1 | /* |
2 | * Copyright (C) 2014-2017 Apple Inc. All rights reserved. |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without |
5 | * modification, are permitted provided that the following conditions |
6 | * are met: |
7 | * 1. Redistributions of source code must retain the above copyright |
8 | * notice, this list of conditions and the following disclaimer. |
9 | * 2. Redistributions in binary form must reproduce the above copyright |
10 | * notice, this list of conditions and the following disclaimer in the |
11 | * documentation and/or other materials provided with the distribution. |
12 | * |
13 | * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' |
14 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
15 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
16 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS |
17 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
18 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
19 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
20 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
21 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
22 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
23 | * THE POSSIBILITY OF SUCH DAMAGE. |
24 | */ |
25 | |
26 | #pragma once |
27 | |
28 | #if ENABLE(ASYNC_SCROLLING) |
29 | |
30 | #include "ScrollingStateTree.h" |
31 | #include "ScrollingTree.h" |
32 | #include <wtf/Condition.h> |
33 | #include <wtf/RefPtr.h> |
34 | |
35 | namespace WebCore { |
36 | |
37 | class AsyncScrollingCoordinator; |
38 | |
39 | // The ThreadedScrollingTree class lives almost exclusively on the scrolling thread and manages the |
40 | // hierarchy of scrollable regions on the page. It's also responsible for dispatching events |
41 | // to the correct scrolling tree nodes or dispatching events back to the ScrollingCoordinator |
42 | // object on the main thread if they can't be handled on the scrolling thread for various reasons. |
43 | class ThreadedScrollingTree : public ScrollingTree { |
44 | public: |
45 | virtual ~ThreadedScrollingTree(); |
46 | |
47 | void commitTreeState(std::unique_ptr<ScrollingStateTree>) override; |
48 | |
49 | ScrollingEventResult handleWheelEvent(const PlatformWheelEvent&) override; |
50 | |
51 | // Can be called from any thread. Will try to handle the wheel event on the scrolling thread. |
52 | // Returns true if the wheel event can be handled on the scrolling thread and false if the |
53 | // event must be sent again to the WebCore event handler. |
54 | ScrollingEventResult tryToHandleWheelEvent(const PlatformWheelEvent&) override; |
55 | |
56 | void invalidate() override; |
57 | |
58 | void incrementPendingCommitCount(); |
59 | void decrementPendingCommitCount(); |
60 | |
61 | protected: |
62 | explicit ThreadedScrollingTree(AsyncScrollingCoordinator&); |
63 | |
64 | void scrollingTreeNodeDidScroll(ScrollingTreeScrollingNode&, ScrollingLayerPositionAction = ScrollingLayerPositionAction::Sync) override; |
65 | #if PLATFORM(MAC) |
66 | void handleWheelEventPhase(PlatformWheelEventPhase) override; |
67 | void setActiveScrollSnapIndices(ScrollingNodeID, unsigned horizontalIndex, unsigned verticalIndex) override; |
68 | void deferTestsForReason(WheelEventTestTrigger::ScrollableAreaIdentifier, WheelEventTestTrigger::DeferTestTriggerReason) override; |
69 | void removeTestDeferralForReason(WheelEventTestTrigger::ScrollableAreaIdentifier, WheelEventTestTrigger::DeferTestTriggerReason) override; |
70 | #endif |
71 | |
72 | #if PLATFORM(COCOA) |
73 | void currentSnapPointIndicesDidChange(ScrollingNodeID, unsigned horizontal, unsigned vertical) override; |
74 | #endif |
75 | |
76 | void reportExposedUnfilledArea(MonotonicTime, unsigned unfilledArea) override; |
77 | void reportSynchronousScrollingReasonsChanged(MonotonicTime, SynchronousScrollingReasons) override; |
78 | |
79 | private: |
80 | bool isThreadedScrollingTree() const override { return true; } |
81 | void applyLayerPositions() override; |
82 | |
83 | RefPtr<AsyncScrollingCoordinator> m_scrollingCoordinator; |
84 | |
85 | void waitForPendingCommits(); |
86 | |
87 | Lock m_pendingCommitCountMutex; |
88 | unsigned m_pendingCommitCount { 0 }; |
89 | Condition m_commitCondition; |
90 | }; |
91 | |
92 | } // namespace WebCore |
93 | |
94 | SPECIALIZE_TYPE_TRAITS_SCROLLING_TREE(WebCore::ThreadedScrollingTree, isThreadedScrollingTree()) |
95 | |
96 | #endif // ENABLE(ASYNC_SCROLLING) |
97 | |