Implement CSSOM smooth scroll for Elements

Source/core/rendering/RenderLayerScrollableArea.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 97 matching lines @@
 RenderLayerScrollableArea::~RenderLayerScrollableArea()
 {
     if (inResizeMode() && !box().documentBeingDestroyed()) {
         if (LocalFrame* frame = box().frame())
             frame->eventHandler().resizeScrollableAreaDestroyed();
     }
 
     if (LocalFrame* frame = box().frame()) {
         if (FrameView* frameView = frame->view()) {
             frameView->removeScrollableArea(this);
+            frameView->removeAnimatingScrollableArea(this);
         }
     }
 
     if (box().frame() && box().frame()->page()) {
         if (ScrollingCoordinator* scrollingCoordinator = box().frame()->page()->scrollingCoordinator())
             scrollingCoordinator->willDestroyScrollableArea(this);
     }
 
     if (!box().documentBeingDestroyed()) {
         Node* node = box().node();
@@ skipping 366 matching lines @@
     if (!view)
         return false;
     return view->frameView()->scrollbarsCanBeActive();
 }
 
 IntRect RenderLayerScrollableArea::scrollableAreaBoundingBox() const
 {
     return box().absoluteBoundingBoxRect();
 }
 
+void RenderLayerScrollableArea::registerForAnimation()
+{
+    if (LocalFrame* frame = box().frame()) {
+        if (FrameView* frameView = frame->view())
+            frameView->addAnimatingScrollableArea(this);
+    }
+}
+
+void RenderLayerScrollableArea::deregisterForAnimation()
+{
+    if (LocalFrame* frame = box().frame()) {
+        if (FrameView* frameView = frame->view())
+            frameView->removeAnimatingScrollableArea(this);
+    }
+}
+
 bool RenderLayerScrollableArea::userInputScrollable(ScrollbarOrientation orientation) const
 {
     if (box().isIntristicallyScrollable(orientation))
         return true;
 
     EOverflow overflowStyle = (orientation == HorizontalScrollbar) ?
         box().style()->overflowX() : box().style()->overflowY();
     return (overflowStyle == OSCROLL || overflowStyle == OAUTO || overflowStyle == OOVERLAY);
 }
 
@@ skipping 51 matching lines @@
     m_scrollDimensionsDirty = false;
 
     m_overflowRect = box().layoutOverflowRect();
     box().flipForWritingMode(m_overflowRect);
 
     int scrollableLeftOverflow = m_overflowRect.x() - box().borderLeft() - (box().style()->shouldPlaceBlockDirectionScrollbarOnLogicalLeft() ? box().verticalScrollbarWidth() : 0);
     int scrollableTopOverflow = m_overflowRect.y() - box().borderTop();
     setScrollOrigin(IntPoint(-scrollableLeftOverflow, -scrollableTopOverflow));
 }
 
-void RenderLayerScrollableArea::scrollToOffset(const DoubleSize& scrollOffset, ScrollOffsetClamping clamp)
+void RenderLayerScrollableArea::scrollToOffset(const DoubleSize& scrollOffset, ScrollOffsetClamping clamp, ScrollBehavior scrollBehavior)
 {
+    cancelProgrammaticScrollAnimation();
     DoubleSize newScrollOffset = clamp == ScrollOffsetClamped ? clampScrollOffset(scrollOffset) : scrollOffset;
     if (newScrollOffset != adjustedScrollOffset()) {
+        if (scrollBehavior == ScrollBehaviorAuto)
+            scrollBehavior = box().style()->scrollBehavior();
         DoublePoint origin(scrollOrigin());
-        // FIXME: Make scrollToOffsetWithoutAnimation take DoublePoint. crbug.com/414283.
-        scrollToOffsetWithoutAnimation(toFloatPoint(-origin + newScrollOffset));
+        if (scrollBehavior == ScrollBehaviorSmooth) {
+            // FIXME: Make programmaticallyScrollSmoothlyToOffset take DoublePoint. crbug.com/243871.
+            programmaticallyScrollSmoothlyToOffset(toFloatPoint(-origin + newScrollOffset));
+        } else {
+            // FIXME: Make scrollToOffsetWithoutAnimation take DoublePoint. crbug.com/414283.
+            scrollToOffsetWithoutAnimation(toFloatPoint(-origin + newScrollOffset));
+        }
     }
 }
 
 void RenderLayerScrollableArea::updateAfterLayout()
 {
     m_scrollDimensionsDirty = true;
     DoubleSize originalScrollOffset = adjustedScrollOffset();
 
     computeScrollDimensions();
 
@@ skipping 738 matching lines @@
 void RenderLayerScrollableArea::setTopmostScrollChild(RenderLayer* scrollChild)
 {
     // We only want to track the topmost scroll child for scrollable areas with
     // overlay scrollbars.
     if (!hasOverlayScrollbars())
         return;
     m_nextTopmostScrollChild = scrollChild;
 }
 
 } // namespace blink