summaryrefslogtreecommitdiffstats
path: root/dom/canvas/ImageBitmap.h
blob: 98a6d3b0b7cf1cedbeba3f047b06d7cb053887e0 (plain)
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
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_ImageBitmap_h
#define mozilla_dom_ImageBitmap_h

#include "mozilla/Attributes.h"
#include "mozilla/SurfaceFromElementResult.h"
#include "mozilla/dom/ImageBitmapBinding.h"
#include "mozilla/dom/ImageBitmapSource.h"
#include "mozilla/dom/TypedArray.h"
#include "mozilla/gfx/Rect.h"
#include "mozilla/Maybe.h"
#include "mozilla/UniquePtr.h"
#include "ImageData.h"
#include "gfxTypes.h"  // for gfxAlphaType
#include "nsCycleCollectionParticipant.h"

struct JSContext;
struct JSStructuredCloneReader;
struct JSStructuredCloneWriter;

class nsIGlobalObject;

namespace mozilla {

class ErrorResult;

namespace gfx {
class DataSourceSurface;
class DrawTarget;
class SourceSurface;
}  // namespace gfx

namespace layers {
class Image;
}

namespace dom {
class OffscreenCanvas;

class ArrayBufferViewOrArrayBuffer;
class CanvasRenderingContext2D;
class CreateImageBitmapFromBlob;
class CreateImageBitmapFromBlobTask;
class CreateImageBitmapFromBlobWorkerTask;
class ImageBitmapShutdownObserver;
class File;
class HTMLCanvasElement;
class HTMLImageElement;
class HTMLVideoElement;
class ImageData;
class ImageUtils;
class Promise;
class PostMessageEvent;  // For StructuredClone between windows.
class SVGImageElement;
class VideoFrame;
class SendShutdownToWorkerThread;

struct ImageBitmapCloneData final {
  RefPtr<gfx::DataSourceSurface> mSurface;
  gfx::IntRect mPictureRect;
  gfxAlphaType mAlphaType;
  bool mWriteOnly;
};

/*
 * ImageBitmap is an opaque handler to several kinds of image-like objects from
 * HTMLImageElement, HTMLVideoElement, HTMLCanvasElement, ImageData to
 * CanvasRenderingContext2D and Image Blob.
 *
 * An ImageBitmap could be painted to a canvas element.
 *
 * Generally, an ImageBitmap only keeps a reference to its source object's
 * buffer, but if the source object is an ImageData, an Blob or a
 * HTMLCanvasElement with WebGL rendering context, the ImageBitmap copy the
 * source object's buffer.
 */
class ImageBitmap final : public nsISupports, public nsWrapperCache {
 public:
  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(ImageBitmap)

  nsCOMPtr<nsIGlobalObject> GetParentObject() const { return mParent; }

  virtual JSObject* WrapObject(JSContext* aCx,
                               JS::Handle<JSObject*> aGivenProto) override;

  uint32_t Width() const { return mPictureRect.Width(); }

  uint32_t Height() const { return mPictureRect.Height(); }

  void Close();

  SurfaceFromElementResult SurfaceFrom(uint32_t aSurfaceFlags);

  /*
   * The PrepareForDrawTarget() might return null if the mPictureRect does not
   * intersect with the size of mData.
   */
  already_AddRefed<gfx::SourceSurface> PrepareForDrawTarget(
      gfx::DrawTarget* aTarget);

  /*
   * Transfer ownership of buffer to caller. So this function call
   * Close() implicitly.
   */
  already_AddRefed<layers::Image> TransferAsImage();

  // This method returns null if the image has been already closed.
  UniquePtr<ImageBitmapCloneData> ToCloneData() const;

  static already_AddRefed<ImageBitmap> CreateFromSourceSurface(
      nsIGlobalObject* aGlobal, gfx::SourceSurface* aSource, ErrorResult& aRv);

  static already_AddRefed<ImageBitmap> CreateFromCloneData(
      nsIGlobalObject* aGlobal, ImageBitmapCloneData* aData);

  static already_AddRefed<ImageBitmap> CreateFromOffscreenCanvas(
      nsIGlobalObject* aGlobal, OffscreenCanvas& aOffscreenCanvas,
      ErrorResult& aRv);

  static already_AddRefed<Promise> Create(nsIGlobalObject* aGlobal,
                                          const ImageBitmapSource& aSrc,
                                          const Maybe<gfx::IntRect>& aCropRect,
                                          const ImageBitmapOptions& aOptions,
                                          ErrorResult& aRv);

  static JSObject* ReadStructuredClone(
      JSContext* aCx, JSStructuredCloneReader* aReader,
      nsIGlobalObject* aParent,
      const nsTArray<RefPtr<gfx::DataSourceSurface>>& aClonedSurfaces,
      uint32_t aIndex);

  static void WriteStructuredClone(
      JSStructuredCloneWriter* aWriter,
      nsTArray<RefPtr<gfx::DataSourceSurface>>& aClonedSurfaces,
      ImageBitmap* aImageBitmap, ErrorResult& aRv);

  friend CreateImageBitmapFromBlob;
  friend CreateImageBitmapFromBlobTask;
  friend CreateImageBitmapFromBlobWorkerTask;
  friend ImageBitmapShutdownObserver;

  size_t GetAllocatedSize() const;

  void OnShutdown();

  bool IsWriteOnly() const { return mWriteOnly; }
  bool IsClosed() const { return !mData; };

 protected:
  /*
   * The default value of aIsPremultipliedAlpha is TRUE because that the
   * data stored in HTMLImageElement, HTMLVideoElement, HTMLCanvasElement,
   * CanvasRenderingContext2D are alpha-premultiplied in default.
   *
   * Actually, if one HTMLCanvasElement's rendering context is WebGLContext, it
   * is possible to get un-premultipliedAlpha data out. But, we do not do it in
   * the CreateInternal(from HTMLCanvasElement) method.
   *
   * It is also possible to decode an image which is encoded with alpha channel
   * to be non-premultipliedAlpha. This could be applied in
   * 1) the CreateInternal(from HTMLImageElement) method (which might trigger
   *    re-decoding if the original decoded data is alpha-premultiplied) and
   * 2) while decoding a blob. But we do not do it in both code path too.
   *
   * ImageData's underlying data is triggered as non-premultipliedAlpha, so set
   * the aIsPremultipliedAlpha to be false in the
   * CreateInternal(from ImageData) method.
   */
  ImageBitmap(nsIGlobalObject* aGlobal, layers::Image* aData, bool aWriteOnly,
              gfxAlphaType aAlphaType = gfxAlphaType::Premult);

  virtual ~ImageBitmap();

  void SetPictureRect(const gfx::IntRect& aRect, ErrorResult& aRv);

  static already_AddRefed<ImageBitmap> CreateImageBitmapInternal(
      nsIGlobalObject* aGlobal, gfx::SourceSurface* aSurface,
      const Maybe<gfx::IntRect>& aCropRect, const ImageBitmapOptions& aOptions,
      const bool aWriteOnly, const bool aAllocatedImageData,
      const bool aMustCopy, const gfxAlphaType aAlphaType, ErrorResult& aRv);

  static already_AddRefed<ImageBitmap> CreateInternal(
      nsIGlobalObject* aGlobal, HTMLImageElement& aImageEl,
      const Maybe<gfx::IntRect>& aCropRect, const ImageBitmapOptions& aOptions,
      ErrorResult& aRv);

  static already_AddRefed<ImageBitmap> CreateInternal(
      nsIGlobalObject* aGlobal, SVGImageElement& aImageEl,
      const Maybe<gfx::IntRect>& aCropRect, const ImageBitmapOptions& aOptions,
      ErrorResult& aRv);

  static already_AddRefed<ImageBitmap> CreateInternal(
      nsIGlobalObject* aGlobal, HTMLVideoElement& aVideoEl,
      const Maybe<gfx::IntRect>& aCropRect, const ImageBitmapOptions& aOptions,
      ErrorResult& aRv);

  static already_AddRefed<ImageBitmap> CreateInternal(
      nsIGlobalObject* aGlobal, HTMLCanvasElement& aCanvasEl,
      const Maybe<gfx::IntRect>& aCropRect, const ImageBitmapOptions& aOptions,
      ErrorResult& aRv);

  static already_AddRefed<ImageBitmap> CreateInternal(
      nsIGlobalObject* aGlobal, OffscreenCanvas& aOffscreenCanvas,
      const Maybe<gfx::IntRect>& aCropRect, const ImageBitmapOptions& aOptions,
      ErrorResult& aRv);

  static already_AddRefed<ImageBitmap> CreateInternal(
      nsIGlobalObject* aGlobal, ImageData& aImageData,
      const Maybe<gfx::IntRect>& aCropRect, const ImageBitmapOptions& aOptions,
      ErrorResult& aRv);

  static already_AddRefed<ImageBitmap> CreateInternal(
      nsIGlobalObject* aGlobal, CanvasRenderingContext2D& aCanvasCtx,
      const Maybe<gfx::IntRect>& aCropRect, const ImageBitmapOptions& aOptions,
      ErrorResult& aRv);

  static already_AddRefed<ImageBitmap> CreateInternal(
      nsIGlobalObject* aGlobal, ImageBitmap& aImageBitmap,
      const Maybe<gfx::IntRect>& aCropRect, const ImageBitmapOptions& aOptions,
      ErrorResult& aRv);

  static already_AddRefed<ImageBitmap> CreateInternal(
      nsIGlobalObject* aGlobal, VideoFrame& aVideoFrame,
      const Maybe<gfx::IntRect>& aCropRect, const ImageBitmapOptions& aOptions,
      ErrorResult& aRv);

  nsCOMPtr<nsIGlobalObject> mParent;

  /*
   * The mData is the data buffer of an ImageBitmap, so the mData must not be
   * null.
   *
   * The mSurface is a cache for drawing the ImageBitmap onto a
   * HTMLCanvasElement. The mSurface is null while the ImageBitmap is created
   * and then will be initialized while the PrepareForDrawTarget() method is
   * called first time.
   *
   * The mSurface might just be a reference to the same data buffer of the mData
   * if the are of mPictureRect is just the same as the mData's size. Or, it is
   * a independent data buffer which is copied and cropped form the mData's data
   * buffer.
   */
  RefPtr<layers::Image> mData;
  RefPtr<gfx::SourceSurface> mSurface;

  /*
   * The mPictureRect is the size of the source image in default, however, if
   * users specify the cropping area while creating an ImageBitmap, then this
   * mPictureRect is the cropping area.
   *
   * Note that if the CreateInternal() copies and crops data from the source
   * image, then this mPictureRect is just the size of the final mData.
   *
   * The mPictureRect will be used at PrepareForDrawTarget() while user is going
   * to draw this ImageBitmap into a HTMLCanvasElement.
   */
  gfx::IntRect mPictureRect;

  gfxAlphaType mAlphaType;

  RefPtr<SendShutdownToWorkerThread> mShutdownRunnable;

  /*
   * Whether this object allocated allocated and owns the image data.
   */
  bool mAllocatedImageData;

  /*
   * Write-Only flag is set to true if this image has been generated from a
   * cross-origin source. This is the opposite of what is called 'origin-clean'
   * in the spec.
   */
  bool mWriteOnly;
};

}  // namespace dom
}  // namespace mozilla

#endif  // mozilla_dom_ImageBitmap_h