Animations: Port ProgrammaticScrollAnimator to use compositor timelines

Source/platform/scroll/ProgrammaticScrollAnimator.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "platform/scroll/ProgrammaticScrollAnimator.h"
 
+#include "platform/RuntimeEnabledFeatures.h"
 #include "platform/geometry/IntPoint.h"
 #include "platform/graphics/GraphicsLayer.h"
 #include "platform/scroll/ScrollableArea.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebCompositorAnimation.h"
+#include "public/platform/WebCompositorAnimationPlayer.h"
+#include "public/platform/WebCompositorAnimationTimeline.h"
 #include "public/platform/WebCompositorSupport.h"
 #include "public/platform/WebScrollOffsetAnimationCurve.h"
 
 namespace blink {
 
 PassOwnPtr<ProgrammaticScrollAnimator> ProgrammaticScrollAnimator::create(ScrollableArea* scrollableArea)
 {
     return adoptPtr(new ProgrammaticScrollAnimator(scrollableArea));
 }
 
 ProgrammaticScrollAnimator::ProgrammaticScrollAnimator(ScrollableArea* scrollableArea)
-    : m_scrollableArea(scrollableArea)
+    : m_compositorAnimationAttachedToLayerId(0)
+    , m_scrollableArea(scrollableArea)
     , m_startTime(0.0)
     , m_runState(RunState::Idle)
     , m_compositorAnimationId(0)
     , m_compositorAnimationGroupId(0)
 {
+    if (RuntimeEnabledFeatures::compositorAnimationTimelinesEnabled()) {
+        ASSERT(Platform::current()->compositorSupport());
+        m_compositorPlayer = adoptPtr(Platform::current()->compositorSupport()->createAnimationPlayer());
+        ASSERT(m_compositorPlayer);
+        m_compositorPlayer->setAnimationDelegate(this);
+    }
 }
 
 ProgrammaticScrollAnimator::~ProgrammaticScrollAnimator()
 {
+    if (m_compositorPlayer) {
+        m_compositorPlayer->setAnimationDelegate(nullptr);
+        m_compositorPlayer.clear();
+    }
 }
 
 void ProgrammaticScrollAnimator::resetAnimationState()
 {
     m_animationCurve.clear();
     m_startTime = 0.0;
     m_runState = RunState::Idle;
     m_compositorAnimationId = 0;
     m_compositorAnimationGroupId = 0;
 }
@@ skipping 85 matching lines @@
 }
 
 void ProgrammaticScrollAnimator::updateCompositorAnimations()
 {
     if (m_compositorAnimationId && m_runState != RunState::RunningOnCompositor) {
         // If the current run state is WaitingToSendToCompositor but we have a
         // non-zero compositor animation id, there's a currently running
         // compositor animation that needs to be removed here before the new
         // animation is added below.
         ASSERT(m_runState == RunState::WaitingToCancelOnCompositor || m_runState == RunState::WaitingToSendToCompositor);
-        if (GraphicsLayer* layer = m_scrollableArea->layerForScrolling())
-            layer->removeAnimation(m_compositorAnimationId);
+
+        if (m_compositorPlayer) {
+            if (m_compositorPlayer->isLayerAttached())
+                m_compositorPlayer->removeAnimation(m_compositorAnimationId);
+        } else {
+            if (GraphicsLayer* layer = m_scrollableArea->layerForScrolling())
+                layer->removeAnimation(m_compositorAnimationId);
+        }
+
         m_compositorAnimationId = 0;
         m_compositorAnimationGroupId = 0;
         if (m_runState == RunState::WaitingToCancelOnCompositor) {
             resetAnimationState();
             return;
         }
     }
 
     if (m_runState == RunState::WaitingToSendToCompositor) {
         bool sentToCompositor = false;
 
         if (GraphicsLayer* layer = m_scrollableArea->layerForScrolling()) {
             if (!layer->platformLayer()->shouldScrollOnMainThread()) {
                 OwnPtr<WebCompositorAnimation> animation = adoptPtr(Platform::current()->compositorSupport()->createAnimation(*m_animationCurve, WebCompositorAnimation::TargetPropertyScrollOffset));
 
                 int animationId = animation->id();
                 int animationGroupId = animation->group();
-                if (m_scrollableArea->layerForScrolling()->addAnimation(animation.release())) {
+
+                bool animationAdded = false;
+                if (m_compositorPlayer) {
+                    if (m_compositorPlayer->isLayerAttached()) {
+                        m_compositorPlayer->addAnimation(animation.leakPtr());
+                        animationAdded = true;
+                    }
+                } else {
+                    animationAdded = m_scrollableArea->layerForScrolling()->addAnimation(animation.release());
+                }
+
+                if (animationAdded) {
                     sentToCompositor = true;
                     m_runState = RunState::RunningOnCompositor;
                     m_compositorAnimationId = animationId;
                     m_compositorAnimationGroupId = animationGroupId;
                 }
             }
         }
 
         if (!sentToCompositor) {
             m_runState = RunState::RunningOnMainThread;
             if (!m_scrollableArea->scheduleAnimation()) {
                 notifyPositionChanged(IntPoint(m_targetOffset.x(), m_targetOffset.y()));
                 resetAnimationState();
             }
         }
     }
 }
 
-void ProgrammaticScrollAnimator::layerForCompositedScrollingDidChange()
+void ProgrammaticScrollAnimator::reattachCompositorPlayerIfNeeded(WebCompositorAnimationTimeline* timeline)
 {
+    int compositorAnimationAttachedToLayerId = 0;
+    if (m_scrollableArea->layerForScrolling())
+        compositorAnimationAttachedToLayerId = m_scrollableArea->layerForScrolling()->platformLayer()->id();
+
+    if (compositorAnimationAttachedToLayerId != m_compositorAnimationAttachedToLayerId) {
+        if (m_compositorPlayer && timeline) {
+            // Detach from old layer (if any).
+            if (m_compositorAnimationAttachedToLayerId) {
+                ASSERT(m_compositorPlayer->isLayerAttached());
+                m_compositorPlayer->detachLayer();
+                timeline->playerDestroyed(*this);
+            }
+            // Attach to new layer (if any).
+            if (compositorAnimationAttachedToLayerId) {
+                ASSERT(m_scrollableArea->layerForScrolling());
+                timeline->playerAttached(*this);
+                m_compositorPlayer->attachLayer(m_scrollableArea->layerForScrolling()->platformLayer());
+            }
+            m_compositorAnimationAttachedToLayerId = compositorAnimationAttachedToLayerId;
+        }
+    }
+}
+
+void ProgrammaticScrollAnimator::layerForCompositedScrollingDidChange(WebCompositorAnimationTimeline* timeline)
+{
+    reattachCompositorPlayerIfNeeded(timeline);
+
     // If the composited scrolling layer is lost during a composited animation,
     // continue the animation on the main thread.
     if (m_runState == RunState::RunningOnCompositor && !m_scrollableArea->layerForScrolling()) {
         m_runState = RunState::RunningOnMainThread;
         m_compositorAnimationId = 0;
         m_compositorAnimationGroupId = 0;
         m_animationCurve->setInitialValue(FloatPoint(m_scrollableArea->scrollPosition()));
         m_scrollableArea->registerForAnimation();
         if (!m_scrollableArea->scheduleAnimation()) {
             resetAnimationState();
@@ skipping 16 matching lines @@
         ASSERT_NOT_REACHED();
         break;
     case RunState::WaitingToSendToCompositor:
         break;
     case RunState::RunningOnCompositor:
     case RunState::WaitingToCancelOnCompositor:
         resetAnimationState();
     }
 }
 
+void ProgrammaticScrollAnimator::notifyAnimationStarted(double monotonicTime, int group)
+{
+}
+
+void ProgrammaticScrollAnimator::notifyAnimationFinished(double monotonicTime, int group)
+{
+    notifyCompositorAnimationFinished(group);
+}
+
+WebCompositorAnimationPlayer* ProgrammaticScrollAnimator::compositorPlayer() const
+{
+    return m_compositorPlayer.get();
+}
+
 } // namespace blink