Implement CSSOM Smooth Scroll API

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 35 matching lines @@
 
 #include "core/css/PseudoStyleRequest.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/editing/FrameSelection.h"
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/page/EventHandler.h"
 #include "core/page/FocusController.h"
 #include "core/frame/Frame.h"
 #include "core/frame/FrameView.h"
+#include "core/frame/Settings.h"
 #include "core/page/Page.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
 #include "core/rendering/CompositedLayerMapping.h"
 #include "core/rendering/LayoutRectRecorder.h"
 #include "core/rendering/RenderGeometryMap.h"
 #include "core/rendering/RenderLayerCompositor.h"
 #include "core/rendering/RenderScrollbar.h"
 #include "core/rendering/RenderScrollbarPart.h"
 #include "core/rendering/RenderView.h"
 #include "platform/PlatformGestureEvent.h"
@@ skipping 37 matching lines @@
 
 RenderLayerScrollableArea::~RenderLayerScrollableArea()
 {
     if (inResizeMode() && !m_box->documentBeingDestroyed()) {
         if (Frame* frame = m_box->frame())
             frame->eventHandler().resizeScrollableAreaDestroyed();
     }
 
     if (Frame* frame = m_box->frame()) {
         if (FrameView* frameView = frame->view()) {
             frameView->removeScrollableArea(this);

[Ian Vollick, 2014/02/06 16:02:31]

Can't we just removeAnimationScrollableArea from removeScrollableArea?

+            frameView->removeAnimatingScrollableArea(this);
         }
     }
 
     if (m_box->frame() && m_box->frame()->page()) {
         if (ScrollingCoordinator* scrollingCoordinator = m_box->frame()->page()->scrollingCoordinator())
             scrollingCoordinator->willDestroyScrollableArea(this);
     }
 
     if (!m_box->documentBeingDestroyed()) {
         Node* node = m_box->node();
@@ skipping 379 matching lines @@
 int RenderLayerScrollableArea::pageStep(ScrollbarOrientation orientation) const
 {
     int length = (orientation == HorizontalScrollbar) ?
         m_box->pixelSnappedClientWidth() : m_box->pixelSnappedClientHeight();
     int minPageStep = static_cast<float>(length) * ScrollableArea::minFractionToStepWhenPaging();
     int pageStep = max(minPageStep, length - ScrollableArea::maxOverlapBetweenPages());
 
     return max(pageStep, 1);
 }
 
+bool RenderLayerScrollableArea::registerForAnimation()
+{
+    if (Frame* frame = m_box->frame()) {
+        if (FrameView* frameView = frame->view())
+            return frameView->addAnimatingScrollableArea(this);
+    }
+    return false;
+}
+
+void RenderLayerScrollableArea::deregisterForAnimation()
+{
+    if (Frame* frame = m_box->frame()) {
+        if (FrameView* frameView = frame->view())
+            frameView->removeAnimatingScrollableArea(this);
+    }
+}
+
+bool RenderLayerScrollableArea::scheduleAnimation()
+{
+    if (Frame* frame = m_box->frame()) {
+        if (FrameView* frameView = frame->view())
+            return frameView->scheduleAnimation();
+    }
+    return false;
+}
+
+bool RenderLayerScrollableArea::compositedScrollAnimationsEnabled() const
+{
+    if (Settings* settings = m_box->document().settings())
+        return settings->compositorDrivenScrollAnimationsEnabled();
+    return false;
+}
+
 RenderLayer* RenderLayerScrollableArea::layer() const
 {
     return m_box->layer();
 }
 
 int RenderLayerScrollableArea::scrollWidth() const
 {
     if (m_scrollDimensionsDirty)
         const_cast<RenderLayerScrollableArea*>(this)->computeScrollDimensions();
     return snapSizeToPixel(m_overflowRect.width(), m_box->clientLeft() + m_box->x());
@@ skipping 11 matching lines @@
     m_scrollDimensionsDirty = false;
 
     m_overflowRect = m_box->layoutOverflowRect();
     m_box->flipForWritingMode(m_overflowRect);
 
     int scrollableLeftOverflow = m_overflowRect.x() - m_box->borderLeft() - (m_box->style()->shouldPlaceBlockDirectionScrollbarOnLogicalLeft() ? m_box->verticalScrollbarWidth() : 0);
     int scrollableTopOverflow = m_overflowRect.y() - m_box->borderTop();
     setScrollOrigin(IntPoint(-scrollableLeftOverflow, -scrollableTopOverflow));
 }
 
-void RenderLayerScrollableArea::scrollToOffset(const IntSize& scrollOffset, ScrollOffsetClamping clamp)
+void RenderLayerScrollableArea::scrollToOffset(const IntSize& scrollOffset, ScrollOffsetClamping clamp, ScrollBehavior scrollBehavior)
 {
+    cancelProgrammaticScrollAnimation();
     IntSize newScrollOffset = clamp == ScrollOffsetClamped ? clampScrollOffset(scrollOffset) : scrollOffset;
-    if (newScrollOffset != adjustedScrollOffset())
-        scrollToOffsetWithoutAnimation(-scrollOrigin() + newScrollOffset);
+    if (scrollBehavior == ScrollBehaviorAuto)
+        scrollBehavior = m_box->style()->scrollBehavior();
+    if (newScrollOffset != adjustedScrollOffset()) {
+        if (scrollBehavior == ScrollBehaviorSmooth)
+            programmaticallyScrollSmoothlyToOffset(-scrollOrigin() + newScrollOffset);
+        else
+            scrollToOffsetWithoutAnimation(-scrollOrigin() + newScrollOffset);
+    }
 }
 
 void RenderLayerScrollableArea::updateAfterLayout()
 {
     // List box parts handle the scrollbars by themselves so we have nothing to do.
     if (m_box->style()->appearance() == ListboxPart)
         return;
 
     LayoutRectRecorder recorder(*m_box);
 
@@ skipping 766 matching lines @@
         element->setInlineStyleProperty(CSSPropertyHeight, roundToInt(baseHeight + difference.height()), CSSPrimitiveValue::CSS_PX);
     }
 
     document.updateLayout();
 
     // FIXME (Radar 4118564): We should also autoscroll the window as necessary to keep the point under the cursor in view.
 }
 
 LayoutRect RenderLayerScrollableArea::exposeRect(const LayoutRect& rect, const ScrollAlignment& alignX, const ScrollAlignment& alignY)
 {
+    cancelProgrammaticScrollAnimation();
     LayoutRect localExposeRect(m_box->absoluteToLocalQuad(FloatQuad(FloatRect(rect)), UseTransforms).boundingBox());
     LayoutRect layerBounds(0, 0, m_box->clientWidth(), m_box->clientHeight());
     LayoutRect r = ScrollAlignment::getRectToExpose(layerBounds, localExposeRect, alignX, alignY);
 
     IntSize clampedScrollOffset = clampScrollOffset(adjustedScrollOffset() + toIntSize(roundedIntRect(r).location()));
     if (clampedScrollOffset == adjustedScrollOffset())
         return rect;
 
     IntSize oldScrollOffset = adjustedScrollOffset();
     scrollToOffset(clampedScrollOffset);
@@ skipping 150 matching lines @@
 void RenderLayerScrollableArea::setForceNeedsCompositedScrolling(ForceNeedsCompositedScrollingMode mode)
 {
     if (m_forceNeedsCompositedScrolling == mode)
         return;
 
     m_forceNeedsCompositedScrolling = mode;
     layer()->didUpdateNeedsCompositedScrolling();
 }
 
 } // Namespace WebCore