1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/*
* Copyright (C) 2011 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.
*/
#ifndef ScrollingCoordinator_h
#define ScrollingCoordinator_h
#include "IntRect.h"
#include "LayoutRect.h"
#include "PlatformWheelEvent.h"
#include "RenderObject.h"
#include "ScrollTypes.h"
#include "Timer.h"
#include <wtf/Forward.h>
#if ENABLE(THREADED_SCROLLING)
#include <wtf/HashMap.h>
#include <wtf/ThreadSafeRefCounted.h>
#include <wtf/Threading.h>
#endif
#if PLATFORM(MAC)
#include <wtf/RetainPtr.h>
#endif
namespace WebCore {
typedef unsigned MainThreadScrollingReasons;
typedef uint64_t ScrollingNodeID;
enum ScrollingNodeType { ScrollingNode, FixedNode, StickyNode };
class Document;
class Frame;
class FrameView;
class GraphicsLayer;
class Page;
class Region;
class ScrollableArea;
class ViewportConstraints;
#if ENABLE(THREADED_SCROLLING)
class ScrollingTree;
#endif
enum SetOrSyncScrollingLayerPosition {
SetScrollingLayerPosition,
SyncScrollingLayerPosition
};
class ScrollingCoordinator : public ThreadSafeRefCounted<ScrollingCoordinator> {
public:
static PassRefPtr<ScrollingCoordinator> create(Page*);
virtual ~ScrollingCoordinator();
virtual void pageDestroyed();
#if ENABLE(THREADED_SCROLLING)
virtual ScrollingTree* scrollingTree() const { return 0; }
#endif
// Return whether this scrolling coordinator handles scrolling for the given frame view.
bool coordinatesScrollingForFrameView(FrameView*) const;
// Should be called whenever the given frame view has been laid out.
virtual void frameViewLayoutUpdated(FrameView*) { }
// Should be called whenever a wheel event handler is added or removed in the
// frame view's underlying document.
void frameViewWheelEventHandlerCountChanged(FrameView*);
// Should be called whenever the slow repaint objects counter changes between zero and one.
void frameViewHasSlowRepaintObjectsDidChange(FrameView*);
// Should be called whenever the set of fixed objects changes.
void frameViewFixedObjectsDidChange(FrameView*);
// Should be called whenever the root layer for the given frame view changes.
virtual void frameViewRootLayerDidChange(FrameView*);
// Return whether this scrolling coordinator can keep fixed position layers fixed to their
// containers while scrolling.
virtual bool supportsFixedPositionLayers() const { return false; }
#if PLATFORM(MAC)
// Dispatched by the scrolling tree during handleWheelEvent. This is required as long as scrollbars are painted on the main thread.
void handleWheelEventPhase(PlatformWheelEventPhase);
#endif
// Force all scroll layer position updates to happen on the main thread.
void setForceMainThreadScrollLayerPositionUpdates(bool);
// These virtual functions are currently unique to the threaded scrolling architecture.
// Their meaningful implementations are in ScrollingCoordinatorMac.
virtual void commitTreeStateIfNeeded() { }
virtual bool requestScrollPositionUpdate(FrameView*, const IntPoint&) { return false; }
virtual bool handleWheelEvent(FrameView*, const PlatformWheelEvent&) { return true; }
virtual ScrollingNodeID attachToStateTree(ScrollingNodeType, ScrollingNodeID newNodeID, ScrollingNodeID /*parentID*/) { return newNodeID; }
virtual void detachFromStateTree(ScrollingNodeID) { }
virtual void clearStateTree() { }
virtual void updateViewportConstrainedNode(ScrollingNodeID, const ViewportConstraints&, GraphicsLayer*) { }
virtual void updateScrollingNode(ScrollingNodeID, GraphicsLayer* /*scrollLayer*/, GraphicsLayer* /*counterScrollingLayer*/) { }
virtual void syncChildPositions(const LayoutRect&) { }
virtual String scrollingStateTreeAsText() const;
virtual bool isRubberBandInProgress() const { return false; }
virtual bool rubberBandsAtBottom() const { return false; }
virtual void setRubberBandsAtBottom(bool) { }
virtual bool rubberBandsAtTop() const { return false; }
virtual void setRubberBandsAtTop(bool) { }
virtual void setScrollPinningBehavior(ScrollPinningBehavior) { }
// Generated a unique id for scroll layers.
ScrollingNodeID uniqueScrollLayerID();
// Dispatched by the scrolling tree whenever the main frame scroll position changes.
void scheduleUpdateMainFrameScrollPosition(const IntPoint&, bool programmaticScroll, SetOrSyncScrollingLayerPosition);
void updateMainFrameScrollPosition(const IntPoint&, bool programmaticScroll, SetOrSyncScrollingLayerPosition);
enum MainThreadScrollingReasonFlags {
ForcedOnMainThread = 1 << 0,
HasSlowRepaintObjects = 1 << 1,
HasViewportConstrainedObjectsWithoutSupportingFixedLayers = 1 << 2,
HasNonLayerViewportConstrainedObjects = 1 << 3,
IsImageDocument = 1 << 4
};
MainThreadScrollingReasons mainThreadScrollingReasons() const;
bool shouldUpdateScrollLayerPositionOnMainThread() const { return mainThreadScrollingReasons() != 0; }
// These virtual functions are currently unique to Chromium's WebLayer approach. Their meaningful
// implementations are in ScrollingCoordinatorChromium.
virtual void willDestroyScrollableArea(ScrollableArea*) { }
virtual void scrollableAreaScrollLayerDidChange(ScrollableArea*) { }
virtual void scrollableAreaScrollbarLayerDidChange(ScrollableArea*, ScrollbarOrientation) { }
virtual void setLayerIsContainerForFixedPositionLayers(GraphicsLayer*, bool) { }
virtual void updateLayerPositionConstraint(RenderLayer*) { }
virtual void touchEventTargetRectsDidChange(const Document*) { }
#if ENABLE(TOUCH_EVENT_TRACKING)
void computeAbsoluteTouchEventTargetRects(const Document*, Vector<IntRect>&);
#endif
static String mainThreadScrollingReasonsAsText(MainThreadScrollingReasons);
String mainThreadScrollingReasonsAsText() const;
Region computeNonFastScrollableRegion(const Frame*, const IntPoint& frameLocation) const;
protected:
explicit ScrollingCoordinator(Page*);
#if USE(ACCELERATED_COMPOSITING)
static GraphicsLayer* scrollLayerForScrollableArea(ScrollableArea*);
static GraphicsLayer* horizontalScrollbarLayerForScrollableArea(ScrollableArea*);
static GraphicsLayer* verticalScrollbarLayerForScrollableArea(ScrollableArea*);
#endif
unsigned computeCurrentWheelEventHandlerCount();
GraphicsLayer* scrollLayerForFrameView(FrameView*);
GraphicsLayer* counterScrollingLayerForFrameView(FrameView*);
GraphicsLayer* headerLayerForFrameView(FrameView*);
GraphicsLayer* footerLayerForFrameView(FrameView*);
Page* m_page;
private:
virtual void recomputeWheelEventHandlerCountForFrameView(FrameView*) { }
virtual void setShouldUpdateScrollLayerPositionOnMainThread(MainThreadScrollingReasons) { }
virtual bool hasVisibleSlowRepaintViewportConstrainedObjects(FrameView*) const;
void updateShouldUpdateScrollLayerPositionOnMainThread();
void updateMainFrameScrollPositionTimerFired(Timer<ScrollingCoordinator>*);
Timer<ScrollingCoordinator> m_updateMainFrameScrollPositionTimer;
IntPoint m_scheduledUpdateScrollPosition;
bool m_scheduledUpdateIsProgrammaticScroll;
SetOrSyncScrollingLayerPosition m_scheduledScrollingLayerPositionAction;
bool m_forceMainThreadScrollLayerPositionUpdates;
};
} // namespace WebCore
#endif // ScrollingCoordinator_h
|
