          break;
        }
      }

      if (isTouchClick) {
        let rect = rects[0];
        // if either width or height is zero, we don't want to move the click to the edge of the element. See bug 757208
        if (rect.width != 0 && rect.height != 0) {
          aX = Math.min(Math.floor(rect.left + rect.width), Math.max(Math.ceil(rect.left), aX));
          aY = Math.min(Math.floor(rect.top + rect.height), Math.max(Math.ceil(rect.top),  aY));
        }
      }
    }
    return [aX, aY];
  },

  _sendMouseEvent: function _sendMouseEvent(aName, aElement, aX, aY) {
    let window = aElement.ownerDocument.defaultView;
    try {
      let cwu = window.top.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
      cwu.sendMouseEventToWindow(aName, aX, aY, 0, 1, 0, true);
    } catch(e) {
      Cu.reportError(e);
    }
  },

  _hasScrollableOverflow: function(elem) {
    var win = elem.ownerDocument.defaultView;
    if (!win)
      return false;
    var computedStyle = win.getComputedStyle(elem);
    if (!computedStyle)
      return false;
    return computedStyle.overflowX == 'auto' || computedStyle.overflowX == 'scroll'
        || computedStyle.overflowY == 'auto' || computedStyle.overflowY == 'scroll';
  },

  _findScrollableElement: function(elem, checkElem) {
    // Walk the DOM tree until we find a scrollable element
    let scrollable = false;
    while (elem) {
      /* Element is scrollable if its scroll-size exceeds its client size, and:
       * - It has overflow 'auto' or 'scroll'
       * - It's a textarea
       * - It's an HTML/BODY node
       * - It's a select element showing multiple rows
       */
      if (checkElem) {
        if (((elem.scrollHeight > elem.clientHeight) ||
             (elem.scrollWidth > elem.clientWidth)) &&
            (this._hasScrollableOverflow(elem) ||
             elem.mozMatchesSelector("html, body, textarea")) ||
            (elem instanceof HTMLSelectElement && (elem.size > 1 || elem.multiple))) {
          scrollable = true;
          break;
        }
      } else {
        checkElem = true;
      }

      // Propagate up iFrames
      if (!elem.parentNode && elem.documentElement && elem.documentElement.ownerDocument)
        elem = elem.documentElement.ownerDocument.defaultView.frameElement;
      else
        elem = elem.parentNode;
    }

    if (!scrollable)
      return null;

    return elem;
  },

  _elementReceivesInput: function(aElement) {
    return aElement instanceof Element &&
        kElementsReceivingInput.hasOwnProperty(aElement.tagName.toLowerCase()) ||
        this._isEditable(aElement);
  },

  _isEditable: function(aElement) {
    let canEdit = false;

    if (aElement.isContentEditable || aElement.designMode == "on") {
      canEdit = true;
    } else if (aElement instanceof HTMLIFrameElement && (aElement.contentDocument.body.isContentEditable || aElement.contentDocument.designMode == "on")) {
      canEdit = true;
    } else {
      canEdit = aElement.ownerDocument && aElement.ownerDocument.designMode == "on";
    }

    return canEdit;
  },

  _scrollElementBy: function(elem, x, y) {
    elem.scrollTop = elem.scrollTop + y;
    elem.scrollLeft = elem.scrollLeft + x;
  },

  _elementCanScroll: function(elem, x, y) {
    let scrollX = (x < 0 && elem.scrollLeft > 0)
               || (x > 0 && elem.scrollLeft < (elem.scrollWidth - elem.clientWidth));

    let scrollY = (y < 0 && elem.scrollTop > 0)
               || (y > 0 && elem.scrollTop < (elem.scrollHeight - elem.clientHeight));

    return scrollX || scrollY;
  }
};

const kReferenceDpi = 240; // standard "pixel" size used in some preferences

const ElementTouchHelper = {
  /* Return the element at the given coordinates, starting from the given window and
     drilling down through frames. If no window is provided, the top-level window of
     the currently selected tab is used. The coordinates provided should be CSS pixels
     relative to the window's scroll position. */
  anyElementFromPoint: function(aX, aY, aWindow) {
    let win = (aWindow ? aWindow : BrowserApp.selectedBrowser.contentWindow);
    let cwu = win.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
    let elem = cwu.elementFromPoint(aX, aY, false, true);

    while (elem && (elem instanceof HTMLIFrameElement || elem instanceof HTMLFrameElement)) {
      let rect = elem.getBoundingClientRect();
      aX -= rect.left;
      aY -= rect.top;
      cwu = elem.contentDocument.defaultView.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
      elem = cwu.elementFromPoint(aX, aY, false, true);
    }

    return elem;
  },

  /* Return the most appropriate clickable element (if any), starting from the given window
     and drilling down through iframes as necessary. If no window is provided, the top-level
     window of the currently selected tab is used. The coordinates provided should be CSS
     pixels relative to the window's scroll position. The element returned may not actually
     contain the coordinates passed in because of touch radius and clickability heuristics. */
  elementFromPoint: function(aX, aY, aWindow) {
    // browser's elementFromPoint expect browser-relative client coordinates.
    // subtract browser's scroll values to adjust
    let win = (aWindow ? aWindow : BrowserApp.selectedBrowser.contentWindow);
    let cwu = win.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
    let elem = this.getClosest(cwu, aX, aY);

    // step through layers of IFRAMEs and FRAMES to find innermost element
    while (elem && (elem instanceof HTMLIFrameElement || elem instanceof HTMLFrameElement)) {
      // adjust client coordinates' origin to be top left of iframe viewport
      let rect = elem.getBoundingClientRect();
      aX -= rect.left;
      aY -= rect.top;
      cwu = elem.contentDocument.defaultView.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
      elem = this.getClosest(cwu, aX, aY);
    }

    return elem;
  },

  /* Returns the touch radius in content px. */
  getTouchRadius: function getTouchRadius() {
    let dpiRatio = ViewportHandler.displayDPI / kReferenceDpi;
    let zoom = BrowserApp.selectedTab._zoom;
    return {
      top: this.radius.top * dpiRatio / zoom,
      right: this.radius.right * dpiRatio / zoom,
      bottom: this.radius.bottom * dpiRatio / zoom,
      left: this.radius.left * dpiRatio / zoom
    };
  },

  /* Returns the touch radius in reference pixels. */
  get radius() {
    let prefs = Services.prefs;
    delete this.radius;
    return this.radius = { "top": prefs.getIntPref("browser.ui.touch.top"),
                           "right": prefs.getIntPref("browser.ui.touch.right"),
                           "bottom": prefs.getIntPref("browser.ui.touch.bottom"),
                           "left": prefs.getIntPref("browser.ui.touch.left")
                         };
  },

  get weight() {
    delete this.weight;
    return this.weight = { "visited": Services.prefs.getIntPref("browser.ui.touch.weight.visited") };
  },

  /* Retrieve the closest element to a point by looking at borders position */
  getClosest: function getClosest(aWindowUtils, aX, aY) {
    let target = aWindowUtils.elementFromPoint(aX, aY,
                                               true,   /* ignore root scroll frame*/
                                               false); /* don't flush layout */

    // if this element is clickable we return quickly. also, if it isn't,
    // use a cache to speed up future calls to isElementClickable in the
    // loop below.
    let unclickableCache = new Array();
    if (this.isElementClickable(target, unclickableCache, false))
      return target;

    target = null;
    let radius = this.getTouchRadius();
    let nodes = aWindowUtils.nodesFromRect(aX, aY, radius.top, radius.right, radius.bottom, radius.left, true, false);

    let threshold = Number.POSITIVE_INFINITY;
    for (let i = 0; i < nodes.length; i++) {
      let current = nodes[i];
      if (!current.mozMatchesSelector || !this.isElementClickable(current, unclickableCache, true))
        continue;

      let rect = current.getBoundingClientRect();
      let distance = this._computeDistanceFromRect(aX, aY, rect);

      // increase a little bit the weight for already visited items
      if (current && current.mozMatchesSelector("*:visited"))
        distance *= (this.weight.visited / 100);

      if (distance < threshold) {
        target = current;
        threshold = distance;
      }
    }

    return target;
  },

  isElementClickable: function isElementClickable(aElement, aUnclickableCache, aAllowBodyListeners) {
    const selector = "a,:link,:visited,[role=button],button,input,select,textarea";

    let stopNode = null;
    if (!aAllowBodyListeners && aElement && aElement.ownerDocument)
      stopNode = aElement.ownerDocument.body;

    for (let elem = aElement; elem && elem != stopNode; elem = elem.parentNode) {
      if (aUnclickableCache && aUnclickableCache.indexOf(elem) != -1)
        continue;
      if (this._hasMouseListener(elem))
        return true;
      if (elem.mozMatchesSelector && elem.mozMatchesSelector(selector))
        return true;
      if (elem instanceof HTMLLabelElement && elem.control != null)
        return true;
      if (aUnclickableCache)
        aUnclickableCache.push(elem);
    }
    return false;
  },

  _computeDistanceFromRect: function _computeDistanceFromRect(aX, aY, aRect) {
    let x = 0, y = 0;
    let xmost = aRect.left + aRect.width;
    let ymost = aRect.top + aRect.height;

    // compute horizontal distance from left/right border depending if X is
    // before/inside/after the element's rectangle
    if (aRect.left < aX && aX < xmost)
      x = Math.min(xmost - aX, aX - aRect.left);
    else if (aX < aRect.left)
      x = aRect.left - aX;
    else if (aX > xmost)
      x = aX - xmost;

    // compute vertical distance from top/bottom border depending if Y is
    // above/inside/below the element's rectangle
    if (aRect.top < aY && aY < ymost)
      y = Math.min(ymost - aY, aY - aRect.top);
    else if (aY < aRect.top)
      y = aRect.top - aY;
    if (aY > ymost)
      y = aY - ymost;

    return Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));
  },

  _els: Cc["@mozilla.org/eventlistenerservice;1"].getService(Ci.nsIEventListenerService),
  _clickableEvents: ["mousedown", "mouseup", "click"],
  _hasMouseListener: function _hasMouseListener(aElement) {
    let els = this._els;
    let listeners = els.getListenerInfoFor(aElement, {});
    for (let i = 0; i < listeners.length; i++) {
      if (this._clickableEvents.indexOf(listeners[i].type) != -1)
        return true;
    }
    return false;
  },

  getContentClientRects: function(aElement) {
    let offset = { x: 0, y: 0 };

    let nativeRects = aElement.getClientRects();
    // step out of iframes and frames, offsetting scroll values
    for (let frame = aElement.ownerDocument.defaultView; frame.frameElement; frame = frame.parent) {
      // adjust client coordinates' origin to be top left of iframe viewport
      let rect = frame.frameElement.getBoundingClientRect();
      let left = frame.getComputedStyle(frame.frameElement, "").borderLeftWidth;
      let top = frame.getComputedStyle(frame.frameElement, "").borderTopWidth;
      offset.x += rect.left + parseInt(left);
      offset.y += rect.top + parseInt(top);
    }

    let result = [];
    for (let i = nativeRects.length - 1; i >= 0; i--) {
      let r = nativeRects[i];
      result.push({ left: r.left + offset.x,
                    top: r.top + offset.y,
                    width: r.width,
                    height: r.height
                  });
    }
    return result;
  },

  getBoundingContentRect: function(aElement) {
    if (!aElement)
      return {x: 0, y: 0, w: 0, h: 0};

    let document = aElement.ownerDocument;
    while (document.defaultView.frameElement)
      document = document.defaultView.frameElement.ownerDocument;

    let cwu = document.defaultView.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
    let scrollX = {}, scrollY = {};
    cwu.getScrollXY(false, scrollX, scrollY);

    let r = aElement.getBoundingClientRect();

    // step out of iframes and frames, offsetting scroll values
    for (let frame = aElement.ownerDocument.defaultView; frame.frameElement && frame != content; frame = frame.parent) {
      // adjust client coordinates' origin to be top left of iframe viewport
      let rect = frame.frameElement.getBoundingClientRect();
      let left = frame.getComputedStyle(frame.frameElement, "").borderLeftWidth;
      let top = frame.getComputedStyle(frame.frameElement, "").borderTopWidth;
      scrollX.value += rect.left + parseInt(left);
      scrollY.value += rect.top + parseInt(top);
    }

    return {x: r.left + scrollX.value,
            y: r.top + scrollY.value,
            w: r.width,
            h: r.height };
  }
};

var ErrorPageEventHandler = {
  handleEvent: function(aEvent) {
    switch (aEvent.type) {
      case "click": {
        // Don't trust synthetic events
        if (!aEvent.isTrusted)
          return;

        let target = aEvent.originalTarget;
        let errorDoc = target.ownerDocument;

        // If the event came from an ssl error page, it is probably either the "Add
        // Exception…" or "Get me out of here!" button
        if (/^about:certerror\?e=nssBadCert/.test(errorDoc.documentURI)) {
          let perm = errorDoc.getElementById("permanentExceptionButton");
          let temp = errorDoc.getElementById("temporaryExceptionButton");
          if (target == temp || target == perm) {
            // Handle setting an cert exception and reloading the page
            try {
              // Add a new SSL exception for this URL
              let uri = Services.io.newURI(errorDoc.location.href, null, null);
              let sslExceptions = new SSLExceptions();

              if (target == perm)
                sslExceptions.addPermanentException(uri, errorDoc.defaultView);
              else
                sslExceptions.addTemporaryException(uri, errorDoc.defaultView);
            } catch (e) {
              dump("Failed to set cert exception: " + e + "\n");
            }
            errorDoc.location.reload();
          } else if (target == errorDoc.getElementById("getMeOutOfHereButton")) {
            errorDoc.location = "about:home";
          }
        } else if (/^about:blocked/.test(errorDoc.documentURI)) {
          // The event came from a button on a malware/phishing block page
          // First check whether it's malware or phishing, so that we can
          // use the right strings/links
          let isMalware = /e=malwareBlocked/.test(errorDoc.documentURI);
          let bucketName = isMalware ? "WARNING_MALWARE_PAGE_" : "WARNING_PHISHING_PAGE_";
          let nsISecTel = Ci.nsISecurityUITelemetry;

          let formatter = Cc["@mozilla.org/toolkit/URLFormatterService;1"].getService(Ci.nsIURLFormatter);

          if (target == errorDoc.getElementById("getMeOutButton")) {
            Telemetry.addData("SECURITY_UI", nsISecTel[bucketName + "GET_ME_OUT_OF_HERE"]);
            errorDoc.location = "about:home";
          } else if (target == errorDoc.getElementById("reportButton")) {
            // We log even if malware/phishing info URL couldn't be found:
            // the measurement is for how many users clicked the WHY BLOCKED button
            Telemetry.addData("SECURITY_UI", nsISecTel[bucketName + "WHY_BLOCKED"]);

            // This is the "Why is this site blocked" button.  For malware,
            // we can fetch a site-specific report, for phishing, we redirect
            // to the generic page describing phishing protection.
            if (isMalware) {
              // Get the stop badware "why is this blocked" report url, append the current url, and go there.
              try {
                let reportURL = formatter.formatURLPref("browser.safebrowsing.malware.reportURL");
                reportURL += errorDoc.location.href;
                BrowserApp.selectedBrowser.loadURI(reportURL);
              } catch (e) {
                Cu.reportError("Couldn't get malware report URL: " + e);
              }
            } else {
              // It's a phishing site, not malware. (There's no report URL)
              try {
                let reportURL = formatter.formatURLPref("browser.safebrowsing.warning.infoURL");
                BrowserApp.selectedBrowser.loadURI(reportURL);
              } catch (e) {
                Cu.reportError("Couldn't get phishing info URL: " + e);
              }
            }
          } else if (target == errorDoc.getElementById("ignoreWarningButton")) {
            Telemetry.addData("SECURITY_UI", nsISecTel[bucketName + "IGNORE_WARNING"]);

            // Allow users to override and continue through to the site,
            let webNav = BrowserApp.selectedBrowser.docShell.QueryInterface(Ci.nsIWebNavigation);
            let location = BrowserApp.selectedBrowser.contentWindow.location;
            webNav.loadURI(location, Ci.nsIWebNavigation.LOAD_FLAGS_BYPASS_CLASSIFIER, null, null, null);

            // ....but add a notify bar as a reminder, so that they don't lose
            // track after, e.g., tab switching.
            NativeWindow.doorhanger.show(Strings.browser.GetStringFromName("safeBrowsingDoorhanger"), "safebrowsing-warning", [], BrowserApp.selectedTab.id);
          }
        }
        break;
      }
    }
  }
};

var FindHelper = {
  _fastFind: null,
  _targetTab: null,
  _initialViewport: null,
  _viewportChanged: false,

  init: function() {
    Services.obs.addObserver(this, "FindInPage:Find", false);
    Services.obs.addObserver(this, "FindInPage:Prev", false);
    Services.obs.addObserver(this, "FindInPage:Next", false);
    Services.obs.addObserver(this, "FindInPage:Closed", false);
    Services.obs.addObserver(this, "Tab:Selected", false);
  },

  uninit: function() {
    Services.obs.removeObserver(this, "FindInPage:Find");
    Services.obs.removeObserver(this, "FindInPage:Prev");
    Services.obs.removeObserver(this, "FindInPage:Next");
    Services.obs.removeObserver(this, "FindInPage:Closed");
    Services.obs.removeObserver(this, "Tab:Selected");
  },

  observe: function(aMessage, aTopic, aData) {
    switch(aTopic) {
      case "FindInPage:Find":
        this.doFind(aData);
        break;

      case "FindInPage:Prev":
        this.findAgain(aData, true);
        break;

      case "FindInPage:Next":
        this.findAgain(aData, false);
        break;

      case "Tab:Selected":
      case "FindInPage:Closed":
        this.findClosed();
        break;
    }
  },

  doFind: function(aSearchString) {
    if (!this._fastFind) {
      this._targetTab = BrowserApp.selectedTab;
      this._fastFind = this._targetTab.browser.fastFind;
      this._initialViewport = JSON.stringify(this._targetTab.getViewport());
      this._viewportChanged = false;
    }

    let result = this._fastFind.find(aSearchString, false);
    this.handleResult(result);
  },

  findAgain: function(aString, aFindBackwards) {
    // This can happen if the user taps next/previous after re-opening the search bar
    if (!this._fastFind) {
      this.doFind(aString);
      return;
    }

    let result = this._fastFind.findAgain(aFindBackwards, false);
    this.handleResult(result);
  },

  findClosed: function() {
    // If there's no find in progress, there's nothing to clean up
    if (!this._fastFind)
      return;

    this._fastFind.collapseSelection();
    this._fastFind = null;
    this._targetTab = null;
    this._initialViewport = null;
    this._viewportChanged = false;
  },

  handleResult: function(aResult) {
    if (aResult == Ci.nsITypeAheadFind.FIND_NOTFOUND) {
      if (this._viewportChanged) {
        if (this._targetTab != BrowserApp.selectedTab) {
          // this should never happen
          Cu.reportError("Warning: selected tab changed during find!");
          // fall through and restore viewport on the initial tab anyway
        }
        this._targetTab.setViewport(JSON.parse(this._initialViewport));
        this._targetTab.sendViewportUpdate();
      }
    } else {
      this._viewportChanged = true;
    }
  }
};

var FormAssistant = {
  QueryInterface: XPCOMUtils.generateQI([Ci.nsIFormSubmitObserver]),

  // Used to keep track of the element that corresponds to the current
  // autocomplete suggestions
  _currentInputElement: null,

  _isBlocklisted: false,

  // Keep track of whether or not an invalid form has been submitted
  _invalidSubmit: false,

  init: function() {
    Services.obs.addObserver(this, "FormAssist:AutoComplete", false);
    Services.obs.addObserver(this, "FormAssist:Blocklisted", false);
    Services.obs.addObserver(this, "FormAssist:Hidden", false);
    Services.obs.addObserver(this, "invalidformsubmit", false);
    Services.obs.addObserver(this, "PanZoom:StateChange", false);

    // We need to use a capturing listener for focus events
    BrowserApp.deck.addEventListener("focus", this, true);
    BrowserApp.deck.addEventListener("click", this, true);
    BrowserApp.deck.addEventListener("input", this, false);
    BrowserApp.deck.addEventListener("pageshow", this, false);
  },

  uninit: function() {
    Services.obs.removeObserver(this, "FormAssist:AutoComplete");
    Services.obs.removeObserver(this, "FormAssist:Blocklisted");
    Services.obs.removeObserver(this, "FormAssist:Hidden");
    Services.obs.removeObserver(this, "invalidformsubmit");
    Services.obs.removeObserver(this, "PanZoom:StateChange");

    BrowserApp.deck.removeEventListener("focus", this);
    BrowserApp.deck.removeEventListener("click", this);
    BrowserApp.deck.removeEventListener("input", this);
    BrowserApp.deck.removeEventListener("pageshow", this);
  },

  observe: function(aSubject, aTopic, aData) {
    switch (aTopic) {
      case "PanZoom:StateChange":
        // If the user is just touching the screen and we haven't entered a pan or zoom state yet do nothing
        if (aData == "TOUCHING" || aData == "WAITING_LISTENERS")
          break;
        if (aData == "NOTHING") {
          // only look for input elements, not contentEditable or multiline text areas
          let focused = BrowserApp.getFocusedInput(BrowserApp.selectedBrowser, true);
          if (!focused)
            break;

          if (this._showValidationMessage(focused))
            break;
          this._showAutoCompleteSuggestions(focused);
        } else {
          // temporarily hide the form assist popup while we're panning or zooming the page
          this._hideFormAssistPopup();
        }
        break;
      case "FormAssist:AutoComplete":
        if (!this._currentInputElement)
          break;

        let editableElement = this._currentInputElement.QueryInterface(Ci.nsIDOMNSEditableElement);

        // If we have an active composition string, commit it before sending
        // the autocomplete event with the text that will replace it.
        try {
          let imeEditor = editableElement.editor.QueryInterface(Ci.nsIEditorIMESupport);
          if (imeEditor.composing)
            imeEditor.forceCompositionEnd();
        } catch (e) {}

        editableElement.setUserInput(aData);

        let event = this._currentInputElement.ownerDocument.createEvent("Events");
        event.initEvent("DOMAutoComplete", true, true);
        this._currentInputElement.dispatchEvent(event);
        break;

      case "FormAssist:Blocklisted":
        this._isBlocklisted = (aData == "true");
        break;

      case "FormAssist:Hidden":
        this._currentInputElement = null;
        break;
    }
  },

  notifyInvalidSubmit: function notifyInvalidSubmit(aFormElement, aInvalidElements) {
    if (!aInvalidElements.length)
      return;

    // Ignore this notificaiton if the current tab doesn't contain the invalid form
    if (BrowserApp.selectedBrowser.contentDocument !=
        aFormElement.ownerDocument.defaultView.top.document)
      return;

    this._invalidSubmit = true;

    // Our focus listener will show the element's validation message
    let currentElement = aInvalidElements.queryElementAt(0, Ci.nsISupports);
    currentElement.focus();
  },

  handleEvent: function(aEvent) {
    switch (aEvent.type) {
      case "focus":
        let currentElement = aEvent.target;

        // Only show a validation message on focus.
        this._showValidationMessage(currentElement);
        break;

      case "click":
        currentElement = aEvent.target;

        // Prioritize a form validation message over autocomplete suggestions
        // when the element is first focused (a form validation message will
        // only be available if an invalid form was submitted)
        if (this._showValidationMessage(currentElement))
          break;
        if (!this._showAutoCompleteSuggestions(currentElement))
          this._hideFormAssistPopup();
        break;
      case "input":
        currentElement = aEvent.target;

        // Since we can only show one popup at a time, prioritze autocomplete
        // suggestions over a form validation message
        if (this._showAutoCompleteSuggestions(currentElement))
          break;
        if (this._showValidationMessage(currentElement))
          break;

        // If we're not showing autocomplete suggestions, hide the form assist popup
        this._hideFormAssistPopup();
        break;

      // Reset invalid submit state on each pageshow
      case "pageshow":
        let target = aEvent.originalTarget;
        let selectedDocument = BrowserApp.selectedBrowser.contentDocument;
        if (target == selectedDocument || target.ownerDocument == selectedDocument)
          this._invalidSubmit = false;
    }
  },

  // We only want to show autocomplete suggestions for certain elements
  _isAutoComplete: function _isAutoComplete(aElement) {
    if (!(aElement instanceof HTMLInputElement) || aElement.readOnly ||
        (aElement.getAttribute("type") == "password") ||
        (aElement.hasAttribute("autocomplete") &&
         aElement.getAttribute("autocomplete").toLowerCase() == "off"))
      return false;

    return true;
  },

  // Retrieves autocomplete suggestions for an element from the form autocomplete service.
  _getAutoCompleteSuggestions: function _getAutoCompleteSuggestions(aSearchString, aElement) {
    // Cache the form autocomplete service for future use
    if (!this._formAutoCompleteService)
      this._formAutoCompleteService = Cc["@mozilla.org/satchel/form-autocomplete;1"].
                                      getService(Ci.nsIFormAutoComplete);

    let results = this._formAutoCompleteService.autoCompleteSearch(aElement.name || aElement.id,
                                                                   aSearchString, aElement, null);
    let suggestions = [];
    for (let i = 0; i < results.matchCount; i++) {
      let value = results.getValueAt(i);

      // Do not show the value if it is the current one in the input field
      if (value == aSearchString)
        continue;

      // Supply a label and value, since they can differ for datalist suggestions
      suggestions.push({ label: value, value: value });
    }

    return suggestions;
  },

  /**
   * (Copied from mobile/xul/chrome/content/forms.js)
   * This function is similar to getListSuggestions from
   * components/satchel/src/nsInputListAutoComplete.js but sadly this one is
   * used by the autocomplete.xml binding which is not in used in fennec
   */
  _getListSuggestions: function _getListSuggestions(aElement) {
    if (!(aElement instanceof HTMLInputElement) || !aElement.list)
      return [];

    let suggestions = [];
    let filter = !aElement.hasAttribute("mozNoFilter");
    let lowerFieldValue = aElement.value.toLowerCase();

    let options = aElement.list.options;
    let length = options.length;
    for (let i = 0; i < length; i++) {
      let item = options.item(i);

      let label = item.value;
      if (item.label)
        label = item.label;
      else if (item.text)
        label = item.text;

      if (filter && label.toLowerCase().indexOf(lowerFieldValue) == -1)
        continue;
      suggestions.push({ label: label, value: item.value });
    }

    return suggestions;
  },

  // Gets the element position data necessary for the Java UI to position
  // the form assist popup.
  _getElementPositionData: function _getElementPositionData(aElement) {
    let rect = ElementTouchHelper.getBoundingContentRect(aElement);
    let viewport = BrowserApp.selectedTab.getViewport();
    
    return { rect: [rect.x - (viewport.x / viewport.zoom),
                    rect.y - (viewport.y / viewport.zoom),
                    rect.w, rect.h],
             zoom: viewport.zoom }
  },

  // Retrieves autocomplete suggestions for an element from the form autocomplete service
  // and sends the suggestions to the Java UI, along with element position data.
  // Returns true if there are suggestions to show, false otherwise.
  _showAutoCompleteSuggestions: function _showAutoCompleteSuggestions(aElement) {
    if (!this._isAutoComplete(aElement))
      return false;

    // Don't display the form auto-complete popup after the user starts typing
    // to avoid confusing somes IME. See bug 758820 and bug 632744.
    if (this._isBlocklisted && aElement.value.length > 0) {
      return false;
    }

    let autoCompleteSuggestions = this._getAutoCompleteSuggestions(aElement.value, aElement);
    let listSuggestions = this._getListSuggestions(aElement);

    // On desktop, we show datalist suggestions below autocomplete suggestions,
    // without duplicates removed.
    let suggestions = autoCompleteSuggestions.concat(listSuggestions);

    // Return false if there are no suggestions to show
    if (!suggestions.length)
      return false;

    let positionData = this._getElementPositionData(aElement);
    sendMessageToJava({
      gecko: {
        type:  "FormAssist:AutoComplete",
        suggestions: suggestions,
        rect: positionData.rect,
        zoom: positionData.zoom
      }
    });

    // Keep track of input element so we can fill it in if the user
    // selects an autocomplete suggestion
    this._currentInputElement = aElement;

    return true;
  },

  // Only show a validation message if the user submitted an invalid form,
  // there's a non-empty message string, and the element is the correct type
  _isValidateable: function _isValidateable(aElement) {
    if (!this._invalidSubmit ||
        !aElement.validationMessage ||
        !(aElement instanceof HTMLInputElement ||
          aElement instanceof HTMLTextAreaElement ||
          aElement instanceof HTMLSelectElement ||
          aElement instanceof HTMLButtonElement))
      return false;

    return true;
  },

  // Sends a validation message and position data for an element to the Java UI.
  // Returns true if there's a validation message to show, false otherwise.
  _showValidationMessage: function _sendValidationMessage(aElement) {
    if (!this._isValidateable(aElement))
      return false;

    let positionData = this._getElementPositionData(aElement);
    sendMessageToJava({
      gecko: {
        type: "FormAssist:ValidationMessage",
        validationMessage: aElement.validationMessage,
        rect: positionData.rect,
        zoom: positionData.zoom
      }
    });

    return true;
  },

  _hideFormAssistPopup: function _hideFormAssistPopup() {
    sendMessageToJava({
      gecko: { type:  "FormAssist:Hide" }
    });
  }
};

var XPInstallObserver = {
  init: function xpi_init() {
    Services.obs.addObserver(XPInstallObserver, "addon-install-blocked", false);
    Services.obs.addObserver(XPInstallObserver, "addon-install-started", false);

    AddonManager.addInstallListener(XPInstallObserver);
  },

  uninit: function xpi_uninit() {
    Services.obs.removeObserver(XPInstallObserver, "addon-install-blocked");
    Services.obs.removeObserver(XPInstallObserver, "addon-install-started");

    AddonManager.removeInstallListener(XPInstallObserver);
  },

  observe: function xpi_observer(aSubject, aTopic, aData) {
    switch (aTopic) {
      case "addon-install-started":
        NativeWindow.toast.show(Strings.browser.GetStringFromName("alertAddonsDownloading"), "short");
        break;
      case "addon-install-blocked":
        let installInfo = aSubject.QueryInterface(Ci.amIWebInstallInfo);
        let win = installInfo.originatingWindow;
        let tab = BrowserApp.getTabForWindow(win.top);
        if (!tab)
          return;

        let host = installInfo.originatingURI.host;

        let brandShortName = Strings.brand.GetStringFromName("brandShortName");
        let notificationName, buttons, message;
        let strings = Strings.browser;
        let enabled = true;
        try {
          enabled = Services.prefs.getBoolPref("xpinstall.enabled");
        }
        catch (e) {}

        if (!enabled) {
          notificationName = "xpinstall-disabled";
          if (Services.prefs.prefIsLocked("xpinstall.enabled")) {
            message = strings.GetStringFromName("xpinstallDisabledMessageLocked");
            buttons = [];
          } else {
            message = strings.formatStringFromName("xpinstallDisabledMessage2", [brandShortName, host], 2);
            buttons = [{
              label: strings.GetStringFromName("xpinstallDisabledButton"),
              callback: function editPrefs() {
                Services.prefs.setBoolPref("xpinstall.enabled", true);
                return false;
              }
            }];
          }
        } else {
          notificationName = "xpinstall";
          message = strings.formatStringFromName("xpinstallPromptWarning2", [brandShortName, host], 2);

          buttons = [{
            label: strings.GetStringFromName("xpinstallPromptAllowButton"),
            callback: function() {
              // Kick off the install
              installInfo.install();
              return false;
            }
          }];
        }
        NativeWindow.doorhanger.show(message, aTopic, buttons, tab.id);
        break;
    }
  },

  onInstallEnded: function(aInstall, aAddon) {
    let needsRestart = false;
    if (aInstall.existingAddon && (aInstall.existingAddon.pendingOperations & AddonManager.PENDING_UPGRADE))
      needsRestart = true;
    else if (aAddon.pendingOperations & AddonManager.PENDING_INSTALL)
      needsRestart = true;

    if (needsRestart) {
      this.showRestartPrompt();
    } else {
      let message = Strings.browser.GetStringFromName("alertAddonsInstalledNoRestart");
      NativeWindow.toast.show(message, "short");
    }
  },

  onInstallFailed: function(aInstall) {
    NativeWindow.toast.show(Strings.browser.GetStringFromName("alertAddonsFail"), "short");
  },

  onDownloadProgress: function xpidm_onDownloadProgress(aInstall) {},

  onDownloadFailed: function(aInstall) {
    this.onInstallFailed(aInstall);
  },

  onDownloadCancelled: function(aInstall) {
    let host = (aInstall.originatingURI instanceof Ci.nsIStandardURL) && aInstall.originatingURI.host;
    if (!host)
      host = (aInstall.sourceURI instanceof Ci.nsIStandardURL) && aInstall.sourceURI.host;

    let error = (host || aInstall.error == 0) ? "addonError" : "addonLocalError";
    if (aInstall.error != 0)
      error += aInstall.error;
    else if (aInstall.addon && aInstall.addon.blocklistState == Ci.nsIBlocklistService.STATE_BLOCKED)
      error += "Blocklisted";
    else if (aInstall.addon && (!aInstall.addon.isCompatible || !aInstall.addon.isPlatformCompatible))
      error += "Incompatible";
    else
      return; // No need to show anything in this case.

    let msg = Strings.browser.GetStringFromName(error);
    // TODO: formatStringFromName
    msg = msg.replace("#1", aInstall.name);
    if (host)
      msg = msg.replace("#2", host);
    msg = msg.replace("#3", Strings.brand.GetStringFromName("brandShortName"));
    msg = msg.replace("#4", Services.appinfo.version);

    NativeWindow.toast.show(msg, "short");
  },

  showRestartPrompt: function() {
    let buttons = [{
      label: Strings.browser.GetStringFromName("notificationRestart.button"),
      callback: function() {
        // Notify all windows that an application quit has been requested
        let cancelQuit = Cc["@mozilla.org/supports-PRBool;1"].createInstance(Ci.nsISupportsPRBool);
        Services.obs.notifyObservers(cancelQuit, "quit-application-requested", "restart");

        // If nothing aborted, quit the app
        if (cancelQuit.data == false) {
          let appStartup = Cc["@mozilla.org/toolkit/app-startup;1"].getService(Ci.nsIAppStartup);
          appStartup.quit(Ci.nsIAppStartup.eRestart | Ci.nsIAppStartup.eAttemptQuit);
        }
      }
    }];

    let message = Strings.browser.GetStringFromName("notificationRestart.normal");
    NativeWindow.doorhanger.show(message, "addon-app-restart", buttons, BrowserApp.selectedTab.id, { persistence: -1 });
  },

  hideRestartPrompt: function() {
    NativeWindow.doorhanger.hide("addon-app-restart", BrowserApp.selectedTab.id);
  }
};

// Blindly copied from Safari documentation for now.
const kViewportMinScale  = 0;
const kViewportMaxScale  = 10;
const kViewportMinWidth  = 200;
const kViewportMaxWidth  = 10000;
const kViewportMinHeight = 223;
const kViewportMaxHeight = 10000;

var ViewportHandler = {
  // The cached viewport metadata for each document. We tie viewport metadata to each document
  // instead of to each tab so that we don't have to update it when the document changes. Using an
  // ES6 weak map lets us avoid leaks.
  _metadata: new WeakMap(),

  init: function init() {
    addEventListener("DOMMetaAdded", this, false);
    Services.obs.addObserver(this, "Window:Resize", false);
  },

  uninit: function uninit() {
    removeEventListener("DOMMetaAdded", this, false);
    Services.obs.removeObserver(this, "Window:Resize", false);
  },

  handleEvent: function handleEvent(aEvent) {
    switch (aEvent.type) {
      case "DOMMetaAdded":
        let target = aEvent.originalTarget;
        if (target.name != "viewport")
          break;
        let document = target.ownerDocument;
        let browser = BrowserApp.getBrowserForDocument(document);
        let tab = BrowserApp.getTabForBrowser(browser);
        if (tab)
          this.updateMetadata(tab, false);
        break;
    }
  },

  observe: function(aSubject, aTopic, aData) {
    switch (aTopic) {
      case "Window:Resize":
        if (window.outerWidth == gScreenWidth && window.outerHeight == gScreenHeight)
          break;
        if (window.outerWidth == 0 || window.outerHeight == 0)
          break;

        let oldScreenWidth = gScreenWidth;
        gScreenWidth = window.outerWidth;
        gScreenHeight = window.outerHeight;
        let tabs = BrowserApp.tabs;
        for (let i = 0; i < tabs.length; i++)
          tabs[i].updateViewportSize(oldScreenWidth);
        break;
    }
  },

  updateMetadata: function updateMetadata(tab, aInitialLoad) {
    let metadata = this.getViewportMetadata(tab.browser.contentWindow);
    tab.updateViewportMetadata(metadata, aInitialLoad);
  },

  /**
   * Returns an object with the page's preferred viewport properties:
   *   defaultZoom (optional float): The initial scale when the page is loaded.
   *   minZoom (optional float): The minimum zoom level.
   *   maxZoom (optional float): The maximum zoom level.
   *   width (optional int): The CSS viewport width in px.
   *   height (optional int): The CSS viewport height in px.
   *   autoSize (boolean): Resize the CSS viewport when the window resizes.
   *   allowZoom (boolean): Let the user zoom in or out.
   */
  getViewportMetadata: function getViewportMetadata(aWindow) {
    let windowUtils = aWindow.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);

    // viewport details found here
    // http://developer.apple.com/safari/library/documentation/AppleApplications/Reference/SafariHTMLRef/Articles/MetaTags.html
    // http://developer.apple.com/safari/library/documentation/AppleApplications/Reference/SafariWebContent/UsingtheViewport/UsingtheViewport.html

    // Note: These values will be NaN if parseFloat or parseInt doesn't find a number.
    // Remember that NaN is contagious: Math.max(1, NaN) == Math.min(1, NaN) == NaN.
    let scale = parseFloat(windowUtils.getDocumentMetadata("viewport-initial-scale"));
    let minScale = parseFloat(windowUtils.getDocumentMetadata("viewport-minimum-scale"));
    let maxScale = parseFloat(windowUtils.getDocumentMetadata("viewport-maximum-scale"));

    let widthStr = windowUtils.getDocumentMetadata("viewport-width");
    let heightStr = windowUtils.getDocumentMetadata("viewport-height");
    let width = this.clamp(parseInt(widthStr), kViewportMinWidth, kViewportMaxWidth);
    let height = this.clamp(parseInt(heightStr), kViewportMinHeight, kViewportMaxHeight);

    // Allow zoom unless explicity disabled or minScale and maxScale are equal.
    // WebKit allows 0, "no", or "false" for viewport-user-scalable.
    // Note: NaN != NaN. Therefore if minScale and maxScale are undefined the clause has no effect.
    let allowZoomStr = windowUtils.getDocumentMetadata("viewport-user-scalable");
    let allowZoom = !/^(0|no|false)$/.test(allowZoomStr) && (minScale != maxScale);

    let autoSize = true;

    if (isNaN(scale) && isNaN(minScale) && isNaN(maxScale) && allowZoomStr == "" && widthStr == "" && heightStr == "") {
      // Only check for HandheldFriendly if we don't have a viewport meta tag
      let handheldFriendly = windowUtils.getDocumentMetadata("HandheldFriendly");
      if (handheldFriendly == "true")
        return { defaultZoom: 1, autoSize: true, allowZoom: true };

      let doctype = aWindow.document.doctype;
      if (doctype && /(WAP|WML|Mobile)/.test(doctype.publicId))
        return { defaultZoom: 1, autoSize: true, allowZoom: true };

      let defaultZoom = Services.prefs.getIntPref("browser.viewport.defaultZoom");
      if (defaultZoom >= 0) {
        scale = defaultZoom / 1000;
        autoSize = false;
      }
    }

    scale = this.clamp(scale, kViewportMinScale, kViewportMaxScale);
    minScale = this.clamp(minScale, kViewportMinScale, kViewportMaxScale);
    maxScale = this.clamp(maxScale, minScale, kViewportMaxScale);

    if (autoSize) {
      // If initial scale is 1.0 and width is not set, assume width=device-width
      autoSize = (widthStr == "device-width" ||
                  (!widthStr && (heightStr == "device-height" || scale == 1.0)));
    }

    return {
      defaultZoom: scale,
      minZoom: minScale,
      maxZoom: maxScale,
      width: width,
      height: height,
      autoSize: autoSize,
      allowZoom: allowZoom
    };
  },

  clamp: function(num, min, max) {
    return Math.max(min, Math.min(max, num));
  },

  // The device-pixel-to-CSS-px ratio used to adjust meta viewport values.
  // This is higher on higher-dpi displays, so pages stay about the same physical size.
  getScaleRatio: function getScaleRatio() {
    let prefValue = Services.prefs.getIntPref("browser.viewport.scaleRatio");
    if (prefValue > 0)
      return prefValue / 100;

    let dpi = this.displayDPI;
    if (dpi < 200) // Includes desktop displays, and LDPI and MDPI Android devices
      return 1;
    else if (dpi < 300) // Includes Nokia N900, and HDPI Android devices
      return 1.5;

    // For very high-density displays like the iPhone 4, calculate an integer ratio.
    return Math.floor(dpi / 150);
  },

  get displayDPI() {
    let utils = window.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
    delete this.displayDPI;
    return this.displayDPI = utils.displayDPI;
  },

  /**
   * Returns the viewport metadata for the given document, or the default metrics if no viewport
   * metadata is available for that document.
   */
  getMetadataForDocument: function getMetadataForDocument(aDocument) {
    let metadata = this._metadata.get(aDocument, this.getDefaultMetadata());
    return metadata;
  },

  /** Updates the saved viewport metadata for the given content document. */
  setMetadataForDocument: function setMetadataForDocument(aDocument, aMetadata) {
    if (!aMetadata)
      this._metadata.delete(aDocument);
    else
      this._metadata.set(aDocument, aMetadata);
  },

  /** Returns the default viewport metadata for a document. */
  getDefaultMetadata: function getDefaultMetadata() {
    return {
      autoSize: false,
      allowZoom: true,
      scaleRatio: ViewportHandler.getScaleRatio()
    };
  }
};

/**
 * Handler for blocked popups, triggered by DOMUpdatePageReport events in browser.xml
 */
var PopupBlockerObserver = {
  onUpdatePageReport: function onUpdatePageReport(aEvent) {
    let browser = BrowserApp.selectedBrowser;
    if (aEvent.originalTarget != browser)
      return;

    if (!browser.pageReport)
      return;

    let result = Services.perms.testExactPermission(BrowserApp.selectedBrowser.currentURI, "popup");
    if (result == Ci.nsIPermissionManager.DENY_ACTION)
      return;

    // Only show the notification again if we've not already shown it. Since
    // notifications are per-browser, we don't need to worry about re-adding
    // it.
    if (!browser.pageReport.reported) {
      if (Services.prefs.getBoolPref("privacy.popups.showBrowserMessage")) {
        let brandShortName = Strings.brand.GetStringFromName("brandShortName");
        let message;
        let popupCount = browser.pageReport.length;

        let strings = Strings.browser;
        if (popupCount > 1)
          message = strings.formatStringFromName("popupWarningMultiple", [brandShortName, popupCount], 2);
        else
          message = strings.formatStringFromName("popupWarning", [brandShortName], 1);

        let buttons = [
          {
            label: strings.GetStringFromName("popupButtonAllowOnce"),
            callback: function() { PopupBlockerObserver.showPopupsForSite(); }
          },
          {
            label: strings.GetStringFromName("popupButtonAlwaysAllow2"),
            callback: function() {
              // Set permission before opening popup windows
              PopupBlockerObserver.allowPopupsForSite(true);
              PopupBlockerObserver.showPopupsForSite();
            }
          },
          {
            label: strings.GetStringFromName("popupButtonNeverWarn2"),
            callback: function() { PopupBlockerObserver.allowPopupsForSite(false); }
          }
        ];

        NativeWindow.doorhanger.show(message, "popup-blocked", buttons);
      }
      // Record the fact that we've reported this blocked popup, so we don't
      // show it again.
      browser.pageReport.reported = true;
    }
  },

  allowPopupsForSite: function allowPopupsForSite(aAllow) {
    let currentURI = BrowserApp.selectedBrowser.currentURI;
    Services.perms.add(currentURI, "popup", aAllow
                       ?  Ci.nsIPermissionManager.ALLOW_ACTION
                       :  Ci.nsIPermissionManager.DENY_ACTION);
    dump("Allowing popups for: " + currentURI);
  },

  showPopupsForSite: function showPopupsForSite() {
    let uri = BrowserApp.selectedBrowser.currentURI;
    let pageReport = BrowserApp.selectedBrowser.pageReport;
    if (pageReport) {
      for (let i = 0; i < pageReport.length; ++i) {
        let popupURIspec = pageReport[i].popupWindowURI.spec;

        // Sometimes the popup URI that we get back from the pageReport
        // isn't useful (for instance, netscape.com's popup URI ends up
        // being "http://www.netscape.com", which isn't really the URI of
        // the popup they're trying to show).  This isn't going to be
        // useful to the user, so we won't create a menu item for it.
        if (popupURIspec == "" || popupURIspec == "about:blank" || popupURIspec == uri.spec)
          continue;

        let popupFeatures = pageReport[i].popupWindowFeatures;
        let popupName = pageReport[i].popupWindowName;

        let parent = BrowserApp.selectedTab;
        BrowserApp.addTab(popupURIspec, { parentId: parent.id });
      }
    }
  }
};


var OfflineApps = {
  init: function() {
    BrowserApp.deck.addEventListener("MozApplicationManifest", this, false);
  },

  uninit: function() {
    BrowserApp.deck.removeEventListener("MozApplicationManifest", this, false);
  },

  handleEvent: function(aEvent) {
    if (aEvent.type == "MozApplicationManifest")
      this.offlineAppRequested(aEvent.originalTarget.defaultView);
  },

  offlineAppRequested: function(aContentWindow) {
    if (!Services.prefs.getBoolPref("browser.offline-apps.notify"))
      return;

    let tab = BrowserApp.getTabForWindow(aContentWindow);
    let currentURI = aContentWindow.document.documentURIObject;

    // Don't bother showing UI if the user has already made a decision
    if (Services.perms.testExactPermission(currentURI, "offline-app") != Services.perms.UNKNOWN_ACTION)
      return;

    try {
      if (Services.prefs.getBoolPref("offline-apps.allow_by_default")) {
        // All pages can use offline capabilities, no need to ask the user
        return;
      }
    } catch(e) {
      // This pref isn't set by default, ignore failures
    }

    let host = currentURI.asciiHost;
    let notificationID = "offline-app-requested-" + host;

    let strings = Strings.browser;
    let buttons = [{
      label: strings.GetStringFromName("offlineApps.allow"),
      callback: function() {
        OfflineApps.allowSite(aContentWindow.document);
      }
    },
    {
      label: strings.GetStringFromName("offlineApps.never"),
      callback: function() {
        OfflineApps.disallowSite(aContentWindow.document);
      }
    },
    {
      label: strings.GetStringFromName("offlineApps.notNow"),
      callback: function() { /* noop */ }
    }];

    let message = strings.formatStringFromName("offlineApps.available2", [host], 1);
    NativeWindow.doorhanger.show(message, notificationID, buttons, tab.id);
  },

  allowSite: function(aDocument) {
    Services.perms.add(aDocument.documentURIObject, "offline-app", Services.perms.ALLOW_ACTION);

    // When a site is enabled while loading, manifest resources will
    // start fetching immediately.  This one time we need to do it
    // ourselves.
    this._startFetching(aDocument);
  },

  disallowSite: function(aDocument) {
    Services.perms.add(aDocument.documentURIObject, "offline-app", Services.perms.DENY_ACTION);
  },

  _startFetching: function(aDocument) {
    if (!aDocument.documentElement)
      return;

    let manifest = aDocument.documentElement.getAttribute("manifest");
    if (!manifest)
      return;

    let manifestURI = Services.io.newURI(manifest, aDocument.characterSet, aDocument.documentURIObject);
    let updateService = Cc["@mozilla.org/offlinecacheupdate-service;1"].getService(Ci.nsIOfflineCacheUpdateService);
    updateService.scheduleUpdate(manifestURI, aDocument.documentURIObject, window);
  }
};

var IndexedDB = {
  _permissionsPrompt: "indexedDB-permissions-prompt",
  _permissionsResponse: "indexedDB-permissions-response",

  _quotaPrompt: "indexedDB-quota-prompt",
  _quotaResponse: "indexedDB-quota-response",
  _quotaCancel: "indexedDB-quota-cancel",

  init: function IndexedDB_init() {
    Services.obs.addObserver(this, this._permissionsPrompt, false);
    Services.obs.addObserver(this, this._quotaPrompt, false);
    Services.obs.addObserver(this, this._quotaCancel, false);
  },

  uninit: function IndexedDB_uninit() {
    Services.obs.removeObserver(this, this._permissionsPrompt, false);
    Services.obs.removeObserver(this, this._quotaPrompt, false);
    Services.obs.removeObserver(this, this._quotaCancel, false);
  },

  observe: function IndexedDB_observe(subject, topic, data) {
    if (topic != this._permissionsPrompt &&
        topic != this._quotaPrompt &&
        topic != this._quotaCancel) {
      throw new Error("Unexpected topic!");
    }

    let requestor = subject.QueryInterface(Ci.nsIInterfaceRequestor);

    let contentWindow = requestor.getInterface(Ci.nsIDOMWindow);
    let contentDocument = contentWindow.document;
    let tab = BrowserApp.getTabForWindow(contentWindow);
    if (!tab)
      return;

    let host = contentDocument.documentURIObject.asciiHost;

    let strings = Strings.browser;

    let message, responseTopic;
    if (topic == this._permissionsPrompt) {
      message = strings.formatStringFromName("offlineApps.available2", [host], 1);
      responseTopic = this._permissionsResponse;
    } else if (topic == this._quotaPrompt) {
      message = strings.formatStringFromName("indexedDBQuota.wantsTo", [ host, data ], 2);
      responseTopic = this._quotaResponse;
    } else if (topic == this._quotaCancel) {
      responseTopic = this._quotaResponse;
    }

    let notificationID = responseTopic + host;
    let observer = requestor.getInterface(Ci.nsIObserver);

    if (topic == this._quotaCancel) {
      NativeWindow.doorhanger.hide(notificationID, tab.id);
      observer.observe(null, responseTopic, Ci.nsIPermissionManager.UNKNOWN_ACTION);
      return;
    }

    let buttons = [{
      label: strings.GetStringFromName("offlineApps.allow"),
      callback: function() {
        observer.observe(null, responseTopic, Ci.nsIPermissionManager.ALLOW_ACTION);
      }
    },
    {
      label: strings.GetStringFromName("offlineApps.never"),
      callback: function() {
        observer.observe(null, responseTopic, Ci.nsIPermissionManager.DENY_ACTION);
      }
    },
    {
      label: strings.GetStringFromName("offlineApps.notNow"),
      callback: function() {
        observer.observe(null, responseTopic, Ci.nsIPermissionManager.UNKNOWN_ACTION);
      }
    }];

    NativeWindow.doorhanger.show(message, notificationID, buttons, tab.id);
  }
};

var ConsoleAPI = {
  init: function init() {
    Services.obs.addObserver(this, "console-api-log-event", false);
  },

  uninit: function uninit() {
    Services.obs.removeObserver(this, "console-api-log-event", false);
  },

  observe: function observe(aMessage, aTopic, aData) {
    aMessage = aMessage.wrappedJSObject;

    let mappedArguments = Array.map(aMessage.arguments, this.formatResult, this);
    let joinedArguments = Array.join(mappedArguments, " ");

    if (aMessage.level == "error" || aMessage.level == "warn") {
      let flag = (aMessage.level == "error" ? Ci.nsIScriptError.errorFlag : Ci.nsIScriptError.warningFlag);
      let consoleMsg = Cc["@mozilla.org/scripterror;1"].createInstance(Ci.nsIScriptError);
      consoleMsg.init(joinedArguments, null, null, 0, 0, flag, "content javascript");
      Services.console.logMessage(consoleMsg);
    } else if (aMessage.level == "trace") {
      let bundle = Services.strings.createBundle("chrome://browser/locale/browser.properties");
      let args = aMessage.arguments;
      let filename = this.abbreviateSourceURL(args[0].filename);
      let functionName = args[0].functionName || bundle.GetStringFromName("stacktrace.anonymousFunction");
      let lineNumber = args[0].lineNumber;

      let body = bundle.formatStringFromName("stacktrace.outputMessage", [filename, functionName, lineNumber], 3);
      body += "\n";
      args.forEach(function(aFrame) {
        let functionName = aFrame.functionName || bundle.GetStringFromName("stacktrace.anonymousFunction");
        body += "  " + aFrame.filename + " :: " + functionName + " :: " + aFrame.lineNumber + "\n";
      });

      Services.console.logStringMessage(body);
    } else if (aMessage.level == "time" && aMessage.arguments) {
      let bundle = Services.strings.createBundle("chrome://browser/locale/browser.properties");
      let body = bundle.formatStringFromName("timer.start", [aMessage.arguments.name], 1);
      Services.console.logStringMessage(body);
    } else if (aMessage.level == "timeEnd" && aMessage.arguments) {
      let bundle = Services.strings.createBundle("chrome://browser/locale/browser.properties");
      let body = bundle.formatStringFromName("timer.end", [aMessage.arguments.name, aMessage.arguments.duration], 2);
      Services.console.logStringMessage(body);
    } else if (["group", "groupCollapsed", "groupEnd"].indexOf(aMessage.level) != -1) {
      // Do nothing yet
    } else {
      Services.console.logStringMessage(joinedArguments);
    }
  },

  getResultType: function getResultType(aResult) {
    let type = aResult === null ? "null" : typeof aResult;
    if (type == "object" && aResult.constructor && aResult.constructor.name)
      type = aResult.constructor.name;
    return type.toLowerCase();
  },

  formatResult: function formatResult(aResult) {
    let output = "";
    let type = this.getResultType(aResult);
    switch (type) {
      case "string":
      case "boolean":
      case "date":
      case "error":
      case "number":
      case "regexp":
        output = aResult.toString();
        break;
      case "null":
      case "undefined":
        output = type;
        break;
      default:
        if (aResult.toSource) {
          try {
            output = aResult.toSource();
          } catch (ex) { }
        }
        if (!output || output == "({})") {
          output = aResult.toString();
        }
        break;
    }

    return output;
  },

  abbreviateSourceURL: function abbreviateSourceURL(aSourceURL) {
    // Remove any query parameters.
    let hookIndex = aSourceURL.indexOf("?");
    if (hookIndex > -1)
      aSourceURL = aSourceURL.substring(0, hookIndex);

    // Remove a trailing "/".
    if (aSourceURL[aSourceURL.length - 1] == "/")
      aSourceURL = aSourceURL.substring(0, aSourceURL.length - 1);

    // Remove all but the last path component.
    let slashIndex = aSourceURL.lastIndexOf("/");
    if (slashIndex > -1)
      aSourceURL = aSourceURL.substring(slashIndex + 1);

    return aSourceURL;
  }
};

var ClipboardHelper = {
  init: function() {
    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.copy"), ClipboardHelper.getCopyContext(false), ClipboardHelper.copy.bind(ClipboardHelper));
    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.copyAll"), ClipboardHelper.getCopyContext(true), ClipboardHelper.copy.bind(ClipboardHelper));
    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.selectWord"), ClipboardHelper.selectWordContext, ClipboardHelper.selectWord.bind(ClipboardHelper));
    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.selectAll"), ClipboardHelper.selectAllContext, ClipboardHelper.selectAll.bind(ClipboardHelper));
    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.share"), ClipboardHelper.shareContext, ClipboardHelper.share.bind(ClipboardHelper));
    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.paste"), ClipboardHelper.pasteContext, ClipboardHelper.paste.bind(ClipboardHelper));
    NativeWindow.contextmenus.add(Strings.browser.GetStringFromName("contextmenu.changeInputMethod"), NativeWindow.contextmenus.textContext, ClipboardHelper.inputMethod.bind(ClipboardHelper));
  },

  get clipboardHelper() {
    delete this.clipboardHelper;
    return this.clipboardHelper = Cc["@mozilla.org/widget/clipboardhelper;1"].getService(Ci.nsIClipboardHelper);
  },

  get clipboard() {
    delete this.clipboard;
    return this.clipboard = Cc["@mozilla.org/widget/clipboard;1"].getService(Ci.nsIClipboard);
  },

  copy: function(aElement, aX, aY) {
    if (SelectionHandler.shouldShowContextMenu(aX, aY)) {
      // Passing coordinates to endSelection takes care of copying for us
      SelectionHandler.endSelection(aX, aY);
      return;
    }

    let selectionStart = aElement.selectionStart;
    let selectionEnd = aElement.selectionEnd;
    if (selectionStart != selectionEnd) {
      string = aElement.value.slice(selectionStart, selectionEnd);
      this.clipboardHelper.copyString(string, aElement.ownerDocument);
    } else {
      this.clipboardHelper.copyString(aElement.value, aElement.ownerDocument);
    }
  },

  selectWord: function(aElement, aX, aY) {
    SelectionHandler.startSelection(aElement, aX, aY);
  },

  selectAll: function(aElement, aX, aY) {
    SelectionHandler.selectAll(aElement, aX, aY);
  },

  share: function() {
    let selectedText = SelectionHandler.endSelection();
    sendMessageToJava({
      gecko: {
        type: "Share:Text",
        text: selectedText
      }
    });
  },

  paste: function(aElement) {
    if (!aElement || !(aElement instanceof Ci.nsIDOMNSEditableElement))
      return;
    let target = aElement.QueryInterface(Ci.nsIDOMNSEditableElement);
    target.editor.paste(Ci.nsIClipboard.kGlobalClipboard);
    target.focus();  
  },

  inputMethod: function(aElement) {
    Cc["@mozilla.org/imepicker;1"].getService(Ci.nsIIMEPicker).show();
  },

  getCopyContext: function(isCopyAll) {
    return {
      matches: function(aElement, aX, aY) {
        // Do not show "Copy All" for normal non-input text selection.
        if (!isCopyAll && SelectionHandler.shouldShowContextMenu(aX, aY))
          return true;

        if (NativeWindow.contextmenus.textContext.matches(aElement)) {
          // Don't include "copy" for password fields.
          // mozIsTextField(true) tests for only non-password fields.
          if (aElement instanceof Ci.nsIDOMHTMLInputElement && !aElement.mozIsTextField(true))
            return false;

          let selectionStart = aElement.selectionStart;
          let selectionEnd = aElement.selectionEnd;
          if (selectionStart != selectionEnd)
            return true;

          if (isCopyAll && aElement.textLength > 0)
            return true;
        }
        return false;
      }
    }
  },

  selectWordContext: {
    matches: function selectWordContextMatches(aElement) {
      if (NativeWindow.contextmenus.textContext.matches(aElement))
        return aElement.textLength > 0;

      return false;
    }
  },

  selectAllContext: {
    matches: function selectAllContextMatches(aElement, aX, aY) {
      if (SelectionHandler.shouldShowContextMenu(aX, aY))
        return true;

      if (NativeWindow.contextmenus.textContext.matches(aElement))
        return (aElement.selectionStart > 0 || aElement.selectionEnd < aElement.textLength);

      return false;
    }
  },

  shareContext: {
    matches: function shareContextMatches(aElement, aX, aY) {
      return SelectionHandler.shouldShowContextMenu(aX, aY);
    }
  },

  pasteContext: {
    matches: function(aElement) {
      if (NativeWindow.contextmenus.textContext.matches(aElement)) {
        let flavors = ["text/unicode"];
        return ClipboardHelper.clipboard.hasDataMatchingFlavors(flavors, flavors.length, Ci.nsIClipboard.kGlobalClipboard);
      }
      return false;
    }
  }
};

var PluginHelper = {
  showDoorHanger: function(aTab) {
    if (!aTab.browser)
      return;

    // Even though we may not end up showing a doorhanger, this flag
    // lets us know that we've tried to show a doorhanger.
    aTab.shouldShowPluginDoorhanger = false;

    let uri = aTab.browser.currentURI;

    // If the user has previously set a plugins permission for this website,
    // either play or don't play the plugins instead of showing a doorhanger.
    let permValue = Services.perms.testPermission(uri, "plugins");
    if (permValue != Services.perms.UNKNOWN_ACTION) {
      if (permValue == Services.perms.ALLOW_ACTION)
        PluginHelper.playAllPlugins(aTab.browser.contentWindow);

      return;
    }

    let message = Strings.browser.formatStringFromName("clickToPlayPlugins.message1",
                                                       [uri.host], 1);
    let buttons = [
      {
        label: Strings.browser.GetStringFromName("clickToPlayPlugins.yes"),
        callback: function(aChecked) {
          // If the user checked "Don't ask again", make a permanent exception
          if (aChecked)
            Services.perms.add(uri, "plugins", Ci.nsIPermissionManager.ALLOW_ACTION);

          PluginHelper.playAllPlugins(aTab.browser.contentWindow);
        }
      },
      {
        label: Strings.browser.GetStringFromName("clickToPlayPlugins.no"),
        callback: function(aChecked) {
          // If the user checked "Don't ask again", make a permanent exception
          if (aChecked)
            Services.perms.add(uri, "plugins", Ci.nsIPermissionManager.DENY_ACTION);

          // Other than that, do nothing
        }
      }
    ];

    // Add a checkbox with a "Don't ask again" message if the uri contains a
    // host. Adding a permanent exception will fail if host is not present.
    let options = uri.host ? { checkbox: Strings.browser.GetStringFromName("clickToPlayPlugins.dontAskAgain") } : {};

    NativeWindow.doorhanger.show(message, "ask-to-play-plugins", buttons, aTab.id, options);
  },

  playAllPlugins: function(aContentWindow) {
    let cwu = aContentWindow.QueryInterface(Ci.nsIInterfaceRequestor)
                            .getInterface(Ci.nsIDOMWindowUtils);
    // XXX not sure if we should enable plugins for the parent documents...
    let plugins = cwu.plugins;
    if (!plugins || !plugins.length)
      return;

    plugins.forEach(this.playPlugin);
  },

  playPlugin: function(plugin) {
    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
    if (!objLoadingContent.activated &&
        objLoadingContent.pluginFallbackType !== Ci.nsIObjectLoadingContent.PLUGIN_PLAY_PREVIEW)
      objLoadingContent.playPlugin();
  },

  stopPlayPreview: function(plugin, playPlugin) {
    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
    if (objLoadingContent.activated)
      return;

    if (playPlugin)
      objLoadingContent.playPlugin();
    else
      objLoadingContent.cancelPlayPreview();
  },

  getPluginPreference: function getPluginPreference() {
    let pluginDisable = Services.prefs.getBoolPref("plugin.disable");
    if (pluginDisable)
      return "0";

    let clickToPlay = Services.prefs.getBoolPref("plugins.click_to_play");
    return clickToPlay ? "2" : "1";
  },

  setPluginPreference: function setPluginPreference(aValue) {
    switch (aValue) {
      case "0": // Enable Plugins = No
        Services.prefs.setBoolPref("plugin.disable", true);
        Services.prefs.clearUserPref("plugins.click_to_play");
        break;
      case "1": // Enable Plugins = Yes
        Services.prefs.clearUserPref("plugin.disable");
        Services.prefs.setBoolPref("plugins.click_to_play", false);
        break;
      case "2": // Enable Plugins = Tap to Play (default)
        Services.prefs.clearUserPref("plugin.disable");
        Services.prefs.clearUserPref("plugins.click_to_play");
        break;
    }
  },

  // Copied from /browser/base/content/browser.js
  isTooSmall : function (plugin, overlay) {
    // Is the <object>'s size too small to hold what we want to show?
    let pluginRect = plugin.getBoundingClientRect();
    // XXX bug 446693. The text-shadow on the submitted-report text at
    //     the bottom causes scrollHeight to be larger than it should be.
    let overflows = (overlay.scrollWidth > pluginRect.width) ||
                    (overlay.scrollHeight - 5 > pluginRect.height);

    return overflows;
  },

  getPluginMimeType: function (plugin) {
    var tagMimetype;
    if (plugin instanceof HTMLAppletElement) {
      tagMimetype = "application/x-java-vm";
    } else {
      tagMimetype = plugin.QueryInterface(Components.interfaces.nsIObjectLoadingContent)
                          .actualType;

      if (tagMimetype == "") {
        tagMimetype = plugin.type;
      }
    }

    return tagMimetype;
  },

  handlePluginBindingAttached: function (aTab, aEvent) {
    let plugin = aEvent.target;
    let doc = plugin.ownerDocument;
    let overlay = doc.getAnonymousElementByAttribute(plugin, "class", "mainBox");
    if (!overlay || overlay._bindingHandled) {
      return;
    }
    overlay._bindingHandled = true;

    let eventType = PluginHelper._getBindingType(plugin);
    if (!eventType) {
      // Not all bindings have handlers
      return;
    }

    switch  (eventType) {
      case "PluginClickToPlay": {
        // Check if plugins have already been activated for this page, or if
        // the user has set a permission to always play plugins on the site
        if (aTab.clickToPlayPluginsActivated ||
            Services.perms.testPermission(aTab.browser.currentURI, "plugins") ==
            Services.perms.ALLOW_ACTION) {
          PluginHelper.playPlugin(plugin);
          return;
        }

        // If the plugin is hidden, or if the overlay is too small, show a 
        // doorhanger notification
        if (PluginHelper.isTooSmall(plugin, overlay)) {
          // To avoid showing the doorhanger if there are also visible plugin
          // overlays on the page, delay showing the doorhanger to check if
          // visible plugins get added in the near future.
          if (!aTab.pluginDoorhangerTimeout) {
            aTab.pluginDoorhangerTimeout = setTimeout(function() {
              if (this.shouldShowPluginDoorhanger) {
                PluginHelper.showDoorHanger(this);
              }
            }.bind(aTab), 500);
          }

        } else {
          // There's a large enough visible overlay that we don't need to show
          // the doorhanger.
          aTab.shouldShowPluginDoorhanger = false;
        }

        // Add click to play listener to the overlay
        overlay.addEventListener("click", function(e) {
          if (!e.isTrusted)
            return;
          e.preventDefault();
          let win = e.target.ownerDocument.defaultView.top;
          let tab = BrowserApp.getTabForWindow(win);
          tab.clickToPlayPluginsActivated = true;
          PluginHelper.playAllPlugins(win);

          NativeWindow.doorhanger.hide("ask-to-play-plugins", tab.id);
        }, true);
        break;
      }

      case "PluginPlayPreview": {
        let previewContent = doc.getAnonymousElementByAttribute(plugin, "class", "previewPluginContent");
        let iframe = previewContent.getElementsByClassName("previewPluginContentFrame")[0];
        if (!iframe) {
          // lazy initialization of the iframe
          iframe = doc.createElementNS("http://www.w3.org/1999/xhtml", "iframe");
          iframe.className = "previewPluginContentFrame";
          previewContent.appendChild(iframe);
        }
        let mimeType = PluginHelper.getPluginMimeType(plugin);
        let playPreviewUri = "data:application/x-moz-playpreview;," + mimeType;
        iframe.src = playPreviewUri;

        // MozPlayPlugin event can be dispatched from the extension chrome
        // code to replace the preview content with the native plugin
        previewContent.addEventListener("MozPlayPlugin", function playPluginHandler(e) {
          if (!e.isTrusted)
            return;

          previewContent.removeEventListener("MozPlayPlugin", playPluginHandler, true);

          let playPlugin = !aEvent.detail;
          PluginHelper.stopPlayPreview(plugin, playPlugin);

          // cleaning up: removes overlay iframe from the DOM
          let iframe = previewContent.getElementsByClassName("previewPluginContentFrame")[0];
          if (iframe)
            previewContent.removeChild(iframe);
        }, true);
        break;
      }

      case "PluginNotFound": {
        // On devices where we don't support Flash, there will be a
        // "Learn More..." link in the missing plugin error message.
        let learnMoreLink = doc.getAnonymousElementByAttribute(plugin, "class", "unsupportedLearnMoreLink");
        let learnMoreUrl = Services.urlFormatter.formatURLPref("app.support.baseURL");
        learnMoreUrl += "why-cant-firefox-mobile-play-flash-on-my-device";
        learnMoreLink.href = learnMoreUrl;
        break;
      }
    }
  },

  // Helper to get the binding handler type from a plugin object
  _getBindingType: function(plugin) {
    if (!(plugin instanceof Ci.nsIObjectLoadingContent))
      return null;

    switch (plugin.pluginFallbackType) {
      case Ci.nsIObjectLoadingContent.PLUGIN_UNSUPPORTED:
        return "PluginNotFound";
      case Ci.nsIObjectLoadingContent.PLUGIN_CLICK_TO_PLAY:
        return "PluginClickToPlay";
      case Ci.nsIObjectLoadingContent.PLUGIN_PLAY_PREVIEW:
        return "PluginPlayPreview";
      default:
        // Not all states map to a handler
        return null;
    }
  },

};

var PermissionsHelper = {

  _permissonTypes: ["password", "geolocation", "popup", "indexedDB",
                    "offline-app", "desktop-notification", "plugins", "native-intent"],
  _permissionStrings: {
    "password": {
      label: "password.rememberPassword",
      allowed: "password.remember",
      denied: "password.never"
    },
    "geolocation": {
      label: "geolocation.shareLocation",
      allowed: "geolocation.alwaysAllow",
      denied: "geolocation.neverAllow"
    },
    "popup": {
      label: "blockPopups.label",
      allowed: "popupButtonAlwaysAllow2",
      denied: "popupButtonNeverWarn2"
    },
    "indexedDB": {
      label: "offlineApps.storeOfflineData",
      allowed: "offlineApps.allow",
      denied: "offlineApps.never"
    },
    "offline-app": {
      label: "offlineApps.storeOfflineData",
      allowed: "offlineApps.allow",
      denied: "offlineApps.never"
    },
    "desktop-notification": {
      label: "desktopNotification.useNotifications",
      allowed: "desktopNotification.allow",
      denied: "desktopNotification.dontAllow"
    },
    "plugins": {
      label: "clickToPlayPlugins.playPlugins",
      allowed: "clickToPlayPlugins.yes",
      denied: "clickToPlayPlugins.no"
    },
    "native-intent": {
      label: "helperapps.openWithList2",
      allowed: "helperapps.always",
      denied: "helperapps.never"
    }
  },

  init: function init() {
    Services.obs.addObserver(this, "Permissions:Get", false);
    Services.obs.addObserver(this, "Permissions:Clear", false);
  },

  observe: function observe(aSubject, aTopic, aData) {
    let uri = BrowserApp.selectedBrowser.currentURI;

    switch (aTopic) {
      case "Permissions:Get":
        let permissions = [];
        for (let i = 0; i < this._permissonTypes.length; i++) {
          let type = this._permissonTypes[i];
          let value = this.getPermission(uri, type);

          // Only add the permission if it was set by the user
          if (value == Services.perms.UNKNOWN_ACTION)
            continue;

          // Get the strings that correspond to the permission type
          let typeStrings = this._permissionStrings[type];
          let label = Strings.browser.GetStringFromName(typeStrings["label"]);

          // Get the key to look up the appropriate string entity
          let valueKey = value == Services.perms.ALLOW_ACTION ?
                         "allowed" : "denied";
          let valueString = Strings.browser.GetStringFromName(typeStrings[valueKey]);

          permissions.push({
            type: type,
            setting: label,
            value: valueString
          });
        }

        // Keep track of permissions, so we know which ones to clear
        this._currentPermissions = permissions;

        let host;
        try {
          host = uri.host;
        } catch(e) {
          host = uri.spec;
        }
        sendMessageToJava({
          gecko: {
            type: "Permissions:Data",
            host: host,
            permissions: permissions
          }
        });
        break;
 
      case "Permissions:Clear":
        // An array of the indices of the permissions we want to clear
        let permissionsToClear = JSON.parse(aData);
        let privacyContext = BrowserApp.selectedBrowser.docShell
                               .QueryInterface(Ci.nsILoadContext);

        for (let i = 0; i < permissionsToClear.length; i++) {
          let indexToClear = permissionsToClear[i];
          let permissionType = this._currentPermissions[indexToClear]["type"];
          this.clearPermission(uri, permissionType, privacyContext);
        }
        break;
    }
  },

  /**
   * Gets the permission value stored for a specified permission type.
   *
   * @param aType
   *        The permission type string stored in permission manager.
   *        e.g. "geolocation", "indexedDB", "popup"
   *
   * @return A permission value defined in nsIPermissionManager.
   */
  getPermission: function getPermission(aURI, aType) {
    // Password saving isn't a nsIPermissionManager permission type, so handle
    // it seperately.
    if (aType == "password") {
      // By default, login saving is enabled, so if it is disabled, the
      // user selected the never remember option
      if (!Services.logins.getLoginSavingEnabled(aURI.prePath))
        return Services.perms.DENY_ACTION;

      // Check to see if the user ever actually saved a login
      if (Services.logins.countLogins(aURI.prePath, "", ""))
        return Services.perms.ALLOW_ACTION;

      return Services.perms.UNKNOWN_ACTION;
    }

    // Geolocation consumers use testExactPermission
    if (aType == "geolocation")
      return Services.perms.testExactPermission(aURI, aType);

    return Services.perms.testPermission(aURI, aType);
  },

  /**
   * Clears a user-set permission value for the site given a permission type.
   *
   * @param aType
   *        The permission type string stored in permission manager.
   *        e.g. "geolocation", "indexedDB", "popup"
   */
  clearPermission: function clearPermission(aURI, aType, aContext) {
    // Password saving isn't a nsIPermissionManager permission type, so handle
    // it seperately.
    if (aType == "password") {
      // Get rid of exisiting stored logings
      let logins = Services.logins.findLogins({}, aURI.prePath, "", "");
      for (let i = 0; i < logins.length; i++) {
        Services.logins.removeLogin(logins[i]);
      }
      // Re-set login saving to enabled
      Services.logins.setLoginSavingEnabled(aURI.prePath, true);
    } else {
      Services.perms.remove(aURI.host, aType);
      // Clear content prefs set in ContentPermissionPrompt.js
      Services.contentPrefs.removePref(aURI, aType + ".request.remember", aContext);
    }
  }
};

var MasterPassword = {
  pref: "privacy.masterpassword.enabled",
  _tokenName: "",

  get _secModuleDB() {
    delete this._secModuleDB;
    return this._secModuleDB = Cc["@mozilla.org/security/pkcs11moduledb;1"].getService(Ci.nsIPKCS11ModuleDB);
  },

  get _pk11DB() {
    delete this._pk11DB;
    return this._pk11DB = Cc["@mozilla.org/security/pk11tokendb;1"].getService(Ci.nsIPK11TokenDB);
  },

  get enabled() {
    let slot = this._secModuleDB.findSlotByName(this._tokenName);
    if (slot) {
      let status = slot.status;
      return status != Ci.nsIPKCS11Slot.SLOT_UNINITIALIZED && status != Ci.nsIPKCS11Slot.SLOT_READY;
    }
    return false;
  },

  setPassword: function setPassword(aPassword) {
    try {
      let status;
      let slot = this._secModuleDB.findSlotByName(this._tokenName);
      if (slot)
        status = slot.status;
      else
        return false;

      let token = this._pk11DB.findTokenByName(this._tokenName);

      if (status == Ci.nsIPKCS11Slot.SLOT_UNINITIALIZED)
        token.initPassword(aPassword);
      else if (status == Ci.nsIPKCS11Slot.SLOT_READY)
        token.changePassword("", aPassword);

      this.updatePref();
      return true;
    } catch(e) {
      dump("MasterPassword.setPassword: " + e);
    }
    return false;
  },

  removePassword: function removePassword(aOldPassword) {
    try {
      let token = this._pk11DB.getInternalKeyToken();
      if (token.checkPassword(aOldPassword)) {
        token.changePassword(aOldPassword, "");
        this.updatePref();
        return true;
      }
    } catch(e) {
      dump("MasterPassword.removePassword: " + e + "\n");
    }
    NativeWindow.toast.show(Strings.browser.GetStringFromName("masterPassword.incorrect"), "short");
    return false;
  },

  updatePref: function() {
    var prefs = [];
    let pref = {
      name: this.pref,
      type: "bool",
      value: this.enabled
    };
    prefs.push(pref);

    sendMessageToJava({
      gecko: {
        type: "Preferences:Data",
        preferences: prefs
      }
    });
  }
};

var CharacterEncoding = {
  _charsets: [],

  init: function init() {
    Services.obs.addObserver(this, "CharEncoding:Get", false);
    Services.obs.addObserver(this, "CharEncoding:Set", false);
    this.sendState();
  },

  uninit: function uninit() {
    Services.obs.removeObserver(this, "CharEncoding:Get", false);
    Services.obs.removeObserver(this, "CharEncoding:Set", false);
  },

  observe: function observe(aSubject, aTopic, aData) {
    switch (aTopic) {
      case "CharEncoding:Get":
        this.getEncoding();
        break;
      case "CharEncoding:Set":
        this.setEncoding(aData);
        break;
    }
  },

  sendState: function sendState() {
    let showCharEncoding = "false";
    try {
      showCharEncoding = Services.prefs.getComplexValue("browser.menu.showCharacterEncoding", Ci.nsIPrefLocalizedString).data;
    } catch (e) { /* Optional */ }

    sendMessageToJava({
      gecko: {
        type: "CharEncoding:State",
        visible: showCharEncoding
      }
    });
  },

  getEncoding: function getEncoding() {
    function normalizeCharsetCode(charsetCode) {
      return charsetCode.trim().toLowerCase();
    }

    function getTitle(charsetCode) {
      let charsetTitle = charsetCode;
      try {
        charsetTitle = Strings.charset.GetStringFromName(charsetCode + ".title");
      } catch (e) {
        dump("error: title not found for " + charsetCode);
      }
      return charsetTitle;
    }

    if (!this._charsets.length) {
      let charsets = Services.prefs.getComplexValue("intl.charsetmenu.browser.static", Ci.nsIPrefLocalizedString).data;
      this._charsets = charsets.split(",").map(function (charset) {
        return {
          code: normalizeCharsetCode(charset),
          title: getTitle(charset)
        };
      });
    }

    // if document charset is not in charset options, add it
    let docCharset = normalizeCharsetCode(BrowserApp.selectedBrowser.contentDocument.characterSet);
    let selected = 0;
    let charsetCount = this._charsets.length;
    for (; selected < charsetCount && this._charsets[selected].code != docCharset; selected++);
    if (selected == charsetCount) {
      this._charsets.push({
        code: docCharset,
        title: getTitle(docCharset)
      });
    }

    sendMessageToJava({
      gecko: {
        type: "CharEncoding:Data",
        charsets: this._charsets,
        selected: selected
      }
    });
  },

  setEncoding: function setEncoding(aEncoding) {
    let browser = BrowserApp.selectedBrowser;
    let docCharset = browser.docShell.QueryInterface(Ci.nsIDocCharset);
    docCharset.charset = aEncoding;
    browser.reload(Ci.nsIWebNavigation.LOAD_FLAGS_CHARSET_CHANGE);
  }
};

var IdentityHandler = {
  // Mode strings used to control CSS display
  IDENTITY_MODE_IDENTIFIED       : "identified", // High-quality identity information
  IDENTITY_MODE_DOMAIN_VERIFIED  : "verified",   // Minimal SSL CA-signed domain verification
  IDENTITY_MODE_UNKNOWN          : "unknown",  // No trusted identity information

  // Cache the most recent SSLStatus and Location seen in getIdentityStrings
  _lastStatus : null,
  _lastLocation : null,

  /**
   * Helper to parse out the important parts of _lastStatus (of the SSL cert in
   * particular) for use in constructing identity UI strings
  */
  getIdentityData : function() {
    let result = {};
    let status = this._lastStatus.QueryInterface(Components.interfaces.nsISSLStatus);
    let cert = status.serverCert;

    // Human readable name of Subject
    result.subjectOrg = cert.organization;

    // SubjectName fields, broken up for individual access
    if (cert.subjectName) {
      result.subjectNameFields = {};
      cert.subjectName.split(",").forEach(function(v) {
        let field = v.split("=");
        this[field[0]] = field[1];
      }, result.subjectNameFields);

      // Call out city, state, and country specifically
      result.city = result.subjectNameFields.L;
      result.state = result.subjectNameFields.ST;
      result.country = result.subjectNameFields.C;
    }

    // Human readable name of Certificate Authority
    result.caOrg =  cert.issuerOrganization || cert.issuerCommonName;
    result.cert = cert;

    return result;
  },

  getIdentityMode: function getIdentityMode(aState) {
    if (aState & Ci.nsIWebProgressListener.STATE_IDENTITY_EV_TOPLEVEL)
      return this.IDENTITY_MODE_IDENTIFIED;

    if (aState & Ci.nsIWebProgressListener.STATE_IS_SECURE)
      return this.IDENTITY_MODE_DOMAIN_VERIFIED;

    return this.IDENTITY_MODE_UNKNOWN;
  },

  /**
   * Determine the identity of the page being displayed by examining its SSL cert
   * (if available). Return the data needed to update the UI.
   */
  checkIdentity: function checkIdentity(aState, aBrowser) {
    this._lastStatus = aBrowser.securityUI
                               .QueryInterface(Components.interfaces.nsISSLStatusProvider)
                               .SSLStatus;

    // Don't pass in the actual location object, since it can cause us to 
    // hold on to the window object too long.  Just pass in the fields we
    // care about. (bug 424829)
    let locationObj = {};
    try {
      let location = aBrowser.contentWindow.location;
      locationObj.host = location.host;
      locationObj.hostname = location.hostname;
      locationObj.port = location.port;
    } catch (ex) {
      // Can sometimes throw if the URL being visited has no host/hostname,
      // e.g. about:blank. The _state for these pages means we won't need these
      // properties anyways, though.
    }
    this._lastLocation = locationObj;

    let mode = this.getIdentityMode(aState);
    let result = { mode: mode };

    // We can't to do anything else for pages without identity data
    if (mode == this.IDENTITY_MODE_UNKNOWN)
      return result;

    // Ideally we'd just make this a Java string
    result.encrypted = Strings.browser.GetStringFromName("identity.encrypted2");
    result.host = this.getEffectiveHost();

    let iData = this.getIdentityData();
    result.verifier = Strings.browser.formatStringFromName("identity.identified.verifier", [iData.caOrg], 1);

    // If the cert is identified, then we can populate the results with credentials
    if (mode == this.IDENTITY_MODE_IDENTIFIED) {
      result.owner = iData.subjectOrg;

      // Build an appropriate supplemental block out of whatever location data we have
      let supplemental = "";
      if (iData.city)
        supplemental += iData.city + "\n";
      if (iData.state && iData.country)
        supplemental += Strings.browser.formatStringFromName("identity.identified.state_and_country", [iData.state, iData.country], 2);
      else if (iData.state) // State only
        supplemental += iData.state;
      else if (iData.country) // Country only
        supplemental += iData.country;
      result.supplemental = supplemental;

      return result;
    }
    
    // Otherwise, we don't know the cert owner
    result.owner = Strings.browser.GetStringFromName("identity.ownerUnknown2");

    // Cache the override service the first time we need to check it
    if (!this._overrideService)
      this._overrideService = Cc["@mozilla.org/security/certoverride;1"].getService(Ci.nsICertOverrideService);

    // Check whether this site is a security exception. XPConnect does the right
    // thing here in terms of converting _lastLocation.port from string to int, but
    // the overrideService doesn't like undefined ports, so make sure we have
    // something in the default case (bug 432241).
    // .hostname can return an empty string in some exceptional cases -
    // hasMatchingOverride does not handle that, so avoid calling it.
    // Updating the tooltip value in those cases isn't critical.
    // FIXME: Fixing bug 646690 would probably makes this check unnecessary
    if (this._lastLocation.hostname &&
        this._overrideService.hasMatchingOverride(this._lastLocation.hostname,
                                                  (this._lastLocation.port || 443),
                                                  iData.cert, {}, {}))
      result.verifier = Strings.browser.GetStringFromName("identity.identified.verified_by_you");

    return result;
  },

  /**
   * Return the eTLD+1 version of the current hostname
   */
  getEffectiveHost: function getEffectiveHost() {
    if (!this._IDNService)
      this._IDNService = Cc["@mozilla.org/network/idn-service;1"]
                         .getService(Ci.nsIIDNService);
    try {
      let baseDomain = Services.eTLD.getBaseDomainFromHost(this._lastLocation.hostname);
      return this._IDNService.convertToDisplayIDN(baseDomain, {});
    } catch (e) {
      // If something goes wrong (e.g. hostname is an IP address) just fail back
      // to the full domain.
      return this._lastLocation.hostname;
    }
  }
};

function OverscrollController(aTab) {
  this.tab = aTab;
}

OverscrollController.prototype = {
  supportsCommand : function supportsCommand(aCommand) {
    if (aCommand != "cmd_linePrevious" && aCommand != "cmd_scrollPageUp")
      return false;

    return (this.tab.getViewport().y == 0);
  },

  isCommandEnabled : function isCommandEnabled(aCommand) {
    return this.supportsCommand(aCommand);
  },

  doCommand : function doCommand(aCommand){
    sendMessageToJava({ gecko: { type: "ToggleChrome:Focus" } });
  },

  onEvent : function onEvent(aEvent) { }
};

var SearchEngines = {
  _contextMenuId: null,
  PREF_SUGGEST_ENABLED: "browser.search.suggest.enabled",
  PREF_SUGGEST_PROMPTED: "browser.search.suggest.prompted",

  init: function init() {
    Services.obs.addObserver(this, "SearchEngines:Get", false);
    let contextName = Strings.browser.GetStringFromName("contextmenu.addSearchEngine");
    let filter = {
      matches: function (aElement) {
        return (aElement.form && NativeWindow.contextmenus.textContext.matches(aElement));
      }
    };
    this._contextMenuId = NativeWindow.contextmenus.add(contextName, filter, this.addEngine);
  },

  uninit: function uninit() {
    Services.obs.removeObserver(this, "SearchEngines:Get");
    if (this._contextMenuId != null)
      NativeWindow.contextmenus.remove(this._contextMenuId);
  },

  _handleSearchEnginesGet: function _handleSearchEnginesGet(rv) {
    if (!Components.isSuccessCode(rv)) {
      Cu.reportError("Could not initialize search service, bailing out.");
      return;
    }
    let engineData = Services.search.getVisibleEngines({});
    let searchEngines = engineData.map(function (engine) {
      return {
        name: engine.name,
        iconURI: (engine.iconURI ? engine.iconURI.spec : null)
      };
    });

    let suggestTemplate = null;
    let suggestEngine = null;
    let engine = this.getSuggestionEngine();
    if (engine != null) {
      suggestEngine = engine.name;
      suggestTemplate = engine.getSubmission("__searchTerms__", "application/x-suggestions+json").uri.spec;
    }

    sendMessageToJava({
      gecko: {
        type: "SearchEngines:Data",
        searchEngines: searchEngines,
        suggest: {
          engine: suggestEngine,
          template: suggestTemplate,
          enabled: Services.prefs.getBoolPref(this.PREF_SUGGEST_ENABLED),
          prompted: Services.prefs.getBoolPref(this.PREF_SUGGEST_PROMPTED)
        }
      }
    });
  },

  observe: function observe(aSubject, aTopic, aData) {
    if (aTopic == "SearchEngines:Get") {
      Services.search.init(this._handleSearchEnginesGet.bind(this));
    }
  },

  getSuggestionEngine: function () {
    let engines = [ Services.search.currentEngine,
                    Services.search.defaultEngine,
                    Services.search.originalDefaultEngine ];

    for (let i = 0; i < engines.length; i++) {
      let engine = engines[i];
      if (engine && engine.supportsResponseType("application/x-suggestions+json"))
        return engine;
    }

    return null;
  },

  addEngine: function addEngine(aElement) {
    let form = aElement.form;
    let charset = aElement.ownerDocument.characterSet;
    let docURI = Services.io.newURI(aElement.ownerDocument.URL, charset, null);
    let formURL = Services.io.newURI(form.getAttribute("action"), charset, docURI).spec;
    let method = form.method.toUpperCase();
    let formData = [];

    for (let i = 0; i < form.elements.length; ++i) {
      let el = form.elements[i];
      if (!el.type)
        continue;

      // make this text field a generic search parameter
      if (aElement == el) {
        formData.push({ name: el.name, value: "{searchTerms}" });
        continue;
      }

      let type = el.type.toLowerCase();
      let escapedName = escape(el.name);
      let escapedValue = escape(el.value);

      // add other form elements as parameters
      switch (el.type) {
        case "checkbox":
        case "radio":
          if (!el.checked) break;
        case "text":
        case "hidden":
        case "textarea":
          formData.push({ name: escapedName, value: escapedValue });
          break;
        case "select-one":
          for each (let option in el.options) {
            if (option.selected) {
              formData.push({ name: escapedName, value: escapedValue });
              break;
            }
          }
      }
    }

    // prompt user for name of search engine
    let promptTitle = Strings.browser.GetStringFromName("contextmenu.addSearchEngine");
    let title = { value: (aElement.ownerDocument.title || docURI.host) };
    if (!Services.prompt.prompt(null, promptTitle, null, title, null, {}))
      return;

    // fetch the favicon for this page
    let dbFile = FileUtils.getFile("ProfD", ["browser.db"]);
    let mDBConn = Services.storage.openDatabase(dbFile);
    let stmts = [];
    stmts[0] = mDBConn.createStatement("SELECT favicon FROM history_with_favicons WHERE url = ?");
    stmts[0].bindStringParameter(0, docURI.spec);
    let favicon = null;
    Services.search.init(function addEngine_cb(rv) {
      if (!Components.isSuccessCode(rv)) {
        Cu.reportError("Could not initialize search service, bailing out.");
        return;
      }
      mDBConn.executeAsync(stmts, stmts.length, {
        handleResult: function (results) {
          let bytes = results.getNextRow().getResultByName("favicon");
          favicon = "data:image/png;base64," + btoa(String.fromCharCode.apply(null, bytes));
        },
        handleCompletion: function (reason) {
          // if there's already an engine with this name, add a number to
          // make the name unique (e.g., "Google" becomes "Google 2")
          let name = title.value;
          for (let i = 2; Services.search.getEngineByName(name); i++)
            name = title.value + " " + i;

          Services.search.addEngineWithDetails(name, favicon, null, null, method, formURL);
          let engine = Services.search.getEngineByName(name);
          engine.wrappedJSObject._queryCharset = charset;
          for (let i = 0; i < formData.length; ++i) {
            let param = formData[i];
            if (param.name && param.value)
              engine.addParam(param.name, param.value, null);
          }
        }
      });
    });
  }
};

var ActivityObserver = {
  init: function ao_init() {
    Services.obs.addObserver(this, "application-background", false);
    Services.obs.addObserver(this, "application-foreground", false);
  },

  observe: function ao_observe(aSubject, aTopic, aData) {
    let isForeground = false
    switch (aTopic) {
      case "application-background" :
        let doc = BrowserApp.selectedTab.browser.contentDocument;
        if (doc.mozFullScreen) {
          doc.mozCancelFullScreen();
        }
        isForeground = false;
        break;
      case "application-foreground" :
        isForeground = true;
        break;
    }

    let tab = BrowserApp.selectedTab;
    if (tab && tab.getActive() != isForeground) {
      tab.setActive(isForeground);
    }
  }
};

var WebappsUI = {
  init: function init() {
    Cu.import("resource://gre/modules/Webapps.jsm");
    Cu.import("resource://gre/modules/AppsUtils.jsm");
    DOMApplicationRegistry.allAppsLaunchable = true;

    Services.obs.addObserver(this, "webapps-ask-install", false);
    Services.obs.addObserver(this, "webapps-launch", false);
    Services.obs.addObserver(this, "webapps-sync-install", false);
    Services.obs.addObserver(this, "webapps-sync-uninstall", false);
    Services.obs.addObserver(this, "webapps-install-error", false);
  },

  uninit: function unint() {
    Services.obs.removeObserver(this, "webapps-ask-install");
    Services.obs.removeObserver(this, "webapps-launch");
    Services.obs.removeObserver(this, "webapps-sync-install");
    Services.obs.removeObserver(this, "webapps-sync-uninstall");
    Services.obs.removeObserver(this, "webapps-install-error", false);
  },

  DEFAULT_PREFS_FILENAME: "default-prefs.js",

  observe: function observe(aSubject, aTopic, aData) {
    let data = {};
    try {
      data = JSON.parse(aData);
      data.mm = aSubject;
    } catch(ex) { }
    switch (aTopic) {
      case "webapps-install-error":
        let msg = "";
        switch (aData) {
          case "INVALID_MANIFEST":
          case "MANIFEST_PARSE_ERROR":
            msg = Strings.browser.GetStringFromName("webapps.manifestInstallError");
            break;
          case "NETWORK_ERROR":
          case "MANIFEST_URL_ERROR":
            msg = Strings.browser.GetStringFromName("webapps.networkInstallError");
            break;
          default:
            msg = Strings.browser.GetStringFromName("webapps.installError");
        }
        NativeWindow.toast.show(msg, "short");
        console.log("Error installing app: " + aData);
        break;
      case "webapps-ask-install":
        this.doInstall(data);
        break;
      case "webapps-launch":
        this.openURL(data.manifestURL, data.origin);
        break;
      case "webapps-sync-install":
        // Create a system notification allowing the user to launch the app
        DOMApplicationRegistry.getManifestFor(data.origin, (function(aManifest) {
          if (!aManifest)
            return;
          let manifest = new ManifestHelper(aManifest, data.origin);

          let observer = {
            observe: function (aSubject, aTopic) {
              if (aTopic == "alertclickcallback") {
                WebappsUI.openURL(data.manifestURL, data.origin);
              }
            }
          };

          let message = Strings.browser.GetStringFromName("webapps.alertSuccess");
          let alerts = Cc["@mozilla.org/alerts-service;1"].getService(Ci.nsIAlertsService);
          alerts.showAlertNotification("drawable://alert_app", manifest.name, message, true, "", observer, "webapp");
        }).bind(this));
        break;
      case "webapps-sync-uninstall":
        sendMessageToJava({
          gecko: {
            type: "WebApps:Uninstall",
            origin: data.origin
          }
        });
        break;
    }
  },

  getBiggestIcon: function getBiggestIcon(aIcons, aOrigin) {
    const DEFAULT_ICON = "chrome://browser/skin/images/default-app-icon.png";
    if (!aIcons)
      return DEFAULT_ICON;
  
    let iconSizes = Object.keys(aIcons);
    if (iconSizes.length == 0)
      return DEFAULT_ICON;
    iconSizes.sort(function(a, b) a - b);

    let biggestIcon = aIcons[iconSizes.pop()];
    let iconURI = null;
    try {
      iconURI = Services.io.newURI(biggestIcon, null, null);
      if (iconURI.scheme == "data") {
        return iconURI.spec;
      }
    } catch (ex) {
      // we don't have a biggestIcon or its not a valid url
    }

    // if we have an origin, try to resolve biggestIcon as a relative url
    if (!iconURI && aOrigin) {
      try {
        iconURI = Services.io.newURI(aOrigin.resolve(biggestIcon), null, null);
      } catch (ex) {
        console.log("Could not resolve url: " + aOrigin.spec + " " + biggestIcon + " - " + ex);
      }
    }

    return iconURI ? iconURI.spec : DEFAULT_ICON;
  },

  doInstall: function doInstall(aData) {
    let manifest = new ManifestHelper(aData.app.manifest, aData.app.origin);
    let name = manifest.name ? manifest.name : manifest.fullLaunchPath();
    let showPrompt = true;

    if (!showPrompt || Services.prompt.confirm(null, Strings.browser.GetStringFromName("webapps.installTitle"), name)) {
      // Add a homescreen shortcut -- we can't use createShortcut, since we need to pass
      // a unique ID for Android webapp allocation
      this.makeBase64Icon(this.getBiggestIcon(manifest.icons, Services.io.newURI(aData.app.origin, null, null)),
        (function(scaledIcon, fullsizeIcon) {
          let profilePath = sendMessageToJava({
            gecko: {
              type: "WebApps:Install",
              name: manifest.name,
              manifestURL: aData.app.manifestURL,
              origin: aData.app.origin,
              iconURL: scaledIcon,
            }
          });

          // if java returned a profile path to us, try to use it to pre-populate the app cache
          let file = null;
          if (profilePath) {
            file = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsILocalFile);
            file.initWithPath(profilePath);

            // build any app specific default prefs
            let prefs = [];
            if (manifest.orientation)
              prefs.push({name:"app.orientation.default", value: manifest.orientation});

            // write them into the app profile
            let defaultPrefsFile = file.clone();
            defaultPrefsFile.append(this.DEFAULT_PREFS_FILENAME);
            this.writeDefaultPrefs(defaultPrefsFile, prefs);

            // also save the icon so that it can be used in the splash screen
            try {
              let iconFile = file.clone();
              iconFile.append("logo.png");
              let persist = Cc["@mozilla.org/embedding/browser/nsWebBrowserPersist;1"].createInstance(Ci.nsIWebBrowserPersist);
              persist.persistFlags = Ci.nsIWebBrowserPersist.PERSIST_FLAGS_REPLACE_EXISTING_FILES;
              persist.persistFlags |= Ci.nsIWebBrowserPersist.PERSIST_FLAGS_AUTODETECT_APPLY_CONVERSION;
  
              let source = Services.io.newURI(fullsizeIcon, "UTF8", null);
              persist.saveURI(source, null, null, null, null, iconFile, null);
            } catch(ex) {
              console.log(ex);
            }
          }
          DOMApplicationRegistry.confirmInstall(aData, false, file);
        }).bind(this));
    } else {
      DOMApplicationRegistry.denyInstall(aData);
    }
  },

  writeDefaultPrefs: function webapps_writeDefaultPrefs(aFile, aPrefs) {
    if (aPrefs.length > 0) {
      let data = JSON.stringify(aPrefs);

      let ostream = Cc["@mozilla.org/network/file-output-stream;1"].createInstance(Ci.nsIFileOutputStream);
      ostream.init(aFile, -1, -1, 0);

      let istream = Cc["@mozilla.org/io/string-input-stream;1"].createInstance(Ci.nsIStringInputStream);
      istream.setData(data, data.length);

      NetUtil.asyncCopy(istream, ostream, function(aResult) {
        if (!Components.isSuccessCode(aResult)) {
          console.log("Error writing default prefs: " + aResult);
        }
      });
    }
  },

  openURL: function openURL(aManifestURL, aOrigin) {
    sendMessageToJava({
      gecko: {
        type: "WebApps:Open",
        manifestURL: aManifestURL,
        origin: aOrigin
      }
    });
  },

  get iconSize() {
    let iconSize = 64;
    try {
      let jni = new JNI();
      let cls = jni.findClass("org/mozilla/gecko/GeckoAppShell");
      let method = jni.getStaticMethodID(cls, "getPreferredIconSize", "()I");
      iconSize = jni.callStaticIntMethod(cls, method);
      jni.close();
    } catch(ex) {
      console.log(ex);
    }

    delete this.iconSize;
    return this.iconSize = iconSize;
  },

  makeBase64Icon: function loadAndMakeBase64Icon(aIconURL, aCallbackFunction) {
    let size = this.iconSize;

    let canvas = document.createElementNS("http://www.w3.org/1999/xhtml", "canvas");
    canvas.width = canvas.height = size;
    let ctx = canvas.getContext("2d");
    let favicon = new Image();
    favicon.onload = function() {
      ctx.drawImage(favicon, 0, 0, size, size);
      let scaledIcon = canvas.toDataURL("image/png", "");

      canvas.width = favicon.width;
      canvas.height = favicon.height;
      ctx.drawImage(favicon, 0, 0, favicon.width, favicon.height);
      let fullsizeIcon = canvas.toDataURL("image/png", "");

      canvas = null;
      aCallbackFunction.call(null, scaledIcon, fullsizeIcon);
    };
    favicon.onerror = function() {
      Cu.reportError("CreateShortcut: favicon image load error");

      // if the image failed to load, and it was not our default icon, attempt to
      // use our default as a fallback
      let uri = Services.io.newURI(favicon.src, null, null);
      if (!/^chrome$/.test(uri.scheme)) {
        favicon.src = WebappsUI.getBiggestIcon(null);
      }
    };
  
    favicon.src = aIconURL;
  },

  createShortcut: function createShortcut(aTitle, aURL, aIconURL, aType) {
    this.makeBase64Icon(aIconURL, function _createShortcut(icon) {
      try {
        let shell = Cc["@mozilla.org/browser/shell-service;1"].createInstance(Ci.nsIShellService);
        shell.createShortcut(aTitle, aURL, icon, aType);
      } catch(e) {
        Cu.reportError(e);
      }
    });
  }
}

var RemoteDebugger = {
  init: function rd_init() {
    Services.prefs.addObserver("devtools.debugger.", this, false);

    if (this._isEnabled())
      this._start();
  },

  observe: function rd_observe(aSubject, aTopic, aData) {
    if (aTopic != "nsPref:changed")
      return;

    switch (aData) {
      case "devtools.debugger.remote-enabled":
        if (this._isEnabled())
          this._start();
        else
          this._stop();
        break;

      case "devtools.debugger.remote-port":
        if (this._isEnabled())
          this._restart();
        break;
    }
  },

  uninit: function rd_uninit() {
    Services.prefs.removeObserver("devtools.debugger.", this);
    this._stop();
  },

  _getPort: function _rd_getPort() {
    return Services.prefs.getIntPref("devtools.debugger.remote-port");
  },

  _isEnabled: function rd_isEnabled() {
    return Services.prefs.getBoolPref("devtools.debugger.remote-enabled");
  },

  /**
   * Prompt the user to accept or decline the incoming connection.
   *
   * @return true if the connection should be permitted, false otherwise
   */
  _allowConnection: function rd_allowConnection() {
    let title = Strings.browser.GetStringFromName("remoteIncomingPromptTitle");
    let msg = Strings.browser.GetStringFromName("remoteIncomingPromptMessage");
    let btn = Strings.browser.GetStringFromName("remoteIncomingPromptDisable");
    let prompt = Services.prompt;
    let flags = prompt.BUTTON_POS_0 * prompt.BUTTON_TITLE_OK +
                prompt.BUTTON_POS_1 * prompt.BUTTON_TITLE_CANCEL +
                prompt.BUTTON_POS_2 * prompt.BUTTON_TITLE_IS_STRING +
                prompt.BUTTON_POS_1_DEFAULT;
    let result = prompt.confirmEx(null, title, msg, flags, null, null, btn, null, { value: false });
    if (result == 0)
      return true;
    if (result == 2) {
      this._stop();
      Services.prefs.setBoolPref("devtools.debugger.remote-enabled", false);
    }
    return false;
  },

  _restart: function rd_restart() {
    this._stop();
    this._start();
  },

  _start: function rd_start() {
    try {
      if (!DebuggerServer.initialized) {
        DebuggerServer.init(this._allowConnection);
        DebuggerServer.addBrowserActors();
        DebuggerServer.addActors("chrome://browser/content/dbg-browser-actors.js");
      }

      let port = this._getPort();
      DebuggerServer.openListener(port);
      dump("Remote debugger listening on port " + port);
    } catch(e) {
      dump("Remote debugger didn't start: " + e);
    }
  },

  _stop: function rd_start() {
    DebuggerServer.closeListener();
    dump("Remote debugger stopped");
  }
};

var Telemetry = {
#ifdef MOZ_TELEMETRY_ON_BY_DEFAULT
  _PREF_TELEMETRY_ENABLED: "toolkit.telemetry.enabledPreRelease",
  _PREF_TELEMETRY_DISPLAYED: "toolkit.telemetry.notifiedOptOut",
#else
  _PREF_TELEMETRY_ENABLED: "toolkit.telemetry.enabled",
  _PREF_TELEMETRY_DISPLAYED: "toolkit.telemetry.prompted",
#endif
  _PREF_TELEMETRY_REJECTED: "toolkit.telemetry.rejected",
  _PREF_TELEMETRY_SERVER_OWNER: "toolkit.telemetry.server_owner",

  // This is used to reprompt Beta/GA users and notify again
  // Nightly/Aurora users when privacy message changes
  _TELEMETRY_DISPLAY_REV: @MOZ_TELEMETRY_DISPLAY_REV@,

  init: function init() {
    Services.obs.addObserver(this, "Preferences:Set", false);
    Services.obs.addObserver(this, "Telemetry:Add", false);
    Services.obs.addObserver(this, "Telemetry:Prompt", false);
  },

  uninit: function uninit() {
    Services.obs.removeObserver(this, "Preferences:Set");
    Services.obs.removeObserver(this, "Telemetry:Add");
    Services.obs.removeObserver(this, "Telemetry:Prompt");
  },

  addData: function addData(aHistogramId, aValue) {
    let telemetry = Cc["@mozilla.org/base/telemetry;1"].getService(Ci.nsITelemetry);
    let histogram = telemetry.getHistogramById(aHistogramId);
    histogram.add(aValue);
  },

  observe: function observe(aSubject, aTopic, aData) {
    if (aTopic == "Preferences:Set") {
      // if user changes telemetry pref, treat it like they have been prompted
      let pref = JSON.parse(aData);
      if (pref.name == this._PREF_TELEMETRY_ENABLED) {
        Services.prefs.setIntPref(this._PREF_TELEMETRY_DISPLAYED, this._TELEMETRY_DISPLAY_REV);
        Services.prefs.setBoolPref(this._PREF_TELEMETRY_REJECTED, !pref.value);
      }
    } else if (aTopic == "Telemetry:Add") {
      let json = JSON.parse(aData);
      this.addData(json.name, json.value);
    } else if (aTopic == "Telemetry:Prompt") {
#ifdef MOZ_TELEMETRY_REPORTING
      this.prompt();
#endif
    }
  },

  prompt: function prompt() {
    let brandShortName = Strings.brand.GetStringFromName("brandShortName");
    let serverOwner = Services.prefs.getCharPref(this._PREF_TELEMETRY_SERVER_OWNER);
    let telemetryEnabled = Services.prefs.getBoolPref(this._PREF_TELEMETRY_ENABLED);
    let message;
    let buttons;
    let self = this;

    /*
     * Display an opt-out notification when telemetry is enabled by default,
     * an opt-in prompt otherwise.
     *
     * But do not display this prompt/notification if:
     *
     * - The last accepted/refused policy (either by accepting the prompt or by
     *   manually flipping the telemetry preference) is already at version
     *   TELEMETRY_DISPLAY_REV or higher (to avoid the prompt in tests).
     */
    let telemetryDisplayed;
    try {
      telemetryDisplayed = Services.prefs.getIntPref(self._PREF_TELEMETRY_DISPLAYED);
    } catch(e) {}
    if (telemetryDisplayed >= self._TELEMETRY_DISPLAY_REV)
      return;

#ifdef MOZ_TELEMETRY_ON_BY_DEFAULT
    /*
     * Additionally, in opt-out builds, don't display the notification if:
     *
     * - Telemetry is disabled
     * - Telemetry was explicitly refused through the UI
     * - Opt-in telemetry was already enabled, don't notify the user until next
     *   policy update. (Do the check only at first run with opt-out builds)
     */

    let telemetryEnabled = Services.prefs.getBoolPref(self._PREF_TELEMETRY_ENABLED);
    if (!telemetryEnabled)
      return;

    // If telemetry was explicitly refused through the UI,
    // also disable opt-out telemetry and bail out.
    let telemetryRejected = false;
    try {
      telemetryRejected = Services.prefs.getBoolPref(self._PREF_TELEMETRY_REJECTED);
    } catch(e) {}
    if (telemetryRejected) {
      Services.prefs.setBoolPref(self._PREF_TELEMETRY_ENABLED, false);
      Services.prefs.setIntPref(self._PREF_TELEMETRY_DISPLAYED, self._TELEMETRY_DISPLAY_REV);
      return;
    }

    // If opt-in telemetry was already enabled, don't notify the user until next
    // policy update. (Do the check only at first run with opt-out builds)
    let optInTelemetryEnabled = false;
    try {
      optInTelemetryEnabled = Services.prefs.getBoolPref("toolkit.telemetry.enabled");
    } catch(e) {}
    if (optInTelemetryEnabled && telemetryDisplayed === undefined) {
      Services.prefs.setBoolPref(self._PREF_TELEMETRY_REJECTED, false);
      Services.prefs.setIntPref(self._PREF_TELEMETRY_DISPLAYED, self._TELEMETRY_DISPLAY_REV);
      return;
    }

    message = Strings.browser.formatStringFromName("telemetry.optout.message",
                                                    [brandShortName, serverOwner, brandShortName], 3);
    buttons = [
      {
        label: Strings.browser.GetStringFromName("telemetry.optout.ok"),
        callback: function () {
          Services.prefs.setIntPref(self._PREF_TELEMETRY_DISPLAYED, self._TELEMETRY_DISPLAY_REV);
        }
      }
    ];
#else
    // Clear old prefs and reprompt
    Services.prefs.clearUserPref(self._PREF_TELEMETRY_DISPLAYED);
    Services.prefs.clearUserPref(self._PREF_TELEMETRY_ENABLED);
    Services.prefs.clearUserPref(self._PREF_TELEMETRY_REJECTED);

    message = Strings.browser.formatStringFromName("telemetry.optin.message2",
                                                  [serverOwner, brandShortName], 2);
    buttons = [
      {
        label: Strings.browser.GetStringFromName("telemetry.optin.yes"),
        callback: function () {
          Services.prefs.setIntPref(self._PREF_TELEMETRY_DISPLAYED, self._TELEMETRY_DISPLAY_REV);
          Services.prefs.setBoolPref(self._PREF_TELEMETRY_ENABLED, true);
        }
      },
      {
        label: Strings.browser.GetStringFromName("telemetry.optin.no"),
        callback: function () {
          Services.prefs.setIntPref(self._PREF_TELEMETRY_DISPLAYED, self._TELEMETRY_DISPLAY_REV);
          Services.prefs.setBoolPref(self._PREF_TELEMETRY_REJECTED, true);
        }
      }
    ];
#endif
    let learnMoreLabel = Strings.browser.GetStringFromName("telemetry.optin.learnMore");
    let learnMoreUrl = Services.urlFormatter.formatURLPref("app.support.baseURL");
    learnMoreUrl += "how-can-i-help-submitting-performance-data";
    let options = {
      link: {
        label: learnMoreLabel,
        url: learnMoreUrl
      }
    };
    NativeWindow.doorhanger.show(message, "telemetry-prompt", buttons, BrowserApp.selectedTab.id, options);
  },
};

let Reader = {
  // Version of the cache database schema
  DB_VERSION: 1,

  DEBUG: 0,

  // Don't try to parse the page if it has too many elements (for memory and
  // performance reasons)
  MAX_ELEMS_TO_PARSE: 3000,

  init: function Reader_init() {
    this.log("Init()");
    this._requests = {};

    Services.obs.addObserver(this, "Reader:Add", false);
    Services.obs.addObserver(this, "Reader:Remove", false);
  },

  observe: function(aMessage, aTopic, aData) {
    switch(aTopic) {
      case "Reader:Add": {
        let tab = BrowserApp.getTabForId(aData);
        let currentURI = tab.browser.currentURI;
        let url = currentURI.spec;

        let sendResult = function(success, title) {
          this.log("Reader:Add success=" + success + ", url=" + url + ", title=" + title);

          sendMessageToJava({
            gecko: {
              type: "Reader:Added",
              success: success,
              title: title,
              url: url,
            }
          });
        }.bind(this);

        this.getArticleForTab(aData, currentURI.specIgnoringRef, function (article) {
          if (!article) {
            sendResult(false, "");
            return;
          }

          this.storeArticleInCache(article, function(success) {
            sendResult(success, article.title);
          });
        }.bind(this));
        break;
      }

      case "Reader:Remove": {
        this.removeArticleFromCache(aData, function(success) {
          this.log("Reader:Remove success=" + success + ", url=" + aData);
        }.bind(this));
        break;
      }
    }
  },

  parseDocumentFromURL: function Reader_parseDocumentFromURL(url, callback) {
    // If there's an on-going request for the same URL, simply append one
    // more callback to it to be called when the request is done.
    if (url in this._requests) {
      let request = this._requests[url];
      request.callbacks.push(callback);
      return;
    }

    let request = { url: url, callbacks: [callback] };
    this._requests[url] = request;

    try {
      this.log("parseDocumentFromURL: " + url);

      // First, try to find a cached parsed article in the DB
      this.getArticleFromCache(url, function(article) {
        if (article) {
          this.log("Page found in cache, return article immediately");
          this._runCallbacksAndFinish(request, article);
          return;
        }

        if (!this._requests) {
          this.log("Reader has been destroyed, abort");
          return;
        }

        // Article hasn't been found in the cache DB, we need to
        // download the page and parse the article out of it.
        this._downloadAndParseDocument(url, request);
      }.bind(this));
    } catch (e) {
      this.log("Error parsing document from URL: " + e);
      this._runCallbacksAndFinish(request, null);
    }
  },

  getArticleForTab: function Reader_getArticleForTab(tabId, url, callback) {
    let tab = BrowserApp.getTabForId(tabId);
    let article = tab.savedArticle;

    if (article && article.url == url) {
      this.log("Saved article found in tab");
      callback(article);
    } else {
      this.parseDocumentFromURL(url, callback);
    }
  },

  parseDocumentFromTab: function(tabId, callback) {
    try {
      this.log("parseDocumentFromTab: " + tabId);

      let tab = BrowserApp.getTabForId(tabId);
      let url = tab.browser.contentWindow.location.href;
      let uri = Services.io.newURI(url, null, null);

      if (!this._shouldCheckUri(uri)) {
        callback(null);
        return;
      }

      // First, try to find a cached parsed article in the DB
      this.getArticleFromCache(url, function(article) {
        if (article) {
          this.log("Page found in cache, return article immediately");
          callback(article);
          return;
        }

        let doc = tab.browser.contentWindow.document;
        this._readerParse(uri, doc, function (article) {
          if (!article) {
            this.log("Failed to parse page");
            callback(null);
            return;
          }

          callback(article);
        }.bind(this));
      }.bind(this));
    } catch (e) {
      this.log("Error parsing document from tab: " + e);
      callback(null);
    }
  },

  getArticleFromCache: function Reader_getArticleFromCache(url, callback) {
    this._getCacheDB(function(cacheDB) {
      if (!cacheDB) {
        callback(false);
        return;
      }

      let transaction = cacheDB.transaction(cacheDB.objectStoreNames);
      let articles = transaction.objectStore(cacheDB.objectStoreNames[0]);

      let request = articles.get(url);

      request.onerror = function(event) {
        this.log("Error getting article from the cache DB: " + url);
        callback(null);
      }.bind(this);

      request.onsuccess = function(event) {
        this.log("Got article from the cache DB: " + event.target.result);
        callback(event.target.result);
      }.bind(this);
    }.bind(this));
  },

  storeArticleInCache: function Reader_storeArticleInCache(article, callback) {
    this._getCacheDB(function(cacheDB) {
      if (!cacheDB) {
        callback(false);
        return;
      }

      let transaction = cacheDB.transaction(cacheDB.objectStoreNames, "readwrite");
      let articles = transaction.objectStore(cacheDB.objectStoreNames[0]);

      let request = articles.add(article);

      request.onerror = function(event) {
        this.log("Error storing article in the cache DB: " + article.url);
        callback(false);
      }.bind(this);

      request.onsuccess = function(event) {
        this.log("Stored article in the cache DB: " + article.url);
        callback(true);
      }.bind(this);
    }.bind(this));
  },

  removeArticleFromCache: function Reader_removeArticleFromCache(url, callback) {
    this._getCacheDB(function(cacheDB) {
      if (!cacheDB) {
        callback(false);
        return;
      }

      let transaction = cacheDB.transaction(cacheDB.objectStoreNames, "readwrite");
      let articles = transaction.objectStore(cacheDB.objectStoreNames[0]);

      let request = articles.delete(url);

      request.onerror = function(event) {
        this.log("Error removing article from the cache DB: " + url);
        callback(false);
      }.bind(this);

      request.onsuccess = function(event) {
        this.log("Removed article from the cache DB: " + url);
        callback(true);
      }.bind(this);
    }.bind(this));
  },

  uninit: function Reader_uninit() {
    Services.obs.removeObserver(this, "Reader:Add", false);
    Services.obs.removeObserver(this, "Reader:Remove", false);

    let requests = this._requests;
    for (let url in requests) {
      let request = requests[url];
      if (request.browser) {
        let browser = request.browser;
        browser.parentNode.removeChild(browser);
      }
    }
    delete this._requests;

    if (this._cacheDB) {
      this._cacheDB.close();
      delete this._cacheDB;
    }
  },

  log: function(msg) {
    if (this.DEBUG)
      dump("Reader: " + msg);
  },

  _shouldCheckUri: function Reader_shouldCheckUri(uri) {
    if ((uri.prePath + "/") === uri.spec) {
      this.log("Not parsing home page: " + uri.spec);
      return false;
    }

    if (!(uri.schemeIs("http") || uri.schemeIs("https") || uri.schemeIs("file"))) {
      this.log("Not parsing URI scheme: " + uri.scheme);
      return false;
    }

    return true;
  },

  _readerParse: function Reader_readerParse(uri, doc, callback) {
    let numTags = doc.getElementsByTagName("*").length;
    if (numTags > this.MAX_ELEMS_TO_PARSE) {
      this.log("Aborting parse for " + uri.spec + "; " + numTags + " elements found");
      callback(null);
      return;
    }

    let worker = new ChromeWorker("readerWorker.js");
    worker.onmessage = function (evt) {
      let article = evt.data;

      // Append URL to the article data. specIgnoringRef will ignore any hash
      // in the URL.
      if (article) {
        article.url = uri.specIgnoringRef;
        let flags = Ci.nsIDocumentEncoder.OutputSelectionOnly | Ci.nsIDocumentEncoder.OutputAbsoluteLinks;
        article.title = Cc["@mozilla.org/parserutils;1"].getService(Ci.nsIParserUtils)
                                                        .convertToPlainText(article.title, flags, 0);
      }

      callback(article);
    };

    try {
      worker.postMessage({
        uri: {
          spec: uri.spec,
          host: uri.host,
          prePath: uri.prePath,
          scheme: uri.scheme,
          pathBase: Services.io.newURI(".", null, uri).spec
        },
        doc: new XMLSerializer().serializeToString(doc)
      });
    } catch (e) {
      dump("Reader: could not build Readability arguments: " + e);
      callback(null);
    }
  },

  _runCallbacksAndFinish: function Reader_runCallbacksAndFinish(request, result) {
    delete this._requests[request.url];

    request.callbacks.forEach(function(callback) {
      callback(result);
    });
  },

  _downloadDocument: function Reader_downloadDocument(url, callback) {
    // We want to parse those arbitrary pages safely, outside the privileged
    // context of chrome. We create a hidden browser element to fetch the
    // loaded page's document object then discard the browser element.

    let browser = document.createElement("browser");
    browser.setAttribute("type", "content");
    browser.setAttribute("collapsed", "true");

    document.documentElement.appendChild(browser);
    browser.stop();

    browser.webNavigation.allowAuth = false;
    browser.webNavigation.allowImages = false;
    browser.webNavigation.allowJavascript = false;
    browser.webNavigation.allowMetaRedirects = true;
    browser.webNavigation.allowPlugins = false;

    browser.addEventListener("DOMContentLoaded", function (event) {
      let doc = event.originalTarget;

      // ignore on frames and other documents
      if (doc != browser.contentDocument)
        return;

      this.log("Done loading: " + doc);
      if (doc.location.href == "about:blank") {
        callback(null);

        // Request has finished with error, remove browser element
        browser.parentNode.removeChild(browser);
        return;
      }

      callback(doc);
    }.bind(this));

    browser.loadURIWithFlags(url, Ci.nsIWebNavigation.LOAD_FLAGS_NONE,
                             null, null, null);

    return browser;
  },

  _downloadAndParseDocument: function Reader_downloadAndParseDocument(url, request) {
    try {
      this.log("Needs to fetch page, creating request: " + url);

      request.browser = this._downloadDocument(url, function(doc) {
        this.log("Finished loading page: " + doc);

        if (!doc) {
          this.log("Error loading page");
          this._runCallbacksAndFinish(request, null);
          return;
        }

        this.log("Parsing response with Readability");

        let uri = Services.io.newURI(url, null, null);
        this._readerParse(uri, doc, function (article) {
          // Delete reference to the browser element as we've finished parsing.
          let browser = request.browser;
          if (browser) {
            browser.parentNode.removeChild(browser);
            delete request.browser;
          }

          if (!article) {
            this.log("Failed to parse page");
            this._runCallbacksAndFinish(request, null);
            return;
          }

          this.log("Parsing has been successful");

          this._runCallbacksAndFinish(request, article);
        }.bind(this));
      }.bind(this));
    } catch (e) {
      this.log("Error downloading and parsing document: " + e);
      this._runCallbacksAndFinish(request, null);
    }
  },

  _getCacheDB: function Reader_getCacheDB(callback) {
    if (this._cacheDB) {
      callback(this._cacheDB);
      return;
    }

    let request = window.indexedDB.open("about:reader", this.DB_VERSION);

    request.onerror = function(event) {
      this.log("Error connecting to the cache DB");
      this._cacheDB = null;
      callback(null);
    }.bind(this);

    request.onsuccess = function(event) {
      this.log("Successfully connected to the cache DB");
      this._cacheDB = event.target.result;
      callback(this._cacheDB);
    }.bind(this);

    request.onupgradeneeded = function(event) {
      this.log("Database schema upgrade from " +
           event.oldVersion + " to " + event.newVersion);

      let cacheDB = event.target.result;

      // Create the articles object store
      this.log("Creating articles object store");
      cacheDB.createObjectStore("articles", { keyPath: "url" });

      this.log("Database upgrade done: " + this.DB_VERSION);
    }.bind(this);
  }
};

var ExternalApps = {
  _contextMenuId: -1,

  init: function helper_init() {
    this._contextMenuId = NativeWindow.contextmenus.add(function(aElement) {
      let uri = null;
      var node = aElement;
      while (node && !uri) {
        uri = NativeWindow.contextmenus._getLink(node);
        node = node.parentNode;
      }
      let apps = [];
      if (uri)
        apps = HelperApps.getAppsForUri(uri);

      return apps.length == 1 ? Strings.browser.formatStringFromName("helperapps.openWithApp2", [apps[0].name], 1) :
                                Strings.browser.GetStringFromName("helperapps.openWithList2");
    }, this.filter, this.openExternal);
  },

  uninit: function helper_uninit() {
    NativeWindow.contextmenus.remove(this._contextMenuId);
  },

  filter: {
    matches: function(aElement) {
      let uri = NativeWindow.contextmenus._getLink(aElement);
      let apps = [];
      if (uri) {
        apps = HelperApps.getAppsForUri(uri);
      }
      return apps.length > 0;
    }
  },

  openExternal: function(aElement) {
    let uri = NativeWindow.contextmenus._getLink(aElement);
    HelperApps.openUriInApp(uri);
  }
};

var MemoryObserver = {
  init: function() {
    Services.obs.addObserver(this, "memory-pressure", false);
    Services.obs.addObserver(this, "Memory:Dump", false);
  },

  uninit: function() {
    Services.obs.removeObserver(this, "memory-pressure");
    Services.obs.removeObserver(this, "Memory:Dump");
  },

  observe: function mo_observe(aSubject, aTopic, aData) {
    if (aTopic == "memory-pressure") {
      if (aData != "heap-minimize") {
        this.handleLowMemory();
      }
      // The JS engine would normally GC on this notification, but since we
      // disabled that in favor of this method (bug 669346), we should gc here.
      // See bug 784040 for when this code was ported from XUL to native Fennec.
      this.gc();
    } else if (aTopic == "Memory:Dump") {
      this.dumpMemoryStats(aData);
    }
  },

  handleLowMemory: function() {
    // do things to reduce memory usage here
    let tabs = BrowserApp.tabs;
    let selected = BrowserApp.selectedTab;
    for (let i = 0; i < tabs.length; i++) {
      if (tabs[i] != selected) {
        this.zombify(tabs[i]);
        Telemetry.addData("FENNEC_TAB_ZOMBIFIED", (Date.now() - tabs[i].lastTouchedAt) / 1000);
      }
    }
    Telemetry.addData("FENNEC_LOWMEM_TAB_COUNT", tabs.length);
  },

  zombify: function(tab) {
    let browser = tab.browser;
    let data = browser.__SS_data;
    let extra = browser.__SS_extdata;

    // We need this data to correctly create and position the new browser
    // If this browser is already a zombie, fallback to the session data
    let currentURL = browser.__SS_restore ? data.entries[0].url : browser.currentURI.spec;
    let sibling = browser.nextSibling;
    let isPrivate = PrivateBrowsingUtils.isWindowPrivate(browser.contentWindow);

    tab.destroy();
    tab.create(currentURL, { sibling: sibling, zombifying: true, delayLoad: true, isPrivate: isPrivate });

    // Reattach session store data and flag this browser so it is restored on select
    browser = tab.browser;
    browser.__SS_data = data;
    browser.__SS_extdata = extra;
    browser.__SS_restore = true;
  },

  gc: function() {
    window.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils).garbageCollect();
    Cu.forceGC();
  },

  dumpMemoryStats: function(aLabel) {
    let memDumper = Cc["@mozilla.org/memory-info-dumper;1"].getService(Ci.nsIMemoryInfoDumper);
    memDumper.dumpMemoryReportsToFile(aLabel, false, true);
  },
};

var Distribution = {
  _file: null,

  init: function dc_init() {
    Services.obs.addObserver(this, "Distribution:Set", false);

    // Look for file outside the APK:
    // /data/data/org.mozilla.fennec/distribution.json
    this._file = Services.dirsvc.get("XCurProcD", Ci.nsIFile);
    this._file.append("distribution.json");
    if (this._file.exists()) {
      let channel = NetUtil.newChannel(this._file);
      channel.contentType = "application/json";
      NetUtil.asyncFetch(channel, function(aStream, aResult) {
        if (!Components.isSuccessCode(aResult)) {
          Cu.reportError("Distribution: Could not read from distribution.json file");
          return;
        }

        let raw = NetUtil.readInputStreamToString(aStream, aStream.available(), { charset : "UTF-8" }) || "";
        aStream.close();

        try {
          this.update(JSON.parse(raw));
        } catch (ex) {
          Cu.reportError("Distribution: Could not parse JSON: " + ex);
        }
      }.bind(this));
    } 
  },

  uninit: function dc_uninit() {
    Services.obs.removeObserver(this, "Distribution:Set");
  },

  observe: function dc_observe(aSubject, aTopic, aData) {
    if (aTopic == "Distribution:Set") {
      // Update the prefs for this session
      try {
        this.update(JSON.parse(aData));
      } catch (ex) {
        Cu.reportError("Distribution: Could not parse JSON: " + ex);
        return;
      }

      // Save the data for the later sessions
      let ostream = Cc["@mozilla.org/network/safe-file-output-stream;1"].createInstance(Ci.nsIFileOutputStream);
      ostream.init(this._file, 0x02 | 0x08 | 0x20, parseInt("600", 8), ostream.DEFER_OPEN);

      let converter = Cc["@mozilla.org/intl/scriptableunicodeconverter"].createInstance(Ci.nsIScriptableUnicodeConverter);
      converter.charset = "UTF-8";

      // Asynchronously copy the data to the file.
      let istream = converter.convertToInputStream(aData);
      NetUtil.asyncCopy(istream, ostream, function(rc) { });
    }
  },

  update: function dc_update(aData) {
    // Force the distribution preferences on the default branch
    let defaults = Services.prefs.getDefaultBranch(null);
    defaults.setCharPref("distribution.id", aData.id);
    defaults.setCharPref("distribution.version", aData.version);
  }
};

#ifdef MOZ_WEBRTC
var WebrtcUI = {
  init: function () {
    Services.obs.addObserver(this, "getUserMedia:request", false);
  },

  uninit: function () {
    Services.obs.removeObserver(this, "getUserMedia:request");
  },

  observe: function(aSubject, aTopic, aData) {
    if (aTopic == "getUserMedia:request") {
      this.handleRequest(aSubject, aTopic, aData);
    }
  },

  handleRequest: function handleRequest(aSubject, aTopic, aData) {
    let { windowID: windowID, callID: callID } = JSON.parse(aData);

    let someWindow = Services.wm.getMostRecentWindow("navigator:browser");
    if (someWindow != window)
      return;

    let contentWindow = someWindow.QueryInterface(Ci.nsIInterfaceRequestor)
          .getInterface(Ci.nsIDOMWindowUtils).getOuterWindowWithId(windowID);
    let browser = BrowserApp.getBrowserForWindow(contentWindow);
    let params = aSubject.QueryInterface(Ci.nsIMediaStreamOptions);

    browser.ownerDocument.defaultView.navigator.mozGetUserMediaDevices(
      function (devices) {
        WebrtcUI.prompt(browser, callID, params.audio, params.video, devices);
      },
      function (error) {
        Cu.reportError(error);
      }
    );
  },

  getDeviceButtons: function(aDevices, aCallID, stringBundle) {
    let buttons = [{
      label: stringBundle.GetStringFromName("getUserMedia.denyRequest.label"),
      callback: function() {
        Services.obs.notifyObservers(null, "getUserMedia:response:deny", aCallID);
      }
    }];
    for (let device of aDevices) {
      let button = {
        label: stringBundle.GetStringFromName("getUserMedia.shareRequest.label"),
        callback: function() {
          let allowedDevices = Cc["@mozilla.org/supports-array;1"].createInstance(Ci.nsISupportsArray);
          allowedDevices.AppendElement(device);
          Services.obs.notifyObservers(allowedDevices, "getUserMedia:response:allow", aCallID);
          // Show browser-specific indicator for the active camera/mic access.
          // XXX: Mobile?
        }
      };
      buttons.push(button);
    }

    return buttons;
  },

  prompt: function prompt(aBrowser, aCallID, aAudioRequested, aVideoRequested, aDevices) {
    let audioDevices = [];
    let videoDevices = [];
    for (let device of aDevices) {
      device = device.QueryInterface(Ci.nsIMediaDevice);
      switch (device.type) {
      case "audio":
        if (aAudioRequested)
          audioDevices.push(device);
        break;
      case "video":
        if (aVideoRequested)
          videoDevices.push(device);
        break;
      }
    }

    let requestType;
    if (audioDevices.length && videoDevices.length)
      requestType = "CameraAndMicrophone";
    else if (audioDevices.length)
      requestType = "Microphone";
    else if (videoDevices.length)
      requestType = "Camera";
    else
      return;

    let host = aBrowser.contentDocument.documentURIObject.asciiHost;
    let stringBundle = Services.strings.createBundle("chrome://browser/locale/browser.properties");
    let message = stringBundle.formatStringFromName("getUserMedia.share" + requestType + ".message", [ host ], 1);

    if (audioDevices.length) {
      let buttons = this.getDeviceButtons(audioDevices, aCallID, stringBundle);
      NativeWindow.doorhanger.show(message, "webrtc-request-audio", buttons, BrowserApp.selectedTab.id);
    }

    if (videoDevices.length) {
      let buttons = this.getDeviceButtons(videoDevices, aCallID, stringBundle);
      NativeWindow.doorhanger.show(message, "webrtc-request-video", buttons, BrowserApp.selectedTab.id);
    }
  }
}
#endif

var Tabs = {
  // This object provides functions to manage a most-recently-used list
  // of tabs. Each tab has a timestamp associated with it that indicates when
  // it was last touched.

  _enableTabExpiration: false,

  init: function() {
    // on low-memory platforms, always allow tab expiration. on high-mem
    // platforms, allow it to be turned on once we hit a low-mem situation
    if (Cc["@mozilla.org/xpcom/memory-service;1"].getService(Ci.nsIMemory).isLowMemoryPlatform()) {
      this._enableTabExpiration = true;
    } else {
      Services.obs.addObserver(this, "memory-pressure", false);
    }
  },

  uninit: function() {
    if (!this._enableTabExpiration) {
      // if _enableTabExpiration is true then we won't have this
      // observer registered any more.
      Services.obs.removeObserver(this, "memory-pressure");
    }
  },

  observe: function(aSubject, aTopic, aData) {
    if (aTopic == "memory-pressure" && aData != "heap-minimize") {
      this._enableTabExpiration = true;
      Services.obs.removeObserver(this, "memory-pressure");
    }
  },

  touch: function(aTab) {
    aTab.lastTouchedAt = Date.now();
  },

  expireLruTab: function() {
    if (!this._enableTabExpiration) {
      return false;
    }
    let expireTimeMs = Services.prefs.getIntPref("browser.tabs.expireTime") * 1000;
    if (expireTimeMs < 0) {
      // this behaviour is disabled
      return false;
    }
    let tabs = BrowserApp.tabs;
    let selected = BrowserApp.selectedTab;
    let lruTab = null;
    // find the least recently used non-zombie tab
    for (let i = 0; i < tabs.length; i++) {
      if (tabs[i] == selected || tabs[i].browser.__SS_restore) {
        // this tab is selected or already a zombie, skip it
        continue;
      }
      if (lruTab == null || tabs[i].lastTouchedAt < lruTab.lastTouchedAt) {
        lruTab = tabs[i];
      }
    }
    // if the tab was last touched more than browser.tabs.expireTime seconds ago,
    // zombify it
    if (lruTab) {
      let tabAgeMs = Date.now() - lruTab.lastTouchedAt;
      if (tabAgeMs > expireTimeMs) {
        MemoryObserver.zombify(lruTab);
        Telemetry.addData("FENNEC_TAB_EXPIRED", tabAgeMs / 1000);
        return true;
      }
    }
    return false;
  },

  // for debugging
  dump: function(aPrefix) {
    let tabs = BrowserApp.tabs;
    for (let i = 0; i < tabs.length; i++) {
      dump(aPrefix + " | " + "Tab [" + tabs[i].browser.contentWindow.location.href + "]: lastTouchedAt:" + tabs[i].lastTouchedAt + ", zombie:" + tabs[i].browser.__SS_restore);
    }
  },
};