1/*
2 * Copyright (C) 2008 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 COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef CSSCanvasValue_h
27#define CSSCanvasValue_h
28
29#include "CSSImageGeneratorValue.h"
30#include "HTMLCanvasElement.h"
31
32namespace WebCore {
33
34class Document;
35
36class CSSCanvasValue : public CSSImageGeneratorValue {
37public:
38    static PassRefPtr<CSSCanvasValue> create(const String& name) { return adoptRef(new CSSCanvasValue(name)); }
39    ~CSSCanvasValue();
40
41    String customCssText() const;
42
43    PassRefPtr<Image> image(RenderObject*, const IntSize&);
44    bool isFixedSize() const { return true; }
45    IntSize fixedSize(const RenderObject*);
46
47    bool isPending() const { return false; }
48    void loadSubimages(CachedResourceLoader*) { }
49
50    bool equals(const CSSCanvasValue&) const;
51
52private:
53    CSSCanvasValue(const String& name)
54        : CSSImageGeneratorValue(CanvasClass)
55        , m_canvasObserver(this)
56        , m_name(name)
57        , m_element(0)
58    {
59    }
60
61    // NOTE: We put the CanvasObserver in a member instead of inheriting from it
62    // to avoid adding a vptr to CSSCanvasValue.
63    class CanvasObserverProxy : public CanvasObserver {
64    public:
65        CanvasObserverProxy(CSSCanvasValue* ownerValue) : m_ownerValue(ownerValue) { }
66        virtual ~CanvasObserverProxy() { }
67        virtual void canvasChanged(HTMLCanvasElement* canvas, const FloatRect& changedRect)
68        {
69            m_ownerValue->canvasChanged(canvas, changedRect);
70        }
71        virtual void canvasResized(HTMLCanvasElement* canvas)
72        {
73            m_ownerValue->canvasResized(canvas);
74        }
75        virtual void canvasDestroyed(HTMLCanvasElement* canvas)
76        {
77            m_ownerValue->canvasDestroyed(canvas);
78        }
79    private:
80        CSSCanvasValue* m_ownerValue;
81    };
82
83    void canvasChanged(HTMLCanvasElement*, const FloatRect& changedRect);
84    void canvasResized(HTMLCanvasElement*);
85    void canvasDestroyed(HTMLCanvasElement*);
86
87    HTMLCanvasElement* element(Document*);
88
89    CanvasObserverProxy m_canvasObserver;
90
91    // The name of the canvas.
92    String m_name;
93    // The document supplies the element and owns it.
94    HTMLCanvasElement* m_element;
95};
96
97} // namespace WebCore
98
99#endif // CSSCanvasValue_h
100