Source code

Revision control

Other Tools

/* -*- 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 */
#ifndef mozilla_dom_MediaTrack_h
#define mozilla_dom_MediaTrack_h
#include "mozilla/DOMEventTargetHelper.h"
namespace mozilla {
namespace dom {
class MediaTrackList;
class VideoTrack;
class AudioTrack;
* Base class of AudioTrack and VideoTrack. The AudioTrack and VideoTrack
* objects represent specific tracks of a media resource. Each track has aspects
* of an identifier, category, label, and language, even if a track is removed
* from its corresponding track list, those aspects do not change.
* When fetching the media resource, an audio/video track is created if the
* media resource is found to have an audio/video track. When the UA has learned
* that an audio/video track has ended, this audio/video track will be removed
* from its corresponding track list.
* Although AudioTrack and VideoTrack are not EventTargets, TextTrack is, and
* TextTrack inherits from MediaTrack as well (or is going to).
class MediaTrack : public DOMEventTargetHelper {
MediaTrack(nsIGlobalObject* aOwnerGlobal, const nsAString& aId,
const nsAString& aKind, const nsAString& aLabel,
const nsAString& aLanguage);
enum {
FIRE_NO_EVENTS = 1 << 0,
// The default behavior of enabling an audio track or selecting a video track
// fires a change event and notifies its media resource about the changes.
// It should not fire any events when fetching media resource.
virtual void SetEnabledInternal(bool aEnabled, int aFlags) = 0;
virtual AudioTrack* AsAudioTrack() { return nullptr; }
virtual VideoTrack* AsVideoTrack() { return nullptr; }
const nsString& GetId() const { return mId; }
// WebIDL
void GetId(nsAString& aId) const { aId = mId; }
void GetKind(nsAString& aKind) const { aKind = mKind; }
void GetLabel(nsAString& aLabel) const { aLabel = mLabel; }
void GetLanguage(nsAString& aLanguage) const { aLanguage = mLanguage; }
friend class MediaTrackList;
virtual ~MediaTrack();
void SetTrackList(MediaTrackList* aList);
RefPtr<MediaTrackList> mList;
nsString mId;
nsString mKind;
nsString mLabel;
nsString mLanguage;
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_MediaTrack_h