Bug 497543 - Part 3 - Browser integration; r=dao

browser/base/content/browser-thumbnails.js

@@ -0,0 +1,119 @@
+#ifdef 0
+/* 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/. */
+#endif
+
+/**
+ * Keeps thumbnails of open web pages up-to-date.
+ */
+let gBrowserThumbnails = {
+  _captureDelayMS: 2000,
+
+  /**
+   * Map of capture() timeouts assigned to their browsers.
+   */
+  _timeouts: null,
+
+  /**
+   * Cache for the PageThumbs module.
+   */
+  _pageThumbs: null,
+
+  /**
+   * List of tab events we want to listen for.
+   */
+  _tabEvents: ["TabClose", "TabSelect"],
+
+  init: function Thumbnails_init() {
+    gBrowser.addTabsProgressListener(this);
+
+    this._tabEvents.forEach(function (aEvent) {
+      gBrowser.tabContainer.addEventListener(aEvent, this, false);
+    }, this);
+
+    this._timeouts = new WeakMap();
+
+    XPCOMUtils.defineLazyModuleGetter(this, "_pageThumbs",
+      "resource:///modules/PageThumbs.jsm", "PageThumbs");
+  },
+
+  uninit: function Thumbnails_uninit() {
+    gBrowser.removeTabsProgressListener(this);
+
+    this._tabEvents.forEach(function (aEvent) {
+      gBrowser.tabContainer.removeEventListener(aEvent, this, false);
+    }, this);
+
+    this._timeouts = null;
+    this._pageThumbs = null;
+  },
+
+  handleEvent: function Thumbnails_handleEvent(aEvent) {
+    switch (aEvent.type) {
+      case "TabSelect":
+        this._delayedCapture(aEvent.target.linkedBrowser);
+        break;
+      case "TabClose": {
+        let browser = aEvent.target.linkedBrowser;
+        if (this._timeouts.has(browser)) {
+          clearTimeout(this._timeouts.get(browser));
+          this._timeouts.delete(browser);
+        }
+        break;
+      }
+    }
+  },
+
+  /**
+   * State change progress listener for all tabs.
+   */
+  onStateChange: function Thumbnails_onStateChange(aBrowser, aWebProgress,
+                                                   aRequest, aStateFlags, aStatus) {
+    if (aStateFlags & Ci.nsIWebProgressListener.STATE_STOP &&
+        aStateFlags & Ci.nsIWebProgressListener.STATE_IS_NETWORK)
+      this._delayedCapture(aBrowser);
+  },
+
+  _capture: function Thumbnails_capture(aBrowser) {
+    if (this._shouldCapture(aBrowser)) {
+      let canvas = this._pageThumbs.capture(aBrowser.contentWindow);
+      this._pageThumbs.store(aBrowser.currentURI.spec, canvas);
+    }
+  },
+
+  _delayedCapture: function Thumbnails_delayedCapture(aBrowser) {
+    if (this._timeouts.has(aBrowser))
+      clearTimeout(this._timeouts.get(aBrowser));
+
+    let timeout = setTimeout(function () {
+      this._timeouts.delete(aBrowser);
+      this._capture(aBrowser);
+    }.bind(this), this._captureDelayMS);
+
+    this._timeouts.set(aBrowser, timeout);
+  },
+
+  _shouldCapture: function Thumbnails_shouldCapture(aBrowser) {
+    // There's no point in taking screenshot of loading pages.
+    if (aBrowser.docShell.busyFlags != Ci.nsIDocShell.BUSY_FLAGS_NONE)
+      return false;
+
+    // Don't take screenshots of about: pages.
+    if (aBrowser.currentURI.schemeIs("about"))
+      return false;
+
+    let channel = aBrowser.docShell.currentDocumentChannel;
+
+    try {
+      // If the channel is a nsIHttpChannel get its http status code.
+      let httpChannel = channel.QueryInterface(Ci.nsIHttpChannel);
+
+      // Continue only if we have a 2xx status code.
+      return Math.floor(httpChannel.responseStatus / 100) == 2;
+    } catch (e) {
+      // Not a http channel, we just assume a success status code.
+      return true;
+    }
+  }
+};

browser/base/content/browser.js

@@ -196,6 +196,7 @@ let gInitialPages = [
 #include browser-places.js
 #include browser-tabPreviews.js
 #include browser-tabview.js
+#include browser-thumbnails.js
 
 #ifdef MOZ_SERVICES_SYNC
 #include browser-syncui.js
@@ -1705,6 +1706,7 @@ function delayedStartup(isLoadingBlank, mustLoadSidebar) {
   gSyncUI.init();
 #endif
 
+  gBrowserThumbnails.init();
   TabView.init();
 
   setUrlAndSearchBarWidthForConditionalForwardButton();
@@ -1827,6 +1829,7 @@ function BrowserShutdown() {
     gPrefService.removeObserver(allTabs.prefName, allTabs);
     ctrlTab.uninit();
     TabView.uninit();
+    gBrowserThumbnails.uninit();
 
     try {
       FullZoom.destroy();