Bug 1022612. Part 15: Add nsDisplayItem::GetVisibleRectForChildren(). r=mattwoodrow

--HG--
extra : rebase_source : cf958f41493ab25762f0c3bcc0361b0810e88549

layout/base/nsDisplayList.cpp

@@ -1044,6 +1044,15 @@ nsDisplayList::GetBounds(nsDisplayListBuilder* aBuilder) const {
   return bounds;
 }
 
+nsRect
+nsDisplayList::GetVisibleRect() const {
+  nsRect result;
+  for (nsDisplayItem* i = GetBottom(); i != nullptr; i = i->GetAbove()) {
+    result.UnionRect(result, i->GetVisibleRect());
+  }
+  return result;
+}
+
 bool
 nsDisplayList::ComputeVisibilityForRoot(nsDisplayListBuilder* aBuilder,
                                         nsRegion* aVisibleRegion,
@@ -4315,12 +4324,15 @@ nsDisplayTransform::GetFrameBoundsForTransform(const nsIFrame* aFrame)
 
 #endif
 
-nsDisplayTransform::nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame,
-                                       nsDisplayList *aList, ComputeTransformFunction aTransformGetter, 
+nsDisplayTransform::nsDisplayTransform(nsDisplayListBuilder* aBuilder,
+                                       nsIFrame *aFrame, nsDisplayList *aList,
+                                       const nsRect& aChildrenVisibleRect,
+                                       ComputeTransformFunction aTransformGetter,
                                        uint32_t aIndex) 
   : nsDisplayItem(aBuilder, aFrame)
   , mStoredList(aBuilder, aFrame, aList)
   , mTransformGetter(aTransformGetter)
+  , mChildrenVisibleRect(aChildrenVisibleRect)
   , mIndex(aIndex)
 {
   MOZ_COUNT_CTOR(nsDisplayTransform);
@@ -4338,11 +4350,14 @@ nsDisplayTransform::SetReferenceFrameToAncestor(nsDisplayListBuilder* aBuilder)
   mVisibleRect = aBuilder->GetDirtyRect() + mToReferenceFrame;
 }
 
-nsDisplayTransform::nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame,
-                                       nsDisplayList *aList, uint32_t aIndex) 
+nsDisplayTransform::nsDisplayTransform(nsDisplayListBuilder* aBuilder,
+                                       nsIFrame *aFrame, nsDisplayList *aList,
+                                       const nsRect& aChildrenVisibleRect,
+                                       uint32_t aIndex)
   : nsDisplayItem(aBuilder, aFrame)
   , mStoredList(aBuilder, aFrame, aList)
   , mTransformGetter(nullptr)
+  , mChildrenVisibleRect(aChildrenVisibleRect)
   , mIndex(aIndex)
 {
   MOZ_COUNT_CTOR(nsDisplayTransform);
@@ -4351,11 +4366,14 @@ nsDisplayTransform::nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame
   mStoredList.SetClip(aBuilder, DisplayItemClip::NoClip());
 }
 
-nsDisplayTransform::nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame,
-                                       nsDisplayItem *aItem, uint32_t aIndex)
+nsDisplayTransform::nsDisplayTransform(nsDisplayListBuilder* aBuilder,
+                                       nsIFrame *aFrame, nsDisplayItem *aItem,
+                                       const nsRect& aChildrenVisibleRect,
+                                       uint32_t aIndex)
   : nsDisplayItem(aBuilder, aFrame)
   , mStoredList(aBuilder, aFrame, aItem)
   , mTransformGetter(nullptr)
+  , mChildrenVisibleRect(aChildrenVisibleRect)
   , mIndex(aIndex)
 {
   MOZ_COUNT_CTOR(nsDisplayTransform);

layout/base/nsDisplayList.h

@@ -1083,7 +1083,7 @@ public:
    * @param aSnap set to true if the edges of the rectangles of the opaque
    * region would be snapped to device pixels when drawing
    * @return a region of the item that is opaque --- that is, every pixel
-   * that is visible (according to ComputeVisibility) is painted with an opaque
+   * that is visible is painted with an opaque
    * color. This is useful for determining when one piece
    * of content completely obscures another so that we can do occlusion
    * culling.
@@ -1270,10 +1270,17 @@ public:
   virtual nsDisplayList* GetChildren() { return nullptr; }
 
   /**
-   * Returns the visible rect. Should only be called after ComputeVisibility
-   * has happened.
+   * Returns the visible rect.
    */
-  const nsRect& GetVisibleRect() { return mVisibleRect; }
+  const nsRect& GetVisibleRect() const { return mVisibleRect; }
+
+  /**
+   * Returns the visible rect for the children, relative to their
+   * reference frame. Can be different from mVisibleRect for nsDisplayTransform,
+   * since the reference frame for the children is different from the reference
+   * frame for the item itself.
+   */
+  virtual const nsRect& GetVisibleRectForChildren() const { return mVisibleRect; }
 
   /**
    * Stores the given opacity value to be applied when drawing. Returns
@@ -1685,6 +1692,11 @@ public:
   void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
                nsDisplayItem::HitTestState* aState,
                nsTArray<nsIFrame*> *aOutFrames) const;
+  /**
+   * Compute the union of the visible rects of the items in the list. The
+   * result is not cached.
+   */
+  nsRect GetVisibleRect() const;
 
 #if defined(DEBUG) || defined(MOZ_DUMP_PAINTING)
   bool DidComputeVisibility() const { return mDidComputeVisibility; }
@@ -1705,8 +1717,6 @@ public:
     mForceTransparentSurface = true;
   }
 
-  nsRect GetVisibleRect() const { return mVisibleRect; }
-
 private:
   // This class is only used on stack, so we don't have to worry about leaking
   // it.  Don't let us be heap-allocated!
@@ -2985,7 +2995,7 @@ public:
 /**
  * This potentially creates a layer for the given list of items, whose
  * visibility is determined by the displayport for the given frame instead of
- * what is passed in to ComputeVisibility.
+ * normal visibility computation.
  *
  * Here in content, we can use this to render more content than is actually
  * visible. Then, the compositing process can manipulate the generated layer
@@ -3245,11 +3255,14 @@ public:
    * ferries the underlying frame to the nsDisplayItem constructor.
    */
   nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame,
-                     nsDisplayList *aList, uint32_t aIndex = 0);
+                     nsDisplayList *aList, const nsRect& aChildrenVisibleRect,
+                     uint32_t aIndex = 0);
   nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame,
-                     nsDisplayItem *aItem, uint32_t aIndex = 0);
+                     nsDisplayItem *aItem, const nsRect& aChildrenVisibleRect,
+                     uint32_t aIndex = 0);
   nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame,
-                     nsDisplayList *aList, ComputeTransformFunction aTransformGetter, uint32_t aIndex = 0);
+                     nsDisplayList *aList, const nsRect& aChildrenVisibleRect,
+                     ComputeTransformFunction aTransformGetter, uint32_t aIndex = 0);
 
 #ifdef NS_BUILD_REFCNT_LOGGING
   virtual ~nsDisplayTransform()
@@ -3307,6 +3320,11 @@ public:
     return nsDisplayItem::ReferenceFrameForChildren(); 
   }
 
+  virtual const nsRect& GetVisibleRectForChildren() const MOZ_OVERRIDE
+  {
+    return mChildrenVisibleRect;
+  }
+
   enum {
     INDEX_MAX = UINT32_MAX >> nsDisplayItem::TYPE_BITS
   };
@@ -3454,6 +3472,7 @@ private:
   nsDisplayWrapList mStoredList;
   gfx3DMatrix mTransform;
   ComputeTransformFunction mTransformGetter;
+  nsRect mChildrenVisibleRect;
   uint32_t mIndex;
 };
 

layout/base/nsLayoutUtils.cpp

@@ -2323,7 +2323,7 @@ nsLayoutUtils::GetLayerTransformForFrame(nsIFrame* aFrame,
                                false/*don't build caret*/);
   nsDisplayList list;  
   nsDisplayTransform* item =
-    new (&builder) nsDisplayTransform(&builder, aFrame, &list);
+    new (&builder) nsDisplayTransform(&builder, aFrame, &list, nsRect());
 
   *aTransform =
     item->GetTransform();

layout/generic/nsFrame.cpp

@@ -1737,7 +1737,9 @@ DisplayDebugBorders(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
 #endif
 
 static nsresult
-WrapPreserve3DListInternal(nsIFrame* aFrame, nsDisplayListBuilder *aBuilder, nsDisplayList *aList, nsDisplayList *aOutput, uint32_t& aIndex, nsDisplayList* aTemp)
+WrapPreserve3DListInternal(nsIFrame* aFrame, nsDisplayListBuilder *aBuilder,
+                           nsDisplayList *aList, nsDisplayList *aOutput,
+                           uint32_t& aIndex, nsDisplayList* aTemp)
 {
   if (aIndex > nsDisplayTransform::INDEX_MAX) {
     return NS_OK;
@@ -1756,7 +1758,8 @@ WrapPreserve3DListInternal(nsIFrame* aFrame, nsDisplayListBuilder *aBuilder, nsD
       switch (item->GetType()) {
         case nsDisplayItem::TYPE_TRANSFORM: {
           if (!aTemp->IsEmpty()) {
-            aOutput->AppendToTop(new (aBuilder) nsDisplayTransform(aBuilder, aFrame, aTemp, aIndex++));
+            aOutput->AppendToTop(new (aBuilder) nsDisplayTransform(aBuilder,
+                aFrame, aTemp, aTemp->GetVisibleRect(), aIndex++));
           }
           // Override item's clipping with our current clip state (if any). Since we're
           // bubbling up a preserve-3d transformed child to a preserve-3d parent,
@@ -1778,7 +1781,8 @@ WrapPreserve3DListInternal(nsIFrame* aFrame, nsDisplayListBuilder *aBuilder, nsD
         }
         case nsDisplayItem::TYPE_OPACITY: {
           if (!aTemp->IsEmpty()) {
-            aOutput->AppendToTop(new (aBuilder) nsDisplayTransform(aBuilder, aFrame, aTemp, aIndex++));
+            aOutput->AppendToTop(new (aBuilder) nsDisplayTransform(aBuilder,
+                aFrame, aTemp, aTemp->GetVisibleRect(), aIndex++));
           }
           nsDisplayOpacity *opacity = static_cast<nsDisplayOpacity*>(item);
           nsDisplayList output;
@@ -1788,7 +1792,8 @@ WrapPreserve3DListInternal(nsIFrame* aFrame, nsDisplayListBuilder *aBuilder, nsD
           rv = WrapPreserve3DListInternal(aFrame, aBuilder,
               opacity->GetChildren(), &output, aIndex, aTemp);
           if (!aTemp->IsEmpty()) {
-            output.AppendToTop(new (aBuilder) nsDisplayTransform(aBuilder, aFrame, aTemp, aIndex++));
+            output.AppendToTop(new (aBuilder) nsDisplayTransform(aBuilder,
+                aFrame, aTemp, aTemp->GetVisibleRect(), aIndex++));
           }
           opacity->GetChildren()->AppendToTop(&output);
           opacity->UpdateBounds(aBuilder);
@@ -1798,10 +1803,12 @@ WrapPreserve3DListInternal(nsIFrame* aFrame, nsDisplayListBuilder *aBuilder, nsD
         default: {
           if (childFrame->StyleDisplay()->BackfaceIsHidden()) {
             if (!aTemp->IsEmpty()) {
-              aOutput->AppendToTop(new (aBuilder) nsDisplayTransform(aBuilder, aFrame, aTemp, aIndex++));
+              aOutput->AppendToTop(new (aBuilder) nsDisplayTransform(aBuilder,
+                  aFrame, aTemp, aTemp->GetVisibleRect(), aIndex++));
             }
 
-            aOutput->AppendToTop(new (aBuilder) nsDisplayTransform(aBuilder, childFrame, item, aIndex++));
+            aOutput->AppendToTop(new (aBuilder) nsDisplayTransform(aBuilder,
+                childFrame, item, item->GetVisibleRect(), aIndex++));
           } else {
             aTemp->AppendToTop(item);
           }
@@ -1826,15 +1833,18 @@ IsScrollFrameActive(nsIScrollableFrame* aScrollableFrame)
 }
 
 static nsresult
-WrapPreserve3DList(nsIFrame* aFrame, nsDisplayListBuilder* aBuilder, nsDisplayList *aList)
+WrapPreserve3DList(nsIFrame* aFrame, nsDisplayListBuilder* aBuilder,
+                   nsDisplayList *aList)
 {
   uint32_t index = 0;
   nsDisplayList temp;
   nsDisplayList output;
-  nsresult rv = WrapPreserve3DListInternal(aFrame, aBuilder, aList, &output, index, &temp);
+  nsresult rv = WrapPreserve3DListInternal(aFrame, aBuilder, aList, &output,
+      index, &temp);
 
   if (!temp.IsEmpty()) {
-    output.AppendToTop(new (aBuilder) nsDisplayTransform(aBuilder, aFrame, &temp, index++));
+    output.AppendToTop(new (aBuilder) nsDisplayTransform(aBuilder, aFrame,
+        &temp, temp.GetVisibleRect(), index++));
   }
 
   aList->AppendToTop(&output);
@@ -2096,7 +2106,7 @@ nsIFrame::BuildDisplayListForStackingContext(nsDisplayListBuilder* aBuilder,
       WrapPreserve3DList(this, aBuilder, &resultList);
     } else {
       resultList.AppendNewToTop(
-        new (aBuilder) nsDisplayTransform(aBuilder, this, &resultList));
+        new (aBuilder) nsDisplayTransform(aBuilder, this, &resultList, dirtyRect));
     }
   }
 

layout/generic/nsPageFrame.cpp

@@ -531,7 +531,8 @@ nsPageFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
       *aBuilder, content, child, backgroundRect, NS_RGBA(0,0,0,0));
   }
 
-  content.AppendNewToTop(new (aBuilder) nsDisplayTransform(aBuilder, child, &content, ::ComputePageTransform));
+  content.AppendNewToTop(new (aBuilder) nsDisplayTransform(aBuilder, child,
+      &content, content.GetVisibleRect(), ::ComputePageTransform));
 
   set.Content()->AppendToTop(&content);
 

layout/generic/nsSimplePageSequenceFrame.cpp

@@ -797,7 +797,8 @@ nsSimplePageSequenceFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
   }
 
   content.AppendNewToTop(new (aBuilder)
-      nsDisplayTransform(aBuilder, this, &content, ::ComputePageSequenceTransform));
+      nsDisplayTransform(aBuilder, this, &content, content.GetVisibleRect(),
+                         ::ComputePageSequenceTransform));
 
   aLists.Content()->AppendToTop(&content);
 }