dom/html/TextTrackManager.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set tw=80 expandtab softtabstop=2 ts=2 sw=2: */
   3
   4 /* This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   6  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   7
   8 #ifndef mozilla_dom_TextTrackManager_h
   9 #define mozilla_dom_TextTrackManager_h
  10
  11 #include "mozilla/dom/TextTrack.h"
  12 #include "mozilla/dom/TextTrackList.h"
  13 #include "mozilla/dom/TextTrackCueList.h"
  14 #include "mozilla/StaticPtr.h"
  15
  16 class nsIWebVTTParserWrapper;
  17
  18 namespace mozilla {
  19 namespace dom {
  20
  21 class HTMLMediaElement;
  22
  23 class CompareTextTracks {
  24 private:
  25   HTMLMediaElement* mMediaElement;
  26 public:
  27   explicit CompareTextTracks(HTMLMediaElement* aMediaElement);
  28   int32_t TrackChildPosition(TextTrack* aTrack) const;
  29   bool Equals(TextTrack* aOne, TextTrack* aTwo) const;
  30   bool LessThan(TextTrack* aOne, TextTrack* aTwo) const;
  31 };
  32
  33 class TextTrack;
  34 class TextTrackCue;
  35
  36 class TextTrackManager MOZ_FINAL : public nsIDOMEventListener
  37 {
  38   ~TextTrackManager();
  39
  40 public:
  41   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  42   NS_DECL_CYCLE_COLLECTION_CLASS(TextTrackManager)
  43
  44   NS_DECL_NSIDOMEVENTLISTENER
  45
  46   explicit TextTrackManager(HTMLMediaElement* aMediaElement);
  47
  48   TextTrackList* GetTextTracks() const;
  49   already_AddRefed<TextTrack> AddTextTrack(TextTrackKind aKind,
  50                                            const nsAString& aLabel,
  51                                            const nsAString& aLanguage,
  52                                            TextTrackMode aMode,
  53                                            TextTrackReadyState aReadyState,
  54                                            TextTrackSource aTextTrackSource);
  55   void AddTextTrack(TextTrack* aTextTrack);
  56   void RemoveTextTrack(TextTrack* aTextTrack, bool aPendingListOnly);
  57   void DidSeek();
  58
  59   void AddCue(TextTrackCue& aCue);
  60   void AddCues(TextTrack* aTextTrack);
  61
  62   /**
  63    * Overview of WebVTT cuetext and anonymous content setup.
  64    *
  65    * WebVTT nodes are the parsed version of WebVTT cuetext. WebVTT cuetext is
  66    * the portion of a WebVTT cue that specifies what the caption will actually
  67    * show up as on screen.
  68    *
  69    * WebVTT cuetext can contain markup that loosely relates to HTML markup. It
  70    * can contain tags like <b>, <u>, <i>, <c>, <v>, <ruby>, <rt>, <lang>,
  71    * including timestamp tags.
  72    *
  73    * When the caption is ready to be displayed the WebVTT nodes are converted
  74    * over to anonymous DOM content. <i>, <u>, <b>, <ruby>, and <rt> all become
  75    * HTMLElements of their corresponding HTML markup tags. <c> and <v> are
  76    * converted to <span> tags. Timestamp tags are converted to XML processing
  77    * instructions. Additionally, all cuetext tags support specifying of classes.
  78    * This takes the form of <foo.class.subclass>. These classes are then parsed
  79    * and set as the anonymous content's class attribute.
  80    *
  81    * Rules on constructing DOM objects from WebVTT nodes can be found here
  82    * http://dev.w3.org/html5/webvtt/#webvtt-cue-text-dom-construction-rules.
  83    * Current rules are taken from revision on April 15, 2013.
  84    */
  85
  86   /**
  87    * Converts the TextTrackCue's cuetext into a tree of DOM objects and attaches
  88    * it to a div on it's owning TrackElement's MediaElement's caption overlay.
  89    */
  90   void UpdateCueDisplay();
  91
  92   void PopulatePendingList();
  93
  94   void AddListeners();
  95
  96   // The HTMLMediaElement that this TextTrackManager manages the TextTracks of.
  97   nsRefPtr<HTMLMediaElement> mMediaElement;
  98 private:
  99   // List of the TextTrackManager's owning HTMLMediaElement's TextTracks.
 100   nsRefPtr<TextTrackList> mTextTracks;
 101   // List of text track objects awaiting loading.
 102   nsRefPtr<TextTrackList> mPendingTextTracks;
 103   // List of newly introduced Text Track cues.
 104   nsRefPtr<TextTrackCueList> mNewCues;
 105
 106   static StaticRefPtr<nsIWebVTTParserWrapper> sParserWrapper;
 107
 108   bool performedTrackSelection;
 109
 110   // Runs the algorithm for performing automatic track selection.
 111   void HonorUserPreferencesForTrackSelection();
 112   // Performs track selection for a single TextTrackKind.
 113   void PerformTrackSelection(TextTrackKind aTextTrackKind);
 114   //Performs track selection for a set of TextTrackKinds, for example,
 115   // 'subtitles' and 'captions' should be selected together.
 116   void PerformTrackSelection(TextTrackKind aTextTrackKinds[], uint32_t size);
 117   void GetTextTracksOfKinds(TextTrackKind aTextTrackKinds[], uint32_t size,
 118                             nsTArray<TextTrack*>& aTextTracks);
 119   void GetTextTracksOfKind(TextTrackKind aTextTrackKind,
 120                            nsTArray<TextTrack*>& aTextTracks);
 121   bool TrackIsDefault(TextTrack* aTextTrack);
 122 };
 123
 124 } // namespace dom
 125 } // namespace mozilla
 126
 127 #endif // mozilla_dom_TextTrackManager_h