Bug 976963 - After invoking the releasePointerCapture method on an element, subsequent events for the specified pointer must follow normal hit testing mechanisms for determining the event target. r=smaug

dom/events/EventStateManager.cpp

@@ -3848,9 +3848,13 @@ EventStateManager::NotifyMouseOver(WidgetMouseEvent* aMouseEvent,
 {
   NS_ASSERTION(aContent, "Mouse must be over something");
 
+  // If pointer capture is set, we should suppress pointerover/pointerenter events
+  // for all elements except element which have pointer capture.
+  bool dispatch = !aMouseEvent->retargetedByPointerCapture;
+
   OverOutElementsWrapper* wrapper = GetWrapperByEventID(aMouseEvent);
 
-  if (wrapper->mLastOverElement == aContent)
+  if (wrapper->mLastOverElement == aContent && dispatch)
     return;
 
   // Before firing mouseover, check for recursion
@@ -3861,12 +3865,9 @@ EventStateManager::NotifyMouseOver(WidgetMouseEvent* aMouseEvent,
   // document's ESM state to indicate that the mouse is over the
   // content associated with our subdocument.
   EnsureDocument(mPresContext);
-  nsIDocument *parentDoc = mDocument->GetParentDocument();
-  if (parentDoc) {
-    nsIContent *docContent = parentDoc->FindContentForSubDocument(mDocument);
-    if (docContent) {
-      nsIPresShell *parentShell = parentDoc->GetShell();
-      if (parentShell) {
+  if (nsIDocument *parentDoc = mDocument->GetParentDocument()) {
+    if (nsIContent *docContent = parentDoc->FindContentForSubDocument(mDocument)) {
+      if (nsIPresShell *parentShell = parentDoc->GetShell()) {
         EventStateManager* parentESM =
           parentShell->GetPresContext()->EventStateManager();
         parentESM->NotifyMouseOver(aMouseEvent, docContent);
@@ -3875,7 +3876,7 @@ EventStateManager::NotifyMouseOver(WidgetMouseEvent* aMouseEvent,
   }
   // Firing the DOM event in the parent document could cause all kinds
   // of havoc.  Reverify and take care.
-  if (wrapper->mLastOverElement == aContent)
+  if (wrapper->mLastOverElement == aContent && dispatch)
     return;
 
   // Remember mLastOverElement as the related content for the
@@ -3883,10 +3884,12 @@ EventStateManager::NotifyMouseOver(WidgetMouseEvent* aMouseEvent,
   nsCOMPtr<nsIContent> lastOverElement = wrapper->mLastOverElement;
 
   bool isPointer = aMouseEvent->eventStructType == NS_POINTER_EVENT;
-  EnterLeaveDispatcher enterDispatcher(this, aContent, lastOverElement,
-                                       aMouseEvent,
-                                       isPointer ? NS_POINTER_ENTER :
-                                                   NS_MOUSEENTER);
+  
+  Maybe<EnterLeaveDispatcher> enterDispatcher;
+  if (dispatch) {
+    enterDispatcher.construct(this, aContent, lastOverElement, aMouseEvent,
+                              isPointer ? NS_POINTER_ENTER : NS_MOUSEENTER);
+  }
 
   NotifyMouseOut(aMouseEvent, aContent);
 
@@ -3898,13 +3901,17 @@ EventStateManager::NotifyMouseOver(WidgetMouseEvent* aMouseEvent,
     SetContentState(aContent, NS_EVENT_STATE_HOVER);
   }
 
+  if (dispatch) {
     // Fire mouseover
     wrapper->mLastOverFrame = 
       DispatchMouseOrPointerEvent(aMouseEvent,
-                                isPointer ? NS_POINTER_OVER :
-                                            NS_MOUSE_ENTER_SYNTH,
+                                  isPointer ? NS_POINTER_OVER : NS_MOUSE_ENTER_SYNTH,
                                   aContent, lastOverElement);
     wrapper->mLastOverElement = aContent;
+  } else {
+    wrapper->mLastOverFrame = nullptr;
+    wrapper->mLastOverElement = nullptr;
+  }
 
   // Turn recursion protection back off
   wrapper->mFirstOverEventElement = nullptr;

layout/base/nsPresShell.cpp

@@ -7179,6 +7179,9 @@ PresShell::HandleEvent(nsIFrame* aFrame,
 
         if (pointerCapturingContent) {
           if (nsIFrame* capturingFrame = pointerCapturingContent->GetPrimaryFrame()) {
+            // If pointer capture is set, we should suppress pointerover/pointerenter events
+            // for all elements except element which have pointer capture. (Code in EventStateManager)
+            pointerEvent->retargetedByPointerCapture = (frame != capturingFrame);
             frame = capturingFrame;
           }
 

widget/MouseEvents.h

@@ -47,8 +47,10 @@ public:
   uint32_t pointerId;
   uint32_t tiltX;
   uint32_t tiltY;
+  bool retargetedByPointerCapture;
 
-  WidgetPointerHelper() : convertToPointer(true), pointerId(0), tiltX(0), tiltY(0) {}
+  WidgetPointerHelper() : convertToPointer(true), pointerId(0), tiltX(0), tiltY(0),
+                          retargetedByPointerCapture(false) {}
 
   void AssignPointerHelperData(const WidgetPointerHelper& aEvent)
   {
@@ -56,6 +58,7 @@ public:
     pointerId = aEvent.pointerId;
     tiltX = aEvent.tiltX;
     tiltY = aEvent.tiltY;
+    retargetedByPointerCapture = aEvent.retargetedByPointerCapture;
   }
 };