Bug 167115 - tree/listbox does't work with background styles (-image,

-attachment) correctly.  Patch by alfredkayser@nl.ibm.com, r=varga, sr=bryner

layout/xul/base/src/nsListBoxBodyFrame.cpp

@@ -471,7 +471,7 @@ nsListBoxBodyFrame::VisibilityChanged(nsISupports* aScrollbar, PRBool aVisible)
   PRInt32 delta = mCurrentIndex - lastPageTopRow;
   if (delta > 0) {
     mCurrentIndex = lastPageTopRow;
-    InternalPositionChanged(PR_TRUE, delta, PR_FALSE);
+    InternalPositionChanged(PR_TRUE, delta);
   }
 
   return NS_OK;
@@ -592,12 +592,6 @@ nsListBoxBodyFrame::EnsureIndexIsVisible(PRInt32 aRowIndex)
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsListBoxBodyFrame::ScrollToIndex(PRInt32 aRowIndex)
-{
-  return DoScrollToIndex(aRowIndex);
-}
-
 NS_IMETHODIMP
 nsListBoxBodyFrame::ScrollByLines(PRInt32 aNumLines)
 {
@@ -864,7 +858,7 @@ nsListBoxBodyFrame::PostReflowCallback()
 ////////// scrolling
 
 NS_IMETHODIMP
-nsListBoxBodyFrame::DoScrollToIndex(PRInt32 aRowIndex, PRBool aForceDestruct)
+nsListBoxBodyFrame::ScrollToIndex(PRInt32 aRowIndex)
 {
   if (( aRowIndex < 0 ) || (mRowHeight == 0))
     return NS_OK;
@@ -882,7 +876,7 @@ nsListBoxBodyFrame::DoScrollToIndex(PRInt32 aRowIndex, PRBool aForceDestruct)
     return NS_OK;
 
   mCurrentIndex = newIndex;
-  InternalPositionChanged(up, delta, aForceDestruct);
+  InternalPositionChanged(up, delta);
 
   // This change has to happen immediately.
   // Flush any pending reflow commands.
@@ -909,7 +903,7 @@ nsListBoxBodyFrame::InternalPositionChangedCallback()
 }
 
 NS_IMETHODIMP
-nsListBoxBodyFrame::InternalPositionChanged(PRBool aUp, PRInt32 aDelta, PRBool aForceDestruct)
+nsListBoxBodyFrame::InternalPositionChanged(PRBool aUp, PRInt32 aDelta)
 {  
   if (aDelta == 0)
     return NS_OK;
@@ -925,7 +919,7 @@ nsListBoxBodyFrame::InternalPositionChanged(PRBool aUp, PRInt32 aDelta, PRBool a
   if (mRowHeight)
 	  visibleRows = GetAvailableHeight()/mRowHeight;
   
-  if (aDelta < visibleRows && !aForceDestruct) {
+  if (aDelta < visibleRows) {
     PRInt32 loseRows = aDelta;
     if (aUp) {
       // scrolling up, destroy rows from the bottom downwards
@@ -963,9 +957,6 @@ nsListBoxBodyFrame::InternalPositionChanged(PRBool aUp, PRInt32 aDelta, PRBool a
   
   VerticalScroll(mYPosition);
 
-  if (aForceDestruct)
-    Redraw(state, nsnull, PR_FALSE);
-  
   PRTime end = PR_Now();
 
   PRTime difTime;

layout/xul/base/src/nsListBoxBodyFrame.h

@@ -105,9 +105,8 @@ public:
   nscoord ComputeIntrinsicWidth(nsBoxLayoutState& aBoxLayoutState);
 
   // scrolling
-  NS_IMETHOD DoScrollToIndex(PRInt32 aRowIndex, PRBool aForceDestruct=PR_FALSE);
   NS_IMETHOD InternalPositionChangedCallback();
-  NS_IMETHOD InternalPositionChanged(PRBool aUp, PRInt32 aDelta, PRBool aForceDestruct=PR_FALSE);
+  NS_IMETHOD InternalPositionChanged(PRBool aUp, PRInt32 aDelta);
   nsListScrollSmoother* GetSmoother();
   void VerticalScroll(PRInt32 aDelta);
 

layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp

@@ -3265,19 +3265,19 @@ nsTreeBodyFrame::ScrollInternal(PRInt32 aRow)
 
   mTopRowIndex += delta;
 
-  float t2p = mPresContext->TwipsToPixels();
-  nscoord rowHeightAsPixels = NSToCoordRound((float)mRowHeight*t2p);
-
-  // See if we have a background image.  If we do, then we cannot blit.
-  PRBool hasBackground = GetStyleBackground()->mBackgroundImage != nsnull;
-
-  PRInt32 absDelta = PR_ABS(delta);
-  if (hasBackground || absDelta*mRowHeight >= mRect.height)
+  // See if we have a transparent background or a background image.  
+  // If we do, then we cannot blit.
+  const nsStyleBackground* background = GetStyleBackground();
+  if (background->mBackgroundImage || background->IsTransparent() || 
+      PR_ABS(delta)*mRowHeight >= mRect.height) {
     Invalidate();
-  else {
+  } else {
     nsIWidget* widget = nsLeafBoxFrame::GetView()->GetWidget();
-    if (widget)
+    if (widget) {
+      float t2p = mPresContext->TwipsToPixels();
+      nscoord rowHeightAsPixels = NSToCoordRound((float)mRowHeight*t2p);
       widget->Scroll(0, -delta*rowHeightAsPixels, nsnull);
+    }
   }
 
   return NS_OK;