dom/media/MediaTrackList.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 et tw=78: */
   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 #ifndef mozilla_dom_MediaTrackList_h
   8 #define mozilla_dom_MediaTrackList_h
   9
  10 #include "mozilla/DOMEventTargetHelper.h"
  11
  12 namespace mozilla {
  13 class DOMMediaStream;
  14
  15 namespace dom {
  16
  17 class AudioStreamTrack;
  18 class AudioTrack;
  19 class AudioTrackList;
  20 class HTMLMediaElement;
  21 class MediaTrack;
  22 class VideoStreamTrack;
  23 class VideoTrack;
  24 class VideoTrackList;
  25
  26 /**
  27  * Base class of AudioTrackList and VideoTrackList. The AudioTrackList and
  28  * VideoTrackList objects represent a dynamic list of zero or more audio and
  29  * video tracks respectively.
  30  *
  31  * When a media element is to forget its media-resource-specific tracks, its
  32  * audio track list and video track list will be emptied.
  33  */
  34 class MediaTrackList : public DOMEventTargetHelper {
  35  public:
  36   MediaTrackList(nsIGlobalObject* aOwnerObject,
  37                  HTMLMediaElement* aMediaElement);
  38
  39   NS_DECL_ISUPPORTS_INHERITED
  40   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(MediaTrackList, DOMEventTargetHelper)
  41
  42   using DOMEventTargetHelper::DispatchTrustedEvent;
  43
  44   // The return value is non-null, assert an error if aIndex is out of bound
  45   // for array mTracks.
  46   MediaTrack* operator[](uint32_t aIndex);
  47
  48   // The track must be from the same Window as this MediaTrackList.
  49   void AddTrack(MediaTrack* aTrack);
  50
  51   // In remove track case, the VideoTrackList::mSelectedIndex should be updated
  52   // due to mTracks changed. No need to take care this in add track case.
  53   virtual void RemoveTrack(const RefPtr<MediaTrack>& aTrack);
  54
  55   void RemoveTracks();
  56
  57   // For the case of src of HTMLMediaElement is non-MediaStream, leave the
  58   // aAudioTrack as default(nullptr).
  59   static already_AddRefed<AudioTrack> CreateAudioTrack(
  60       nsIGlobalObject* aOwnerGlobal, const nsAString& aId,
  61       const nsAString& aKind, const nsAString& aLabel,
  62       const nsAString& aLanguage, bool aEnabled,
  63       AudioStreamTrack* aAudioTrack = nullptr);
  64
  65   // For the case of src of HTMLMediaElement is non-MediaStream, leave the
  66   // aVideoTrack as default(nullptr).
  67   static already_AddRefed<VideoTrack> CreateVideoTrack(
  68       nsIGlobalObject* aOwnerGlobal, const nsAString& aId,
  69       const nsAString& aKind, const nsAString& aLabel,
  70       const nsAString& aLanguage, VideoStreamTrack* aVideoTrack = nullptr);
  71
  72   virtual void EmptyTracks();
  73
  74   void CreateAndDispatchChangeEvent();
  75
  76   // WebIDL
  77   MediaTrack* IndexedGetter(uint32_t aIndex, bool& aFound);
  78
  79   MediaTrack* GetTrackById(const nsAString& aId);
  80
  81   bool IsEmpty() const { return mTracks.IsEmpty(); }
  82
  83   uint32_t Length() const { return mTracks.Length(); }
  84
  85   IMPL_EVENT_HANDLER(change)
  86   IMPL_EVENT_HANDLER(addtrack)
  87   IMPL_EVENT_HANDLER(removetrack)
  88
  89   friend class AudioTrack;
  90   friend class VideoTrack;
  91
  92  protected:
  93   virtual ~MediaTrackList();
  94
  95   void CreateAndDispatchTrackEventRunner(MediaTrack* aTrack,
  96                                          const nsAString& aEventName);
  97
  98   virtual AudioTrackList* AsAudioTrackList() { return nullptr; }
  99
 100   virtual VideoTrackList* AsVideoTrackList() { return nullptr; }
 101
 102   HTMLMediaElement* GetMediaElement() { return mMediaElement; }
 103
 104   nsTArray<RefPtr<MediaTrack>> mTracks;
 105   RefPtr<HTMLMediaElement> mMediaElement;
 106 };
 107
 108 }  // namespace dom
 109 }  // namespace mozilla
 110
 111 #endif  // mozilla_dom_MediaTrackList_h