Bug 1504131 - part 2: Remove ResizerMouseMotionListener r=m_kato

ResizerMouseMotionListener listens to "mousemove" events for resizers
or grabber to move absolutely position element and it calls only
HTMLEditor::MouseMove().  Fortunately, neither EditorEventListener not
HTMLEditorEventListener listens to "mousemove" events.  Therefore, we
can use HTMLEditorEventListener instead.

Differential Revision: https://phabricator.services.mozilla.com/D10869

--HG--
extra : moz-landing-system : lando

editor/libeditor/HTMLAbsPositionEditor.cpp

@@ -6,6 +6,7 @@
 
 #include <math.h>
 
+#include "HTMLEditorEventListener.h"
 #include "HTMLEditorObjectResizerUtils.h"
 #include "HTMLEditRules.h"
 #include "HTMLEditUtils.h"
@@ -436,20 +437,14 @@ HTMLEditor::SnapToGrid(int32_t& newX, int32_t& newY)
 nsresult
 HTMLEditor::GrabberClicked()
 {
-  // add a mouse move listener to the editor
-  nsresult rv = NS_OK;
-  if (!mMouseMotionListenerP) {
-    EventTarget* eventTarget = GetDOMEventTarget();
-    if (NS_WARN_IF(!eventTarget)) {
-      return NS_ERROR_FAILURE;
-    }
-    mMouseMotionListenerP = new ResizerMouseMotionListener(*this);
-    EventListenerManager* eventListenerManager =
-      eventTarget->GetOrCreateListenerManager();
-    eventListenerManager->AddEventListenerByType(
-                            mMouseMotionListenerP,
-                            NS_LITERAL_STRING("mousemove"),
-                            TrustedEventsAtSystemGroupBubble());
+  if (NS_WARN_IF(!mEventListener)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+  nsresult rv =
+    static_cast<HTMLEditorEventListener*>(mEventListener.get())->
+      ListenToMouseMoveEventForGrabber(true);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return NS_OK;
   }
   mGrabberClicked = true;
   return rv;
@@ -467,16 +462,13 @@ HTMLEditor::EndMoving()
     mPositioningShadow = nullptr;
   }
 
-  EventTarget* eventTarget = GetDOMEventTarget();
-  if (eventTarget && mMouseMotionListenerP) {
-    EventListenerManager* eventListenerManager =
-      eventTarget->GetOrCreateListenerManager();
-    eventListenerManager->RemoveEventListenerByType(
-                            mMouseMotionListenerP,
-                            NS_LITERAL_STRING("mousemove"),
-                            TrustedEventsAtSystemGroupBubble());
+  if (mEventListener) {
+    DebugOnly<nsresult> rvIgnored =
+      static_cast<HTMLEditorEventListener*>(mEventListener.get())->
+        ListenToMouseMoveEventForGrabber(false);
+    NS_WARNING_ASSERTION(NS_SUCCEEDED(rvIgnored),
+                         "Failed to remove mousemove event listener");
   }
-  mMouseMotionListenerP = nullptr;
 
   mGrabberClicked = false;
   mIsMoving = false;

editor/libeditor/HTMLEditor.cpp

@@ -286,7 +286,6 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(HTMLEditor, TextEditor)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mResizingShadow)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mResizingInfo)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mResizedObject)
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mMouseMotionListenerP)
 
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAbsolutelyPositionedObject)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mGrabber)
@@ -543,27 +542,6 @@ HTMLEditor::RemoveEventListeners()
     return;
   }
 
-  RefPtr<EventTarget> target = GetDOMEventTarget();
-
-  if (target) {
-    // mMouseMotionListenerP can be registerd with other targets than the DOM
-    // event receiver that we can reach from here. But nonetheless, unregister
-    // the event listener with the DOM event receiver (if it's registerd with
-    // other targets, it'll get unregisterd once the target goes
-    // away).
-
-    if (mMouseMotionListenerP) {
-      // mMouseMotionListenerP might be registerd either as bubbling or
-      // capturing, unregister by both.
-      target->RemoveEventListener(NS_LITERAL_STRING("mousemove"),
-                                  mMouseMotionListenerP, false);
-      target->RemoveEventListener(NS_LITERAL_STRING("mousemove"),
-                                  mMouseMotionListenerP, true);
-    }
-  }
-
-  mMouseMotionListenerP = nullptr;
-
   TextEditor::RemoveEventListeners();
 }
 

editor/libeditor/HTMLEditor.h

@@ -227,7 +227,7 @@ public:
    * event callback when the mouse pointer is moved
    * @param aMouseEvent [IN] the event
    */
-  nsresult OnMouseMove(dom::MouseEvent* aMouseEvent);
+  MOZ_CAN_RUN_SCRIPT nsresult OnMouseMove(dom::MouseEvent* aMouseEvent);
 
   /**
    * IsCSSEnabled() returns true if this editor treats styles with style
@@ -2559,8 +2559,6 @@ protected:
 
   RefPtr<Element> mResizedObject;
 
-  nsCOMPtr<nsIDOMEventListener>  mMouseMotionListenerP;
-
   int32_t mOriginalX;
   int32_t mOriginalY;
 

editor/libeditor/HTMLEditorEventListener.cpp

@@ -45,6 +45,16 @@ HTMLEditorEventListener::Disconnect()
     EditorEventListener::Disconnect();
   }
 
+  if (mListeningToMouseMoveEventForResizers) {
+    DebugOnly<nsresult> rvIgnored = ListenToMouseMoveEventForResizers(false);
+    NS_WARNING_ASSERTION(NS_SUCCEEDED(rvIgnored),
+                         "Failed to remove resize event listener of resizers");
+  }
+  if (mListeningToMouseMoveEventForGrabber) {
+    DebugOnly<nsresult> rvIgnored = ListenToMouseMoveEventForGrabber(false);
+    NS_WARNING_ASSERTION(NS_SUCCEEDED(rvIgnored),
+                         "Failed to remove resize event listener of grabber");
+  }
   if (mListeningToResizeEvent) {
     DebugOnly<nsresult> rvIgnored = ListenToWindowResizeEvent(false);
     NS_WARNING_ASSERTION(NS_SUCCEEDED(rvIgnored),
@@ -59,6 +69,23 @@ HTMLEditorEventListener::HandleEvent(Event* aEvent)
 {
   WidgetEvent* internalEvent = aEvent->WidgetEventPtr();
   switch (internalEvent->mMessage) {
+    case eMouseMove: {
+      if (DetachedFromEditor()) {
+        return NS_OK;
+      }
+
+      RefPtr<MouseEvent> mouseEvent = aEvent->AsMouseEvent();
+      if (NS_WARN_IF(!mouseEvent)) {
+        return NS_ERROR_FAILURE;
+      }
+
+      RefPtr<HTMLEditor> htmlEditor = mEditorBase->AsHTMLEditor();
+      MOZ_ASSERT(htmlEditor);
+      DebugOnly<nsresult> rvIgnored = htmlEditor->OnMouseMove(mouseEvent);
+      NS_WARNING_ASSERTION(NS_SUCCEEDED(rvIgnored),
+                           "Resizers failed to handle mousemove events");
+      return NS_OK;
+    }
     case eResize: {
       if (DetachedFromEditor()) {
         return NS_OK;
@@ -80,6 +107,82 @@ HTMLEditorEventListener::HandleEvent(Event* aEvent)
       return NS_OK;
   }
 }
+
+nsresult
+HTMLEditorEventListener::ListenToMouseMoveEventForResizersOrGrabber(
+                           bool aListen,
+                           bool aForGrabber)
+{
+  MOZ_ASSERT(aForGrabber ?
+    mListeningToMouseMoveEventForGrabber != aListen :
+    mListeningToMouseMoveEventForResizers != aListen);
+
+  if (NS_WARN_IF(DetachedFromEditor())) {
+    return aListen ? NS_ERROR_FAILURE : NS_OK;
+  }
+
+  if (aListen) {
+    if (aForGrabber && mListeningToMouseMoveEventForResizers) {
+      // We've already added mousemove event listener for resizers.
+      mListeningToMouseMoveEventForGrabber = true;
+      return NS_OK;
+    }
+    if (!aForGrabber && mListeningToMouseMoveEventForGrabber) {
+      // We've already added mousemove event listener for grabber.
+      mListeningToMouseMoveEventForResizers = true;
+      return NS_OK;
+    }
+  } else {
+    if (aForGrabber && mListeningToMouseMoveEventForResizers) {
+      // We need to keep listening to mousemove event listener for resizers.
+      mListeningToMouseMoveEventForGrabber = false;
+      return NS_OK;
+    }
+    if (!aForGrabber && mListeningToMouseMoveEventForGrabber) {
+      // We need to keep listening to mousemove event listener for grabber.
+      mListeningToMouseMoveEventForResizers = false;
+      return NS_OK;
+    }
+  }
+
+  EventTarget* target = mEditorBase->AsHTMLEditor()->GetDOMEventTarget();
+  if (NS_WARN_IF(!target)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Listen to mousemove events in the system group since web apps may stop
+  // propagation before we receive the events.
+  EventListenerManager* eventListenerManager =
+    target->GetOrCreateListenerManager();
+  if (NS_WARN_IF(!eventListenerManager)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (aListen) {
+    eventListenerManager->AddEventListenerByType(
+                            this,
+                            NS_LITERAL_STRING("mousemove"),
+                            TrustedEventsAtSystemGroupBubble());
+    if (aForGrabber) {
+      mListeningToMouseMoveEventForGrabber = true;
+    } else {
+      mListeningToMouseMoveEventForResizers = true;
+    }
+    return NS_OK;
+  }
+
+  eventListenerManager->RemoveEventListenerByType(
+                          this,
+                          NS_LITERAL_STRING("mousemove"),
+                          TrustedEventsAtSystemGroupBubble());
+  if (aForGrabber) {
+    mListeningToMouseMoveEventForGrabber = false;
+  } else {
+    mListeningToMouseMoveEventForResizers = false;
+  }
+  return NS_OK;
+}
+
 nsresult
 HTMLEditorEventListener::ListenToWindowResizeEvent(bool aListen)
 {

editor/libeditor/HTMLEditorEventListener.h

@@ -18,6 +18,8 @@ class HTMLEditorEventListener final : public EditorEventListener
 public:
   HTMLEditorEventListener()
     : EditorEventListener()
+    , mListeningToMouseMoveEventForResizers(false)
+    , mListeningToMouseMoveEventForGrabber(false)
     , mListeningToResizeEvent(false)
   {
   }
@@ -37,6 +39,41 @@ public:
 
   virtual void Disconnect() override;
 
+  /**
+   * ListenToMouseMoveEventForResizers() starts to listen to or stop
+   * listening to "mousemove" events for resizers.
+   */
+  nsresult ListenToMouseMoveEventForResizers(bool aListen)
+  {
+    if (aListen == mListeningToMouseMoveEventForResizers) {
+      return NS_OK;
+    }
+    nsresult rv =
+      ListenToMouseMoveEventForResizersOrGrabber(aListen, false);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+    return NS_OK;
+  }
+
+  /**
+   * ListenToMouseMoveEventForResizers() starts to listen to or stop
+   * listening to "mousemove" events for grabber to move absolutely
+   * positioned element.
+   */
+  nsresult ListenToMouseMoveEventForGrabber(bool aListen)
+  {
+    if (aListen == mListeningToMouseMoveEventForGrabber) {
+      return NS_OK;
+    }
+    nsresult rv =
+      ListenToMouseMoveEventForResizersOrGrabber(aListen, true);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+    return NS_OK;
+  }
+
   /**
    * ListenToWindowResizeEvent() starts to listen to or stop listening to
    * "resize" events of the document.
@@ -50,6 +87,11 @@ protected:
   MOZ_CAN_RUN_SCRIPT
   virtual nsresult MouseClick(WidgetMouseEvent* aMouseClickEvent) override;
 
+  nsresult
+  ListenToMouseMoveEventForResizersOrGrabber(bool aListen, bool aForGrabber);
+
+  bool mListeningToMouseMoveEventForResizers;
+  bool mListeningToMouseMoveEventForGrabber;
   bool mListeningToResizeEvent;
 };
 

editor/libeditor/HTMLEditorObjectResizer.cpp

@@ -39,36 +39,6 @@ namespace mozilla {
 
 using namespace dom;
 
-/******************************************************************************
- * mozilla::ResizerMouseMotionListener
- ******************************************************************************/
-
-NS_IMPL_ISUPPORTS(ResizerMouseMotionListener, nsIDOMEventListener)
-
-ResizerMouseMotionListener::ResizerMouseMotionListener(HTMLEditor& aHTMLEditor)
-  : mHTMLEditorWeak(&aHTMLEditor)
-{
-}
-
-NS_IMETHODIMP
-ResizerMouseMotionListener::HandleEvent(Event* aMouseEvent)
-{
-  MouseEvent* mouseEvent = aMouseEvent->AsMouseEvent();
-  if (!mouseEvent) {
-    //non-ui event passed in.  bad things.
-    return NS_OK;
-  }
-
-  // Don't do anything special if not an HTML object resizer editor
-  RefPtr<HTMLEditor> htmlEditor = mHTMLEditorWeak.get();
-  if (htmlEditor) {
-    // check if we have to redisplay a resizing shadow
-    htmlEditor->OnMouseMove(mouseEvent);
-  }
-
-  return NS_OK;
-}
-
 /******************************************************************************
  * mozilla::HTMLEditor
  ******************************************************************************/
@@ -529,8 +499,6 @@ HTMLEditor::HideResizersInternal()
   ManualNACPtr resizingShadow(std::move(mResizingShadow));
   ManualNACPtr resizingInfo(std::move(mResizingInfo));
   RefPtr<Element> activatedHandle(std::move(mActivatedHandle));
-  nsCOMPtr<nsIDOMEventListener> mouseMotionListener(
-                                  std::move(mMouseMotionListenerP));
   RefPtr<Element> resizedObject(std::move(mResizedObject));
 
   // Remvoe all handles.
@@ -573,13 +541,15 @@ HTMLEditor::HideResizersInternal()
   // Remove resizing state of the target element.
   resizedObject->UnsetAttr(kNameSpaceID_None, nsGkAtoms::_moz_resizing, true);
 
-  // Remove mousemove event listener from the event target.
-  nsCOMPtr<EventTarget> target = GetDOMEventTarget();
-  NS_WARNING_ASSERTION(target, "GetDOMEventTarget() returned nullptr");
+  if (!mEventListener) {
+    return NS_OK;
+  }
 
-  if (target && mouseMotionListener) {
-    target->RemoveEventListener(NS_LITERAL_STRING("mousemove"),
-                                mouseMotionListener, true);
+  nsresult rv =
+    static_cast<HTMLEditorEventListener*>(mEventListener.get())->
+      ListenToMouseMoveEventForResizers(false);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
   }
 
   // Remove resize event listener from the window.
@@ -587,9 +557,8 @@ HTMLEditor::HideResizersInternal()
     return NS_OK;
   }
 
-  nsresult rv =
-    static_cast<HTMLEditorEventListener*>(mEventListener.get())->
-      ListenToWindowResizeEvent(false);
+  rv = static_cast<HTMLEditorEventListener*>(mEventListener.get())->
+         ListenToWindowResizeEvent(false);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
@@ -654,22 +623,16 @@ HTMLEditor::StartResizing(Element* aHandle)
                                       mResizedObjectHeight);
 
   // add a mouse move listener to the editor
-  nsresult result = NS_OK;
-  if (!mMouseMotionListenerP) {
-    mMouseMotionListenerP = new ResizerMouseMotionListener(*this);
-    if (!mMouseMotionListenerP) {
-      return NS_ERROR_OUT_OF_MEMORY;
-    }
-
-    EventTarget* target = GetDOMEventTarget();
-    NS_ENSURE_TRUE(target, NS_ERROR_FAILURE);
-
-    result = target->AddEventListener(NS_LITERAL_STRING("mousemove"),
-                                      mMouseMotionListenerP, true);
-    NS_ASSERTION(NS_SUCCEEDED(result),
-                 "failed to register mouse motion listener");
+  if (NS_WARN_IF(!mEventListener)) {
+    return NS_ERROR_NOT_INITIALIZED;
   }
-  return result;
+  nsresult rv =
+    static_cast<HTMLEditorEventListener*>(mEventListener.get())->
+      ListenToMouseMoveEventForResizers(true);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  return NS_OK;
 }
 
 nsresult

editor/libeditor/HTMLEditorObjectResizerUtils.h

@@ -26,23 +26,6 @@ namespace mozilla {
 #define kBottom        NS_LITERAL_STRING("s")
 #define kBottomRight   NS_LITERAL_STRING("se")
 
-/******************************************************************************
- * mozilla::ResizerMouseMotionListener
- ******************************************************************************/
-
-class ResizerMouseMotionListener final : public nsIDOMEventListener
-{
-public:
-  explicit ResizerMouseMotionListener(HTMLEditor& aHTMLEditor);
-
-  NS_DECL_ISUPPORTS
-  NS_DECL_NSIDOMEVENTLISTENER
-
-protected:
-  virtual ~ResizerMouseMotionListener() {}
-  CachedWeakPtr<HTMLEditor, nsIHTMLEditor> mHTMLEditorWeak;
-};
-
 } // namespace mozilla
 
 #endif // #ifndef HTMLEditorObjectResizerUtils_h