1/*
2 * Copyright (C) 2012-2015 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 "PlatformWheelEvent.h"
31#include "Region.h"
32#include "ScrollingCoordinator.h"
33#include "TouchAction.h"
34#include "WheelEventTestTrigger.h"
35#include <wtf/HashMap.h>
36#include <wtf/Lock.h>
37#include <wtf/ThreadSafeRefCounted.h>
38#include <wtf/TypeCasts.h>
39
40namespace WebCore {
41
42class IntPoint;
43class ScrollingStateTree;
44class ScrollingStateNode;
45class ScrollingTreeFrameScrollingNode;
46class ScrollingTreeNode;
47class ScrollingTreeScrollingNode;
48
49class ScrollingTree : public ThreadSafeRefCounted<ScrollingTree> {
50public:
51 WEBCORE_EXPORT ScrollingTree();
52 WEBCORE_EXPORT virtual ~ScrollingTree();
53
54 virtual bool isThreadedScrollingTree() const { return false; }
55 virtual bool isRemoteScrollingTree() const { return false; }
56 virtual bool isScrollingTreeIOS() const { return false; }
57
58 // This implies that we'll do hit-testing in the scrolling tree.
59 bool asyncFrameOrOverflowScrollingEnabled() const { return m_asyncFrameOrOverflowScrollingEnabled; }
60 void setAsyncFrameOrOverflowScrollingEnabled(bool);
61
62 virtual ScrollingEventResult tryToHandleWheelEvent(const PlatformWheelEvent&) = 0;
63 WEBCORE_EXPORT bool shouldHandleWheelEventSynchronously(const PlatformWheelEvent&);
64
65 void setMainFrameIsRubberBanding(bool);
66 bool isRubberBandInProgress();
67 void setMainFrameIsScrollSnapping(bool);
68 bool isScrollSnapInProgress();
69
70 virtual void invalidate() { }
71 WEBCORE_EXPORT virtual void commitTreeState(std::unique_ptr<ScrollingStateTree>);
72
73 WEBCORE_EXPORT virtual void applyLayerPositions();
74
75 virtual Ref<ScrollingTreeNode> createScrollingTreeNode(ScrollingNodeType, ScrollingNodeID) = 0;
76
77 WEBCORE_EXPORT ScrollingTreeNode* nodeForID(ScrollingNodeID) const;
78
79 // Called after a scrolling tree node has handled a scroll and updated its layers.
80 // Updates FrameView/RenderLayer scrolling state and GraphicsLayers.
81 virtual void scrollingTreeNodeDidScroll(ScrollingTreeScrollingNode&, ScrollingLayerPositionAction = ScrollingLayerPositionAction::Sync) = 0;
82
83 // Called for requested scroll position updates.
84 virtual void scrollingTreeNodeRequestsScroll(ScrollingNodeID, const FloatPoint& /*scrollPosition*/, bool /*representsProgrammaticScroll*/) { }
85
86 // Delegated scrolling/zooming has caused the viewport to change, so update viewport-constrained layers
87 // (but don't cause scroll events to be fired).
88 WEBCORE_EXPORT virtual void mainFrameViewportChangedViaDelegatedScrolling(const FloatPoint& scrollPosition, const WebCore::FloatRect& layoutViewport, double scale);
89
90 void notifyRelatedNodesAfterScrollPositionChange(ScrollingTreeScrollingNode& changedNode);
91
92 virtual void reportSynchronousScrollingReasonsChanged(MonotonicTime, SynchronousScrollingReasons) { }
93 virtual void reportExposedUnfilledArea(MonotonicTime, unsigned /* unfilledArea */) { }
94
95#if PLATFORM(IOS_FAMILY)
96 virtual void scrollingTreeNodeWillStartPanGesture() { }
97 virtual void scrollingTreeNodeWillStartScroll() { }
98 virtual void scrollingTreeNodeDidEndScroll() { }
99#endif
100
101 WEBCORE_EXPORT TrackingType eventTrackingTypeForPoint(const AtomicString& eventName, IntPoint);
102#if ENABLE(POINTER_EVENTS)
103 WEBCORE_EXPORT Optional<TouchActionData> touchActionDataAtPoint(IntPoint) const;
104#endif
105
106#if PLATFORM(MAC)
107 virtual void handleWheelEventPhase(PlatformWheelEventPhase) = 0;
108 virtual void setActiveScrollSnapIndices(ScrollingNodeID, unsigned /*horizontalIndex*/, unsigned /*verticalIndex*/) { }
109 virtual void deferTestsForReason(WheelEventTestTrigger::ScrollableAreaIdentifier, WheelEventTestTrigger::DeferTestTriggerReason) { }
110 virtual void removeTestDeferralForReason(WheelEventTestTrigger::ScrollableAreaIdentifier, WheelEventTestTrigger::DeferTestTriggerReason) { }
111#endif
112
113#if PLATFORM(COCOA)
114 WEBCORE_EXPORT virtual void currentSnapPointIndicesDidChange(ScrollingNodeID, unsigned horizontal, unsigned vertical) = 0;
115#endif
116
117 void setMainFramePinState(bool pinnedToTheLeft, bool pinnedToTheRight, bool pinnedToTheTop, bool pinnedToTheBottom);
118
119 // Can be called from any thread. Will update what edges allow rubber-banding.
120 WEBCORE_EXPORT void setCanRubberBandState(bool canRubberBandAtLeft, bool canRubberBandAtRight, bool canRubberBandAtTop, bool canRubberBandAtBottom);
121
122 bool isHandlingProgrammaticScroll() const { return m_isHandlingProgrammaticScroll; }
123 void setIsHandlingProgrammaticScroll(bool isHandlingProgrammaticScroll) { m_isHandlingProgrammaticScroll = isHandlingProgrammaticScroll; }
124
125 void setScrollPinningBehavior(ScrollPinningBehavior);
126 WEBCORE_EXPORT ScrollPinningBehavior scrollPinningBehavior();
127
128 WEBCORE_EXPORT bool willWheelEventStartSwipeGesture(const PlatformWheelEvent&);
129
130 WEBCORE_EXPORT void setScrollingPerformanceLoggingEnabled(bool flag);
131 bool scrollingPerformanceLoggingEnabled();
132
133 ScrollingTreeFrameScrollingNode* rootNode() const { return m_rootNode.get(); }
134
135 ScrollingNodeID latchedNode();
136 void setLatchedNode(ScrollingNodeID);
137 void clearLatchedNode();
138
139 bool hasLatchedNode() const { return m_treeState.latchedNodeID; }
140 void setOrClearLatchedNode(const PlatformWheelEvent&, ScrollingNodeID);
141
142 bool hasFixedOrSticky() const { return !!m_fixedOrStickyNodeCount; }
143 void fixedOrStickyNodeAdded() { ++m_fixedOrStickyNodeCount; }
144 void fixedOrStickyNodeRemoved()
145 {
146 ASSERT(m_fixedOrStickyNodeCount);
147 --m_fixedOrStickyNodeCount;
148 }
149
150 // A map of overflow scrolling nodes to positioned nodes which need to be updated
151 // when the scroller changes, but are not descendants.
152 using RelatedNodesMap = HashMap<ScrollingNodeID, Vector<ScrollingNodeID>>;
153 RelatedNodesMap& overflowRelatedNodes() { return m_overflowRelatedNodesMap; }
154
155 HashSet<ScrollingNodeID>& positionedNodesWithRelatedOverflow() { return m_positionedNodesWithRelatedOverflow; }
156
157 WEBCORE_EXPORT String scrollingTreeAsText(ScrollingStateTreeAsTextBehavior = ScrollingStateTreeAsTextBehaviorNormal);
158
159protected:
160 void setMainFrameScrollPosition(FloatPoint);
161
162 WEBCORE_EXPORT virtual ScrollingEventResult handleWheelEvent(const PlatformWheelEvent&);
163
164private:
165 using OrphanScrollingNodeMap = HashMap<ScrollingNodeID, RefPtr<ScrollingTreeNode>>;
166 void updateTreeFromStateNode(const ScrollingStateNode*, OrphanScrollingNodeMap&, HashSet<ScrollingNodeID>& unvisitedNodes);
167
168 void applyLayerPositionsRecursive(ScrollingTreeNode&, FloatRect layoutViewport, FloatSize cumulativeDelta);
169
170 void notifyRelatedNodesRecursive(ScrollingTreeScrollingNode& changedNode, ScrollingTreeNode& currNode, const FloatRect& layoutViewport, FloatSize cumulativeDelta);
171
172 Lock m_treeMutex; // Protects the scrolling tree.
173
174 RefPtr<ScrollingTreeFrameScrollingNode> m_rootNode;
175
176 using ScrollingTreeNodeMap = HashMap<ScrollingNodeID, ScrollingTreeNode*>;
177 ScrollingTreeNodeMap m_nodeMap;
178
179 RelatedNodesMap m_overflowRelatedNodesMap;
180 HashSet<ScrollingNodeID> m_positionedNodesWithRelatedOverflow;
181
182 struct TreeState {
183 ScrollingNodeID latchedNodeID { 0 };
184 EventTrackingRegions eventTrackingRegions;
185 FloatPoint mainFrameScrollPosition;
186 bool mainFrameIsRubberBanding { false };
187 bool mainFrameIsScrollSnapping { false };
188 };
189
190 Lock m_treeStateMutex;
191 TreeState m_treeState;
192
193 struct SwipeState {
194 ScrollPinningBehavior scrollPinningBehavior { DoNotPin };
195 bool rubberBandsAtLeft { true };
196 bool rubberBandsAtRight { true };
197 bool rubberBandsAtTop { true };
198 bool rubberBandsAtBottom { true };
199 bool mainFramePinnedToTheLeft { true };
200 bool mainFramePinnedToTheRight { true };
201 bool mainFramePinnedToTheTop { true };
202 bool mainFramePinnedToTheBottom { true };
203 };
204
205 Lock m_swipeStateMutex;
206 SwipeState m_swipeState;
207
208 unsigned m_fixedOrStickyNodeCount { 0 };
209 bool m_isHandlingProgrammaticScroll { false };
210 bool m_scrollingPerformanceLoggingEnabled { false };
211 bool m_asyncFrameOrOverflowScrollingEnabled { false };
212};
213
214} // namespace WebCore
215
216#define SPECIALIZE_TYPE_TRAITS_SCROLLING_TREE(ToValueTypeName, predicate) \
217SPECIALIZE_TYPE_TRAITS_BEGIN(ToValueTypeName) \
218 static bool isType(const WebCore::ScrollingTree& tree) { return tree.predicate; } \
219SPECIALIZE_TYPE_TRAITS_END()
220#endif // ENABLE(ASYNC_SCROLLING)
221