1 files changed, 83 insertions, 0 deletions
diff --git a/dom/canvas/CanvasRenderingContextHelper.h b/dom/canvas/CanvasRenderingContextHelper.h
new file mode 100644
index 000000000..d28864f02
--- /dev/null
+++ b/dom/canvas/CanvasRenderingContextHelper.h
@@ -0,0 +1,83 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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_CANVASRENDERINGCONTEXTHELPER_H_
+#define MOZILLA_DOM_CANVASRENDERINGCONTEXTHELPER_H_
+
+#include "mozilla/dom/BindingDeclarations.h"
+#include "mozilla/layers/LayersTypes.h"
+#include "nsSize.h"
+
+class nsICanvasRenderingContextInternal;
+class nsIGlobalObject;
+
+namespace mozilla {
+
+class ErrorResult;
+
+namespace dom {
+
+class BlobCallback;
+class EncodeCompleteCallback;
+
+enum class CanvasContextType : uint8_t {
+  NoContext,
+  Canvas2D,
+  WebGL1,
+  WebGL2,
+  ImageBitmap
+};
+
+/**
+ * Povides common RenderingContext functionality used by both OffscreenCanvas
+ * and HTMLCanvasElement.
+ */
+class CanvasRenderingContextHelper
+{
+public:
+  virtual already_AddRefed<nsISupports>
+  GetContext(JSContext* aCx,
+             const nsAString& aContextId,
+             JS::Handle<JS::Value> aContextOptions,
+             ErrorResult& aRv);
+
+  virtual bool GetOpaqueAttr() = 0;
+
+protected:
+  virtual nsresult UpdateContext(JSContext* aCx,
+                                 JS::Handle<JS::Value> aNewContextOptions,
+                                 ErrorResult& aRvForDictionaryInit);
+
+  virtual nsresult ParseParams(JSContext* aCx,
+                               const nsAString& aType,
+                               const JS::Value& aEncoderOptions,
+                               nsAString& outParams,
+                               bool* const outCustomParseOptions);
+
+  void ToBlob(JSContext* aCx, nsIGlobalObject* global, BlobCallback& aCallback,
+              const nsAString& aType, JS::Handle<JS::Value> aParams,
+              ErrorResult& aRv);
+
+  void ToBlob(JSContext* aCx, nsIGlobalObject* aGlobal, EncodeCompleteCallback* aCallback,
+              const nsAString& aType, JS::Handle<JS::Value> aParams,
+              ErrorResult& aRv);
+
+  virtual already_AddRefed<nsICanvasRenderingContextInternal>
+  CreateContext(CanvasContextType aContextType);
+
+  already_AddRefed<nsICanvasRenderingContextInternal>
+  CreateContextHelper(CanvasContextType aContextType,
+                      layers::LayersBackend aCompositorBackend);
+
+  virtual nsIntSize GetWidthHeight() = 0;
+
+  CanvasContextType mCurrentContextType;
+  nsCOMPtr<nsICanvasRenderingContextInternal> mCurrentContext;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // MOZILLA_DOM_CANVASRENDERINGCONTEXTHELPER_H_