gecko-dev/dom/media/MediaTrackList.h
Andreas Pehrson 4b3fa9c67e Bug 1493613 - Move MediaStream control from DOMMediaStream to MediaStreamTrack. r=padenot
This is inherently large, because modifying these bits of DOMMediaStream and
MediaStreamTrack affects all consumers and producers of all DOMMediaStreams and
MediaStreamTracks.

Things are generally much simpler now.

Producers of tracks now create a MediaStream in the graph, add it to a
MediaStreamTrackSource subclass that takes ownership of it, and add the source
to a MediaStreamTrack. Should the producer need a DOMMediaStream it is now much
simpler to create as the only thing needed is the current window. The stream is
a rather simple wrapper around an array of MediaStreamTracks.

HTMLMediaElement is still not as straight forward as other consumers since it
consumes the DOMMediaStream directly, as opposed to a set of tracks.
The new MediaStreamRenderer helper class helps bridge the gap between this fact
and the new track-based MediaStreamGraph interface, as it needs to juggle
registering multiple audio tracks for audio output. This hooks into existing
HTMLMediaElement logic and brings a welcome simplification to all the glue
previously needed there.

Differential Revision: https://phabricator.services.mozilla.com/D37934

--HG--
extra : moz-landing-system : lando
2019-07-31 07:58:17 +00:00

112 lines
3.5 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/. */
#ifndef mozilla_dom_MediaTrackList_h
#define mozilla_dom_MediaTrackList_h
#include "mozilla/DOMEventTargetHelper.h"
namespace mozilla {
class DOMMediaStream;
namespace dom {
class AudioStreamTrack;
class AudioTrack;
class AudioTrackList;
class HTMLMediaElement;
class MediaTrack;
class VideoStreamTrack;
class VideoTrack;
class VideoTrackList;
/**
* Base class of AudioTrackList and VideoTrackList. The AudioTrackList and
* VideoTrackList objects represent a dynamic list of zero or more audio and
* video tracks respectively.
*
* When a media element is to forget its media-resource-specific tracks, its
* audio track list and video track list will be emptied.
*/
class MediaTrackList : public DOMEventTargetHelper {
public:
MediaTrackList(nsIGlobalObject* aOwnerObject,
HTMLMediaElement* aMediaElement);
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(MediaTrackList, DOMEventTargetHelper)
using DOMEventTargetHelper::DispatchTrustedEvent;
// The return value is non-null, assert an error if aIndex is out of bound
// for array mTracks.
MediaTrack* operator[](uint32_t aIndex);
// The track must be from the same Window as this MediaTrackList.
void AddTrack(MediaTrack* aTrack);
// In remove track case, the VideoTrackList::mSelectedIndex should be updated
// due to mTracks changed. No need to take care this in add track case.
virtual void RemoveTrack(const RefPtr<MediaTrack>& aTrack);
void RemoveTracks();
// For the case of src of HTMLMediaElement is non-MediaStream, leave the
// aAudioTrack as default(nullptr).
static already_AddRefed<AudioTrack> CreateAudioTrack(
nsIGlobalObject* aOwnerGlobal, const nsAString& aId,
const nsAString& aKind, const nsAString& aLabel,
const nsAString& aLanguage, bool aEnabled,
AudioStreamTrack* aAudioTrack = nullptr);
// For the case of src of HTMLMediaElement is non-MediaStream, leave the
// aVideoTrack as default(nullptr).
static already_AddRefed<VideoTrack> CreateVideoTrack(
nsIGlobalObject* aOwnerGlobal, const nsAString& aId,
const nsAString& aKind, const nsAString& aLabel,
const nsAString& aLanguage, VideoStreamTrack* aVideoTrack = nullptr);
virtual void EmptyTracks();
void CreateAndDispatchChangeEvent();
// WebIDL
MediaTrack* IndexedGetter(uint32_t aIndex, bool& aFound);
MediaTrack* GetTrackById(const nsAString& aId);
bool IsEmpty() const { return mTracks.IsEmpty(); }
uint32_t Length() const { return mTracks.Length(); }
IMPL_EVENT_HANDLER(change)
IMPL_EVENT_HANDLER(addtrack)
IMPL_EVENT_HANDLER(removetrack)
friend class AudioTrack;
friend class VideoTrack;
protected:
virtual ~MediaTrackList();
void CreateAndDispatchTrackEventRunner(MediaTrack* aTrack,
const nsAString& aEventName);
virtual AudioTrackList* AsAudioTrackList() { return nullptr; }
virtual VideoTrackList* AsVideoTrackList() { return nullptr; }
HTMLMediaElement* GetMediaElement() { return mMediaElement; }
nsTArray<RefPtr<MediaTrack>> mTracks;
RefPtr<HTMLMediaElement> mMediaElement;
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_MediaTrackList_h