dom/canvas/CanvasRenderingContextHelper.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   4  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef MOZILLA_DOM_CANVASRENDERINGCONTEXTHELPER_H_
   7 #define MOZILLA_DOM_CANVASRENDERINGCONTEXTHELPER_H_
   8
   9 #include "mozilla/dom/BindingDeclarations.h"
  10 #include "mozilla/layers/LayersTypes.h"
  11 #include "nsSize.h"
  12
  13 class nsICanvasRenderingContextInternal;
  14 class nsIGlobalObject;
  15
  16 namespace mozilla {
  17
  18 class ErrorResult;
  19
  20 namespace dom {
  21
  22 class BlobCallback;
  23 class EncodeCompleteCallback;
  24
  25 enum class CanvasContextType : uint8_t {
  26   NoContext,
  27   Canvas2D,
  28   WebGL1,
  29   WebGL2,
  30   WebGPU,
  31   ImageBitmap
  32 };
  33
  34 /**
  35  * Povides common RenderingContext functionality used by both OffscreenCanvas
  36  * and HTMLCanvasElement.
  37  */
  38 class CanvasRenderingContextHelper {
  39  public:
  40   CanvasRenderingContextHelper();
  41
  42   virtual already_AddRefed<nsISupports> GetContext(
  43       JSContext* aCx, const nsAString& aContextId,
  44       JS::Handle<JS::Value> aContextOptions, ErrorResult& aRv);
  45
  46   virtual bool GetOpaqueAttr() = 0;
  47
  48  protected:
  49   virtual nsresult UpdateContext(JSContext* aCx,
  50                                  JS::Handle<JS::Value> aNewContextOptions,
  51                                  ErrorResult& aRvForDictionaryInit);
  52
  53   virtual nsresult ParseParams(JSContext* aCx, const nsAString& aType,
  54                                const JS::Value& aEncoderOptions,
  55                                nsAString& outParams,
  56                                bool* const outCustomParseOptions);
  57
  58   void ToBlob(JSContext* aCx, nsIGlobalObject* global, BlobCallback& aCallback,
  59               const nsAString& aType, JS::Handle<JS::Value> aParams,
  60               bool aUsePlaceholder, ErrorResult& aRv);
  61
  62   void ToBlob(JSContext* aCx, nsIGlobalObject* aGlobal,
  63               EncodeCompleteCallback* aCallback, const nsAString& aType,
  64               JS::Handle<JS::Value> aParams, bool aUsePlaceholder,
  65               ErrorResult& aRv);
  66
  67   virtual already_AddRefed<nsICanvasRenderingContextInternal> CreateContext(
  68       CanvasContextType aContextType);
  69
  70   already_AddRefed<nsICanvasRenderingContextInternal> CreateContextHelper(
  71       CanvasContextType aContextType, layers::LayersBackend aCompositorBackend);
  72
  73   virtual nsIntSize GetWidthHeight() = 0;
  74
  75   CanvasContextType mCurrentContextType;
  76   nsCOMPtr<nsICanvasRenderingContextInternal> mCurrentContext;
  77 };
  78
  79 }  // namespace dom
  80 namespace CanvasUtils {
  81 bool GetCanvasContextType(const nsAString&, dom::CanvasContextType* const);
  82 }  // namespace CanvasUtils
  83 }  // namespace mozilla
  84
  85 #endif  // MOZILLA_DOM_CANVASRENDERINGCONTEXTHELPER_H_