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 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 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 PassRef<CSSCanvasValue> create(const String& name) { return adoptRef(*new CSSCanvasValue(name)); }
39    ~CSSCanvasValue();
40
41    String customCSSText() const;
42
43    PassRefPtr<Image> image(RenderElement*, const FloatSize&);
44    bool isFixedSize() const { return true; }
45    FloatSize fixedSize(const RenderElement*);
46
47    bool isPending() const { return false; }
48    void loadSubimages(CachedResourceLoader*) { }
49
50    bool equals(const CSSCanvasValue&) const;
51
52private:
53    explicit 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 final : public CanvasObserver {
64    public:
65        explicit CanvasObserverProxy(CSSCanvasValue& ownerValue)
66            : m_ownerValue(ownerValue)
67        {
68        }
69
70        virtual ~CanvasObserverProxy()
71        {
72        }
73
74    private:
75        virtual void canvasChanged(HTMLCanvasElement& canvas, const FloatRect& changedRect) override
76        {
77            m_ownerValue.canvasChanged(canvas, changedRect);
78        }
79        virtual void canvasResized(HTMLCanvasElement& canvas) override
80        {
81            m_ownerValue.canvasResized(canvas);
82        }
83        virtual void canvasDestroyed(HTMLCanvasElement& canvas) override
84        {
85            m_ownerValue.canvasDestroyed(canvas);
86        }
87
88        CSSCanvasValue& m_ownerValue;
89    };
90
91    void canvasChanged(HTMLCanvasElement&, const FloatRect& changedRect);
92    void canvasResized(HTMLCanvasElement&);
93    void canvasDestroyed(HTMLCanvasElement&);
94
95    HTMLCanvasElement* element(Document&);
96
97    CanvasObserverProxy m_canvasObserver;
98
99    // The name of the canvas.
100    String m_name;
101    // The document supplies the element and owns it.
102    HTMLCanvasElement* m_element;
103};
104
105CSS_VALUE_TYPE_CASTS(CSSCanvasValue, isCanvasValue())
106
107} // namespace WebCore
108
109#endif // CSSCanvasValue_h
110