Implement CSSOM Smooth Scroll API

Source/platform/scroll/ScrollableArea.cpp

 /*
  * Copyright (c) 2010, Google Inc. All rights reserved.
  * Copyright (C) 2008, 2011 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 16 matching lines @@
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "platform/scroll/ScrollableArea.h"
 
 #include "platform/graphics/GraphicsLayer.h"
 #include "platform/geometry/FloatPoint.h"
+#include "platform/scroll/ProgrammaticScrollAnimator.h"
 #include "platform/scroll/ScrollbarTheme.h"
 #include "wtf/PassOwnPtr.h"
 
 #include "platform/TraceEvent.h"
 
 static const int kPixelsPerLineStep = 40;
 static const float kMinFractionToStepWhenPaging = 0.875f;
 
 namespace WebCore {
 
 struct SameSizeAsScrollableArea {
     virtual ~SameSizeAsScrollableArea();
     unsigned damageBits : 2;
     IntRect scrollbarDamage[2];
-    void* pointer;
+    void* pointer[2];
     unsigned bitfields : 16;
     IntPoint origin;
 };
 
 COMPILE_ASSERT(sizeof(ScrollableArea) == sizeof(SameSizeAsScrollableArea), ScrollableArea_should_stay_small);
 
 int ScrollableArea::pixelsPerLineStep()
 {
     return kPixelsPerLineStep;
 }
@@ skipping 26 matching lines @@
 }
 
 ScrollAnimator* ScrollableArea::scrollAnimator() const
 {
     if (!m_scrollAnimator)
         m_scrollAnimator = ScrollAnimator::create(const_cast<ScrollableArea*>(this));
 
     return m_scrollAnimator.get();
 }
 
+ProgrammaticScrollAnimator* ScrollableArea::programmaticScrollAnimator() const
+{
+    if (!m_programmaticScrollAnimator)
+        m_programmaticScrollAnimator = ProgrammaticScrollAnimator::create(const_cast<ScrollableArea*>(this));
+
+    return m_programmaticScrollAnimator.get();
+}
+
 void ScrollableArea::setScrollOrigin(const IntPoint& origin)
 {
     if (m_scrollOrigin != origin) {
         m_scrollOrigin = origin;
         m_scrollOriginChanged = true;
     }
 }
 
 GraphicsLayer* ScrollableArea::layerForContainer() const
 {
     return layerForScrolling() ? layerForScrolling()->parent() : 0;
 }
 
 bool ScrollableArea::scroll(ScrollDirection direction, ScrollGranularity granularity, float delta)
 {
     ScrollbarOrientation orientation;
 
     if (direction == ScrollUp || direction == ScrollDown)
         orientation = VerticalScrollbar;
     else
         orientation = HorizontalScrollbar;
 
     if (!userInputScrollable(orientation))
         return false;
 
+    cancelProgrammaticScrollAnimation();
+
     float step = 0;
     switch (granularity) {
     case ScrollByLine:
         step = lineStep(orientation);
         break;
     case ScrollByPage:
         step = pageStep(orientation);
         break;
     case ScrollByDocument:
         step = documentStep(orientation);
         break;
     case ScrollByPixel:
     case ScrollByPrecisePixel:
         step = pixelStep(orientation);
         break;
     }
 
     if (direction == ScrollUp || direction == ScrollLeft)
         delta = -delta;
 
     return scrollAnimator()->scroll(orientation, granularity, step, delta);
 }
 
 void ScrollableArea::scrollToOffsetWithoutAnimation(const FloatPoint& offset)
 {
+    cancelProgrammaticScrollAnimation();
     scrollAnimator()->scrollToOffsetWithoutAnimation(offset);
 }
 
 void ScrollableArea::scrollToOffsetWithoutAnimation(ScrollbarOrientation orientation, float offset)
 {
     if (orientation == HorizontalScrollbar)
         scrollToOffsetWithoutAnimation(FloatPoint(offset, scrollAnimator()->currentPosition().y()));
     else
         scrollToOffsetWithoutAnimation(FloatPoint(scrollAnimator()->currentPosition().x(), offset));
 }
 
+void ScrollableArea::programmaticallyScrollSmoothlyToOffset(const FloatPoint& offset)
+{
+    if (ScrollAnimator* scrollAnimator = existingScrollAnimator())
+        scrollAnimator->cancelAnimations();
+    cancelProgrammaticScrollAnimation();
+    programmaticScrollAnimator()->animateToOffset(offset);
+}
+
 void ScrollableArea::notifyScrollPositionChanged(const IntPoint& position)
 {
     scrollPositionChanged(position);
     scrollAnimator()->setCurrentPosition(position);
 }
 
 void ScrollableArea::scrollPositionChanged(const IntPoint& position)
 {
     TRACE_EVENT0("blink", "ScrollableArea::scrollPositionChanged");
 
@@ skipping 41 matching lines @@
 
     return true;
 }
 
 bool ScrollableArea::handleWheelEvent(const PlatformWheelEvent& wheelEvent)
 {
     // ctrl+wheel events are used to trigger zooming, not scrolling.
     if (wheelEvent.modifiers() & PlatformEvent::CtrlKey)
         return false;
 
+    cancelProgrammaticScrollAnimation();
     return scrollAnimator()->handleWheelEvent(wheelEvent);
 }
 
 // NOTE: Only called from Internals for testing.
 void ScrollableArea::setScrollOffsetFromInternals(const IntPoint& offset)
 {
     setScrollOffsetFromAnimation(offset);
 }
 
 void ScrollableArea::setScrollOffsetFromAnimation(const IntPoint& offset)
@@ skipping 155 matching lines @@
 bool ScrollableArea::hasLayerForVerticalScrollbar() const
 {
     return layerForVerticalScrollbar();
 }
 
 bool ScrollableArea::hasLayerForScrollCorner() const
 {
     return layerForScrollCorner();
 }
 
-void ScrollableArea::serviceScrollAnimations()
+void ScrollableArea::serviceScrollAnimations(double monotonicTime)
 {
     if (ScrollAnimator* scrollAnimator = existingScrollAnimator())
         scrollAnimator->serviceScrollAnimations();
+    if (ProgrammaticScrollAnimator* programmaticScrollAnimator = existingProgrammaticScrollAnimator())
+        programmaticScrollAnimator->tickAnimation(monotonicTime);
+}
+
+void ScrollableArea::notifyAnimationStarted(double monotonicTime)
+{
+    programmaticScrollAnimator()->notifyAnimationStarted(monotonicTime);
+}
+
+void ScrollableArea::notifyAnimationFinished(double monotonicTime)
+{
+    programmaticScrollAnimator()->notifyAnimationFinished(monotonicTime);
+}
+
+void ScrollableArea::layerForScrollingDidChange()
+{
+    if (ProgrammaticScrollAnimator* programmaticScrollAnimator = existingProgrammaticScrollAnimator())
+        programmaticScrollAnimator->canUseCompositedScrollAnimationsDidChange();
+}
+
+void ScrollableArea::requiresMainThreadScrollingDidChange()
+{
+    if (ProgrammaticScrollAnimator* programmaticScrollAnimator = existingProgrammaticScrollAnimator())
+        programmaticScrollAnimator->canUseCompositedScrollAnimationsDidChange();
+}
+
+bool ScrollableArea::canUseCompositedScrollAnimations() const
+{
+    return layerForScrolling() && !layerForScrolling()->platformLayer()->shouldScrollOnMainThread();
+}
+
+void ScrollableArea::cancelProgrammaticScrollAnimation()
+{
+    if (ProgrammaticScrollAnimator* programmaticScrollAnimator = existingProgrammaticScrollAnimator())
+        programmaticScrollAnimator->cancelAnimation();
 }
 
 IntRect ScrollableArea::visibleContentRect(IncludeScrollbarsInRect scrollbarInclusion) const
 {
     int verticalScrollbarWidth = 0;
     int horizontalScrollbarHeight = 0;
 
     if (scrollbarInclusion == IncludeScrollbars) {
         if (Scrollbar* verticalBar = verticalScrollbar())
             verticalScrollbarWidth = !verticalBar->isOverlayScrollbar() ? verticalBar->width() : 0;
@@ skipping 30 matching lines @@
 {
     return scrollSize(orientation);
 }
 
 float ScrollableArea::pixelStep(ScrollbarOrientation) const
 {
     return 1;
 }
 
 } // namespace WebCore