Bug 455553 - Part 3 - about:newtab integration; r=fryn,gavin

accessible/tests/mochitest/events/docload_wnd.xul

@@ -12,6 +12,8 @@
 
   <script type="application/javascript"
           src="chrome://mochikit/content/tests/SimpleTest/EventUtils.js"/>
+  <script type="application/javascript"
+          src="chrome://browser/content/utilityOverlay.js"/>
 
   <script type="application/javascript">
   <![CDATA[

accessible/tests/mochitest/events/test_scroll.xul

@@ -15,6 +15,8 @@
 
   <script type="application/javascript"
           src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js" />
+  <script type="application/javascript"
+          src="chrome://browser/content/utilityOverlay.js"/>
 
   <script type="application/javascript"
           src="../common.js" />

accessible/tests/mochitest/name/nsRootAcc_wnd.xul

@@ -10,6 +10,9 @@
 
 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
 
+  <script type="application/javascript"
+          src="chrome://browser/content/utilityOverlay.js"/>
+
   <script type="application/javascript">
   <![CDATA[
     var gOpenerWnd = window.opener.wrappedJSObject;

accessible/tests/mochitest/relations/test_tabbrowser.xul

@@ -15,6 +15,8 @@
 
   <script type="application/javascript"
           src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js" />
+  <script type="application/javascript"
+          src="chrome://browser/content/utilityOverlay.js"/>
 
   <script type="application/javascript"
           src="../common.js" />

accessible/tests/mochitest/tree/test_tabbrowser.xul

@@ -16,6 +16,8 @@
 
   <script type="application/javascript"
           src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js" />
+  <script type="application/javascript"
+          src="chrome://browser/content/utilityOverlay.js"/>
 
   <script type="application/javascript"
           src="../common.js" />

browser/app/profile/firefox.js

@@ -1110,5 +1110,11 @@ pref("prompts.tab_modal.enabled", true);
 // Whether the Panorama should animate going in/out of tabs
 pref("browser.panorama.animate_zoom", true);
 
+// Defines the url to be used for new tabs.
+pref("browser.newtab.url", "about:blank");
+
+// Toggles the content of 'about:newtab'. Shows the grid when enabled.
+pref("browser.newtabpage.enabled", false);
+
 // Enable the DOM full-screen API.
 pref("full-screen-api.enabled", true);

browser/base/content/browser-fullZoom.js

@@ -225,7 +225,7 @@ var FullZoom = {
       return;
 
     // Avoid the cps roundtrip and apply the default/global pref.
-    if (aURI.spec == "about:blank") {
+    if (isBlankPageURL(aURI.spec)) {
       this._applyPrefToSetting(undefined, aBrowser);
       return;
     }

browser/base/content/browser-places.js

@@ -1012,7 +1012,7 @@ var PlacesStarButton = {
     }
 
     // We can load about:blank before the actual page, but there is no point in handling that page.
-    if (this._uri.spec == "about:blank") {
+    if (isBlankPageURL(this._uri.spec)) {
       return;
     }
 

browser/base/content/browser.js

@@ -174,6 +174,9 @@ XPCOMUtils.defineLazyGetter(this, "PopupNotifications", function () {
   }
 });
 
+XPCOMUtils.defineLazyModuleGetter(this, "NewTabUtils",
+  "resource:///modules/NewTabUtils.jsm");
+
 XPCOMUtils.defineLazyGetter(this, "InspectorUI", function() {
   let tmp = {};
   Cu.import("resource:///modules/inspector.jsm", tmp);
@@ -188,6 +191,7 @@ XPCOMUtils.defineLazyGetter(this, "Tilt", function() {
 
 let gInitialPages = [
   "about:blank",
+  "about:newtab",
   "about:privatebrowsing",
   "about:sessionrestore"
 ];
@@ -1707,6 +1711,7 @@ function delayedStartup(isLoadingBlank, mustLoadSidebar) {
 #endif
 
   gBrowserThumbnails.init();
+  NewTabUtils.init();
   TabView.init();
 
   setUrlAndSearchBarWidthForConditionalForwardButton();
@@ -2204,7 +2209,7 @@ function openLocation() {
     else {
       // If there are no open browser windows, open a new one
       win = window.openDialog("chrome://browser/content/", "_blank",
-                              "chrome,all,dialog=no", "about:blank");
+                              "chrome,all,dialog=no", BROWSER_NEW_TAB_URL);
       win.addEventListener("load", openLocationCallback, false);
     }
     return;
@@ -2222,7 +2227,7 @@ function openLocationCallback()
 
 function BrowserOpenTab()
 {
-  openUILinkIn("about:blank", "tab");
+  openUILinkIn(BROWSER_NEW_TAB_URL, "tab");
 }
 
 /* Called from the openLocation dialog. This allows that dialog to instruct
@@ -2557,7 +2562,7 @@ function URLBarSetURI(aURI) {
     else
       value = losslessDecodeURI(uri);
 
-    valid = (uri.spec != "about:blank");
+    valid = !isBlankPageURL(uri.spec);
   }
 
   gURLBar.value = value;
@@ -2874,7 +2879,7 @@ function getMeOutOfHere() {
   // Get the start page from the *default* pref branch, not the user's
   var prefs = Cc["@mozilla.org/preferences-service;1"]
              .getService(Ci.nsIPrefService).getDefaultBranch(null);
-  var url = "about:blank";
+  var url = BROWSER_NEW_TAB_URL;
   try {
     url = prefs.getComplexValue("browser.startup.homepage",
                                 Ci.nsIPrefLocalizedString).data;
@@ -5191,7 +5196,7 @@ nsBrowserAccess.prototype = {
       case Ci.nsIBrowserDOMWindow.OPEN_NEWWINDOW :
         // FIXME: Bug 408379. So how come this doesn't send the
         // referrer like the other loads do?
-        var url = aURI ? aURI.spec : "about:blank";
+        var url = aURI ? aURI.spec : BROWSER_NEW_TAB_URL;
         // Pass all params to openDialog to ensure that "url" isn't passed through
         // loadOneOrMoreURIs, which splits based on "|"
         newWindow = openDialog(getBrowserURL(), "_blank", "all,dialog=no", url, null, null, null);
@@ -5224,7 +5229,7 @@ nsBrowserAccess.prototype = {
         let loadInBackground = gPrefService.getBoolPref("browser.tabs.loadDivertedInBackground");
         let referrer = aOpener ? makeURI(aOpener.location.href) : null;
 
-        let tab = win.gBrowser.loadOneTab(aURI ? aURI.spec : "about:blank", {
+        let tab = win.gBrowser.loadOneTab(aURI ? aURI.spec : BROWSER_NEW_TAB_URL, {
                                           referrerURI: referrer,
                                           fromExternal: isExternal,
                                           inBackground: loadInBackground});
@@ -7773,9 +7778,11 @@ function undoCloseWindow(aIndex) {
  */
 function isTabEmpty(aTab) {
   let browser = aTab.linkedBrowser;
+  let uri = browser.currentURI.spec;
+  let body = browser.contentDocument.body;
   return browser.sessionHistory.count < 2 &&
-         browser.currentURI.spec == "about:blank" &&
+         isBlankPageURL(uri) &&
-         !browser.contentDocument.body.hasChildNodes() &&
+         (!body || !body.hasChildNodes()) &&
          !aTab.hasAttribute("busy");
 }
 

browser/base/content/tabbrowser.xml

@@ -632,7 +632,7 @@
                   autocomplete.unregisterOpenPage(this.mBrowser.registeredOpenURI);
                   delete this.mBrowser.registeredOpenURI;
                 }
-                if (aLocation.spec != "about:blank") {
+                if (!isBlankPageURL(aLocation.spec)) {
                   autocomplete.registerOpenPage(aLocation);
                   this.mBrowser.registeredOpenURI = aLocation;
                 }
@@ -1065,7 +1065,7 @@
                 }
               }
 
-              if (title && title != "about:blank") {
+              if (title && !isBlankPageURL(title)) {
                 // At this point, we now have a URI.
                 // Let's try to unescape it using a character set
                 // in case the URI is not ASCII.
@@ -1589,7 +1589,7 @@
             aTab.closing = true;
             this._removingTabs.push(aTab);
             if (newTab)
-              this.addTab("about:blank", {skipAnimation: true});
+              this.addTab(BROWSER_NEW_TAB_URL, {skipAnimation: true});
             else
               this.tabContainer.updateVisibility();
 

browser/base/content/utilityOverlay.js

@@ -41,11 +41,23 @@
 
 // Services = object with smart getters for common XPCOM services
 Components.utils.import("resource://gre/modules/Services.jsm");
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+
+XPCOMUtils.defineLazyGetter(this, "BROWSER_NEW_TAB_URL", function () {
+  return Services.prefs.getCharPref("browser.newtab.url") || "about:blank";
+});
 
 var TAB_DROP_TYPE = "application/x-moz-tabbrowser-tab";
 
 var gBidiUI = false;
 
+/**
+ * Determines whether the given url is considered a special URL for new tabs.
+ */
+function isBlankPageURL(aURL) {
+  return aURL == "about:blank" || aURL == BROWSER_NEW_TAB_URL;
+}
+
 function getBrowserURL()
 {
   return "chrome://browser/content/browser.xul";
@@ -299,7 +311,7 @@ function openLinkIn(url, where, params) {
   else
     w.gBrowser.selectedBrowser.focus();
 
-  if (!loadInBackground && url == "about:blank")
+  if (!loadInBackground && isBlankPageURL(url))
     w.focusAndSelectUrlBar();
 }
 

browser/components/about/AboutRedirector.cpp

@@ -105,6 +105,8 @@ static RedirEntry kRedirMap[] = {
   { "home", "chrome://browser/content/aboutHome.xhtml",
     nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT |
     nsIAboutModule::ALLOW_SCRIPT },
+  { "newtab", "chrome://browser/content/newtab/newTab.xul",
+    nsIAboutModule::ALLOW_SCRIPT },
   { "permissions", "chrome://browser/content/preferences/aboutPermissions.xul",
     nsIAboutModule::ALLOW_SCRIPT },
 };

browser/components/build/nsModule.cpp

@@ -143,6 +143,7 @@ static const mozilla::Module::ContractIDEntry kBrowserContracts[] = {
     { NS_ABOUT_MODULE_CONTRACTID_PREFIX "sync-progress", &kNS_BROWSER_ABOUT_REDIRECTOR_CID },
 #endif
     { NS_ABOUT_MODULE_CONTRACTID_PREFIX "home", &kNS_BROWSER_ABOUT_REDIRECTOR_CID },
+    { NS_ABOUT_MODULE_CONTRACTID_PREFIX "newtab", &kNS_BROWSER_ABOUT_REDIRECTOR_CID },
     { NS_ABOUT_MODULE_CONTRACTID_PREFIX "permissions", &kNS_BROWSER_ABOUT_REDIRECTOR_CID },
 #if defined(XP_WIN) && !defined(__MINGW32__)
     { NS_BROWSERPROFILEMIGRATOR_CONTRACTID_PREFIX "ie", &kNS_WINIEPROFILEMIGRATOR_CID },