Bug 539356 - Add an option for frames to invalid just a rect instead of the frame bounds. r=roc

layout/base/FrameLayerBuilder.cpp

@@ -2114,7 +2114,8 @@ ContainerState::ProcessDisplayItems(const nsDisplayList& aList,
         continue;
       }
 
-      if (item->IsInvalid()) {
+      nsRect invalid;
+      if (item->IsInvalid(invalid)) {
         ownLayer->SetInvalidRectToVisibleRegion();
       }
 
@@ -2252,8 +2253,10 @@ ContainerState::InvalidateForLayerChange(nsDisplayItem* aItem,
 
   ThebesDisplayItemLayerUserData* data =
     static_cast<ThebesDisplayItemLayerUserData*>(newThebesLayer->GetUserData(&gThebesDisplayItemLayerUserData));
-  // If the frame is marked as invalidated then we want to invalidate both the old and new bounds,
-  // otherwise we only want to invalidate the changed areas.
+  // If the frame is marked as invalidated, and didn't specify a rect to invalidate  then we want to 
+  // invalidate both the old and new bounds, otherwise we only want to invalidate the changed areas.
+  // If we do get an invalid rect, then we want to add this on top of the change areas.
+  nsRect invalid;
   nsRegion combined;
   if (!oldLayer) {
     // This item is being added for the first time, invalidate its entire area.
@@ -2262,7 +2265,7 @@ ContainerState::InvalidateForLayerChange(nsDisplayItem* aItem,
 #ifdef DEBUG_INVALIDATIONS
     printf("Display item type %s(%p) added to layer %p!\n", aItem->Name(), f, aNewLayer);
 #endif
-  } else if (aItem->IsInvalid()) {
+  } else if (aItem->IsInvalid(invalid) && invalid.IsEmpty()) {
     // Either layout marked item as needing repainting, invalidate the entire old and new areas.
     combined.Or(geometry->ComputeInvalidationRegion(), oldGeometry->ComputeInvalidationRegion());
 #ifdef DEBUG_INVALIDATIONS
@@ -2277,6 +2280,9 @@ ContainerState::InvalidateForLayerChange(nsDisplayItem* aItem,
     oldClip->AddOffsetAndComputeDifference(shift, oldGeometry->ComputeInvalidationRegion(),
                                            aClip, geometry->ComputeInvalidationRegion(),
                                            &combined);
+
+    // Add in any rect that the frame specified
+    combined = combined.Or(combined, invalid);
 #ifdef DEBUG_INVALIDATIONS
     if (!combined.IsEmpty()) {
       printf("Display item type %s(%p) (in layer %p) changed geometry!\n", aItem->Name(), f, aNewLayer);

layout/base/nsDisplayList.h

@@ -774,7 +774,11 @@ public:
    * Checks if the frame(s) owning this display item have been marked as invalid,
    * and needing repainting.
    */
-  virtual bool IsInvalid() { return mFrame ? mFrame->IsInvalid() : false; }
+  virtual bool IsInvalid(nsRect& aRect) { 
+    bool result = mFrame ? mFrame->IsInvalid(aRect) : false;
+    aRect += ToReferenceFrame();
+    return result;
+  }
 
   /**
    * Creates and initializes an nsDisplayItemGeometry object that retains the current
@@ -2005,17 +2009,21 @@ public:
   {
     aFrames->AppendElements(mMergedFrames);
   }
-  virtual bool IsInvalid()
+  virtual bool IsInvalid(nsRect& aRect)
   {
-    if (mFrame->IsInvalid()) {
+    if (mFrame->IsInvalid(aRect) && aRect.IsEmpty()) {
       return true;
     }
+    nsRect temp;
     for (uint32_t i = 0; i < mMergedFrames.Length(); i++) {
-      if (mMergedFrames[i]->IsInvalid()) {
+      if (mMergedFrames[i]->IsInvalid(temp) && temp.IsEmpty()) {
+        aRect.SetEmpty();
         return true;
       }
+      aRect = aRect.Union(temp);
     }
-    return false;
+    aRect += ToReferenceFrame();
+    return !aRect.IsEmpty();
   }
   NS_DISPLAY_DECL_NAME("WrapList", TYPE_WRAP_LIST)
 

layout/generic/nsFrame.cpp

@@ -4806,12 +4806,50 @@ nsIFrame::InvalidateFrame()
   if (!parent) {
     SchedulePaint();
   }
+  if (HasAnyStateBits(NS_FRAME_HAS_INVALID_RECT)) {
+    Properties().Delete(InvalidationRect());
+    RemoveStateBits(NS_FRAME_HAS_INVALID_RECT);
+  }
+}
+
+void
+nsIFrame::InvalidateFrameWithRect(const nsRect& aRect)
+{
+  bool alreadyInvalid = false;
+  if (!HasAnyStateBits(NS_FRAME_NEEDS_PAINT)) {
+    InvalidateFrame();
+  } else {
+    alreadyInvalid = true;
+  } 
+
+  nsRect *rect = static_cast<nsRect*>(Properties().Get(InvalidationRect()));
+  if (!rect) {
+    if (alreadyInvalid) {
+      return;
+    }
+    rect = new nsRect();
+    Properties().Set(InvalidationRect(), rect);
+    AddStateBits(NS_FRAME_HAS_INVALID_RECT);
+  }
+
+  *rect = rect->Union(aRect);
 }
   
 bool 
-nsIFrame::IsInvalid() 
+nsIFrame::IsInvalid(nsRect& aRect)
 {
-  return HasAnyStateBits(NS_FRAME_NEEDS_PAINT);
+  if (!HasAnyStateBits(NS_FRAME_NEEDS_PAINT)) {
+    return false;
+  }
+  
+  if (HasAnyStateBits(NS_FRAME_HAS_INVALID_RECT)) {
+    nsRect *rect = static_cast<nsRect*>(Properties().Get(InvalidationRect()));
+    NS_ASSERTION(rect, "Must have an invalid rect if NS_FRAME_HAS_INVALID_RECT is set!");
+    aRect = *rect;
+  } else {
+    aRect.SetEmpty();
+  }
+  return true;
 }
 
 void

layout/generic/nsIFrame.h

@@ -319,6 +319,10 @@ typedef uint64_t nsFrameState;
 // have no display items.
 #define NS_FRAME_ALL_DESCENDANTS_NEED_PAINT         NS_FRAME_STATE_BIT(51)
 
+// Frame is marked as NS_FRAME_NEEDS_PAINT and also has an explicit
+// rect stored to invalidate.
+#define NS_FRAME_HAS_INVALID_RECT                   NS_FRAME_STATE_BIT(52)
+
 // Box layout bits
 #define NS_STATE_IS_HORIZONTAL                      NS_FRAME_STATE_BIT(22)
 #define NS_STATE_IS_DIRECTION_NORMAL                NS_FRAME_STATE_BIT(31)
@@ -955,6 +959,8 @@ public:
 
   NS_DECLARE_FRAME_PROPERTY(CachedBackgroundImage, DestroySurface)
 
+  NS_DECLARE_FRAME_PROPERTY(InvalidationRect, DestroyRect)
+
   /**
    * Return the distance between the border edge of the frame and the
    * margin edge of the frame.  Like GetRect(), returns the dimensions
@@ -2179,6 +2185,15 @@ public:
    * container types.
    */
   virtual void InvalidateFrame();
+
+  /**
+   * Same as InvalidateFrame(), but only mark a fixed rect as needing
+   * repainting.
+   *
+   * @param aRect The rect to invalidate, relative to the TopLeft of the
+   * frame's border box.
+   */
+  virtual void InvalidateFrameWithRect(const nsRect& aRect);
   
   /**
    * Calls InvalidateFrame() on all frames descendant frames (including
@@ -2192,8 +2207,13 @@ public:
   /**
    * Checks if a frame has had InvalidateFrame() called on it since the
    * last paint.
+   *
+   * If true, then the invalid rect is returned in aRect, with an
+   * empty rect meaning all pixels drawn by this frame should be
+   * invalidated.
+   * If false, aRect is left unchanged.
    */
-  bool IsInvalid();
+  bool IsInvalid(nsRect& aRect);
  
   /**
    * Check if any frame within the frame subtree (including this frame) 

layout/generic/nsImageFrame.cpp

@@ -587,12 +587,16 @@ nsImageFrame::OnDataAvailable(imgIRequest *aRequest,
   // from
   if (!aCurrentFrame)
     return NS_OK;
-
+  
 #ifdef DEBUG_decode
   printf("Source rect (%d,%d,%d,%d)\n",
          aRect->x, aRect->y, aRect->width, aRect->height);
 #endif
-  InvalidateFrame();
+  if (aRect->IsEqualInterior(nsIntRect::GetMaxSizedIntRect())) {
+    InvalidateFrame();
+  } else {
+    InvalidateFrameWithRect(SourceRectToDest(*aRect));
+  }
   
   return NS_OK;
 }
@@ -671,8 +675,11 @@ nsImageFrame::FrameChanged(imgIRequest *aRequest,
     return NS_OK;
   }
 
-  // Update border+content to account for image change
-  InvalidateFrame();
+  if (aDirtyRect->IsEqualInterior(nsIntRect::GetMaxSizedIntRect())) {
+    InvalidateFrame();
+  } else {
+    InvalidateFrameWithRect(SourceRectToDest(*aDirtyRect));
+  }
   return NS_OK;
 }
 

layout/svg/nsSVGOuterSVGFrame.h

@@ -155,7 +155,8 @@ public:
   void ClearInvalidRegion() { mInvalidRegion.SetEmpty(); }
 
   const nsRegion& GetInvalidRegion() {
-    if (!IsInvalid()) {
+    nsRect rect;
+    if (!IsInvalid(rect)) {
       mInvalidRegion.SetEmpty();
     }
     return mInvalidRegion;