1/*
2 * Copyright (C) 2012 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) || USE(COORDINATED_GRAPHICS)
29
30#include "GraphicsLayer.h"
31#include "ScrollingCoordinator.h"
32#include <stdint.h>
33#include <wtf/RefCounted.h>
34#include <wtf/TypeCasts.h>
35#include <wtf/Vector.h>
36
37namespace WTF {
38class TextStream;
39}
40
41namespace WebCore {
42
43class GraphicsLayer;
44class ScrollingStateTree;
45
46// Used to allow ScrollingStateNodes to refer to layers in various contexts:
47// a) Async scrolling, main thread: ScrollingStateNode holds onto a GraphicsLayer, and uses m_layerID
48// to detect whether that GraphicsLayer's underlying PlatformLayer changed.
49// b) Threaded scrolling, commit to scrolling thread: ScrollingStateNode wraps a PlatformLayer, which
50// can be passed to the Scrolling Thread
51// c) Remote scrolling UI process, where LayerRepresentation wraps just a PlatformLayerID.
52class LayerRepresentation {
53public:
54 enum Type {
55 EmptyRepresentation,
56 GraphicsLayerRepresentation,
57 PlatformLayerRepresentation,
58 PlatformLayerIDRepresentation
59 };
60
61 LayerRepresentation() = default;
62
63 LayerRepresentation(GraphicsLayer* graphicsLayer)
64 : m_graphicsLayer(graphicsLayer)
65 , m_layerID(graphicsLayer ? graphicsLayer->primaryLayerID() : 0)
66 , m_representation(GraphicsLayerRepresentation)
67 { }
68
69 LayerRepresentation(PlatformLayer* platformLayer)
70 : m_typelessPlatformLayer(makePlatformLayerTypeless(platformLayer))
71 , m_representation(PlatformLayerRepresentation)
72 {
73 retainPlatformLayer(m_typelessPlatformLayer);
74 }
75
76 LayerRepresentation(GraphicsLayer::PlatformLayerID layerID)
77 : m_layerID(layerID)
78 , m_representation(PlatformLayerIDRepresentation)
79 {
80 }
81
82 LayerRepresentation(const LayerRepresentation& other)
83 : m_typelessPlatformLayer(other.m_typelessPlatformLayer)
84 , m_layerID(other.m_layerID)
85 , m_representation(other.m_representation)
86 {
87 if (m_representation == PlatformLayerRepresentation)
88 retainPlatformLayer(m_typelessPlatformLayer);
89 }
90
91 ~LayerRepresentation()
92 {
93 if (m_representation == PlatformLayerRepresentation)
94 releasePlatformLayer(m_typelessPlatformLayer);
95 }
96
97 operator GraphicsLayer*() const
98 {
99 ASSERT(m_representation == GraphicsLayerRepresentation);
100 return m_graphicsLayer.get();
101 }
102
103 operator PlatformLayer*() const
104 {
105 ASSERT(m_representation == PlatformLayerRepresentation);
106 return makePlatformLayerTyped(m_typelessPlatformLayer);
107 }
108
109 GraphicsLayer::PlatformLayerID layerID() const
110 {
111 return m_layerID;
112 }
113
114 operator GraphicsLayer::PlatformLayerID() const
115 {
116 ASSERT(m_representation != PlatformLayerRepresentation);
117 return m_layerID;
118 }
119
120 LayerRepresentation& operator=(const LayerRepresentation& other)
121 {
122 m_graphicsLayer = other.m_graphicsLayer;
123 m_typelessPlatformLayer = other.m_typelessPlatformLayer;
124 m_layerID = other.m_layerID;
125 m_representation = other.m_representation;
126
127 if (m_representation == PlatformLayerRepresentation)
128 retainPlatformLayer(m_typelessPlatformLayer);
129
130 return *this;
131 }
132
133 bool operator==(const LayerRepresentation& other) const
134 {
135 if (m_representation != other.m_representation)
136 return false;
137 switch (m_representation) {
138 case EmptyRepresentation:
139 return true;
140 case GraphicsLayerRepresentation:
141 return m_graphicsLayer == other.m_graphicsLayer
142 && m_layerID == other.m_layerID;
143 case PlatformLayerRepresentation:
144 return m_typelessPlatformLayer == other.m_typelessPlatformLayer;
145 case PlatformLayerIDRepresentation:
146 return m_layerID == other.m_layerID;
147 }
148 ASSERT_NOT_REACHED();
149 return true;
150 }
151
152 LayerRepresentation toRepresentation(Type representation) const
153 {
154 switch (representation) {
155 case EmptyRepresentation:
156 return LayerRepresentation();
157 case GraphicsLayerRepresentation:
158 ASSERT(m_representation == GraphicsLayerRepresentation);
159 return LayerRepresentation(m_graphicsLayer.get());
160 case PlatformLayerRepresentation:
161 return m_graphicsLayer ? m_graphicsLayer->platformLayer() : nullptr;
162 case PlatformLayerIDRepresentation:
163 return LayerRepresentation(m_layerID);
164 }
165 return LayerRepresentation();
166 }
167
168 bool representsGraphicsLayer() const { return m_representation == GraphicsLayerRepresentation; }
169 bool representsPlatformLayerID() const { return m_representation == PlatformLayerIDRepresentation; }
170
171private:
172 WEBCORE_EXPORT static void retainPlatformLayer(void* typelessPlatformLayer);
173 WEBCORE_EXPORT static void releasePlatformLayer(void* typelessPlatformLayer);
174 WEBCORE_EXPORT static PlatformLayer* makePlatformLayerTyped(void* typelessPlatformLayer);
175 WEBCORE_EXPORT static void* makePlatformLayerTypeless(PlatformLayer*);
176
177 RefPtr<GraphicsLayer> m_graphicsLayer;
178 void* m_typelessPlatformLayer { nullptr };
179 GraphicsLayer::PlatformLayerID m_layerID { 0 };
180 Type m_representation { EmptyRepresentation };
181};
182
183class ScrollingStateNode : public RefCounted<ScrollingStateNode> {
184 WTF_MAKE_FAST_ALLOCATED;
185public:
186 ScrollingStateNode(ScrollingNodeType, ScrollingStateTree&, ScrollingNodeID);
187 virtual ~ScrollingStateNode();
188
189 ScrollingNodeType nodeType() const { return m_nodeType; }
190
191 bool isFixedNode() const { return m_nodeType == ScrollingNodeType::Fixed; }
192 bool isStickyNode() const { return m_nodeType == ScrollingNodeType::Sticky; }
193 bool isPositionedNode() const { return m_nodeType == ScrollingNodeType::Positioned; }
194 bool isScrollingNode() const { return isFrameScrollingNode() || isOverflowScrollingNode(); }
195 bool isFrameScrollingNode() const { return m_nodeType == ScrollingNodeType::MainFrame || m_nodeType == ScrollingNodeType::Subframe; }
196 bool isFrameHostingNode() const { return m_nodeType == ScrollingNodeType::FrameHosting; }
197 bool isOverflowScrollingNode() const { return m_nodeType == ScrollingNodeType::Overflow; }
198
199 virtual Ref<ScrollingStateNode> clone(ScrollingStateTree& adoptiveTree) = 0;
200 Ref<ScrollingStateNode> cloneAndReset(ScrollingStateTree& adoptiveTree);
201 void cloneAndResetChildren(ScrollingStateNode&, ScrollingStateTree& adoptiveTree);
202
203 // FIXME: using an OptionSet<> for these and derived class bits would simplify code.
204 enum {
205 Layer = 0,
206 ChildNodes,
207 NumStateNodeBits // This must remain at the last position.
208 };
209 typedef uint64_t ChangedProperties;
210
211 bool hasChangedProperties() const { return m_changedProperties; }
212 bool hasChangedProperty(unsigned propertyBit) const { return m_changedProperties & (static_cast<ChangedProperties>(1) << propertyBit); }
213 void resetChangedProperties() { m_changedProperties = 0; }
214 void setPropertyChanged(unsigned propertyBit);
215 virtual void setAllPropertiesChanged();
216
217 ChangedProperties changedProperties() const { return m_changedProperties; }
218 void setChangedProperties(ChangedProperties changedProperties) { m_changedProperties = changedProperties; }
219
220 virtual void reconcileLayerPositionForViewportRect(const LayoutRect& /*viewportRect*/, ScrollingLayerPositionAction) { }
221
222 const LayerRepresentation& layer() const { return m_layer; }
223 WEBCORE_EXPORT void setLayer(const LayerRepresentation&);
224
225 ScrollingStateTree& scrollingStateTree() const { return m_scrollingStateTree; }
226
227 ScrollingNodeID scrollingNodeID() const { return m_nodeID; }
228
229 ScrollingStateNode* parent() const { return m_parent; }
230 void setParent(ScrollingStateNode* parent) { m_parent = parent; }
231 ScrollingNodeID parentNodeID() const { return m_parent ? m_parent->scrollingNodeID() : 0; }
232
233 Vector<RefPtr<ScrollingStateNode>>* children() const { return m_children.get(); }
234 std::unique_ptr<Vector<RefPtr<ScrollingStateNode>>> takeChildren() { return WTFMove(m_children); }
235
236 void appendChild(Ref<ScrollingStateNode>&&);
237 void insertChild(Ref<ScrollingStateNode>&&, size_t index);
238
239 // Note that node ownership is via the parent, so these functions can trigger node deletion.
240 void removeFromParent();
241 void removeChildAtIndex(size_t index);
242 void removeChild(ScrollingStateNode&);
243
244 size_t indexOfChild(ScrollingStateNode&) const;
245
246 String scrollingStateTreeAsText(ScrollingStateTreeAsTextBehavior = ScrollingStateTreeAsTextBehaviorNormal) const;
247
248protected:
249 ScrollingStateNode(const ScrollingStateNode&, ScrollingStateTree&);
250
251 virtual void dumpProperties(WTF::TextStream&, ScrollingStateTreeAsTextBehavior) const;
252
253 inline void setPropertyChangedBit(unsigned propertyBit);
254
255private:
256 void dump(WTF::TextStream&, ScrollingStateTreeAsTextBehavior) const;
257
258 const ScrollingNodeType m_nodeType;
259 const ScrollingNodeID m_nodeID;
260 ChangedProperties m_changedProperties { 0 };
261
262 ScrollingStateTree& m_scrollingStateTree;
263
264 ScrollingStateNode* m_parent { nullptr };
265 std::unique_ptr<Vector<RefPtr<ScrollingStateNode>>> m_children;
266
267 LayerRepresentation m_layer;
268};
269
270void ScrollingStateNode::setPropertyChangedBit(unsigned propertyBit)
271{
272 m_changedProperties |= (static_cast<ChangedProperties>(1) << propertyBit);
273}
274
275} // namespace WebCore
276
277#define SPECIALIZE_TYPE_TRAITS_SCROLLING_STATE_NODE(ToValueTypeName, predicate) \
278SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::ToValueTypeName) \
279 static bool isType(const WebCore::ScrollingStateNode& node) { return node.predicate; } \
280SPECIALIZE_TYPE_TRAITS_END()
281
282#endif // ENABLE(ASYNC_SCROLLING) || USE(COORDINATED_GRAPHICS)
283