Bug 168294. Make sure all types of clipping are applied using the zParent view chain. r=kmcclusk,sr=kin

view/src/nsView.cpp

@@ -985,8 +985,9 @@ PRBool nsView::PointIsInside(nsView& aView, nscoord x, nscoord y) const
 
 NS_IMETHODIMP nsView::GetClippedRect(nsRect& aClippedRect, PRBool& aIsClipped, PRBool& aEmpty) const
 {
-  // Keep track of the view's offset
-  // from its ancestor.
+  // Keep track of the view's offset from its ancestor.
+  // This is the origin of this view's parent view in the
+  // coordinate space of 'parentView' below.
   nscoord ancestorX = 0;
   nscoord ancestorY = 0;
 
@@ -994,13 +995,39 @@ NS_IMETHODIMP nsView::GetClippedRect(nsRect& aClippedRect, PRBool& aIsClipped, P
   aIsClipped = PR_FALSE;
   
   GetBounds(aClippedRect);
-  const nsView* parentView = GetParent();
   PRBool lastViewIsFloating = GetFloating();
 
   // Walk all of the way up the views to see if any
   // ancestor sets the NS_VIEW_PUBLIC_FLAG_CLIPCHILDREN.
   // don't consider non-floating ancestors of a floating view.
-  while (parentView) {
+  const nsView* view = this;
+  while (PR_TRUE) {
+    const nsView* zParent = view->GetZParent();
+    const nsView* parentView = view->GetParent();
+    if (zParent) {
+      // This view was reparented. We need to move back down the view tree
+      // to where it should be to collect whatever might be clipping it there.
+
+      // parentView is an ancestor of zParent ... this is guaranteed by the way these
+      // reparented views are set up; a reparented view is always reparented to one of its
+      // own ancestors
+
+      // we need to get ancestorX and ancestorY into the right coordinate system.
+      // They are the offset of this view within parentView
+      const nsView* zParentChain;
+      for (zParentChain = zParent; zParentChain != parentView;
+           zParentChain = zParentChain->GetParent()) {
+        NS_ASSERTION(zParentChain != nsnull, "Error in view reparenting logic");
+        zParentChain->ConvertFromParentCoords(&ancestorX, &ancestorY);
+      }
+      parentView = zParent;
+      // Now start again at zParent to collect all its clip information
+    }
+    
+    if (!parentView) {
+      break;
+    }
+
     PRBool parentIsFloating = parentView->GetFloating();
     if (lastViewIsFloating && !parentIsFloating) {
       break;
@@ -1012,8 +1039,8 @@ NS_IMETHODIMP nsView::GetClippedRect(nsRect& aClippedRect, PRBool& aIsClipped, P
       nsRect clipRect;
       parentView->GetChildClip(clipRect);
       //Offset the cliprect by the amount the child offsets from the parent
-      clipRect.x += ancestorX;
-      clipRect.y += ancestorY;
+      clipRect.x -= ancestorX;
+      clipRect.y -= ancestorY;
       PRBool overlap = aClippedRect.IntersectRect(clipRect, aClippedRect);
       if (!overlap) {
         aEmpty = PR_TRUE; // Does not intersect so the rect is empty.
@@ -1021,13 +1048,12 @@ NS_IMETHODIMP nsView::GetClippedRect(nsRect& aClippedRect, PRBool& aIsClipped, P
       }
     }
 
-    parentView->ConvertFromParentCoords(&ancestorX, &ancestorY);
+    parentView->ConvertToParentCoords(&ancestorX, &ancestorY);
 
     lastViewIsFloating = parentIsFloating;
-    parentView = parentView->GetParent();
+    view = parentView;
   }
  
   return NS_OK;
 }
 
-

view/src/nsViewManager.cpp

@@ -1075,13 +1075,9 @@ void nsViewManager::RenderViews(nsView *aRootView, nsIRenderingContext& aRC, con
 {
   BuildDisplayList(aRootView, aRect, PR_FALSE, PR_FALSE);
 
-  nsRect fakeClipRect;
-  PRInt32 index = 0;
   PRBool anyRendered;
   nsRect finalTransparentRect;
 
-  ReapplyClipInstructions(PR_FALSE, fakeClipRect, index);
-    
   nsRegion opaqueRgn;
   AddCoveringWidgetsToOpaqueRegion(opaqueRgn, mContext, aRootView);
   OptimizeDisplayList(aRect, finalTransparentRect, opaqueRgn);
@@ -1103,7 +1099,8 @@ void nsViewManager::RenderViews(nsView *aRootView, nsIRenderingContext& aRC, con
   mTranslucentViewCount = 0;
   mTranslucentArea.SetRect(0, 0, 0, 0);
     
-  index = 0;
+  PRInt32 index = 0;
+  nsRect fakeClipRect;
   OptimizeDisplayListClipping(PR_FALSE, fakeClipRect, index, anyRendered);
     
   // We keep a list of all the rendering contexts whose clip rects
@@ -2625,9 +2622,6 @@ PRBool nsViewManager::CanScrollWithBitBlt(nsView* aView)
   }
 
   nsRect r;
-  nsRect fakeClipRect;
-  PRInt32 index = 0;
-
   // Only check the area that intersects the view's non clipped rectangle
   PRBool isClipped;
   PRBool isEmpty;
@@ -2638,7 +2632,6 @@ PRBool nsViewManager::CanScrollWithBitBlt(nsView* aView)
   aView->ConvertFromParentCoords(&r.x, &r.y);
 
   BuildDisplayList(aView, r, PR_FALSE, PR_FALSE);
-  ReapplyClipInstructions(PR_FALSE, fakeClipRect, index);
 
   PRInt32 i;
   for (i = 0; i < mDisplayListCount; i++) {
@@ -3566,6 +3559,7 @@ PRBool nsViewManager::AddToDisplayList(nsView *aView, DisplayZTreeNode* &aParent
 // They might not be because of the Z-reparenting mess: a fixed-position view might have
 // created a display element with bounds that do not reflect the clipping instructions that now
 // surround the element. This would cause problems in the optimizer.
+// XXX No longer used. REMOVE IN THE GREAT VIEW MANAGER PURGE
 void nsViewManager::ReapplyClipInstructions(PRBool aHaveClip, nsRect& aClipRect, PRInt32& aIndex)
 {   
   while (aIndex < mDisplayListCount) {
@@ -3731,14 +3725,15 @@ void nsViewManager::ShowDisplayList(PRInt32 flatlen)
     view->GetPosition(&vx, &vy);
     nsView* parent = view->GetParent();
     PRInt32 zindex = view->GetZIndex();
+    nsView* zParent = view->GetZParent();
 
     nest[nestcnt << 1] = 0;
 
-    printf("%snsIView@%p{%d,%d,%d,%d @ %d,%d; p=%p,m=%p z=%d} [x=%d, y=%d, w=%d, h=%d, absX=%d, absY=%d]\n",
+    printf("%snsIView@%p{%d,%d,%d,%d @ %d,%d; p=%p,m=%p z=%d,zp=%p} [x=%d, y=%d, w=%d, h=%d, absX=%d, absY=%d]\n",
            nest, (void*)view,
            dim.x, dim.y, dim.width, dim.height,
            vx, vy,
-           (void*)parent, (void*)view->GetViewManager(), zindex,
+           (void*)parent, (void*)view->GetViewManager(), zindex, (void*)zParent,
            rect.x, rect.y, rect.width, rect.height,
            element->mAbsX, element->mAbsY);