gecko-dev/dom/canvas/CanvasRenderingContextHelpe...

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/* -*- 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/. */
#include "CanvasRenderingContextHelper.h"
#include "ImageBitmapRenderingContext.h"
#include "ImageEncoder.h"
#include "mozilla/dom/CanvasRenderingContext2D.h"
#include "mozilla/Telemetry.h"
#include "mozilla/UniquePtr.h"
#include "nsContentUtils.h"
#include "nsDOMJSUtils.h"
#include "nsIScriptContext.h"
#include "nsJSUtils.h"
#include "WebGL1Context.h"
#include "WebGL2Context.h"
namespace mozilla {
namespace dom {
void
CanvasRenderingContextHelper::ToBlob(JSContext* aCx,
nsIGlobalObject* aGlobal,
FileCallback& aCallback,
const nsAString& aType,
JS::Handle<JS::Value> aParams,
ErrorResult& aRv)
{
// Encoder callback when encoding is complete.
class EncodeCallback : public EncodeCompleteCallback
{
public:
EncodeCallback(nsIGlobalObject* aGlobal, FileCallback* aCallback)
: mGlobal(aGlobal)
, mFileCallback(aCallback) {}
// This is called on main thread.
nsresult ReceiveBlob(already_AddRefed<Blob> aBlob)
{
RefPtr<Blob> blob = aBlob;
ErrorResult rv;
uint64_t size = blob->GetSize(rv);
if (rv.Failed()) {
rv.SuppressException();
} else {
AutoJSAPI jsapi;
if (jsapi.Init(mGlobal)) {
JS_updateMallocCounter(jsapi.cx(), size);
}
}
RefPtr<Blob> newBlob = Blob::Create(mGlobal, blob->Impl());
mFileCallback->Call(*newBlob, rv);
mGlobal = nullptr;
mFileCallback = nullptr;
return rv.StealNSResult();
}
nsCOMPtr<nsIGlobalObject> mGlobal;
RefPtr<FileCallback> mFileCallback;
};
RefPtr<EncodeCompleteCallback> callback =
new EncodeCallback(aGlobal, &aCallback);
ToBlob(aCx, aGlobal, callback, aType, aParams, aRv);
}
void
CanvasRenderingContextHelper::ToBlob(JSContext* aCx,
nsIGlobalObject* aGlobal,
EncodeCompleteCallback* aCallback,
const nsAString& aType,
JS::Handle<JS::Value> aParams,
ErrorResult& aRv)
{
nsAutoString type;
nsContentUtils::ASCIIToLower(aType, type);
nsAutoString params;
bool usingCustomParseOptions;
aRv = ParseParams(aCx, type, aParams, params, &usingCustomParseOptions);
if (aRv.Failed()) {
return;
}
if (mCurrentContext) {
// We disallow canvases of width or height zero, and set them to 1, so
// we will have a discrepancy with the sizes of the canvas and the context.
// That discrepancy is OK, the rest are not.
nsIntSize elementSize = GetWidthHeight();
if ((elementSize.width != mCurrentContext->GetWidth() &&
(elementSize.width != 0 || mCurrentContext->GetWidth() != 1)) ||
(elementSize.height != mCurrentContext->GetHeight() &&
(elementSize.height != 0 || mCurrentContext->GetHeight() != 1))) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
}
UniquePtr<uint8_t[]> imageBuffer;
int32_t format = 0;
if (mCurrentContext) {
imageBuffer = mCurrentContext->GetImageBuffer(&format);
}
RefPtr<EncodeCompleteCallback> callback = aCallback;
aRv = ImageEncoder::ExtractDataAsync(type,
params,
usingCustomParseOptions,
Move(imageBuffer),
format,
GetWidthHeight(),
callback);
}
already_AddRefed<nsICanvasRenderingContextInternal>
CanvasRenderingContextHelper::CreateContext(CanvasContextType aContextType)
{
MOZ_ASSERT(aContextType != CanvasContextType::NoContext);
RefPtr<nsICanvasRenderingContextInternal> ret;
switch (aContextType) {
case CanvasContextType::NoContext:
break;
case CanvasContextType::Canvas2D:
Telemetry::Accumulate(Telemetry::CANVAS_2D_USED, 1);
ret = new CanvasRenderingContext2D();
break;
case CanvasContextType::WebGL1:
Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_USED, 1);
ret = WebGL1Context::Create();
if (!ret)
return nullptr;
break;
case CanvasContextType::WebGL2:
Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_USED, 1);
ret = WebGL2Context::Create();
if (!ret)
return nullptr;
break;
case CanvasContextType::ImageBitmap:
ret = new ImageBitmapRenderingContext();
break;
}
MOZ_ASSERT(ret);
return ret.forget();
}
already_AddRefed<nsISupports>
CanvasRenderingContextHelper::GetContext(JSContext* aCx,
const nsAString& aContextId,
JS::Handle<JS::Value> aContextOptions,
ErrorResult& aRv)
{
CanvasContextType contextType;
if (!CanvasUtils::GetCanvasContextType(aContextId, &contextType))
return nullptr;
if (!mCurrentContext) {
// This canvas doesn't have a context yet.
RefPtr<nsICanvasRenderingContextInternal> context;
context = CreateContext(contextType);
if (!context) {
return nullptr;
}
// Ensure that the context participates in CC. Note that returning a
// CC participant from QI doesn't addref.
nsXPCOMCycleCollectionParticipant* cp = nullptr;
CallQueryInterface(context, &cp);
if (!cp) {
aRv.Throw(NS_ERROR_FAILURE);
return nullptr;
}
mCurrentContext = context.forget();
mCurrentContextType = contextType;
nsresult rv = UpdateContext(aCx, aContextOptions, aRv);
if (NS_FAILED(rv)) {
// See bug 645792 and bug 1215072.
// We want to throw only if dictionary initialization fails,
// so only in case aRv has been set to some error value.
return nullptr;
}
} else {
// We already have a context of some type.
if (contextType != mCurrentContextType)
return nullptr;
}
nsCOMPtr<nsICanvasRenderingContextInternal> context = mCurrentContext;
return context.forget();
}
nsresult
CanvasRenderingContextHelper::UpdateContext(JSContext* aCx,
JS::Handle<JS::Value> aNewContextOptions,
ErrorResult& aRvForDictionaryInit)
{
if (!mCurrentContext)
return NS_OK;
nsIntSize sz = GetWidthHeight();
nsCOMPtr<nsICanvasRenderingContextInternal> currentContext = mCurrentContext;
nsresult rv = currentContext->SetIsOpaque(GetOpaqueAttr());
if (NS_FAILED(rv)) {
mCurrentContext = nullptr;
return rv;
}
rv = currentContext->SetContextOptions(aCx, aNewContextOptions,
aRvForDictionaryInit);
if (NS_FAILED(rv)) {
mCurrentContext = nullptr;
return rv;
}
rv = currentContext->SetDimensions(sz.width, sz.height);
if (NS_FAILED(rv)) {
mCurrentContext = nullptr;
}
return rv;
}
nsresult
CanvasRenderingContextHelper::ParseParams(JSContext* aCx,
const nsAString& aType,
const JS::Value& aEncoderOptions,
nsAString& outParams,
bool* const outUsingCustomParseOptions)
{
// Quality parameter is only valid for the image/jpeg MIME type
if (aType.EqualsLiteral("image/jpeg")) {
if (aEncoderOptions.isNumber()) {
double quality = aEncoderOptions.toNumber();
// Quality must be between 0.0 and 1.0, inclusive
if (quality >= 0.0 && quality <= 1.0) {
outParams.AppendLiteral("quality=");
outParams.AppendInt(NS_lround(quality * 100.0));
}
}
}
// If we haven't parsed the aParams check for proprietary options.
// The proprietary option -moz-parse-options will take a image lib encoder
// parse options string as is and pass it to the encoder.
*outUsingCustomParseOptions = false;
if (outParams.Length() == 0 && aEncoderOptions.isString()) {
NS_NAMED_LITERAL_STRING(mozParseOptions, "-moz-parse-options:");
nsAutoJSString paramString;
if (!paramString.init(aCx, aEncoderOptions.toString())) {
return NS_ERROR_FAILURE;
}
if (StringBeginsWith(paramString, mozParseOptions)) {
nsDependentSubstring parseOptions = Substring(paramString,
mozParseOptions.Length(),
paramString.Length() -
mozParseOptions.Length());
outParams.Append(parseOptions);
*outUsingCustomParseOptions = true;
}
}
return NS_OK;
}
} // namespace dom
} // namespace mozilla