dom/bindings/StructuredClone.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "mozilla/dom/StructuredClone.h"
   8
   9 #include "js/StructuredClone.h"
  10 #include "mozilla/dom/ImageData.h"
  11 #include "mozilla/dom/StructuredCloneTags.h"
  12
  13 namespace mozilla {
  14 namespace dom {
  15
  16 JSObject*
  17 ReadStructuredCloneImageData(JSContext* aCx, JSStructuredCloneReader* aReader)
  18 {
  19   // Read the information out of the stream.
  20   uint32_t width, height;
  21   JS::Rooted<JS::Value> dataArray(aCx);
  22   if (!JS_ReadUint32Pair(aReader, &width, &height) ||
  23       !JS_ReadTypedArray(aReader, &dataArray)) {
  24     return nullptr;
  25   }
  26   MOZ_ASSERT(dataArray.isObject());
  27
  28   // Protect the result from a moving GC in ~nsRefPtr.
  29   JS::Rooted<JSObject*> result(aCx);
  30   {
  31     // Construct the ImageData.
  32     nsRefPtr<ImageData> imageData = new ImageData(width, height,
  33                                                   dataArray.toObject());
  34     // Wrap it in a JS::Value.
  35     result = imageData->WrapObject(aCx);
  36   }
  37   return result;
  38 }
  39
  40 bool
  41 WriteStructuredCloneImageData(JSContext* aCx, JSStructuredCloneWriter* aWriter,
  42                               ImageData* aImageData)
  43 {
  44   uint32_t width = aImageData->Width();
  45   uint32_t height = aImageData->Height();
  46   JS::Rooted<JSObject*> dataArray(aCx, aImageData->GetDataObject());
  47
  48   JSAutoCompartment ac(aCx, dataArray);
  49   JS::Rooted<JS::Value> arrayValue(aCx, JS::ObjectValue(*dataArray));
  50   return JS_WriteUint32Pair(aWriter, SCTAG_DOM_IMAGEDATA, 0) &&
  51          JS_WriteUint32Pair(aWriter, width, height) &&
  52          JS_WriteTypedArray(aWriter, arrayValue);
  53 }
  54
  55 } // namespace dom
  56 } // namespace mozilla