already_AddRefed<ImageBitmap> OffscreenCanvas::TransferToImageBitmap(
ErrorResult& aRv) {
nsCOMPtr<nsIGlobalObject> globalObject = GetGlobalObject();
RefPtr<ImageBitmap> result =
ImageBitmap::CreateFromOffscreenCanvas(globalObject, *this, aRv);
if (aRv.Failed()) {
return nullptr;
}
// TODO: Clear the content?
return result.forget();
}
already_AddRefed<ImageBitmap>
OffscreenCanvas::TransferToImageBitmap()
{
ErrorResult rv;
nsCOMPtr<nsIGlobalObject> globalObject = GetGlobalObject();
RefPtr<ImageBitmap> result = ImageBitmap::CreateFromOffscreenCanvas(globalObject, *this, rv);
// Clear the content.
if ((mCurrentContextType == CanvasContextType::WebGL1 ||
mCurrentContextType == CanvasContextType::WebGL2))
{
WebGLContext* webGL = static_cast<WebGLContext*>(mCurrentContext.get());
webGL->ClearScreen();
}
return result.forget();
}
already_AddRefed<Promise>
OffscreenCanvas::ToBlob(JSContext* aCx,
const nsAString& aType,
JS::Handle<JS::Value> aParams,
ErrorResult& aRv)
{
// do a trust check if this is a write-only canvas
if (mIsWriteOnly) {
aRv.Throw(NS_ERROR_DOM_SECURITY_ERR);
return nullptr;
}
nsCOMPtr<nsIGlobalObject> global = GetGlobalObject();
RefPtr<Promise> promise = Promise::Create(global, aRv);
if (aRv.Failed()) {
return nullptr;
}
// Encoder callback when encoding is complete.
class EncodeCallback : public EncodeCompleteCallback
{
public:
EncodeCallback(nsIGlobalObject* aGlobal, Promise* aPromise)
: mGlobal(aGlobal)
, mPromise(aPromise) {}
// 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);
}
}
if (mPromise) {
RefPtr<Blob> newBlob = Blob::Create(mGlobal, blob->Impl());
mPromise->MaybeResolve(newBlob);
}
mGlobal = nullptr;
mPromise = nullptr;
return rv.StealNSResult();
}
nsCOMPtr<nsIGlobalObject> mGlobal;
RefPtr<Promise> mPromise;
};
RefPtr<EncodeCompleteCallback> callback =
new EncodeCallback(global, promise);
CanvasRenderingContextHelper::ToBlob(aCx, global,
callback, aType, aParams, aRv);
return promise.forget();
}