Bug 455884 - nsIDOMDataTransfer's dropEffect not updated after drag operation completes; r=enndeakin sr=roc

widget/src/windows/nsDragService.cpp

@@ -80,7 +80,7 @@
 //
 //-------------------------------------------------------------------------
 nsDragService::nsDragService()
-  : mNativeDragSrc(nsnull), mNativeDragTarget(nsnull), mDataObject(nsnull)
+  : mNativeDragSrc(nsnull), mNativeDragTarget(nsnull), mDataObject(nsnull), mSentLocalDropEvent(PR_FALSE)
 {
 }
 
@@ -278,7 +278,7 @@ nsDragService::StartInvokingDragSession(IDataObject * aDataObj,
   mNativeDragSrc->AddRef();
 
   // Now figure out what the native drag effect should be
-  DWORD dropRes;
+  DWORD winDropRes;
   DWORD effects = DROPEFFECT_SCROLL;
   if (aActionType & DRAGDROP_ACTION_COPY) {
     effects |= DROPEFFECT_COPY;
@@ -294,6 +294,7 @@ nsDragService::StartInvokingDragSession(IDataObject * aDataObj,
   // the drag
   mDragAction = aActionType;
   mDoingDrag  = PR_TRUE;
+  mSentLocalDropEvent = PR_FALSE;
 
   // Start dragging
   StartDragSession();
@@ -311,7 +312,7 @@ nsDragService::StartInvokingDragSession(IDataObject * aDataObj,
   }
 
   // Call the native D&D method
-  HRESULT res = ::DoDragDrop(aDataObj, mNativeDragSrc, effects, &dropRes);
+  HRESULT res = ::DoDragDrop(aDataObj, mNativeDragSrc, effects, &winDropRes);
 
   if (isAsyncAvailable)
   {
@@ -326,6 +327,31 @@ nsDragService::StartInvokingDragSession(IDataObject * aDataObj,
     }
   }
 
+  // In  cases where the drop operation completed outside the application, update
+  // the source node's nsIDOMNSDataTransfer dropEffect value so it is up to date.  
+  if (!mSentLocalDropEvent) {
+    PRUint32 dropResult;
+    // Order is important, since multiple flags can be returned.
+    if (winDropRes & DROPEFFECT_COPY)
+        dropResult = DRAGDROP_ACTION_COPY;
+    else if (winDropRes & DROPEFFECT_LINK)
+        dropResult = DRAGDROP_ACTION_LINK;
+    else if (winDropRes & DROPEFFECT_MOVE)
+        dropResult = DRAGDROP_ACTION_MOVE;
+    else
+        dropResult = DRAGDROP_ACTION_NONE;
+    
+    nsCOMPtr<nsIDOMNSDataTransfer> dataTransfer =
+      do_QueryInterface(mDataTransfer);
+
+    if (dataTransfer) {
+      if (res == DRAGDROP_S_DROP) // Success 
+        dataTransfer->SetDropEffectInt(dropResult);
+      else
+        dataTransfer->SetDropEffectInt(DRAGDROP_ACTION_NONE);
+    }
+  }
+      
   // We're done dragging
   EndDragSession(PR_TRUE);
 
@@ -468,6 +494,16 @@ nsDragService::SetIDataObject(IDataObject * aDataObj)
   return NS_OK;
 }
 
+//---------------------------------------------------------
+void
+nsDragService::SetDroppedLocal()
+{
+  // Sent from the native drag handler, letting us know
+  // a drop occured within the application vs. outside of it.
+  mSentLocalDropEvent = PR_TRUE;
+  return;
+}
+
 //-------------------------------------------------------------------------
 NS_IMETHODIMP
 nsDragService::IsDataFlavorSupported(const char *aDataFlavor, PRBool *_retval)

widget/src/windows/nsDragService.h

@@ -75,6 +75,9 @@ public:
   NS_IMETHOD StartInvokingDragSession(IDataObject * aDataObj,
                                       PRUint32 aActionType);
 
+  // A drop occured within the application vs. outside of it.
+  void SetDroppedLocal();
+
 protected:
   nsDataObjCollection* GetDataObjCollection(IDataObject * aDataObj);
 
@@ -93,6 +96,7 @@ protected:
   IDropSource * mNativeDragSrc;
   nsNativeDragTarget * mNativeDragTarget;
   IDataObject * mDataObject;
+  PRPackedBool mSentLocalDropEvent;
 };
 
 #endif // nsDragService_h__

widget/src/windows/nsNativeDragTarget.cpp

@@ -421,6 +421,11 @@ nsNativeDragTarget::Drop(LPDATAOBJECT pData,
   // Now process the native drag state and then dispatch the event
   ProcessDrag(pData, NS_DRAGDROP_DROP, grfKeyState, aPT, pdwEffect);
 
+  // Let the win drag service know whether this session experienced 
+  // a drop event within the application. Drop will not oocur if the
+  // drop landed outside the app. (used in tab tear off, bug 455884)
+  winDragService->SetDroppedLocal();
+
   // tell the drag service we're done with the session
   serv->EndDragSession(PR_TRUE);
   return S_OK;