gecko-dev/dom/media/MediaTrack.h

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2.7 KiB
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/* -*- 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_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
{
public:
MediaTrack(nsIGlobalObject* aOwnerGlobal,
const nsAString& aId,
const nsAString& aKind,
const nsAString& aLabel,
const nsAString& aLanguage);
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(MediaTrack, DOMEventTargetHelper)
enum {
DEFAULT = 0,
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;
protected:
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