Source/WebCore/page/scrolling/AsyncScrollingCoordinator.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2014 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY 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"

 #if ENABLE(ASYNC_SCROLLING)
 #include "AsyncScrollingCoordinator.h"

 #include "Frame.h"
 #include "FrameView.h"
 #include "GraphicsLayer.h"
 #include "MainFrame.h"
 #include "Page.h"
 #include "ScrollingConstraints.h"
 #include "ScrollingStateFixedNode.h"
 #include "ScrollingStateFrameScrollingNode.h"
 #include "ScrollingStateOverflowScrollingNode.h"
 #include "ScrollingStateStickyNode.h"
 #include "ScrollingStateTree.h"

 namespace WebCore {

 AsyncScrollingCoordinator::AsyncScrollingCoordinator(Page* page)
     : ScrollingCoordinator(page)
     , m_updateNodeScrollPositionTimer(this, &AsyncScrollingCoordinator::updateScrollPositionAfterAsyncScrollTimerFired)
     , m_scrollingStateTree(ScrollingStateTree::create(this))
 {
 }

 AsyncScrollingCoordinator::~AsyncScrollingCoordinator()
 {
 }

 void AsyncScrollingCoordinator::scrollingStateTreePropertiesChanged()
 {
     scheduleTreeStateCommit();
 }

 void AsyncScrollingCoordinator::frameViewLayoutUpdated(FrameView* frameView)
 {
     ASSERT(isMainThread());
     ASSERT(m_page);

     // If there isn't a root node yet, don't do anything. We'll be called again after creating one.
     if (!m_scrollingStateTree->rootStateNode())
         return;

     // Compute the region of the page that we can't do fast scrolling for. This currently includes
     // all scrollable areas, such as subframes, overflow divs and list boxes. We need to do this even if the
     // frame view whose layout was updated is not the main frame.
     // In the future, we may want to have the ability to set non-fast scrolling regions for more than
     // just the root node. But right now, this concept only applies to the root.
     if (frameView->frame().isMainFrame())
         m_scrollingStateTree->rootStateNode()->setNonFastScrollableRegion(computeNonFastScrollableRegion(&frameView->frame(), IntPoint()));

     if (!coordinatesScrollingForFrameView(frameView))
         return;

     ScrollingStateFrameScrollingNode* node = toScrollingStateFrameScrollingNode(m_scrollingStateTree->stateNodeForID(frameView->scrollLayerID()));
     if (!node)
         return;

     Scrollbar* verticalScrollbar = frameView->verticalScrollbar();
     Scrollbar* horizontalScrollbar = frameView->horizontalScrollbar();
     node->setScrollbarPaintersFromScrollbars(verticalScrollbar, horizontalScrollbar);

     node->setFrameScaleFactor(frameView->frame().frameScaleFactor());
     node->setHeaderHeight(frameView->headerHeight());
     node->setFooterHeight(frameView->footerHeight());
     node->setTopContentInset(frameView->topContentInset());

     node->setScrollOrigin(frameView->scrollOrigin());
     node->setScrollableAreaSize(frameView->visibleContentRect().size());
     node->setTotalContentsSize(frameView->totalContentsSize());

     ScrollableAreaParameters scrollParameters;
     scrollParameters.horizontalScrollElasticity = frameView->horizontalScrollElasticity();
     scrollParameters.verticalScrollElasticity = frameView->verticalScrollElasticity();
     scrollParameters.hasEnabledHorizontalScrollbar = horizontalScrollbar && horizontalScrollbar->enabled();
     scrollParameters.hasEnabledVerticalScrollbar = verticalScrollbar && verticalScrollbar->enabled();
     scrollParameters.horizontalScrollbarMode = frameView->horizontalScrollbarMode();
     scrollParameters.verticalScrollbarMode = frameView->verticalScrollbarMode();

     node->setScrollableAreaParameters(scrollParameters);
 }

 void AsyncScrollingCoordinator::frameViewNonFastScrollableRegionChanged(FrameView* frameView)
 {
     if (!m_scrollingStateTree->rootStateNode())
         return;

     if (frameView->frame().isMainFrame())
         m_scrollingStateTree->rootStateNode()->setNonFastScrollableRegion(computeNonFastScrollableRegion(&frameView->frame(), IntPoint()));
 }

 void AsyncScrollingCoordinator::frameViewRootLayerDidChange(FrameView* frameView)
 {
     ASSERT(isMainThread());
     ASSERT(m_page);

     if (!coordinatesScrollingForFrameView(frameView))
         return;

     // FIXME: In some navigation scenarios, the FrameView has no RenderView or that RenderView has not been composited.
     // This needs cleaning up: https://bugs.webkit.org/show_bug.cgi?id=132724
     if (!frameView->scrollLayerID())
         return;

     // If the root layer does not have a ScrollingStateNode, then we should create one.
     ensureRootStateNodeForFrameView(frameView);
     ASSERT(m_scrollingStateTree->rootStateNode());

     ScrollingCoordinator::frameViewRootLayerDidChange(frameView);

     ScrollingStateFrameScrollingNode* node = toScrollingStateFrameScrollingNode(m_scrollingStateTree->stateNodeForID(frameView->scrollLayerID()));
     node->setLayer(scrollLayerForFrameView(frameView));
     node->setScrolledContentsLayer(rootContentLayerForFrameView(frameView));
     node->setCounterScrollingLayer(counterScrollingLayerForFrameView(frameView));
     node->setInsetClipLayer(insetClipLayerForFrameView(frameView));
     node->setContentShadowLayer(contentShadowLayerForFrameView(frameView));
     node->setHeaderLayer(headerLayerForFrameView(frameView));
     node->setFooterLayer(footerLayerForFrameView(frameView));
     node->setScrollBehaviorForFixedElements(frameView->scrollBehaviorForFixedElements());
 }

 bool AsyncScrollingCoordinator::requestScrollPositionUpdate(FrameView* frameView, const IntPoint& scrollPosition)
 {
     ASSERT(isMainThread());
     ASSERT(m_page);

     if (!coordinatesScrollingForFrameView(frameView))
         return false;

     if (frameView->inProgrammaticScroll() || frameView->frame().document()->inPageCache())
         updateScrollPositionAfterAsyncScroll(frameView->scrollLayerID(), scrollPosition, frameView->inProgrammaticScroll(), SetScrollingLayerPosition);

     // If this frame view's document is being put into the page cache, we don't want to update our
     // main frame scroll position. Just let the FrameView think that we did.
     if (frameView->frame().document()->inPageCache())
         return true;

     ScrollingStateScrollingNode* stateNode = toScrollingStateScrollingNode(m_scrollingStateTree->stateNodeForID(frameView->scrollLayerID()));
     if (!stateNode)
         return false;

     stateNode->setRequestedScrollPosition(scrollPosition, frameView->inProgrammaticScroll());
     return true;
 }

 void AsyncScrollingCoordinator::scheduleUpdateScrollPositionAfterAsyncScroll(ScrollingNodeID nodeID, const FloatPoint& scrollPosition, bool programmaticScroll, SetOrSyncScrollingLayerPosition scrollingLayerPositionAction)
 {
     ScheduledScrollUpdate scrollUpdate(nodeID, scrollPosition, programmaticScroll, scrollingLayerPositionAction);

     if (m_updateNodeScrollPositionTimer.isActive()) {
         if (m_scheduledScrollUpdate.matchesUpdateType(scrollUpdate)) {
             m_scheduledScrollUpdate.scrollPosition = scrollPosition;
             return;
         }

         // If the parameters don't match what was previously scheduled, dispatch immediately.
         m_updateNodeScrollPositionTimer.stop();
         updateScrollPositionAfterAsyncScroll(m_scheduledScrollUpdate.nodeID, m_scheduledScrollUpdate.scrollPosition, m_scheduledScrollUpdate.isProgrammaticScroll, m_scheduledScrollUpdate.updateLayerPositionAction);
         updateScrollPositionAfterAsyncScroll(nodeID, scrollPosition, programmaticScroll, scrollingLayerPositionAction);
         return;
     }

     m_scheduledScrollUpdate = scrollUpdate;
     m_updateNodeScrollPositionTimer.startOneShot(0);
 }

 void AsyncScrollingCoordinator::updateScrollPositionAfterAsyncScrollTimerFired(Timer<AsyncScrollingCoordinator>*)
 {
     updateScrollPositionAfterAsyncScroll(m_scheduledScrollUpdate.nodeID, m_scheduledScrollUpdate.scrollPosition, m_scheduledScrollUpdate.isProgrammaticScroll, m_scheduledScrollUpdate.updateLayerPositionAction);
 }

 FrameView* AsyncScrollingCoordinator::frameViewForScrollingNode(ScrollingNodeID scrollingNodeID) const
 {
     if (!m_scrollingStateTree->rootStateNode())
         return nullptr;

     if (scrollingNodeID == m_scrollingStateTree->rootStateNode()->scrollingNodeID())
         return m_page->mainFrame().view();

     ScrollingStateNode* stateNode = m_scrollingStateTree->stateNodeForID(scrollingNodeID);
     if (!stateNode)
         return nullptr;

     // Find the enclosing frame scrolling node.
     ScrollingStateNode* parentNode = stateNode;
     while (parentNode && parentNode->nodeType() != FrameScrollingNode)
         parentNode = parentNode->parent();

     if (!parentNode)
         return nullptr;

     // Walk the frame tree to find the matching FrameView. This is not ideal, but avoids back pointers to FrameViews
     // from ScrollingTreeStateNodes.
     for (Frame* frame = &m_page->mainFrame(); frame; frame = frame->tree().traverseNext()) {
         if (FrameView* view = frame->view()) {
             if (view->scrollLayerID() == parentNode->scrollingNodeID())
                 return view;
         }
     }

     return nullptr;
 }

 void AsyncScrollingCoordinator::updateScrollPositionAfterAsyncScroll(ScrollingNodeID scrollingNodeID, const FloatPoint& scrollPosition, bool programmaticScroll, SetOrSyncScrollingLayerPosition scrollingLayerPositionAction)
 {
     ASSERT(isMainThread());

     if (!m_page)
         return;

     FrameView* frameView = frameViewForScrollingNode(scrollingNodeID);
     if (!frameView)
         return;

     if (scrollingNodeID == frameView->scrollLayerID()) {
         bool oldProgrammaticScroll = frameView->inProgrammaticScroll();
         frameView->setInProgrammaticScroll(programmaticScroll);

         frameView->setConstrainsScrollingToContentEdge(false);
         frameView->notifyScrollPositionChanged(roundedIntPoint(scrollPosition));
         frameView->setConstrainsScrollingToContentEdge(true);

         frameView->setInProgrammaticScroll(oldProgrammaticScroll);

         if (GraphicsLayer* scrollLayer = scrollLayerForFrameView(frameView)) {
             GraphicsLayer* counterScrollingLayer = counterScrollingLayerForFrameView(frameView);
             GraphicsLayer* insetClipLayer = insetClipLayerForFrameView(frameView);
             GraphicsLayer* contentShadowLayer = contentShadowLayerForFrameView(frameView);
             GraphicsLayer* scrolledContentsLayer = rootContentLayerForFrameView(frameView);
             GraphicsLayer* headerLayer = headerLayerForFrameView(frameView);
             GraphicsLayer* footerLayer = footerLayerForFrameView(frameView);
             LayoutSize scrollOffsetForFixed = frameView->scrollOffsetForFixedPosition();

             float topContentInset = frameView->topContentInset();
             FloatPoint positionForInsetClipLayer = FloatPoint(0, FrameView::yPositionForInsetClipLayer(scrollPosition, topContentInset));
             FloatPoint positionForContentsLayer = FloatPoint(scrolledContentsLayer->position().x(),
                 FrameView::yPositionForRootContentLayer(scrollPosition, topContentInset, frameView->headerHeight()));
             FloatPoint positionForHeaderLayer = FloatPoint(scrollOffsetForFixed.width(), FrameView::yPositionForHeaderLayer(scrollPosition, topContentInset));
             FloatPoint positionForFooterLayer = FloatPoint(scrollOffsetForFixed.width(),
                 FrameView::yPositionForFooterLayer(scrollPosition, topContentInset, frameView->totalContentsSize().height(), frameView->footerHeight()));

             if (programmaticScroll || scrollingLayerPositionAction == SetScrollingLayerPosition) {
                 scrollLayer->setPosition(-frameView->scrollPosition());
                 if (counterScrollingLayer)
                     counterScrollingLayer->setPosition(toLayoutPoint(scrollOffsetForFixed));
                 if (insetClipLayer)
                     insetClipLayer->setPosition(positionForInsetClipLayer);
                 if (contentShadowLayer)
                     contentShadowLayer->setPosition(positionForContentsLayer);
                 if (scrolledContentsLayer)
                     scrolledContentsLayer->setPosition(positionForContentsLayer);
                 if (headerLayer)
                     headerLayer->setPosition(positionForHeaderLayer);
                 if (footerLayer)
                     footerLayer->setPosition(positionForFooterLayer);
             } else {
                 scrollLayer->syncPosition(-frameView->scrollPosition());
                 if (counterScrollingLayer)
                     counterScrollingLayer->syncPosition(toLayoutPoint(scrollOffsetForFixed));
                 if (insetClipLayer)
                     insetClipLayer->syncPosition(positionForInsetClipLayer);
                 if (contentShadowLayer)
                     contentShadowLayer->syncPosition(positionForContentsLayer);
                 if (scrolledContentsLayer)
                     scrolledContentsLayer->syncPosition(positionForContentsLayer);
                 if (headerLayer)
                     headerLayer->syncPosition(positionForHeaderLayer);
                 if (footerLayer)
                     footerLayer->syncPosition(positionForFooterLayer);

                 LayoutRect viewportRect = frameView->viewportConstrainedVisibleContentRect();
                 syncChildPositions(viewportRect);
             }
         }

         return;
     }

     // Overflow-scroll area.
     if (ScrollableArea* scrollableArea = frameView->scrollableAreaForScrollLayerID(scrollingNodeID)) {
         scrollableArea->setIsUserScroll(scrollingLayerPositionAction == SyncScrollingLayerPosition);
         scrollableArea->scrollToOffsetWithoutAnimation(scrollPosition);
         scrollableArea->setIsUserScroll(false);
     }
 }

 void AsyncScrollingCoordinator::scrollableAreaScrollbarLayerDidChange(ScrollableArea* scrollableArea, ScrollbarOrientation orientation)
 {
     ASSERT(isMainThread());
     ASSERT(m_page);

     if (scrollableArea != static_cast<ScrollableArea*>(m_page->mainFrame().view()))
         return;

     if (orientation == VerticalScrollbar)
         scrollableArea->verticalScrollbarLayerDidChange();
     else
         scrollableArea->horizontalScrollbarLayerDidChange();
 }

 ScrollingNodeID AsyncScrollingCoordinator::attachToStateTree(ScrollingNodeType nodeType, ScrollingNodeID newNodeID, ScrollingNodeID parentID)
 {
     return m_scrollingStateTree->attachNode(nodeType, newNodeID, parentID);
 }

 void AsyncScrollingCoordinator::detachFromStateTree(ScrollingNodeID nodeID)
 {
     m_scrollingStateTree->detachNode(nodeID);
 }

 void AsyncScrollingCoordinator::clearStateTree()
 {
     m_scrollingStateTree->clear();
 }

 void AsyncScrollingCoordinator::syncChildPositions(const LayoutRect& viewportRect)
 {
     if (!m_scrollingStateTree->rootStateNode())
         return;

     auto children = m_scrollingStateTree->rootStateNode()->children();
     if (!children)
         return;

     // FIXME: We'll have to traverse deeper into the tree at some point.
     for (auto& child : *children)
         child->syncLayerPositionForViewportRect(viewportRect);
 }

 void AsyncScrollingCoordinator::ensureRootStateNodeForFrameView(FrameView* frameView)
 {
     ASSERT(frameView->scrollLayerID());
     attachToStateTree(FrameScrollingNode, frameView->scrollLayerID(), 0);
 }

 void AsyncScrollingCoordinator::updateFrameScrollingNode(ScrollingNodeID nodeID, GraphicsLayer* layer, GraphicsLayer* scrolledContentsLayer, GraphicsLayer* counterScrollingLayer, GraphicsLayer* insetClipLayer, const ScrollingGeometry* scrollingGeometry)
 {
     ScrollingStateFrameScrollingNode* node = toScrollingStateFrameScrollingNode(m_scrollingStateTree->stateNodeForID(nodeID));
     ASSERT(node);
     if (!node)
         return;

     node->setLayer(layer);
     node->setInsetClipLayer(insetClipLayer);
     node->setScrolledContentsLayer(scrolledContentsLayer);
     node->setCounterScrollingLayer(counterScrollingLayer);

     if (scrollingGeometry) {
         node->setScrollOrigin(scrollingGeometry->scrollOrigin);
         node->setScrollPosition(scrollingGeometry->scrollPosition);
         node->setTotalContentsSize(scrollingGeometry->contentSize);
         node->setScrollableAreaSize(scrollingGeometry->scrollableAreaSize);
     }
 }

 void AsyncScrollingCoordinator::updateOverflowScrollingNode(ScrollingNodeID nodeID, GraphicsLayer* layer, GraphicsLayer* scrolledContentsLayer, const ScrollingGeometry* scrollingGeometry)
 {
     ScrollingStateOverflowScrollingNode* node = toScrollingStateOverflowScrollingNode(m_scrollingStateTree->stateNodeForID(nodeID));
     ASSERT(node);
     if (!node)
         return;

     node->setLayer(layer);
     node->setScrolledContentsLayer(scrolledContentsLayer);

     if (scrollingGeometry) {
         node->setScrollOrigin(scrollingGeometry->scrollOrigin);
         node->setScrollPosition(scrollingGeometry->scrollPosition);
         node->setTotalContentsSize(scrollingGeometry->contentSize);
         node->setScrollableAreaSize(scrollingGeometry->scrollableAreaSize);
     }
 }

 void AsyncScrollingCoordinator::updateViewportConstrainedNode(ScrollingNodeID nodeID, const ViewportConstraints& constraints, GraphicsLayer* graphicsLayer)
 {
     ASSERT(supportsFixedPositionLayers());

     ScrollingStateNode* node = m_scrollingStateTree->stateNodeForID(nodeID);
     if (!node)
         return;

     switch (constraints.constraintType()) {
     case ViewportConstraints::FixedPositionConstraint: {
         ScrollingStateFixedNode* fixedNode = toScrollingStateFixedNode(node);
         fixedNode->setLayer(graphicsLayer);
         fixedNode->updateConstraints((const FixedPositionViewportConstraints&)constraints);
         break;
     }
     case ViewportConstraints::StickyPositionConstraint: {
         ScrollingStateStickyNode* stickyNode = toScrollingStateStickyNode(node);
         stickyNode->setLayer(graphicsLayer);
         stickyNode->updateConstraints((const StickyPositionViewportConstraints&)constraints);
         break;
     }
     }
 }

 void AsyncScrollingCoordinator::setSynchronousScrollingReasons(SynchronousScrollingReasons reasons)
 {
     if (!m_scrollingStateTree->rootStateNode())
         return;

     // The FrameView's GraphicsLayer is likely to be out-of-synch with the PlatformLayer
     // at this point. So we'll update it before we switch back to main thread scrolling
     // in order to avoid layer positioning bugs.
     if (reasons)
         updateMainFrameScrollLayerPosition();
     m_scrollingStateTree->rootStateNode()->setSynchronousScrollingReasons(reasons);
 }

 void AsyncScrollingCoordinator::updateMainFrameScrollLayerPosition()
 {
     ASSERT(isMainThread());

     if (!m_page)
         return;

     FrameView* frameView = m_page->mainFrame().view();
     if (!frameView)
         return;

     if (GraphicsLayer* scrollLayer = scrollLayerForFrameView(frameView))
         scrollLayer->setPosition(-frameView->scrollPosition());
 }

 void AsyncScrollingCoordinator::recomputeWheelEventHandlerCountForFrameView(FrameView* frameView)
 {
     ScrollingStateFrameScrollingNode* node = toScrollingStateFrameScrollingNode(m_scrollingStateTree->stateNodeForID(frameView->scrollLayerID()));
     if (!node)
         return;
     node->setWheelEventHandlerCount(computeCurrentWheelEventHandlerCount());
 }

 bool AsyncScrollingCoordinator::isRubberBandInProgress() const
 {
     return scrollingTree()->isRubberBandInProgress();
 }

 void AsyncScrollingCoordinator::setScrollPinningBehavior(ScrollPinningBehavior pinning)
 {
     scrollingTree()->setScrollPinningBehavior(pinning);
 }

 String AsyncScrollingCoordinator::scrollingStateTreeAsText() const
 {
     if (m_scrollingStateTree->rootStateNode())
         return m_scrollingStateTree->rootStateNode()->scrollingStateTreeAsText();

     return String();
 }

 } // namespace WebCore

 #endif // ENABLE(ASYNC_SCROLLING)
	/*
	* Copyright (C) 2014 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:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY 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"

	#if ENABLE(ASYNC_SCROLLING)
	#include "AsyncScrollingCoordinator.h"

	#include "Frame.h"
	#include "FrameView.h"
	#include "GraphicsLayer.h"
	#include "MainFrame.h"
	#include "Page.h"
	#include "ScrollingConstraints.h"
	#include "ScrollingStateFixedNode.h"
	#include "ScrollingStateFrameScrollingNode.h"
	#include "ScrollingStateOverflowScrollingNode.h"
	#include "ScrollingStateStickyNode.h"
	#include "ScrollingStateTree.h"

	namespace WebCore {

	AsyncScrollingCoordinator::AsyncScrollingCoordinator(Page* page)
	: ScrollingCoordinator(page)
	, m_updateNodeScrollPositionTimer(this, &AsyncScrollingCoordinator::updateScrollPositionAfterAsyncScrollTimerFired)
	, m_scrollingStateTree(ScrollingStateTree::create(this))
	{
	}

	AsyncScrollingCoordinator::~AsyncScrollingCoordinator()
	{
	}

	void AsyncScrollingCoordinator::scrollingStateTreePropertiesChanged()
	{
	scheduleTreeStateCommit();
	}

	void AsyncScrollingCoordinator::frameViewLayoutUpdated(FrameView* frameView)
	{
	ASSERT(isMainThread());
	ASSERT(m_page);

	// If there isn't a root node yet, don't do anything. We'll be called again after creating one.
	if (!m_scrollingStateTree->rootStateNode())
	return;

	// Compute the region of the page that we can't do fast scrolling for. This currently includes
	// all scrollable areas, such as subframes, overflow divs and list boxes. We need to do this even if the
	// frame view whose layout was updated is not the main frame.
	// In the future, we may want to have the ability to set non-fast scrolling regions for more than
	// just the root node. But right now, this concept only applies to the root.
	if (frameView->frame().isMainFrame())
	m_scrollingStateTree->rootStateNode()->setNonFastScrollableRegion(computeNonFastScrollableRegion(&frameView->frame(), IntPoint()));

	if (!coordinatesScrollingForFrameView(frameView))
	return;

	ScrollingStateFrameScrollingNode* node = toScrollingStateFrameScrollingNode(m_scrollingStateTree->stateNodeForID(frameView->scrollLayerID()));
	if (!node)
	return;

	Scrollbar* verticalScrollbar = frameView->verticalScrollbar();
	Scrollbar* horizontalScrollbar = frameView->horizontalScrollbar();
	node->setScrollbarPaintersFromScrollbars(verticalScrollbar, horizontalScrollbar);

	node->setFrameScaleFactor(frameView->frame().frameScaleFactor());
	node->setHeaderHeight(frameView->headerHeight());
	node->setFooterHeight(frameView->footerHeight());
	node->setTopContentInset(frameView->topContentInset());

	node->setScrollOrigin(frameView->scrollOrigin());
	node->setScrollableAreaSize(frameView->visibleContentRect().size());
	node->setTotalContentsSize(frameView->totalContentsSize());

	ScrollableAreaParameters scrollParameters;
	scrollParameters.horizontalScrollElasticity = frameView->horizontalScrollElasticity();
	scrollParameters.verticalScrollElasticity = frameView->verticalScrollElasticity();
	scrollParameters.hasEnabledHorizontalScrollbar = horizontalScrollbar && horizontalScrollbar->enabled();
	scrollParameters.hasEnabledVerticalScrollbar = verticalScrollbar && verticalScrollbar->enabled();
	scrollParameters.horizontalScrollbarMode = frameView->horizontalScrollbarMode();
	scrollParameters.verticalScrollbarMode = frameView->verticalScrollbarMode();

	node->setScrollableAreaParameters(scrollParameters);
	}

	void AsyncScrollingCoordinator::frameViewNonFastScrollableRegionChanged(FrameView* frameView)
	{
	if (!m_scrollingStateTree->rootStateNode())
	return;

	if (frameView->frame().isMainFrame())
	m_scrollingStateTree->rootStateNode()->setNonFastScrollableRegion(computeNonFastScrollableRegion(&frameView->frame(), IntPoint()));
	}

	void AsyncScrollingCoordinator::frameViewRootLayerDidChange(FrameView* frameView)
	{
	ASSERT(isMainThread());
	ASSERT(m_page);

	if (!coordinatesScrollingForFrameView(frameView))
	return;

	// FIXME: In some navigation scenarios, the FrameView has no RenderView or that RenderView has not been composited.
	// This needs cleaning up: https://bugs.webkit.org/show_bug.cgi?id=132724
	if (!frameView->scrollLayerID())
	return;

	// If the root layer does not have a ScrollingStateNode, then we should create one.
	ensureRootStateNodeForFrameView(frameView);
	ASSERT(m_scrollingStateTree->rootStateNode());

	ScrollingCoordinator::frameViewRootLayerDidChange(frameView);

	ScrollingStateFrameScrollingNode* node = toScrollingStateFrameScrollingNode(m_scrollingStateTree->stateNodeForID(frameView->scrollLayerID()));
	node->setLayer(scrollLayerForFrameView(frameView));
	node->setScrolledContentsLayer(rootContentLayerForFrameView(frameView));
	node->setCounterScrollingLayer(counterScrollingLayerForFrameView(frameView));
	node->setInsetClipLayer(insetClipLayerForFrameView(frameView));
	node->setContentShadowLayer(contentShadowLayerForFrameView(frameView));
	node->setHeaderLayer(headerLayerForFrameView(frameView));
	node->setFooterLayer(footerLayerForFrameView(frameView));
	node->setScrollBehaviorForFixedElements(frameView->scrollBehaviorForFixedElements());
	}

	bool AsyncScrollingCoordinator::requestScrollPositionUpdate(FrameView* frameView, const IntPoint& scrollPosition)
	{
	ASSERT(isMainThread());
	ASSERT(m_page);

	if (!coordinatesScrollingForFrameView(frameView))
	return false;

	if (frameView->inProgrammaticScroll() \|\| frameView->frame().document()->inPageCache())
	updateScrollPositionAfterAsyncScroll(frameView->scrollLayerID(), scrollPosition, frameView->inProgrammaticScroll(), SetScrollingLayerPosition);

	// If this frame view's document is being put into the page cache, we don't want to update our
	// main frame scroll position. Just let the FrameView think that we did.
	if (frameView->frame().document()->inPageCache())
	return true;

	ScrollingStateScrollingNode* stateNode = toScrollingStateScrollingNode(m_scrollingStateTree->stateNodeForID(frameView->scrollLayerID()));
	if (!stateNode)
	return false;

	stateNode->setRequestedScrollPosition(scrollPosition, frameView->inProgrammaticScroll());
	return true;
	}

	void AsyncScrollingCoordinator::scheduleUpdateScrollPositionAfterAsyncScroll(ScrollingNodeID nodeID, const FloatPoint& scrollPosition, bool programmaticScroll, SetOrSyncScrollingLayerPosition scrollingLayerPositionAction)
	{
	ScheduledScrollUpdate scrollUpdate(nodeID, scrollPosition, programmaticScroll, scrollingLayerPositionAction);

	if (m_updateNodeScrollPositionTimer.isActive()) {
	if (m_scheduledScrollUpdate.matchesUpdateType(scrollUpdate)) {
	m_scheduledScrollUpdate.scrollPosition = scrollPosition;
	return;
	}

	// If the parameters don't match what was previously scheduled, dispatch immediately.
	m_updateNodeScrollPositionTimer.stop();
	updateScrollPositionAfterAsyncScroll(m_scheduledScrollUpdate.nodeID, m_scheduledScrollUpdate.scrollPosition, m_scheduledScrollUpdate.isProgrammaticScroll, m_scheduledScrollUpdate.updateLayerPositionAction);
	updateScrollPositionAfterAsyncScroll(nodeID, scrollPosition, programmaticScroll, scrollingLayerPositionAction);
	return;
	}

	m_scheduledScrollUpdate = scrollUpdate;
	m_updateNodeScrollPositionTimer.startOneShot(0);
	}

	void AsyncScrollingCoordinator::updateScrollPositionAfterAsyncScrollTimerFired(Timer<AsyncScrollingCoordinator>*)
	{
	updateScrollPositionAfterAsyncScroll(m_scheduledScrollUpdate.nodeID, m_scheduledScrollUpdate.scrollPosition, m_scheduledScrollUpdate.isProgrammaticScroll, m_scheduledScrollUpdate.updateLayerPositionAction);
	}

	FrameView* AsyncScrollingCoordinator::frameViewForScrollingNode(ScrollingNodeID scrollingNodeID) const
	{
	if (!m_scrollingStateTree->rootStateNode())
	return nullptr;

	if (scrollingNodeID == m_scrollingStateTree->rootStateNode()->scrollingNodeID())
	return m_page->mainFrame().view();

	ScrollingStateNode* stateNode = m_scrollingStateTree->stateNodeForID(scrollingNodeID);
	if (!stateNode)
	return nullptr;

	// Find the enclosing frame scrolling node.
	ScrollingStateNode* parentNode = stateNode;
	while (parentNode && parentNode->nodeType() != FrameScrollingNode)
	parentNode = parentNode->parent();

	if (!parentNode)
	return nullptr;

	// Walk the frame tree to find the matching FrameView. This is not ideal, but avoids back pointers to FrameViews
	// from ScrollingTreeStateNodes.
	for (Frame* frame = &m_page->mainFrame(); frame; frame = frame->tree().traverseNext()) {
	if (FrameView* view = frame->view()) {
	if (view->scrollLayerID() == parentNode->scrollingNodeID())
	return view;
	}
	}

	return nullptr;
	}

	void AsyncScrollingCoordinator::updateScrollPositionAfterAsyncScroll(ScrollingNodeID scrollingNodeID, const FloatPoint& scrollPosition, bool programmaticScroll, SetOrSyncScrollingLayerPosition scrollingLayerPositionAction)
	{
	ASSERT(isMainThread());

	if (!m_page)
	return;

	FrameView* frameView = frameViewForScrollingNode(scrollingNodeID);
	if (!frameView)
	return;

	if (scrollingNodeID == frameView->scrollLayerID()) {
	bool oldProgrammaticScroll = frameView->inProgrammaticScroll();
	frameView->setInProgrammaticScroll(programmaticScroll);

	frameView->setConstrainsScrollingToContentEdge(false);
	frameView->notifyScrollPositionChanged(roundedIntPoint(scrollPosition));
	frameView->setConstrainsScrollingToContentEdge(true);

	frameView->setInProgrammaticScroll(oldProgrammaticScroll);

	if (GraphicsLayer* scrollLayer = scrollLayerForFrameView(frameView)) {
	GraphicsLayer* counterScrollingLayer = counterScrollingLayerForFrameView(frameView);
	GraphicsLayer* insetClipLayer = insetClipLayerForFrameView(frameView);
	GraphicsLayer* contentShadowLayer = contentShadowLayerForFrameView(frameView);
	GraphicsLayer* scrolledContentsLayer = rootContentLayerForFrameView(frameView);
	GraphicsLayer* headerLayer = headerLayerForFrameView(frameView);
	GraphicsLayer* footerLayer = footerLayerForFrameView(frameView);
	LayoutSize scrollOffsetForFixed = frameView->scrollOffsetForFixedPosition();

	float topContentInset = frameView->topContentInset();
	FloatPoint positionForInsetClipLayer = FloatPoint(0, FrameView::yPositionForInsetClipLayer(scrollPosition, topContentInset));
	FloatPoint positionForContentsLayer = FloatPoint(scrolledContentsLayer->position().x(),
	FrameView::yPositionForRootContentLayer(scrollPosition, topContentInset, frameView->headerHeight()));
	FloatPoint positionForHeaderLayer = FloatPoint(scrollOffsetForFixed.width(), FrameView::yPositionForHeaderLayer(scrollPosition, topContentInset));
	FloatPoint positionForFooterLayer = FloatPoint(scrollOffsetForFixed.width(),
	FrameView::yPositionForFooterLayer(scrollPosition, topContentInset, frameView->totalContentsSize().height(), frameView->footerHeight()));

	if (programmaticScroll \|\| scrollingLayerPositionAction == SetScrollingLayerPosition) {
	scrollLayer->setPosition(-frameView->scrollPosition());
	if (counterScrollingLayer)
	counterScrollingLayer->setPosition(toLayoutPoint(scrollOffsetForFixed));
	if (insetClipLayer)
	insetClipLayer->setPosition(positionForInsetClipLayer);
	if (contentShadowLayer)
	contentShadowLayer->setPosition(positionForContentsLayer);
	if (scrolledContentsLayer)
	scrolledContentsLayer->setPosition(positionForContentsLayer);
	if (headerLayer)
	headerLayer->setPosition(positionForHeaderLayer);
	if (footerLayer)
	footerLayer->setPosition(positionForFooterLayer);
	} else {
	scrollLayer->syncPosition(-frameView->scrollPosition());
	if (counterScrollingLayer)
	counterScrollingLayer->syncPosition(toLayoutPoint(scrollOffsetForFixed));
	if (insetClipLayer)
	insetClipLayer->syncPosition(positionForInsetClipLayer);
	if (contentShadowLayer)
	contentShadowLayer->syncPosition(positionForContentsLayer);
	if (scrolledContentsLayer)
	scrolledContentsLayer->syncPosition(positionForContentsLayer);
	if (headerLayer)
	headerLayer->syncPosition(positionForHeaderLayer);
	if (footerLayer)
	footerLayer->syncPosition(positionForFooterLayer);

	LayoutRect viewportRect = frameView->viewportConstrainedVisibleContentRect();
	syncChildPositions(viewportRect);
	}
	}

	return;
	}

	// Overflow-scroll area.
	if (ScrollableArea* scrollableArea = frameView->scrollableAreaForScrollLayerID(scrollingNodeID)) {
	scrollableArea->setIsUserScroll(scrollingLayerPositionAction == SyncScrollingLayerPosition);
	scrollableArea->scrollToOffsetWithoutAnimation(scrollPosition);
	scrollableArea->setIsUserScroll(false);
	}
	}

	void AsyncScrollingCoordinator::scrollableAreaScrollbarLayerDidChange(ScrollableArea* scrollableArea, ScrollbarOrientation orientation)
	{
	ASSERT(isMainThread());
	ASSERT(m_page);

	if (scrollableArea != static_cast<ScrollableArea*>(m_page->mainFrame().view()))
	return;

	if (orientation == VerticalScrollbar)
	scrollableArea->verticalScrollbarLayerDidChange();
	else
	scrollableArea->horizontalScrollbarLayerDidChange();
	}

	ScrollingNodeID AsyncScrollingCoordinator::attachToStateTree(ScrollingNodeType nodeType, ScrollingNodeID newNodeID, ScrollingNodeID parentID)
	{
	return m_scrollingStateTree->attachNode(nodeType, newNodeID, parentID);
	}

	void AsyncScrollingCoordinator::detachFromStateTree(ScrollingNodeID nodeID)
	{
	m_scrollingStateTree->detachNode(nodeID);
	}

	void AsyncScrollingCoordinator::clearStateTree()
	{
	m_scrollingStateTree->clear();
	}

	void AsyncScrollingCoordinator::syncChildPositions(const LayoutRect& viewportRect)
	{
	if (!m_scrollingStateTree->rootStateNode())
	return;

	auto children = m_scrollingStateTree->rootStateNode()->children();
	if (!children)
	return;

	// FIXME: We'll have to traverse deeper into the tree at some point.
	for (auto& child : *children)
	child->syncLayerPositionForViewportRect(viewportRect);
	}

	void AsyncScrollingCoordinator::ensureRootStateNodeForFrameView(FrameView* frameView)
	{
	ASSERT(frameView->scrollLayerID());
	attachToStateTree(FrameScrollingNode, frameView->scrollLayerID(), 0);
	}

	void AsyncScrollingCoordinator::updateFrameScrollingNode(ScrollingNodeID nodeID, GraphicsLayer* layer, GraphicsLayer* scrolledContentsLayer, GraphicsLayer* counterScrollingLayer, GraphicsLayer* insetClipLayer, const ScrollingGeometry* scrollingGeometry)
	{
	ScrollingStateFrameScrollingNode* node = toScrollingStateFrameScrollingNode(m_scrollingStateTree->stateNodeForID(nodeID));
	ASSERT(node);
	if (!node)
	return;

	node->setLayer(layer);
	node->setInsetClipLayer(insetClipLayer);
	node->setScrolledContentsLayer(scrolledContentsLayer);
	node->setCounterScrollingLayer(counterScrollingLayer);

	if (scrollingGeometry) {
	node->setScrollOrigin(scrollingGeometry->scrollOrigin);
	node->setScrollPosition(scrollingGeometry->scrollPosition);
	node->setTotalContentsSize(scrollingGeometry->contentSize);
	node->setScrollableAreaSize(scrollingGeometry->scrollableAreaSize);
	}
	}

	void AsyncScrollingCoordinator::updateOverflowScrollingNode(ScrollingNodeID nodeID, GraphicsLayer* layer, GraphicsLayer* scrolledContentsLayer, const ScrollingGeometry* scrollingGeometry)
	{
	ScrollingStateOverflowScrollingNode* node = toScrollingStateOverflowScrollingNode(m_scrollingStateTree->stateNodeForID(nodeID));
	ASSERT(node);
	if (!node)
	return;

	node->setLayer(layer);
	node->setScrolledContentsLayer(scrolledContentsLayer);

	if (scrollingGeometry) {
	node->setScrollOrigin(scrollingGeometry->scrollOrigin);
	node->setScrollPosition(scrollingGeometry->scrollPosition);
	node->setTotalContentsSize(scrollingGeometry->contentSize);
	node->setScrollableAreaSize(scrollingGeometry->scrollableAreaSize);
	}
	}

	void AsyncScrollingCoordinator::updateViewportConstrainedNode(ScrollingNodeID nodeID, const ViewportConstraints& constraints, GraphicsLayer* graphicsLayer)
	{
	ASSERT(supportsFixedPositionLayers());

	ScrollingStateNode* node = m_scrollingStateTree->stateNodeForID(nodeID);
	if (!node)
	return;

	switch (constraints.constraintType()) {
	case ViewportConstraints::FixedPositionConstraint: {
	ScrollingStateFixedNode* fixedNode = toScrollingStateFixedNode(node);
	fixedNode->setLayer(graphicsLayer);
	fixedNode->updateConstraints((const FixedPositionViewportConstraints&)constraints);
	break;
	}
	case ViewportConstraints::StickyPositionConstraint: {
	ScrollingStateStickyNode* stickyNode = toScrollingStateStickyNode(node);
	stickyNode->setLayer(graphicsLayer);
	stickyNode->updateConstraints((const StickyPositionViewportConstraints&)constraints);
	break;
	}
	}
	}

	void AsyncScrollingCoordinator::setSynchronousScrollingReasons(SynchronousScrollingReasons reasons)
	{
	if (!m_scrollingStateTree->rootStateNode())
	return;

	// The FrameView's GraphicsLayer is likely to be out-of-synch with the PlatformLayer
	// at this point. So we'll update it before we switch back to main thread scrolling
	// in order to avoid layer positioning bugs.
	if (reasons)
	updateMainFrameScrollLayerPosition();
	m_scrollingStateTree->rootStateNode()->setSynchronousScrollingReasons(reasons);
	}

	void AsyncScrollingCoordinator::updateMainFrameScrollLayerPosition()
	{
	ASSERT(isMainThread());

	if (!m_page)
	return;

	FrameView* frameView = m_page->mainFrame().view();
	if (!frameView)
	return;

	if (GraphicsLayer* scrollLayer = scrollLayerForFrameView(frameView))
	scrollLayer->setPosition(-frameView->scrollPosition());
	}

	void AsyncScrollingCoordinator::recomputeWheelEventHandlerCountForFrameView(FrameView* frameView)
	{
	ScrollingStateFrameScrollingNode* node = toScrollingStateFrameScrollingNode(m_scrollingStateTree->stateNodeForID(frameView->scrollLayerID()));
	if (!node)
	return;
	node->setWheelEventHandlerCount(computeCurrentWheelEventHandlerCount());
	}

	bool AsyncScrollingCoordinator::isRubberBandInProgress() const
	{
	return scrollingTree()->isRubberBandInProgress();
	}

	void AsyncScrollingCoordinator::setScrollPinningBehavior(ScrollPinningBehavior pinning)
	{
	scrollingTree()->setScrollPinningBehavior(pinning);
	}

	String AsyncScrollingCoordinator::scrollingStateTreeAsText() const
	{
	if (m_scrollingStateTree->rootStateNode())
	return m_scrollingStateTree->rootStateNode()->scrollingStateTreeAsText();

	return String();
	}

	} // namespace WebCore

	#endif // ENABLE(ASYNC_SCROLLING)