/* * Copyright (C) 2014-2017 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. */ #pragma once #if ENABLE(ASYNC_SCROLLING) #include "ScrollingStateTree.h" #include "ScrollingTree.h" #include <wtf/RefPtr.h> namespace WebCore { class AsyncScrollingCoordinator; // The ThreadedScrollingTree class lives almost exclusively on the scrolling thread and manages the // hierarchy of scrollable regions on the page. It's also responsible for dispatching events // to the correct scrolling tree nodes or dispatching events back to the ScrollingCoordinator // object on the main thread if they can't be handled on the scrolling thread for various reasons. class ThreadedScrollingTree : public ScrollingTree { public: virtual ~ThreadedScrollingTree(); void commitTreeState(std::unique_ptr<ScrollingStateTree>) override; void handleWheelEvent(const PlatformWheelEvent&) override; // Can be called from any thread. Will try to handle the wheel event on the scrolling thread. // Returns true if the wheel event can be handled on the scrolling thread and false if the // event must be sent again to the WebCore event handler. EventResult tryToHandleWheelEvent(const PlatformWheelEvent&) override; void invalidate() override; protected: explicit ThreadedScrollingTree(AsyncScrollingCoordinator&); void scrollingTreeNodeDidScroll(ScrollingNodeID, const FloatPoint& scrollPosition, const std::optional<FloatPoint>& layoutViewportOrigin, ScrollingLayerPositionAction = ScrollingLayerPositionAction::Sync) override; void currentSnapPointIndicesDidChange(ScrollingNodeID, unsigned horizontal, unsigned vertical) override; #if PLATFORM(MAC) void handleWheelEventPhase(PlatformWheelEventPhase) override; void setActiveScrollSnapIndices(ScrollingNodeID, unsigned horizontalIndex, unsigned verticalIndex) override; void deferTestsForReason(WheelEventTestTrigger::ScrollableAreaIdentifier, WheelEventTestTrigger::DeferTestTriggerReason) override; void removeTestDeferralForReason(WheelEventTestTrigger::ScrollableAreaIdentifier, WheelEventTestTrigger::DeferTestTriggerReason) override; #endif void reportExposedUnfilledArea(MonotonicTime, unsigned unfilledArea) override; void reportSynchronousScrollingReasonsChanged(MonotonicTime, SynchronousScrollingReasons) override; private: bool isThreadedScrollingTree() const override { return true; } RefPtr<AsyncScrollingCoordinator> m_scrollingCoordinator; }; } // namespace WebCore SPECIALIZE_TYPE_TRAITS_SCROLLING_TREE(WebCore::ThreadedScrollingTree, isThreadedScrollingTree()) #endif // ENABLE(ASYNC_SCROLLING)