gecko-dev/dom/canvas/ImageData.cpp

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4.4 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 et tw=78: */
/* 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/. */
#include "mozilla/dom/ImageData.h"
#include "ErrorList.h"
#include "js/StructuredClone.h"
#include "js/Value.h"
#include "jsapi.h"
#include "jsfriendapi.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/ErrorResult.h"
#include "mozilla/HoldDropJSObjects.h"
#include "mozilla/RefPtr.h"
#include "mozilla/dom/BindingDeclarations.h"
#include "mozilla/dom/ImageDataBinding.h"
#include "nsCycleCollectionNoteChild.h"
namespace mozilla::dom {
NS_IMPL_CYCLE_COLLECTING_ADDREF(ImageData)
NS_IMPL_CYCLE_COLLECTING_RELEASE(ImageData)
NS_IMPL_CYCLE_COLLECTION_CLASS(ImageData)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ImageData)
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(ImageData)
NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mData)
NS_IMPL_CYCLE_COLLECTION_TRACE_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(ImageData)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(ImageData)
tmp->DropData();
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
// static
already_AddRefed<ImageData> ImageData::Constructor(const GlobalObject& aGlobal,
const uint32_t aWidth,
const uint32_t aHeight,
ErrorResult& aRv) {
if (aWidth == 0 || aHeight == 0) {
aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return nullptr;
}
// Restrict the typed array length to INT32_MAX because that's all we support
// in dom::TypedArray::ComputeState.
CheckedInt<uint32_t> length = CheckedInt<uint32_t>(aWidth) * aHeight * 4;
if (!length.isValid() || length.value() > INT32_MAX) {
aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return nullptr;
}
js::AssertSameCompartment(aGlobal.Context(), aGlobal.Get());
JSObject* data = Uint8ClampedArray::Create(aGlobal.Context(), length.value());
if (!data) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return nullptr;
}
RefPtr<ImageData> imageData = new ImageData(aWidth, aHeight, *data);
return imageData.forget();
}
// static
already_AddRefed<ImageData> ImageData::Constructor(
const GlobalObject& aGlobal, const Uint8ClampedArray& aData,
const uint32_t aWidth, const Optional<uint32_t>& aHeight,
ErrorResult& aRv) {
aData.ComputeState();
uint32_t length = aData.Length();
if (length == 0 || length % 4) {
aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
return nullptr;
}
length /= 4;
if (aWidth == 0) {
aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return nullptr;
}
uint32_t height = length / aWidth;
if (length != aWidth * height ||
(aHeight.WasPassed() && aHeight.Value() != height)) {
aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return nullptr;
}
RefPtr<ImageData> imageData = new ImageData(aWidth, height, *aData.Obj());
return imageData.forget();
}
void ImageData::HoldData() { mozilla::HoldJSObjects(this); }
void ImageData::DropData() {
if (mData) {
mozilla::DropJSObjects(this);
}
}
bool ImageData::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto,
JS::MutableHandle<JSObject*> aReflector) {
return ImageData_Binding::Wrap(aCx, this, aGivenProto, aReflector);
}
// static
already_AddRefed<ImageData> ImageData::ReadStructuredClone(
JSContext* aCx, nsIGlobalObject* aGlobal,
JSStructuredCloneReader* aReader) {
// Read the information out of the stream.
uint32_t width, height;
JS::Rooted<JS::Value> dataArray(aCx);
if (!JS_ReadUint32Pair(aReader, &width, &height) ||
!JS_ReadTypedArray(aReader, &dataArray)) {
return nullptr;
}
MOZ_ASSERT(dataArray.isObject());
RefPtr<ImageData> imageData =
new ImageData(width, height, dataArray.toObject());
return imageData.forget();
}
bool ImageData::WriteStructuredClone(JSContext* aCx,
JSStructuredCloneWriter* aWriter) const {
JS::Rooted<JS::Value> arrayValue(aCx, JS::ObjectValue(*GetDataObject()));
if (!JS_WrapValue(aCx, &arrayValue)) {
return false;
}
return JS_WriteUint32Pair(aWriter, Width(), Height()) &&
JS_WriteTypedArray(aWriter, arrayValue);
}
} // namespace mozilla::dom