1 files changed, 274 insertions, 0 deletions
diff --git a/dom/canvas/ImageBitmap.h b/dom/canvas/ImageBitmap.h
new file mode 100644
index 0000000000..8f95225e41
--- /dev/null
+++ b/dom/canvas/ImageBitmap.h
@@ -0,0 +1,274 @@
+/* -*- 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/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 File;
+class HTMLCanvasElement;
+class HTMLImageElement;
+class HTMLVideoElement;
+class ImageBitmapShutdownObserver;
+class ImageData;
+class ImageUtils;
+class Promise;
+class PostMessageEvent;  // For StructuredClone between windows.
+class SVGImageElement;
+
+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();
+
+  /*
+   * 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;
+
+  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);
+
+  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<ImageBitmapShutdownObserver> mShutdownObserver;
+
+  /*
+   * 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