1/*
2 * Copyright (C) 2004, 2006, 2009, 2010 Apple Inc. All rights reserved.
3 * Copyright (C) 2007 Alp Toker <alp@atoker.com>
4 * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
22 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
23 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#ifndef HTMLCanvasElement_h
29#define HTMLCanvasElement_h
30
31#include "FloatRect.h"
32#include "HTMLElement.h"
33#include "IntSize.h"
34
35#if PLATFORM(CHROMIUM) || PLATFORM(QT)
36#define DefaultInterpolationQuality InterpolationMedium
37#elif USE(CG)
38#define DefaultInterpolationQuality InterpolationLow
39#else
40#define DefaultInterpolationQuality InterpolationDefault
41#endif
42
43namespace WebCore {
44
45class CanvasContextAttributes;
46class CanvasRenderingContext;
47class GraphicsContext;
48class HTMLCanvasElement;
49class Image;
50class ImageData;
51class ImageBuffer;
52class IntSize;
53
54class CanvasObserver {
55public:
56    virtual ~CanvasObserver() { }
57
58    virtual void canvasChanged(HTMLCanvasElement*, const FloatRect& changedRect) = 0;
59    virtual void canvasResized(HTMLCanvasElement*) = 0;
60    virtual void canvasDestroyed(HTMLCanvasElement*) = 0;
61};
62
63class HTMLCanvasElement : public HTMLElement {
64public:
65    static PassRefPtr<HTMLCanvasElement> create(Document*);
66    static PassRefPtr<HTMLCanvasElement> create(const QualifiedName&, Document*);
67    virtual ~HTMLCanvasElement();
68
69    void addObserver(CanvasObserver*);
70    void removeObserver(CanvasObserver*);
71
72    // Attributes and functions exposed to script
73    int width() const { return size().width(); }
74    int height() const { return size().height(); }
75
76    const IntSize& size() const { return m_size; }
77
78    void setWidth(int);
79    void setHeight(int);
80
81    void setSize(const IntSize& newSize)
82    {
83        if (newSize == size())
84            return;
85        m_ignoreReset = true;
86        setWidth(newSize.width());
87        setHeight(newSize.height());
88        m_ignoreReset = false;
89        reset();
90    }
91
92    CanvasRenderingContext* getContext(const String&, CanvasContextAttributes* attributes = 0);
93
94    String toDataURL(const String& mimeType, const double* quality, ExceptionCode&);
95    String toDataURL(const String& mimeType, ExceptionCode& ec) { return toDataURL(mimeType, 0, ec); }
96
97    // Used for rendering
98    void didDraw(const FloatRect&);
99
100    void paint(GraphicsContext*, const IntRect&);
101
102    GraphicsContext* drawingContext() const;
103
104    CanvasRenderingContext* renderingContext() const { return m_context.get(); }
105
106    ImageBuffer* buffer() const;
107    Image* copiedImage() const;
108    void clearCopiedImage();
109    PassRefPtr<ImageData> getImageData();
110    void makePresentationCopy();
111    void clearPresentationCopy();
112
113    IntRect convertLogicalToDevice(const FloatRect&) const;
114    IntSize convertLogicalToDevice(const FloatSize&) const;
115    IntSize convertToValidDeviceSize(float width, float height) const;
116
117    const SecurityOrigin& securityOrigin() const;
118    void setOriginTainted() { m_originClean = false; }
119    bool originClean() const { return m_originClean; }
120
121    CSSStyleSelector* styleSelector();
122
123    AffineTransform baseTransform() const;
124
125#if ENABLE(WEBGL)
126    bool is3D() const;
127#endif
128
129    void makeRenderingResultsAvailable();
130
131#if PLATFORM(ANDROID)
132    void clearDirtyRect() { m_dirtyRect = FloatRect(); }
133#endif
134
135private:
136    HTMLCanvasElement(const QualifiedName&, Document*);
137
138    virtual void parseMappedAttribute(Attribute*);
139    virtual RenderObject* createRenderer(RenderArena*, RenderStyle*);
140
141    void reset();
142
143    void createImageBuffer() const;
144
145    void setSurfaceSize(const IntSize&);
146    bool hasCreatedImageBuffer() const { return m_hasCreatedImageBuffer; }
147
148    HashSet<CanvasObserver*> m_observers;
149
150    IntSize m_size;
151
152    OwnPtr<CanvasRenderingContext> m_context;
153
154    bool m_rendererIsCanvas;
155
156    bool m_ignoreReset;
157    FloatRect m_dirtyRect;
158
159    float m_pageScaleFactor;
160    bool m_originClean;
161
162    // m_createdImageBuffer means we tried to malloc the buffer.  We didn't necessarily get it.
163    mutable bool m_hasCreatedImageBuffer;
164    mutable OwnPtr<ImageBuffer> m_imageBuffer;
165
166    mutable RefPtr<Image> m_presentedImage;
167    mutable RefPtr<Image> m_copiedImage; // FIXME: This is temporary for platforms that have to copy the image buffer to render (and for CSSCanvasValue).
168};
169
170} //namespace
171
172#endif
173