Modifying view event flow to always start processing from top view, not enter at children

view/public/nsIView.h

@@ -421,6 +421,13 @@ public:
    */
   virtual void List(FILE* out = stdout, PRInt32 aIndent = 0) const = 0;
 
+  /**
+   * Set flags on view to allow customization of view behavior during
+   * event handling
+   * @param aFlags flags to be added to view
+   */
+  NS_IMETHOD SetViewFlags(PRInt32 aFlags) = 0;
+
 private:
   NS_IMETHOD_(nsrefcnt) AddRef(void) = 0;
   NS_IMETHOD_(nsrefcnt) Release(void) = 0;
@@ -455,4 +462,8 @@ private:
 //while in the front to back pass
 #define NS_VIEW_FLAG_FRONT_TO_BACK  0x0040
 
+//Flag to determine whether the view will check if events can be handled
+//by its children or just handle the events itself
+#define NS_VIEW_FLAG_DONT_CHECK_CHILDREN  0x0001
+
 #endif

view/src/nsScrollingView.cpp

@@ -711,9 +711,9 @@ NS_IMETHODIMP nsScrollingView :: HandleEvent(nsGUIEvent *aEvent, PRUint32 aEvent
       } // switch
     } break;
 
+#if 0
     case NS_MOUSE_MOVE:
     {
-#if 0
       nsRect  brect;
       nscoord lx, ly;
 
@@ -751,7 +751,6 @@ NS_IMETHODIMP nsScrollingView :: HandleEvent(nsGUIEvent *aEvent, PRUint32 aEvent
         mScrollingTimer->Cancel();
         NS_RELEASE(mScrollingTimer);
       }
-#endif
       break;
     }
 
@@ -799,6 +798,7 @@ NS_IMETHODIMP nsScrollingView :: HandleEvent(nsGUIEvent *aEvent, PRUint32 aEvent
       }
       break;
     }
+#endif
 
     default:
       break;

view/src/nsView.cpp

@@ -72,6 +72,7 @@ nsView :: nsView()
   mVis = nsViewVisibility_kShow;
   mXForm = nsnull;
   mVFlags = ~ALL_VIEW_FLAGS;
+  mEventFlags = 0;
   mOpacity = 1.0f;
 }
 
@@ -740,9 +741,10 @@ NS_IMETHODIMP nsView :: HandleEvent(nsGUIEvent *event, PRUint32 aEventFlags,
 //printf(" %d %d %d %d (%d,%d) \n", this, event->widget, event->widgetSupports, 
 //       event->message, event->point.x, event->point.y);
   aStatus = nsEventStatus_eIgnore;
+  PRBool handledByChild = PR_FALSE;
 
   //see if any of this view's children can process the event
-  if (aStatus == nsEventStatus_eIgnore) {
+  if (aStatus == nsEventStatus_eIgnore && !(mEventFlags & NS_VIEW_FLAG_DONT_CHECK_CHILDREN)) {
     PRInt32 numkids;
     nsRect  trect;
     nscoord x, y;
@@ -760,6 +762,7 @@ NS_IMETHODIMP nsView :: HandleEvent(nsGUIEvent *event, PRUint32 aEventFlags,
 
       if (trect.Contains(x, y))
       {
+        handledByChild = PR_TRUE;
         //the x, y position of the event in question
         //is inside this child view, so give it the
         //opportunity to handle the event
@@ -778,8 +781,8 @@ NS_IMETHODIMP nsView :: HandleEvent(nsGUIEvent *event, PRUint32 aEventFlags,
     }
   }
 
-  //if the view's children didn't take the event, check the view itself.
-  if ((aStatus == nsEventStatus_eIgnore) && (nsnull != mClientData))
+  //if no child's bounds matched the event, check the view itself.
+  if (!handledByChild && nsnull != mClientData)
   {
     nsIViewObserver *obs;
 
@@ -1252,6 +1255,12 @@ void nsView :: List(FILE* out, PRInt32 aIndent) const
   fputs(">\n", out);
 }
 
+NS_IMETHODIMP nsView :: SetViewFlags(PRInt32 aFlags)
+{
+  mVFlags &= aFlags;
+  return NS_OK;
+}
+
 NS_IMETHODIMP nsView :: GetOffsetFromWidget(nscoord *aDx, nscoord *aDy, nsIWidget *&aWidget)
 {
   nsIView   *ancestor;

view/src/nsView.h

@@ -98,6 +98,7 @@ public:
   NS_IMETHOD  SetWidget(nsIWidget *aWidget);
   NS_IMETHOD  GetWidget(nsIWidget *&aWidget);
   virtual void List(FILE* out = stdout, PRInt32 aIndent = 0) const;
+  NS_IMETHOD SetViewFlags(PRInt32 aFlags);
 
   // Helper function to get the view that's associated with a widget
   static nsIView*  GetViewFor(nsIWidget* aWidget);
@@ -125,6 +126,7 @@ protected:
   float             mOpacity;
   PRInt32           mVFlags;
   nsIRegion*        mDirtyRegion;
+  PRInt32           mEventFlags;
 
 private:
   NS_IMETHOD_(nsrefcnt) AddRef(void);

view/src/nsViewManager.cpp

@@ -25,8 +25,10 @@
 #include "nsIScrollableView.h"
 #include "nsIRegion.h"
 #include "nsView.h"
+#include "nsIScrollbar.h"
 
 static NS_DEFINE_IID(kIScrollableViewIID, NS_ISCROLLABLEVIEW_IID);
+static NS_DEFINE_IID(kIScrollbarIID, NS_ISCROLLBAR_IID);
 
 static const PRBool gsDebug = PR_FALSE;
 
@@ -793,33 +795,77 @@ NS_IMETHODIMP nsViewManager :: DispatchEvent(nsGUIEvent *aEvent, nsEventStatus &
 
     default:
     {
+      nsIView* baseView;
       nsIView* view;
+      nsPoint offset;
+      nsIScrollbar* sb;
+
+      //Find the view whose coordinates system we're in.
+      baseView = nsView::GetViewFor(aEvent->widget);
         
-      if (nsnull != mMouseGrabber && NS_IS_MOUSE_EVENT(aEvent))
+      //Find the view to which we're initially going to send the event 
+      //for hittesting.
+      if (nsnull != mMouseGrabber && NS_IS_MOUSE_EVENT(aEvent)) {
         view = mMouseGrabber;
-      else if (nsnull != mKeyGrabber && NS_IS_KEY_EVENT(aEvent))
+      }
+      else if (nsnull != mKeyGrabber && NS_IS_KEY_EVENT(aEvent)) {
         view = mKeyGrabber;
-      else
-        view = nsView::GetViewFor(aEvent->widget);
+      }
+      else if (NS_OK == aEvent->widget->QueryInterface(kIScrollbarIID, (void**)&sb)) {
+        view = baseView;
+        NS_RELEASE(sb);
+      }
+      else {
+        view = mRootView;
+      }
 
-      if (nsnull != view)
-      {
+      if (nsnull != view) {
+        //Calculate the proper offset for the view we're going to
+        offset.x = offset.y = 0;
+        if (baseView != view) {
+          //Get offset from root of baseView
+          nsIView *parent;
+          nsRect bounds;
+
+          parent = baseView;
+          while (nsnull != parent) {
+            parent->GetBounds(bounds);
+            offset.x += bounds.x;
+            offset.y += bounds.y;
+            parent->GetParent(parent);
+          }
+
+          //Subtract back offset from root of view
+          parent = view;
+          while (nsnull != parent) {
+            parent->GetBounds(bounds);
+            offset.x -= bounds.x;
+            offset.y -= bounds.y;
+            parent->GetParent(parent);
+          }
+      
+        }
+
+        //Dispatch the event
         float p2t, t2p;
 
-        // pass on to view somewhere else to deal with
-
         mContext->GetDevUnitsToAppUnits(p2t);
         mContext->GetAppUnitsToDevUnits(t2p);
 
         aEvent->point.x = NSIntPixelsToTwips(aEvent->point.x, p2t);
         aEvent->point.y = NSIntPixelsToTwips(aEvent->point.y, p2t);
 
-        
+        aEvent->point.x += offset.x;
+        aEvent->point.y += offset.y;
+
         view->HandleEvent(aEvent, NS_VIEW_FLAG_CHECK_CHILDREN | 
                                   NS_VIEW_FLAG_CHECK_PARENT |
                                   NS_VIEW_FLAG_CHECK_SIBLINGS,
                           aStatus);
 
+        aEvent->point.x -= offset.x;
+        aEvent->point.y -= offset.y;
+
         aEvent->point.x = NSTwipsToIntPixels(aEvent->point.x, t2p);
         aEvent->point.y = NSTwipsToIntPixels(aEvent->point.y, t2p);
       }