File: HTMLCanvasElement.h

package info (click to toggle)
webkit2gtk 2.48.5-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 429,764 kB
  • sloc: cpp: 3,697,587; javascript: 194,444; ansic: 169,997; python: 46,499; asm: 19,295; ruby: 18,528; perl: 16,602; xml: 4,650; yacc: 2,360; sh: 2,098; java: 1,993; lex: 1,327; pascal: 366; makefile: 298
file content (215 lines) | stat: -rw-r--r-- 8,537 bytes parent folder | download | duplicates (8)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
/*
 * Copyright (C) 2004-2023 Apple Inc. All rights reserved.
 * Copyright (C) 2007 Alp Toker <alp@atoker.com>
 * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#pragma once

#include "ActiveDOMObject.h"
#include "CanvasBase.h"
#include "Document.h"
#include "FloatRect.h"
#include "GraphicsTypes.h"
#include "HTMLElement.h"
#include <memory>
#include <wtf/Forward.h>

#if ENABLE(WEBGL)
#include "WebGLContextAttributes.h"
#endif

namespace WebCore {

class BlobCallback;
class CanvasRenderingContext;
class CanvasRenderingContext2D;
class GPU;
class GPUCanvasContext;
class GraphicsContext;
class Image;
class ImageBitmapRenderingContext;
class ImageBuffer;
class ImageData;
class MediaStream;
class OffscreenCanvas;
class VideoFrame;
class WebGLRenderingContextBase;
class WebCoreOpaqueRoot;
struct CanvasRenderingContext2DSettings;
struct ImageBitmapRenderingContextSettings;
struct UncachedString;

class HTMLCanvasElement final : public HTMLElement, public ActiveDOMObject, public CanvasBase {
    WTF_MAKE_TZONE_OR_ISO_ALLOCATED(HTMLCanvasElement);
    WTF_OVERRIDE_DELETE_FOR_CHECKED_PTR(HTMLCanvasElement);
public:
    USING_CAN_MAKE_WEAKPTR(HTMLElement);

    static Ref<HTMLCanvasElement> create(Document&);
    static Ref<HTMLCanvasElement> create(const QualifiedName&, Document&);
    virtual ~HTMLCanvasElement();

    WEBCORE_EXPORT ExceptionOr<void> setWidth(unsigned);
    WEBCORE_EXPORT ExceptionOr<void> setHeight(unsigned);

    void setSize(const IntSize& newSize) override;

    CanvasRenderingContext* renderingContext() const final { return m_context.get(); }
    ExceptionOr<std::optional<RenderingContext>> getContext(JSC::JSGlobalObject&, const String& contextId, FixedVector<JSC::Strong<JSC::Unknown>>&& arguments);

    CanvasRenderingContext* getContext(const String&);

    static bool is2dType(const String&);
    CanvasRenderingContext2D* createContext2d(const String&, CanvasRenderingContext2DSettings&&);
    CanvasRenderingContext2D* getContext2d(const String&, CanvasRenderingContext2DSettings&&);

#if ENABLE(WEBGL)
    static bool isWebGLType(const String&);
    static WebGLVersion toWebGLVersion(const String&);
    WebGLRenderingContextBase* createContextWebGL(WebGLVersion type, WebGLContextAttributes&& = { });
    WebGLRenderingContextBase* getContextWebGL(WebGLVersion type, WebGLContextAttributes&& = { });
#endif

    static bool isBitmapRendererType(const String&);
    ImageBitmapRenderingContext* createContextBitmapRenderer(const String&, ImageBitmapRenderingContextSettings&&);
    ImageBitmapRenderingContext* getContextBitmapRenderer(const String&, ImageBitmapRenderingContextSettings&&);

    static bool isWebGPUType(const String&);
    GPUCanvasContext* createContextWebGPU(const String&, GPU*);
    GPUCanvasContext* getContextWebGPU(const String&, GPU*);

    WEBCORE_EXPORT ExceptionOr<UncachedString> toDataURL(const String& mimeType, JSC::JSValue quality);
    WEBCORE_EXPORT ExceptionOr<UncachedString> toDataURL(const String& mimeType);
    ExceptionOr<void> toBlob(Ref<BlobCallback>&&, const String& mimeType, JSC::JSValue quality);
#if ENABLE(OFFSCREEN_CANVAS)
    ExceptionOr<Ref<OffscreenCanvas>> transferControlToOffscreen();
#endif

    // Used for rendering
    void didDraw(const std::optional<FloatRect>&, ShouldApplyPostProcessingToDirtyRect) final;

    void paint(GraphicsContext&, const LayoutRect&);

#if ENABLE(MEDIA_STREAM) || ENABLE(WEB_CODECS)
    // Returns the context drawing buffer as a VideoFrame.
    RefPtr<VideoFrame> toVideoFrame();
#endif
#if ENABLE(MEDIA_STREAM)
    ExceptionOr<Ref<MediaStream>> captureStream(std::optional<double>&& frameRequestRate);
#endif

    const CSSParserContext& cssParserContext() const final;

    Image* copiedImage() const final;
    void clearCopiedImage() const final;
    RefPtr<ImageData> getImageData();

    SecurityOrigin* securityOrigin() const final;

    // FIXME(https://bugs.webkit.org/show_bug.cgi?id=275100): Only some canvas rendering contexts need an ImageBuffer.
    // It would be better to have the contexts own the buffers.
    void setImageBufferAndMarkDirty(RefPtr<ImageBuffer>&&) final;

    bool needsPreparationForDisplay();
    void prepareForDisplay();

    void setIsSnapshotting(bool isSnapshotting) { m_isSnapshotting = isSnapshotting; }
    bool isSnapshotting() const { return m_isSnapshotting; }

    bool isControlledByOffscreen() const;

    void queueTaskKeepingObjectAlive(TaskSource, Function<void()>&&) final;
    void dispatchEvent(Event&) final;

    // ActiveDOMObject.
    void ref() const final { HTMLElement::ref(); }
    void deref() const final { HTMLElement::deref(); }

    using HTMLElement::scriptExecutionContext;

private:
    HTMLCanvasElement(const QualifiedName&, Document&);

    bool isHTMLCanvasElement() const final { return true; }

    // ActiveDOMObject.
    bool virtualHasPendingActivity() const final;

    // EventTarget.
    void eventListenersDidChange() final;

    void attributeChanged(const QualifiedName&, const AtomString& oldValue, const AtomString& newValue, AttributeModificationReason) final;
    bool hasPresentationalHintsForAttribute(const QualifiedName&) const final;
    void collectPresentationalHintsForAttribute(const QualifiedName&, const AtomString&, MutableStyleProperties&) final;
    RenderPtr<RenderElement> createElementRenderer(RenderStyle&&, const RenderTreePosition&) final;
    bool isReplaced(const RenderStyle&) const final;

    bool canContainRangeEndPoint() const final;
    bool canStartSelection() const final;

    void reset();

    void createImageBuffer() const final;
    void clearImageBuffer() const;

    void setSurfaceSize(const IntSize&);

    bool usesContentsAsLayerContents() const;

    ScriptExecutionContext* canvasBaseScriptExecutionContext() const final { return HTMLElement::scriptExecutionContext(); }

    void didMoveToNewDocument(Document& oldDocument, Document& newDocument) final;

    bool m_ignoreReset { false };
    mutable bool m_didClearImageBuffer { false };
#if ENABLE(WEBGL)
    bool m_hasRelevantWebGLEventListener { false };
#endif
    bool m_isSnapshotting { false };

    std::unique_ptr<CanvasRenderingContext> m_context;
    mutable RefPtr<Image> m_copiedImage; // FIXME: This is temporary for platforms that have to copy the image buffer to render (and for CSSCanvasValue).
    mutable std::unique_ptr<CSSParserContext> m_cssParserContext;
};

WebCoreOpaqueRoot root(HTMLCanvasElement*);

} // namespace WebCore

namespace WTF {
template<typename ArgType> class TypeCastTraits<const WebCore::HTMLCanvasElement, ArgType, false /* isBaseType */> {
public:
    static bool isOfType(ArgType& node) { return checkTagName(node); }
private:
    static bool checkTagName(const WebCore::CanvasBase& base) { return base.isHTMLCanvasElement(); }
    static bool checkTagName(const WebCore::HTMLElement& element) { return element.hasTagName(WebCore::HTMLNames::canvasTag); }
    static bool checkTagName(const WebCore::Node& node) { return node.hasTagName(WebCore::HTMLNames::canvasTag); }
    static bool checkTagName(const WebCore::EventTarget& target)
    {
        auto* node = dynamicDowncast<WebCore::Node>(target);
        return node && checkTagName(*node);
    }
};
}