Bug 1017912 - Restore tab in correct position when undoing close tab. r=bnicholson

mobile/android/base/Tabs.java

@@ -188,13 +188,18 @@ public class Tabs implements GeckoEventListener {
         }
     }
 
-    private Tab addTab(int id, String url, boolean external, int parentId, String title, boolean isPrivate) {
+    private Tab addTab(int id, String url, boolean external, int parentId, String title, boolean isPrivate, int tabIndex) {
         final Tab tab = isPrivate ? new PrivateTab(mAppContext, id, url, external, parentId, title) :
                                     new Tab(mAppContext, id, url, external, parentId, title);
         synchronized (this) {
             lazyRegisterBookmarkObserver();
             mTabs.put(id, tab);
-            mOrder.add(tab);
+
+            if (tabIndex > -1) {
+                mOrder.add(tabIndex, tab);
+            } else {
+                mOrder.add(tab);
+            }
         }
 
         // Suppress the ADDED event to prevent animation of tabs created via session restore.
@@ -427,7 +432,8 @@ public class Tabs implements GeckoEventListener {
                     tab = addTab(id, url, message.getBoolean("external"),
                                           message.getInt("parentId"),
                                           message.getString("title"),
-                                          message.getBoolean("isPrivate"));
+                                          message.getBoolean("isPrivate"),
+                                          message.getInt("tabIndex"));
 
                     // If we added the tab as a stub, we should have already
                     // selected it, so ignore this flag for stubbed tabs.
@@ -799,7 +805,10 @@ public class Tabs implements GeckoEventListener {
                 // long as it's a valid URI.
                 String tabUrl = (url != null && Uri.parse(url).getScheme() != null) ? url : null;
 
-                added = addTab(tabId, tabUrl, external, parentId, url, isPrivate);
+                // Add the new tab to the end of the tab order.
+                final int tabIndex = -1;
+
+                added = addTab(tabId, tabUrl, external, parentId, url, isPrivate, tabIndex);
                 added.setDesktopMode(desktopMode);
             }
         } catch (Exception e) {

mobile/android/chrome/content/browser.js

@@ -921,7 +921,12 @@ var BrowserApp = {
     aParams = aParams || {};
 
     let newTab = new Tab(aURI, aParams);
-    this._tabs.push(newTab);
+
+    if (typeof aParams.tabIndex == "number") {
+      this._tabs.splice(aParams.tabIndex, 0, newTab);
+    } else {
+      this._tabs.push(newTab);
+    }
 
     let selected = "selected" in aParams ? aParams.selected : true;
     if (selected)
@@ -972,12 +977,14 @@ var BrowserApp = {
     if (aTab == this.selectedTab)
       this.selectedTab = null;
 
+    let tabIndex = this._tabs.indexOf(aTab);
+
     let evt = document.createEvent("UIEvents");
-    evt.initUIEvent("TabClose", true, false, window, null);
+    evt.initUIEvent("TabClose", true, false, window, tabIndex);
     aTab.browser.dispatchEvent(evt);
 
     aTab.destroy();
-    this._tabs.splice(this._tabs.indexOf(aTab), 1);
+    this._tabs.splice(tabIndex, 1);
 
     if (aShowUndoToast) {
       // Get a title for the undo close toast. Fall back to the URL if there is no title.
@@ -3053,6 +3060,7 @@ Tab.prototype = {
         tabID: this.id,
         uri: uri,
         parentId: ("parentId" in aParams) ? aParams.parentId : -1,
+        tabIndex: ("tabIndex" in aParams) ? aParams.tabIndex : -1,
         external: ("external" in aParams) ? aParams.external : false,
         selected: ("selected" in aParams) ? aParams.selected : true,
         title: title,

mobile/android/components/SessionStore.js

@@ -46,6 +46,10 @@ SessionStore.prototype = {
   _maxTabsUndo: 1,
   _pendingWrite: 0,
 
+  // The index where the most recently closed tab was in the tabs array
+  // when it was closed.
+  _lastClosedTabIndex: -1,
+
   init: function ss_init() {
     // Get file references
     this._sessionFile = Services.dirsvc.get("ProfD", Ci.nsILocalFile);
@@ -98,6 +102,8 @@ SessionStore.prototype = {
         for (let [ssid, win] in Iterator(this._windows))
           win.closedTabs = [];
 
+        this._lastClosedTabIndex = -1;
+
         if (this._loadState == STATE_RUNNING) {
           // Save the purged state immediately
           this.saveState();
@@ -164,7 +170,7 @@ SessionStore.prototype = {
       }
       case "TabClose": {
         let browser = aEvent.target;
-        this.onTabClose(window, browser);
+        this.onTabClose(window, browser, aEvent.detail);
         this.onTabRemove(window, browser);
         break;
       }
@@ -269,7 +275,7 @@ SessionStore.prototype = {
       this.saveStateDelayed();
   },
 
-  onTabClose: function ss_onTabClose(aWindow, aBrowser) {
+  onTabClose: function ss_onTabClose(aWindow, aBrowser, aTabIndex) {
     if (this._maxTabsUndo == 0)
       return;
 
@@ -283,6 +289,8 @@ SessionStore.prototype = {
       let length = this._windows[aWindow.__SSID].closedTabs.length;
       if (length > this._maxTabsUndo)
         this._windows[aWindow.__SSID].closedTabs.splice(this._maxTabsUndo, length - this._maxTabsUndo);
+
+      this._lastClosedTabIndex = aTabIndex;
     }
   },
 
@@ -845,11 +853,14 @@ SessionStore.prototype = {
     let params = {
       selected: true,
       isPrivate: closedTab.isPrivate,
-      desktopMode: closedTab.desktopMode
+      desktopMode: closedTab.desktopMode,
+      tabIndex: this._lastClosedTabIndex
     };
     let tab = aWindow.BrowserApp.addTab(closedTab.entries[closedTab.index - 1].url, params);
     this._restoreHistory(closedTab, tab.browser.sessionHistory);
 
+    this._lastClosedTabIndex = -1;
+
     // Put back the extra data
     tab.browser.__SS_extdata = closedTab.extData;
 
@@ -869,6 +880,11 @@ SessionStore.prototype = {
 
     // remove closed tab from the array
     closedTabs.splice(aIndex, 1);
+
+    // Forget the last closed tab index if we're forgetting the last closed tab.
+    if (aIndex == 0) {
+      this._lastClosedTabIndex = -1;
+    }
   },
 
   getTabValue: function ss_getTabValue(aTab, aKey) {