Bug 563738 (part2) - Add current Mozilla "snippets" (links and special events) in the about:home page. r=gavin,Pike a=blocking

browser/base/content/aboutHome.css

@@ -109,3 +109,7 @@ body[dir="rtl"] #searchEngineLinks {
 #aboutMozilla {
   text-align: center;
 }
+
+#defaultSnippets {
+  text-align: center;
+}

browser/base/content/aboutHome.js

@@ -54,16 +54,31 @@ const SEARCH_ENGINES = {
   }
 };
 
+// The process of adding a new default snippet involves:
+//   * add a new entity to aboutHome.dtd
+//   * add a <span/> for it in aboutHome.xhtml
+//   * add an entry here in the proper ordering (based on spans)
+// The <a/> part of the snippet will be linked to the corresponding url.
+const DEFAULT_SNIPPETS_URLS = [
+  "http://www.mozilla.com/firefox/4.0/features"
+, "https://addons.mozilla.org/firefox/?browse=featured"
+];
+
+const SNIPPETS_UPDATE_INTERVAL_MS = 86400000; // 1 Day.
+
 let gSearchEngine;
 
 function onLoad(event)
 {
   setupSearchEngine();
   document.getElementById("searchText").focus();
+
+  loadSnippets();
 }
 
 
-function onSearchSubmit(aEvent) {
+function onSearchSubmit(aEvent)
+{
   let searchTerms = document.getElementById("searchText").value;
   if (gSearchEngine && searchTerms.length > 0) {
     const SEARCH_TOKENS = {
@@ -80,7 +95,8 @@ function onSearchSubmit(aEvent) {
 }
 
 
-function setupSearchEngine() {
+function setupSearchEngine()
+{
   gSearchEngine = JSON.parse(localStorage["search-engine"]);
 
   // Look for extended information, like logo and links.
@@ -115,3 +131,56 @@ function setupSearchEngine() {
     }
   }
 }
+
+function loadSnippets()
+{
+  // Check last snippets update.
+  let lastUpdate = localStorage["snippets-last-update"];
+  let updateURL = localStorage["snippets-update-url"];
+  if (updateURL && (!lastUpdate ||
+                    Date.now() - lastUpdate > SNIPPETS_UPDATE_INTERVAL_MS)) {
+    // Try to update from network.
+    let xhr = new XMLHttpRequest();
+    xhr.mozBackgroundRequest = true;
+    xhr.open('GET', updateURL, true);
+    xhr.onerror = function (event) {
+      showSnippets();
+    };
+    xhr.onload = function (event)
+    {
+      if (xhr.status == 200) {
+        localStorage["snippets"] = xhr.responseText;
+        localStorage["snippets-last-update"] = Date.now();
+      }
+      showSnippets();
+    };
+    xhr.send(null);
+  } else {
+    showSnippets();
+  }
+}
+
+function showSnippets()
+{
+  let snippets = localStorage["snippets"];
+  if (snippets) {
+    let snippetsElt = document.getElementById("snippets");
+    snippetsElt.innerHTML = snippets;
+    snippetsElt.hidden = false;
+  } else {
+    // If there are no saved snippets, show one of the default ones.
+    let defaultSnippetsElt = document.getElementById("defaultSnippets");
+    let entries = defaultSnippetsElt.querySelectorAll("span");
+    // Choose a random snippet.  Assume there is always at least one.
+    let randIndex = Math.round(Math.random() * (entries.length - 1));
+    let entry = entries[randIndex];
+    // Inject url in the eventual link.
+    if (DEFAULT_SNIPPETS_URLS[randIndex]) {
+      let links = entry.getElementsByTagName("a");
+      if (links.length != 1)
+        return; // Something is messed up in this entry, we support just 1 link.
+      links[0].href = DEFAULT_SNIPPETS_URLS[randIndex];
+    }
+    entry.hidden = false;
+  }
+}

browser/base/content/aboutHome.xhtml

@@ -81,7 +81,11 @@
           </form>
         </div>
       </div>
-
+      <div id="defaultSnippets">
+        <span hidden="true">&abouthome.defaultSnippet1.v1;</span>
+        <span hidden="true">&abouthome.defaultSnippet2.v1;</span>
+      </div>
+      <div id="snippets" hidden="true"/>
       <div id="bottomSection">
         <div id="aboutMozilla">
           <a href="http://www.mozilla.com/about/">&abouthome.aboutMozilla;</a>

browser/components/nsBrowserContentHandler.js

@@ -585,6 +585,7 @@ nsBrowserContentHandler.prototype = {
       if (override != OVERRIDE_NONE) {
         // Setup the default search engine to about:home page.
         AboutHomeUtils.loadDefaultSearchEngine();
+        AboutHomeUtils.loadSnippetsURL();
 
         switch (override) {
           case OVERRIDE_NEW_PROFILE:
@@ -903,7 +904,17 @@ let AboutHomeUtils = {
     , searchUrl: submission.uri.spec
     }
     this._storage.setItem("search-engine", JSON.stringify(engine));
-  }
+  },
+
+  loadSnippetsURL: function AHU_loadSnippetsURL()
+  {
+    const STARTPAGE_VERSION = 1;
+    const SNIPPETS_URL = "http://snippets.mozilla.com/" + STARTPAGE_VERSION + "/%NAME%/%VERSION%/%APPBUILDID%/%BUILD_TARGET%/%LOCALE%/%CHANNEL%/%OS_VERSION%/%DISTRIBUTION%/%DISTRIBUTION_VERSION%/";
+    let updateURL = Components.classes["@mozilla.org/toolkit/URLFormatterService;1"].
+                    getService(Components.interfaces.nsIURLFormatter).
+                    formatURL(SNIPPETS_URL);
+    this._storage.setItem("snippets-update-url", updateURL);
+  },
 };
 
 var components = [nsBrowserContentHandler, nsDefaultCommandLineHandler];

browser/locales/en-US/chrome/browser/aboutHome.dtd

@@ -6,7 +6,9 @@
 
 <!ENTITY abouthome.pageTitle "&brandFullName; Start Page">
 
-<!-- LOCALIZATION NOTE (brandStart): brandShortName must be in a <span/> -->
+<!-- LOCALIZATION NOTE (abouthome.brandStart):
+     brandShortName must be in a <span/>
+-->
 <!ENTITY abouthome.brandStart "<span>&brandShortName;</span> Start">
 
 <!ENTITY abouthome.searchEngineButton.label "Search">
@@ -15,3 +17,12 @@
 <!ENTITY abouthome.searchEngineLinks.preferences "Preferences">
 
 <!ENTITY abouthome.aboutMozilla "About Mozilla">
+
+<!-- LOCALIZATION NOTE (abouthome.defaultSnippet1.v1):
+     text in <a/> will be linked to the Firefox features page on mozilla.com
+-->
+<!ENTITY abouthome.defaultSnippet1.v1 "Thanks for choosing Firefox! To get the most out of your browser, learn more about the <a>latest features</a>.">
+<!-- LOCALIZATION NOTE (abouthome.defaultSnippet2.v1):
+     text in <a/> will be linked to the featured add-ons on addons.mozilla.org
+-->
+<!ENTITY abouthome.defaultSnippet2.v1 "It's easy to customize your Firefox exactly the way you want it. <a>Choose from thousands of add-ons</a>.">