1 files changed, 105 insertions, 0 deletions
diff --git a/dom/media/webaudio/MediaElementAudioSourceNode.cpp b/dom/media/webaudio/MediaElementAudioSourceNode.cpp
new file mode 100644
index 0000000000..d02ef2f4de
--- /dev/null
+++ b/dom/media/webaudio/MediaElementAudioSourceNode.cpp
@@ -0,0 +1,105 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 "MediaElementAudioSourceNode.h"
+#include "mozilla/dom/MediaElementAudioSourceNodeBinding.h"
+#include "AudioDestinationNode.h"
+#include "AudioNodeTrack.h"
+#include "MediaStreamTrack.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(MediaElementAudioSourceNode)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(MediaElementAudioSourceNode)
+  tmp->Destroy();
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mElement)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END_INHERITED(AudioNode)
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(MediaElementAudioSourceNode,
+                                                  MediaStreamAudioSourceNode)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mElement)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaElementAudioSourceNode)
+NS_INTERFACE_MAP_END_INHERITING(MediaStreamAudioSourceNode)
+
+NS_IMPL_ADDREF_INHERITED(MediaElementAudioSourceNode,
+                         MediaStreamAudioSourceNode)
+NS_IMPL_RELEASE_INHERITED(MediaElementAudioSourceNode,
+                          MediaStreamAudioSourceNode)
+
+MediaElementAudioSourceNode::MediaElementAudioSourceNode(
+    AudioContext* aContext, HTMLMediaElement* aElement)
+    : MediaStreamAudioSourceNode(aContext, TrackChangeBehavior::FollowChanges),
+      mElement(aElement) {
+  MOZ_ASSERT(aElement);
+}
+
+/* static */
+already_AddRefed<MediaElementAudioSourceNode>
+MediaElementAudioSourceNode::Create(
+    AudioContext& aAudioContext, const MediaElementAudioSourceOptions& aOptions,
+    ErrorResult& aRv) {
+  // The spec has a pointless check here.  See
+  // https://github.com/WebAudio/web-audio-api/issues/2149
+  MOZ_RELEASE_ASSERT(!aAudioContext.IsOffline(), "Bindings messed up?");
+
+  RefPtr<MediaElementAudioSourceNode> node =
+      new MediaElementAudioSourceNode(&aAudioContext, aOptions.mMediaElement);
+
+  RefPtr<DOMMediaStream> stream = aOptions.mMediaElement->CaptureAudio(
+      aRv, aAudioContext.Destination()->Track()->Graph());
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+  MOZ_ASSERT(stream, "CaptureAudio should report failure via aRv!");
+
+  node->Init(*stream, aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  node->ListenForAllowedToPlay(aOptions);
+  return node.forget();
+}
+
+JSObject* MediaElementAudioSourceNode::WrapObject(
+    JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
+  return MediaElementAudioSourceNode_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+void MediaElementAudioSourceNode::ListenForAllowedToPlay(
+    const MediaElementAudioSourceOptions& aOptions) {
+  if (!GetAbstractMainThread()) {
+    // The AudioContext must have been closed. It won't be able to start anyway.
+    return;
+  }
+
+  aOptions.mMediaElement->GetAllowedToPlayPromise()
+      ->Then(
+          GetAbstractMainThread(), __func__,
+          // Capture by reference to bypass the mozilla-refcounted-inside-lambda
+          // static analysis. We capture a non-owning reference so as to allow
+          // cycle collection of the node. The reference is cleared via
+          // DisconnectIfExists() from Destroy() when the node is collected.
+          [&self = *this]() {
+            self.Context()->StartBlockedAudioContextIfAllowed();
+            self.mAllowedToPlayRequest.Complete();
+          })
+      ->Track(mAllowedToPlayRequest);
+}
+
+void MediaElementAudioSourceNode::Destroy() {
+  mAllowedToPlayRequest.DisconnectIfExists();
+  MediaStreamAudioSourceNode::Destroy();
+}
+
+HTMLMediaElement* MediaElementAudioSourceNode::MediaElement() {
+  return mElement;
+}
+
+}  // namespace mozilla::dom