Bug 655269 - Don't rely on 'domwindowclosed' being fired in the expected order; f=raymond, r=dao

browser/base/content/browser-tabview.js

@@ -40,6 +40,7 @@ let TabView = {
   _deck: null,
   _iframe: null,
   _window: null,
+  _initialized: false,
   _browserKeyHandlerInitialized: false,
   _isFrameLoading: false,
   _initFrameCallbacks: [],
@@ -89,6 +90,9 @@ let TabView = {
 
   // ----------
   init: function TabView_init() {
+    if (this._initialized)
+      return;
+
     if (this.firstUseExperienced) {
       if ((gBrowser.tabs.length - gBrowser.visibleTabs.length) > 0)
         this._setBrowserKeyHandlers();
@@ -124,6 +128,8 @@ let TabView = {
     }
 
     Services.prefs.addObserver(this.PREF_BRANCH, this, false);
+
+    this._initialized = true;
   },
 
   // ----------
@@ -138,12 +144,17 @@ let TabView = {
   // ----------
   // Uninitializes TabView.
   uninit: function TabView_uninit() {
+    if (!this._initialized)
+      return;
+
     Services.prefs.removeObserver(this.PREF_BRANCH, this);
 
     if (this._tabShowEventListener) {
       gBrowser.tabContainer.removeEventListener(
         "TabShow", this._tabShowEventListener, true);
     }
+
+    this._initialized = false;
   },
 
   // ----------

browser/base/content/tabview/ui.js

@@ -128,8 +128,7 @@ let UI = {
   _storageBusyCount: 0,
 
   // Variable: isDOMWindowClosing
-  // Tells wether we already received the "domwindowclosed" event and the parent
-  // windows is about to close.
+  // Tells wether the parent window is about to close
   isDOMWindowClosing: false,
 
   // Variable: _browserKeys
@@ -257,21 +256,18 @@ let UI = {
         self._resize();
       });
 
-      // ___ setup observer to save canvas images
-      function domWinClosedObserver(subject, topic, data) {
-        if (topic == "domwindowclosed" && subject == gWindow) {
-          self.isDOMWindowClosing = true;
-          if (self.isTabViewVisible())
-            GroupItems.removeHiddenGroups();
-          TabItems.saveAll(true);
-          self._save();
-        }
-      }
-      Services.obs.addObserver(
-        domWinClosedObserver, "domwindowclosed", false);
-      this._cleanupFunctions.push(function() {
-        Services.obs.removeObserver(domWinClosedObserver, "domwindowclosed");
-      });
+      // ___ setup event listener to save canvas images
+      gWindow.addEventListener("SSWindowClosing", function onWindowClosing() {
+        gWindow.removeEventListener("SSWindowClosing", onWindowClosing, false);
+
+        self.isDOMWindowClosing = true;
+
+        if (self.isTabViewVisible())
+          GroupItems.removeHiddenGroups();
+
+        TabItems.saveAll(true);
+        self._save();
+      }, false);
 
       // ___ Done
       this._frameInitialized = true;

browser/base/content/test/tabview/Makefile.in

@@ -143,6 +143,7 @@ _BROWSER_FILES = \
                  browser_tabview_bug650573.js \
                  browser_tabview_bug651311.js \
                  browser_tabview_bug654941.js \
+                 browser_tabview_bug655269.js \
                  browser_tabview_bug656778.js \
                  browser_tabview_bug656913.js \
                  browser_tabview_dragdrop.js \

browser/base/content/test/tabview/browser_tabview_bug655269.js

@@ -0,0 +1,20 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test() {
+  waitForExplicitFinish();
+
+  newWindowWithTabView(function (win) {
+    let cw = win.TabView.getContentWindow();
+    let tabItem = win.gBrowser.tabs[0]._tabViewTabItem;
+
+    tabItem.addSubscriber(tabItem, "savedCachedImageData", function () {
+      tabItem.removeSubscriber(tabItem, "savedCachedImageData");
+
+      ok(cw.UI.isDOMWindowClosing, "dom window is closing");
+      waitForFocus(finish);
+    });
+
+    win.close();
+  });
+}