tor-browser

The Tor Browser
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MediaElementAudioSourceNode.cpp (3706B)

      1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
      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 "MediaElementAudioSourceNode.h"
      8 
      9 #include "AudioDestinationNode.h"
     10 #include "AudioNodeTrack.h"
     11 #include "MediaStreamTrack.h"
     12 #include "mozilla/dom/MediaElementAudioSourceNodeBinding.h"
     13 
     14 namespace mozilla::dom {
     15 
     16 NS_IMPL_CYCLE_COLLECTION_CLASS(MediaElementAudioSourceNode)
     17 
     18 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(MediaElementAudioSourceNode)
     19  tmp->Destroy();
     20  NS_IMPL_CYCLE_COLLECTION_UNLINK(mElement)
     21 NS_IMPL_CYCLE_COLLECTION_UNLINK_END_INHERITED(AudioNode)
     22 
     23 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(MediaElementAudioSourceNode,
     24                                                  MediaStreamAudioSourceNode)
     25  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mElement)
     26 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
     27 
     28 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaElementAudioSourceNode)
     29 NS_INTERFACE_MAP_END_INHERITING(MediaStreamAudioSourceNode)
     30 
     31 NS_IMPL_ADDREF_INHERITED(MediaElementAudioSourceNode,
     32                         MediaStreamAudioSourceNode)
     33 NS_IMPL_RELEASE_INHERITED(MediaElementAudioSourceNode,
     34                          MediaStreamAudioSourceNode)
     35 
     36 MediaElementAudioSourceNode::MediaElementAudioSourceNode(
     37    AudioContext* aContext, HTMLMediaElement* aElement)
     38    : MediaStreamAudioSourceNode(aContext, TrackChangeBehavior::FollowChanges),
     39      mElement(aElement) {
     40  MOZ_ASSERT(aElement);
     41 }
     42 
     43 /* static */
     44 already_AddRefed<MediaElementAudioSourceNode>
     45 MediaElementAudioSourceNode::Create(
     46    AudioContext& aAudioContext, const MediaElementAudioSourceOptions& aOptions,
     47    ErrorResult& aRv) {
     48  // The spec has a pointless check here.  See
     49  // https://github.com/WebAudio/web-audio-api/issues/2149
     50  MOZ_RELEASE_ASSERT(!aAudioContext.IsOffline(), "Bindings messed up?");
     51 
     52  RefPtr<MediaElementAudioSourceNode> node =
     53      new MediaElementAudioSourceNode(&aAudioContext, aOptions.mMediaElement);
     54 
     55  RefPtr<DOMMediaStream> stream = aOptions.mMediaElement->CaptureAudio(
     56      aRv, aAudioContext.Destination()->Track()->Graph());
     57  if (aRv.Failed()) {
     58    return nullptr;
     59  }
     60  MOZ_ASSERT(stream, "CaptureAudio should report failure via aRv!");
     61 
     62  node->Init(*stream, aRv);
     63  if (aRv.Failed()) {
     64    return nullptr;
     65  }
     66 
     67  node->ListenForAllowedToPlay(aOptions);
     68  return node.forget();
     69 }
     70 
     71 JSObject* MediaElementAudioSourceNode::WrapObject(
     72    JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
     73  return MediaElementAudioSourceNode_Binding::Wrap(aCx, this, aGivenProto);
     74 }
     75 
     76 void MediaElementAudioSourceNode::ListenForAllowedToPlay(
     77    const MediaElementAudioSourceOptions& aOptions) {
     78  aOptions.mMediaElement->GetAllowedToPlayPromise()
     79      ->Then(
     80          AbstractThread::MainThread(), __func__,
     81          // Capture by reference to bypass the mozilla-refcounted-inside-lambda
     82          // static analysis. We capture a non-owning reference so as to allow
     83          // cycle collection of the node. The reference is cleared via
     84          // DisconnectIfExists() from Destroy() when the node is collected.
     85          [&self = *this]() {
     86            self.Context()->StartBlockedAudioContextIfAllowed();
     87            self.mAllowedToPlayRequest.Complete();
     88          })
     89      ->Track(mAllowedToPlayRequest);
     90 }
     91 
     92 void MediaElementAudioSourceNode::Destroy() {
     93  mAllowedToPlayRequest.DisconnectIfExists();
     94  MediaStreamAudioSourceNode::Destroy();
     95 }
     96 
     97 HTMLMediaElement* MediaElementAudioSourceNode::MediaElement() {
     98  return mElement;
     99 }
    100 
    101 }  // namespace mozilla::dom