Bug 593243: Clip invalidations to the displayport when one is set. r=tn

layout/base/nsPresShell.cpp

@@ -6062,21 +6062,11 @@ void PresShell::SetRenderingState(const RenderingState& aState)
   mXResolution = aState.mXResolution;
   mYResolution = aState.mYResolution;
 
-  // FIXME (Bug 593243 should fix this.)
-  //
-  // Invalidated content does not pay any attention to the displayport, so
-  // invalidating the subdocument's root frame could end up not repainting
-  // visible content.
-  //
-  // For instance, imagine the iframe is located at y=1000. Even though the
-  // displayport may intersect the iframe's viewport, the visual overflow
-  // rect of the root content could be (0, 0, 800, 500). Since the dirty region
-  // does not intersect the visible overflow rect, the display list for the
-  // iframe will not even be generated.
-  //
-  // Here, we find the very top presShell and use its root frame for
-  // invalidation instead.
-  //
+  nsIView* rootView;
+  if (NS_SUCCEEDED(mViewManager->GetRootView(rootView)) && rootView) {
+    rootView->SetInvalidationDimensions(&mDisplayPort);
+  }
+
   nsPresContext* rootPresContext = mPresContext->GetRootPresContext();
   if (rootPresContext) {
     nsIPresShell* rootPresShell = rootPresContext->GetPresShell();

layout/generic/nsGfxScrollFrame.cpp

@@ -195,7 +195,15 @@ nsHTMLScrollFrame::InvalidateInternal(const nsRect& aDamageRect,
       nsRect damage = aDamageRect + nsPoint(aX, aY);
       // This is the damage rect that we're going to pass up to our parent.
       nsRect parentDamage;
-      parentDamage.IntersectRect(damage, mInner.mScrollPort);
+      nsIPresShell* presShell = PresContext()->PresShell();
+      // If we're using a displayport, we might be displaying an area
+      // different than our scroll port and the damage needs to be
+      // clipped to that instead.
+      if (mInner.mIsRoot && presShell->UsingDisplayPort()) {
+        parentDamage.IntersectRect(damage, presShell->GetDisplayPort());
+      } else {
+        parentDamage.IntersectRect(damage, mInner.mScrollPort);
+      }
 
       if (IsScrollingActive()) {
         // This is the damage rect that we're going to pass up and
@@ -1104,7 +1112,15 @@ nsXULScrollFrame::InvalidateInternal(const nsRect& aDamageRect,
     nsRect damage = aDamageRect + nsPoint(aX, aY);
     // This is the damage rect that we're going to pass up to our parent.
     nsRect parentDamage;
-    parentDamage.IntersectRect(damage, mInner.mScrollPort);
+    nsIPresShell* presShell = PresContext()->PresShell();
+    // If we're using a displayport, we might be displaying an area
+    // different than our scroll port and the damage needs to be
+    // clipped to that instead.
+    if (mInner.mIsRoot && presShell->UsingDisplayPort()) {
+      parentDamage.IntersectRect(damage, presShell->GetDisplayPort());
+    } else {
+      parentDamage.IntersectRect(damage, mInner.mScrollPort);
+    }
 
     if (IsScrollingActive()) {
       // This is the damage rect that we're going to pass up and

view/public/nsIView.h

@@ -173,6 +173,17 @@ public:
    */
   nsRect GetBounds() const { return mDimBounds; }
 
+  /**
+   * Set the dimensions at which invalidations are clipped, which can
+   * be different than |GetDimensions()|.  |aRect| is relative to
+   * |this|.  It can be null, in which case invalidations return to
+   * being clipped to the view dimensions.
+   *
+   * The caller is responsible for invalidating the area that may lie
+   * outside the view dimensions but inside |aRect| after this call.
+   */
+  void SetInvalidationDimensions(const nsRect* aRect);
+
   /**
    * Get the offset between the coordinate systems of |this| and aOther.
    * Adding the return value to a point in the coordinate system of |this|

view/src/nsView.cpp

@@ -209,6 +209,7 @@ nsView::nsView(nsViewManager* aViewManager, nsViewVisibility aVisibility)
   mViewManager = aViewManager;
   mDirtyRegion = nsnull;
   mDeletionObserver = nsnull;
+  mHaveInvalidationDimensions = PR_FALSE;
   mWidgetIsTopLevel = PR_FALSE;
 }
 
@@ -350,6 +351,11 @@ void nsView::SetPosition(nscoord aX, nscoord aY)
   ResetWidgetBounds(PR_TRUE, PR_TRUE, PR_FALSE);
 }
 
+void nsIView::SetInvalidationDimensions(const nsRect* aRect)
+{
+  return Impl()->SetInvalidationDimensions(aRect);
+}
+
 void nsView::SetPositionIgnoringChildWidgets(nscoord aX, nscoord aY)
 {
   mDimBounds.x += aX - mPosX;
@@ -495,6 +501,13 @@ void nsView::SetDimensions(const nsRect& aRect, PRBool aPaint, PRBool aResizeWid
   }
 }
 
+void nsView::SetInvalidationDimensions(const nsRect* aRect)
+{
+  if ((mHaveInvalidationDimensions = !!aRect)) {
+    mInvalidationDimensions = *aRect;
+  }
+}
+
 void nsView::NotifyEffectiveVisibilityChanged(PRBool aEffectivelyVisible)
 {
   if (!aEffectivelyVisible)

view/src/nsView.h

@@ -76,6 +76,7 @@ public:
    */
   virtual void SetDimensions(const nsRect &aRect, PRBool aPaint = PR_TRUE,
                              PRBool aResizeWidget = PR_TRUE);
+  void SetInvalidationDimensions(const nsRect* aRect);
   void GetDimensions(nsRect &aRect) const { aRect = mDimBounds; aRect.x -= mPosX; aRect.y -= mPosY; }
   void GetDimensions(nsSize &aSize) const { aSize.width = mDimBounds.width; aSize.height = mDimBounds.height; }
 
@@ -148,6 +149,11 @@ public:
   nsRect GetDimensions() const { nsRect r = mDimBounds; r.MoveBy(-mPosX, -mPosY); return r; }
   // Same as GetBounds but converts to parent appunits if they are different.
   nsRect GetBoundsInParentUnits() const;
+
+  nsRect GetInvalidationDimensions() const {
+    return mHaveInvalidationDimensions ? mInvalidationDimensions : GetDimensions();
+  }
+
   // These are defined exactly the same in nsIView, but for now they have to be redeclared
   // here because of stupid C++ method hiding rules
 
@@ -202,6 +208,13 @@ protected:
   void DoResetWidgetBounds(PRBool aMoveOnly, PRBool aInvalidateChangedSize);
 
   nsRegion*    mDirtyRegion;
+  // invalidations are clipped to mInvalidationDimensions, not
+  // GetDimensions(), when mHaveInvalidationDimensions is true.  This
+  // is used to support persistent "displayport" rendering; see
+  // nsPresShell.cpp.  The coordinates of mInvalidationDimensions are
+  // relative to |this|.
+  nsRect       mInvalidationDimensions;
+  PRPackedBool mHaveInvalidationDimensions;
 
 private:
   void InitializeWindow(PRBool aEnableDragDrop, PRBool aResetVisibility);

view/src/nsViewManager.cpp

@@ -571,7 +571,7 @@ nsViewManager::UpdateWidgetArea(nsView *aWidgetView, nsIWidget* aWidget,
 
   // If the bounds don't overlap at all, there's nothing to do
   nsRegion intersection;
-  intersection.And(aWidgetView->GetDimensions(), aDamagedRegion);
+  intersection.And(aWidgetView->GetInvalidationDimensions(), aDamagedRegion);
   if (intersection.IsEmpty()) {
     return;
   }
@@ -1623,7 +1623,7 @@ nsIntRect nsViewManager::ViewToWidget(nsView *aView, const nsRect &aRect) const
   NS_ASSERTION(aView->GetViewManager() == this, "wrong view manager");
 
   // intersect aRect with bounds of aView, to prevent generating any illegal rectangles.
-  nsRect bounds = aView->GetDimensions();
+  nsRect bounds = aView->GetInvalidationDimensions();
   nsRect rect;
   rect.IntersectRect(aRect, bounds);