Bug 1176955 part.1 TextComposition should guarantee that WidgetSelectionEvent should be handled by same content as the target of composition events when there is a composition r=smaug

dom/events/EventStateManager.cpp

@@ -805,18 +805,8 @@ EventStateManager::PreHandleEvent(nsPresContext* aPresContext,
     }
     break;
   case NS_SELECTION_SET:
-    {
-      WidgetSelectionEvent* selectionEvent = aEvent->AsSelectionEvent();
-      if (IsTargetCrossProcess(selectionEvent)) {
-        // Will not be handled locally, remote the event
-        if (GetCrossProcessTarget()->SendSelectionEvent(*selectionEvent)) {
-          selectionEvent->mSucceeded = true;
-        }
-        break;
-      }
-      ContentEventHandler handler(mPresContext);
-      handler.OnSelectionEvent(selectionEvent);
-    }
+    IMEStateManager::HandleSelectionEvent(aPresContext, GetFocusedContent(),
+                                          aEvent->AsSelectionEvent());
     break;
   case NS_CONTENT_COMMAND_CUT:
   case NS_CONTENT_COMMAND_COPY:

dom/events/IMEStateManager.cpp

@@ -149,6 +149,8 @@ GetEventMessageName(uint32_t aMessage)
       return "NS_COMPOSITION_COMMIT_AS_IS";
     case NS_COMPOSITION_COMMIT:
       return "NS_COMPOSITION_COMMIT";
+    case NS_SELECTION_SET:
+      return "NS_SELECTION_SET";
     default:
       return "unacceptable event message";
   }
@@ -1205,6 +1207,56 @@ IMEStateManager::DispatchCompositionEvent(
   }
 }
 
+// static
+nsIContent*
+IMEStateManager::GetRootContent(nsPresContext* aPresContext)
+{
+  nsIDocument* doc = aPresContext->Document();
+  if (NS_WARN_IF(!doc)) {
+    return nullptr;
+  }
+  return doc->GetRootElement();
+}
+
+// static
+void
+IMEStateManager::HandleSelectionEvent(nsPresContext* aPresContext,
+                                      nsIContent* aEventTargetContent,
+                                      WidgetSelectionEvent* aSelectionEvent)
+{
+  nsIContent* eventTargetContent =
+    aEventTargetContent ? aEventTargetContent :
+                          GetRootContent(aPresContext);
+  nsRefPtr<TabParent> tabParent =
+    eventTargetContent ? TabParent::GetFrom(eventTargetContent) : nullptr;
+
+  MOZ_LOG(sISMLog, LogLevel::Info,
+    ("ISM: IMEStateManager::HandleSelectionEvent(aPresContext=0x%p, "
+     "aEventTargetContent=0x%p, aSelectionEvent={ message=%s, "
+     "mFlags={ mIsTrusted=%s } }), tabParent=%p",
+     aPresContext, aEventTargetContent,
+     GetEventMessageName(aSelectionEvent->message),
+     GetBoolName(aSelectionEvent->mFlags.mIsTrusted),
+     tabParent.get()));
+
+  if (!aSelectionEvent->mFlags.mIsTrusted) {
+    return;
+  }
+
+  nsRefPtr<TextComposition> composition = sTextCompositions ?
+    sTextCompositions->GetCompositionFor(aSelectionEvent->widget) : nullptr;
+  if (composition) {
+    // When there is a composition, TextComposition should guarantee that the
+    // selection event will be handled in same target as composition events.
+    composition->HandleSelectionEvent(aSelectionEvent);
+  } else {
+    // When there is no composition, the selection event should be handled
+    // in the aPresContext or tabParent.
+    TextComposition::HandleSelectionEvent(aPresContext, tabParent,
+                                          aSelectionEvent);
+  }
+}
+
 // static
 void
 IMEStateManager::OnCompositionEventDiscarded(

dom/events/IMEStateManager.h

@@ -152,6 +152,15 @@ public:
                 EventDispatchingCallback* aCallBack,
                 bool aIsSynthesized = false);
 
+  /**
+   * All selection events must be handled via HandleSelectionEvent()
+   * because they must be handled by same target as composition events when
+   * there is a composition.
+   */
+  static void HandleSelectionEvent(nsPresContext* aPresContext,
+                                   nsIContent* aEventTargetContent,
+                                   WidgetSelectionEvent* aSelectionEvent);
+
   /**
    * This is called when PresShell ignores a composition event due to not safe
    * to dispatch events.
@@ -212,6 +221,8 @@ protected:
 
   static bool IsIMEObserverNeeded(const IMEState& aState);
 
+  static nsIContent* GetRootContent(nsPresContext* aPresContext);
+
   static StaticRefPtr<nsIContent> sContent;
   static nsPresContext* sPresContext;
   static StaticRefPtr<nsIWidget> sFocusedIMEWidget;

dom/events/TextComposition.cpp

@@ -374,6 +374,24 @@ TextComposition::DispatchCompositionEvent(
   NotityUpdateComposition(aCompositionEvent);
 }
 
+// static
+void
+TextComposition::HandleSelectionEvent(nsPresContext* aPresContext,
+                                      TabParent* aTabParent,
+                                      WidgetSelectionEvent* aSelectionEvent)
+{
+  // If the content is a container of TabParent, composition should be in the
+  // remote process.
+  if (aTabParent) {
+    unused << aTabParent->SendSelectionEvent(*aSelectionEvent);
+    aSelectionEvent->mFlags.mPropagationStopped = true;
+    return;
+  }
+
+  ContentEventHandler handler(aPresContext);
+  handler.OnSelectionEvent(aSelectionEvent);
+}
+
 void
 TextComposition::NotityUpdateComposition(
                    const WidgetCompositionEvent* aCompositionEvent)

dom/events/TextComposition.h

@@ -284,6 +284,18 @@ private:
                                 EventDispatchingCallback* aCallBack,
                                 bool aIsSynthesized);
 
+  /**
+   * HandleSelectionEvent() sends the selection event to ContentEventHandler
+   * or dispatches it to the focused child process.
+   */
+  void HandleSelectionEvent(WidgetSelectionEvent* aSelectionEvent)
+  {
+    HandleSelectionEvent(mPresContext, mTabParent, aSelectionEvent);
+  }
+  static void HandleSelectionEvent(nsPresContext* aPresContext,
+                                   TabParent* aTabParent,
+                                   WidgetSelectionEvent* aSelectionEvent);
+
   /**
    * MaybeDispatchCompositionUpdate() may dispatch a compositionupdate event
    * if aCompositionEvent changes composition string.

dom/ipc/TabParent.cpp

@@ -2298,7 +2298,11 @@ TabParent::SendSelectionEvent(WidgetSelectionEvent& event)
     return true;
   }
   mContentCache.OnSelectionEvent(event);
-  return PBrowserParent::SendSelectionEvent(event);
+  if (NS_WARN_IF(!PBrowserParent::SendSelectionEvent(event))) {
+    return false;
+  }
+  event.mSucceeded = true;
+  return true;
 }
 
 /*static*/ TabParent*