Bug 1384027 - part3: Don't send blur notification to IME from IMEStateManager::OnChangeFocusInternal() if no window becomes active and IME wants to keep composition during deactive r=m_kato

Currently, IMEStateManager::OnChangeFocusInternal() sends blur notification to IME when a remote process has IME focus and focus is moving from the process.  However, if IME wants to keep composition even during deactive and nobody will gets focus (i.e., all windows becomes deactive), IMEStateManager shouldn't send the blur notification because it causes committing composition.

Therefore, it should send blur notification only when focus is moving to a PresContext (that means that not all windows becomes deactive) or IME doesn't want to keep composition during deactive.

Then, even if another window becomes active next time, IMEStateManager can send "stop IME state management" message to the composing remote process and the remote process can commit composition normally.

Additionally, this patch ensures to send blur notification when IME focused TabParent or widget is being destroyed.  This fixes new memory leak bug of this patch (sFocusedIMETabParent keeps grabbing the instance until shutting down in some mochitests).

MozReview-Commit-ID: KYiFGo970a8

--HG--
extra : rebase_source : c3de0df442420979414b47d8d20c7988c49b205b

dom/events/IMEStateManager.cpp

@@ -197,9 +197,14 @@ IMEStateManager::Shutdown()
 void
 IMEStateManager::OnTabParentDestroying(TabParent* aTabParent)
 {
+  if (sFocusedIMETabParent == aTabParent) {
+    NotifyIMEOfBlurForChildProcess();
+  }
+
   if (sActiveTabParent != aTabParent) {
     return;
   }
+
   MOZ_LOG(sISMLog, LogLevel::Info,
     ("OnTabParentDestroying(aTabParent=0x%p), "
      "The active TabParent is being destroyed", aTabParent));
@@ -207,8 +212,7 @@ IMEStateManager::OnTabParentDestroying(TabParent* aTabParent)
   // The active remote process might have crashed.
   sActiveTabParent = nullptr;
 
-  // TODO: Need to cancel composition without TextComposition and make
-  //       disable IME.
+  // XXX: Need to disable IME?
 }
 
 // static
@@ -219,6 +223,7 @@ IMEStateManager::WidgetDestroyed(nsIWidget* aWidget)
     sWidget = nullptr;
   }
   if (sFocusedIMEWidget == aWidget) {
+    NotifyIMEOfBlurForChildProcess();
     sFocusedIMEWidget = nullptr;
   }
   if (sActiveInputContextWidget == aWidget) {
@@ -246,6 +251,27 @@ IMEStateManager::StopIMEStateManagement()
   DestroyIMEContentObserver();
 }
 
+// static
+void
+IMEStateManager::NotifyIMEOfBlurForChildProcess()
+{
+  MOZ_LOG(sISMLog, LogLevel::Debug,
+    ("NotifyIMEOfBlurForChildProcess(), sFocusedIMETabParent=0x%p, "
+     "sFocusedIMEWidget=0x%p",
+     sFocusedIMETabParent.get(), sFocusedIMEWidget));
+
+  if (!sFocusedIMETabParent) {
+    MOZ_ASSERT(!sFocusedIMEWidget);
+    return;
+  }
+
+  MOZ_ASSERT(sFocusedIMEWidget);
+  NotifyIME(NOTIFY_IME_OF_BLUR, sFocusedIMEWidget, sFocusedIMETabParent);
+
+  MOZ_ASSERT(!sFocusedIMETabParent);
+  MOZ_ASSERT(!sFocusedIMEWidget);
+}
+
 // static
 void
 IMEStateManager::MaybeStartOffsetUpdatedInChild(nsIWidget* aWidget,
@@ -488,13 +514,19 @@ IMEStateManager::OnChangeFocusInternal(nsPresContext* aPresContext,
     // process while the process has IME focus too, we need to notify IME of
     // blur here because it may be too late the blur notification to reach
     // this process especially when closing active window.
-    if (sFocusedIMETabParent &&
+    // However, don't send blur if we're being deactivated and IME wants to
+    // keep composition during deactive because notifying blur will commit
+    // or cancel composition.
+    if (sFocusedIMETabParent && sFocusedIMEWidget &&
+        (aPresContext ||
+         !sFocusedIMEWidget->IMENotificationRequestsRef().
+           WantDuringDeactive()) &&
         !IsSameProcess(sFocusedIMETabParent, newTabParent)) {
       MOZ_LOG(sISMLog, LogLevel::Info,
         ("  OnChangeFocusInternal(), notifying IME of blur of previous focused "
          "remote process because it may be too late actual notification to "
          "reach this process"));
-      NotifyIME(NOTIFY_IME_OF_BLUR, sFocusedIMEWidget, sFocusedIMETabParent);
+      NotifyIMEOfBlurForChildProcess();
     }
   }
 

dom/events/IMEStateManager.h

@@ -274,6 +274,12 @@ protected:
   static void CreateIMEContentObserver(EditorBase* aEditorBase);
   static void DestroyIMEContentObserver();
 
+  /**
+   * NotifyIMEOfBlurForChildProcess() tries to send blur notification when
+   * a remote process has IME focus.  Otherwise, do nothing.
+   */
+  static void NotifyIMEOfBlurForChildProcess();
+
   static bool IsEditable(nsINode* node);
 
   static bool IsIMEObserverNeeded(const IMEState& aState);