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   ImageBitmap
  31 };
  32
  33 /**
  34  * Povides common RenderingContext functionality used by both OffscreenCanvas
  35  * and HTMLCanvasElement.
  36  */
  37 class CanvasRenderingContextHelper {
  38  public:
  39   virtual already_AddRefed<nsISupports> GetContext(
  40       JSContext* aCx, const nsAString& aContextId,
  41       JS::Handle<JS::Value> aContextOptions, ErrorResult& aRv);
  42
  43   virtual bool GetOpaqueAttr() = 0;
  44
  45  protected:
  46   virtual nsresult UpdateContext(JSContext* aCx,
  47                                  JS::Handle<JS::Value> aNewContextOptions,
  48                                  ErrorResult& aRvForDictionaryInit);
  49
  50   virtual nsresult ParseParams(JSContext* aCx, const nsAString& aType,
  51                                const JS::Value& aEncoderOptions,
  52                                nsAString& outParams,
  53                                bool* const outCustomParseOptions);
  54
  55   void ToBlob(JSContext* aCx, nsIGlobalObject* global, BlobCallback& aCallback,
  56               const nsAString& aType, JS::Handle<JS::Value> aParams,
  57               bool aUsePlaceholder, ErrorResult& aRv);
  58
  59   void ToBlob(JSContext* aCx, nsIGlobalObject* aGlobal,
  60               EncodeCompleteCallback* aCallback, const nsAString& aType,
  61               JS::Handle<JS::Value> aParams, bool aUsePlaceholder,
  62               ErrorResult& aRv);
  63
  64   virtual already_AddRefed<nsICanvasRenderingContextInternal> CreateContext(
  65       CanvasContextType aContextType);
  66
  67   already_AddRefed<nsICanvasRenderingContextInternal> CreateContextHelper(
  68       CanvasContextType aContextType, layers::LayersBackend aCompositorBackend);
  69
  70   virtual nsIntSize GetWidthHeight() = 0;
  71
  72   CanvasContextType mCurrentContextType;
  73   nsCOMPtr<nsICanvasRenderingContextInternal> mCurrentContext;
  74 };
  75
  76 }  // namespace dom
  77 }  // namespace mozilla
  78
  79 #endif  // MOZILLA_DOM_CANVASRENDERINGCONTEXTHELPER_H_