Bug 681867. text-overflow only needs to affect the scrolling behavior of the block container with text-overflow. r=mats

layout/generic/TextOverflow.cpp

@@ -51,6 +51,7 @@
 #include "nsRect.h"
 #include "nsRenderingContext.h"
 #include "nsTextFrame.h"
+#include "nsGfxScrollFrame.h"
 
 namespace mozilla {
 namespace css {
@@ -278,6 +279,8 @@ TextOverflow::WillProcessLines(nsDisplayListBuilder*   aBuilder,
     textOverflow->mCanHaveHorizontalScrollbar =
       scroll->GetScrollbarStyles().mHorizontal != NS_STYLE_OVERFLOW_HIDDEN;
     textOverflow->mContentArea.MoveBy(scroll->GetScrollPosition());
+    nsIFrame* scrollFrame = do_QueryFrame(scroll);
+    scrollFrame->AddStateBits(NS_SCROLLFRAME_INVALIDATE_CONTENTS_ON_SCROLL);
   }
   PRUint8 direction = aBlockFrame->GetStyleVisibility()->mDirection;
   textOverflow->mBlockIsRTL = direction == NS_STYLE_DIRECTION_RTL;
@@ -290,23 +293,6 @@ TextOverflow::WillProcessLines(nsDisplayListBuilder*   aBuilder,
   return textOverflow.forget();
 }
 
-void
-TextOverflow::DidProcessLines()
-{
-  nsIScrollableFrame* scroll = nsLayoutUtils::GetScrollableFrameFor(mBlock);
-  if (scroll) {
-    // Create a dummy item covering the entire area, it doesn't paint
-    // but reports true for IsVaryingRelativeToMovingFrame().
-    nsIFrame* scrollFrame = do_QueryFrame(scroll);
-    nsDisplayItem* marker = new (mBuilder)
-      nsDisplayForcePaintOnScroll(mBuilder, scrollFrame);
-    if (marker) {
-      mMarkerList->AppendNewToBottom(marker);
-      mBlock->PresContext()->SetHasFixedBackgroundFrame();
-    }
-  }
-}
-
 void
 TextOverflow::ExamineFrameSubtree(nsIFrame*       aFrame,
                                   const nsRect&   aContentArea,

layout/generic/TextOverflow.h

@@ -52,7 +52,6 @@ namespace css {
  * Usage:
  *  1. allocate an object using WillProcessLines
  *  2. then call ProcessLine for each line you are building display lists for
- *  3. finally call DidProcessLines
  */
 class TextOverflow {
  public:
@@ -70,12 +69,6 @@ class TextOverflow {
    */
   void ProcessLine(const nsDisplayListSet& aLists, nsLineBox* aLine);
 
-  /**
-   * Do final processing, currently just adds a dummy item for scroll frames
-   * to make IsVaryingRelativeToMovingFrame() true for the entire area.
-   */
-  void DidProcessLines();
-
   /**
    * @return true if aBlockFrame needs analysis for text overflow.
    */

layout/generic/nsBlockFrame.cpp

@@ -6247,11 +6247,6 @@ nsBlockFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
     }
   }
 
-  // Finalize text-overflow processing.
-  if (textOverflow) {
-    textOverflow->DidProcessLines();
-  }
-
   if (NS_SUCCEEDED(rv) && (nsnull != mBullet) && HaveOutsideBullet()) {
     // Display outside bullets manually
     rv = BuildDisplayListForChild(aBuilder, mBullet, aDirtyRect, aLists);

layout/generic/nsGfxScrollFrame.cpp

@@ -1619,6 +1619,9 @@ static void AdjustViews(nsIFrame* aFrame)
 static bool
 CanScrollWithBlitting(nsIFrame* aFrame)
 {
+  if (aFrame->GetStateBits() & NS_SCROLLFRAME_INVALIDATE_CONTENTS_ON_SCROLL)
+    return false;
+
   for (nsIFrame* f = aFrame; f;
        f = nsLayoutUtils::GetCrossDocParentFrame(f)) {
     if (nsSVGIntegrationUtils::UsingEffectsForFrame(f) ||
@@ -1732,6 +1735,7 @@ void nsGfxScrollFrameInner::ScrollVisual()
   // to be consistent with the frame hierarchy.
   PRUint32 flags = nsIFrame::INVALIDATE_REASON_SCROLL_REPAINT;
   bool canScrollWithBlitting = CanScrollWithBlitting(mOuter);
+  mOuter->RemoveStateBits(NS_SCROLLFRAME_INVALIDATE_CONTENTS_ON_SCROLL);
   if (IsScrollingActive()) {
     if (!canScrollWithBlitting) {
       MarkInactive();

layout/generic/nsGfxScrollFrame.h

@@ -64,6 +64,12 @@ class nsIScrollFrameInternal;
 class nsPresState;
 struct ScrollReflowState;
 
+// When set, the next scroll operation on the scrollframe will invalidate its
+// entire contents. Useful for text-overflow.
+// This bit is cleared after each time the scrollframe is scrolled. Whoever
+// needs to set it should set it again on each paint.
+#define NS_SCROLLFRAME_INVALIDATE_CONTENTS_ON_SCROLL NS_FRAME_STATE_BIT(20)
+
 class nsGfxScrollFrameInner : public nsIReflowCallback {
 public:
   class AsyncScroll;