Fix coordinate transformations used for computing mMouseLocation so they're relative to the root view rather than the end of the parent chain (which differ for, e.g., frames). Add some debugging code (turned off). b=248606 r+sr=roc

view/src/nsViewManager.cpp

@@ -407,6 +407,8 @@ nsViewManager::PostInvalidateEvent()
   }
 }
 
+#undef DEBUG_MOUSE_LOCATION
+
 PRInt32 nsViewManager::mVMCount = 0;
 nsIRenderingContext* nsViewManager::gCleanupContext = nsnull;
 
@@ -1920,22 +1922,25 @@ NS_IMETHODIMP nsViewManager::DispatchEvent(nsGUIEvent *aEvent, nsEventStatus *aS
           float t2p = mContext->AppUnitsToDevUnits();
           float p2t = mContext->DevUnitsToAppUnits();
 
-          //Calculate the proper offset for the view we're going to
-          nsPoint offset(0, 0);
-
-          //Get offset from root of baseView
-          nsView *parent;
-          for (parent = baseView; parent; parent = parent->GetParent())
-            parent->ConvertToParentCoords(&offset.x, &offset.y);
-
           if ((aEvent->message == NS_MOUSE_MOVE &&
                NS_STATIC_CAST(nsMouseEvent*,aEvent)->reason ==
                  nsMouseEvent::eReal) ||
               aEvent->message == NS_MOUSE_ENTER) {
-            mMouseLocation.MoveTo(NSTwipsToIntPixels(offset.x, t2p) +
+            nsPoint rootOffset(0, 0);
+            for (nsView *v = baseView; v != mRootView; v = v->GetParent())
+              v->ConvertToParentCoords(&rootOffset.x, &rootOffset.y);
+
+            mMouseLocation.MoveTo(NSTwipsToIntPixels(rootOffset.x, t2p) +
                                     aEvent->point.x,
-                                  NSTwipsToIntPixels(offset.y, t2p) +
+                                  NSTwipsToIntPixels(rootOffset.y, t2p) +
                                     aEvent->point.y);
+#ifdef DEBUG_MOUSE_LOCATION
+            if (aEvent->message == NS_MOUSE_ENTER)
+              printf("[vm=%p]got mouse enter for %p\n",
+                     this, aEvent->widget);
+            printf("[vm=%p]setting mouse location to (%d,%d)\n",
+                   this, mMouseLocation.x, mMouseLocation.y);
+#endif
           } else if (aEvent->message == NS_MOUSE_EXIT) {
             // Although we only care about the mouse moving into an area
             // for which this view manager doesn't receive mouse move
@@ -1945,11 +1950,27 @@ NS_IMETHODIMP nsViewManager::DispatchEvent(nsGUIEvent *aEvent, nsEventStatus *aS
             // enter after the mouse exit when the mouse moves from one
             // of our widgets into another.
             mMouseLocation.MoveTo(NSCOORD_NONE, NSCOORD_NONE);
+#ifdef DEBUG_MOUSE_LOCATION
+            printf("[vm=%p]got mouse exit for %p\n",
+                   this, aEvent->widget);
+            printf("[vm=%p]clearing mouse location\n",
+                   this);
+#endif
           }
 
-          //Subtract back offset from root of view
-          for (parent = view; parent; parent = parent->GetParent())
-            parent->ConvertFromParentCoords(&offset.x, &offset.y);
+          //Calculate the proper offset for the view we're going to
+          nsPoint offset(0, 0);
+
+          if (view != baseView) {
+            //Get offset from root of baseView
+            nsView *parent;
+            for (parent = baseView; parent; parent = parent->GetParent())
+              parent->ConvertToParentCoords(&offset.x, &offset.y);
+
+            //Subtract back offset from root of view
+            for (parent = view; parent; parent = parent->GetParent())
+              parent->ConvertFromParentCoords(&offset.x, &offset.y);
+          }
 
           //Dispatch the event
           //Before we start mucking with coords, make sure we know our baseline
@@ -4074,6 +4095,11 @@ nsViewManager::ProcessSynthMouseMoveEvent(PRBool aFromScroll)
     return;
   }
 
+#ifdef DEBUG_MOUSE_LOCATION
+  printf("[vm=%p]synthesizing mouse move to (%d,%d)\n",
+         this, mMouseLocation.x, mMouseLocation.y);
+#endif
+
   nsMouseEvent event(NS_MOUSE_MOVE, mRootView->GetWidget(),
                      nsMouseEvent::eSynthesized);
   event.point = mMouseLocation;