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#ifndef ScrollingStateNode_h
27#define ScrollingStateNode_h
28
29#if ENABLE(THREADED_SCROLLING) || USE(COORDINATED_GRAPHICS)
30
31#include "PlatformLayer.h"
32#include "ScrollingCoordinator.h"
33#include <wtf/OwnPtr.h>
34#include <wtf/PassOwnPtr.h>
35#include <wtf/Vector.h>
36
37#if PLATFORM(MAC)
38#include <wtf/RetainPtr.h>
39#endif
40
41namespace WebCore {
42
43class GraphicsLayer;
44class ScrollingStateTree;
45class TextStream;
46
47class ScrollingStateNode {
48public:
49    ScrollingStateNode(ScrollingStateTree*, ScrollingNodeID);
50    virtual ~ScrollingStateNode();
51
52    virtual bool isScrollingNode() { return false; }
53    virtual bool isFixedNode() { return false; }
54    virtual bool isStickyNode() { return false; }
55
56    virtual PassOwnPtr<ScrollingStateNode> clone() = 0;
57    PassOwnPtr<ScrollingStateNode> cloneAndReset();
58    void cloneAndResetChildren(ScrollingStateNode*);
59
60    enum {
61        ScrollLayer = 0,
62        NumStateNodeBits = 1
63    };
64    typedef unsigned ChangedProperties;
65
66    bool hasChangedProperties() const { return m_changedProperties; }
67    bool hasChangedProperty(unsigned propertyBit) { return m_changedProperties & (1 << propertyBit); }
68    void resetChangedProperties() { m_changedProperties = 0; }
69    void setPropertyChanged(unsigned propertyBit) { m_changedProperties |= (1 << propertyBit); }
70
71    virtual void syncLayerPositionForViewportRect(const LayoutRect& /*viewportRect*/) { }
72
73    GraphicsLayer* graphicsLayer() { return m_graphicsLayer; }
74    PlatformLayer* platformScrollLayer() const;
75    void setScrollLayer(GraphicsLayer*);
76    void setScrollPlatformLayer(PlatformLayer*);
77
78    ScrollingStateTree* scrollingStateTree() const { return m_scrollingStateTree; }
79    void setScrollingStateTree(ScrollingStateTree* tree) { m_scrollingStateTree = tree; }
80
81    ScrollingNodeID scrollingNodeID() const { return m_nodeID; }
82
83    ScrollingStateNode* parent() const { return m_parent; }
84    void setParent(ScrollingStateNode* parent) { m_parent = parent; }
85
86    Vector<OwnPtr<ScrollingStateNode> >* children() const { return m_children.get(); }
87
88    void appendChild(PassOwnPtr<ScrollingStateNode>);
89    void removeChild(ScrollingStateNode*);
90
91    String scrollingStateTreeAsText() const;
92
93protected:
94    ScrollingStateNode(const ScrollingStateNode&);
95    static void writeIndent(TextStream&, int indent);
96
97    ScrollingStateTree* m_scrollingStateTree;
98
99private:
100    void dump(TextStream&, int indent) const;
101
102    virtual void dumpProperties(TextStream&, int indent) const = 0;
103    ChangedProperties changedProperties() const { return m_changedProperties; }
104    void willBeRemovedFromStateTree();
105
106    ScrollingNodeID m_nodeID;
107    ChangedProperties m_changedProperties;
108
109    ScrollingStateNode* m_parent;
110    OwnPtr<Vector<OwnPtr<ScrollingStateNode> > > m_children;
111
112#if PLATFORM(MAC)
113    RetainPtr<PlatformLayer> m_platformScrollLayer;
114#endif
115    GraphicsLayer* m_graphicsLayer;
116
117};
118
119} // namespace WebCore
120
121#endif // ENABLE(THREADED_SCROLLING) || USE(COORDINATED_GRAPHICS)
122
123#endif // ScrollingStateNode_h
124