dom/media/TextTrackCue.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "mozilla/dom/HTMLTrackElement.h"
   7 #include "mozilla/dom/TextTrackCue.h"
   8 #include "mozilla/dom/TextTrackList.h"
   9 #include "mozilla/dom/TextTrackRegion.h"
  10 #include "nsComponentManagerUtils.h"
  11 #include "mozilla/ClearOnShutdown.h"
  12
  13 namespace mozilla {
  14 namespace dom {
  15
  16 NS_IMPL_CYCLE_COLLECTION_INHERITED(TextTrackCue, DOMEventTargetHelper,
  17                                    mDocument, mTrack, mTrackElement,
  18                                    mDisplayState, mRegion)
  19
  20 NS_IMPL_ADDREF_INHERITED(TextTrackCue, DOMEventTargetHelper)
  21 NS_IMPL_RELEASE_INHERITED(TextTrackCue, DOMEventTargetHelper)
  22 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TextTrackCue)
  23 NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
  24
  25 StaticRefPtr<nsIWebVTTParserWrapper> TextTrackCue::sParserWrapper;
  26
  27 // Set cue setting defaults based on step 19 & seq.
  28 // in http://dev.w3.org/html5/webvtt/#parsing
  29 void TextTrackCue::SetDefaultCueSettings() {
  30   mPositionIsAutoKeyword = true;
  31   mPositionAlign = PositionAlignSetting::Center;
  32   mSize = 100.0;
  33   mPauseOnExit = false;
  34   mSnapToLines = true;
  35   mLineIsAutoKeyword = true;
  36   mAlign = AlignSetting::Center;
  37   mLineAlign = LineAlignSetting::Start;
  38   mVertical = DirectionSetting::_empty;
  39   mActive = false;
  40 }
  41
  42 TextTrackCue::TextTrackCue(nsPIDOMWindowInner* aOwnerWindow, double aStartTime,
  43                            double aEndTime, const nsAString& aText,
  44                            ErrorResult& aRv)
  45     : DOMEventTargetHelper(aOwnerWindow),
  46       mText(aText),
  47       mStartTime(aStartTime),
  48       mEndTime(aEndTime),
  49       mPosition(0.0),
  50       mLine(0.0),
  51       mReset(false, "TextTrackCue::mReset"),
  52       mHaveStartedWatcher(false),
  53       mWatchManager(
  54           this, GetOwnerGlobal()->AbstractMainThreadFor(TaskCategory::Other)) {
  55   SetDefaultCueSettings();
  56   MOZ_ASSERT(aOwnerWindow);
  57   if (NS_FAILED(StashDocument())) {
  58     aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
  59   }
  60 }
  61
  62 TextTrackCue::TextTrackCue(nsPIDOMWindowInner* aOwnerWindow, double aStartTime,
  63                            double aEndTime, const nsAString& aText,
  64                            HTMLTrackElement* aTrackElement, ErrorResult& aRv)
  65     : DOMEventTargetHelper(aOwnerWindow),
  66       mText(aText),
  67       mStartTime(aStartTime),
  68       mEndTime(aEndTime),
  69       mTrackElement(aTrackElement),
  70       mPosition(0.0),
  71       mLine(0.0),
  72       mReset(false, "TextTrackCue::mReset"),
  73       mHaveStartedWatcher(false),
  74       mWatchManager(
  75           this, GetOwnerGlobal()->AbstractMainThreadFor(TaskCategory::Other)) {
  76   SetDefaultCueSettings();
  77   MOZ_ASSERT(aOwnerWindow);
  78   if (NS_FAILED(StashDocument())) {
  79     aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
  80   }
  81 }
  82
  83 TextTrackCue::~TextTrackCue() {}
  84
  85 /** Save a reference to our creating document so we don't have to
  86  *  keep getting it from our window.
  87  */
  88 nsresult TextTrackCue::StashDocument() {
  89   nsPIDOMWindowInner* window = GetOwner();
  90   if (!window) {
  91     return NS_ERROR_NO_INTERFACE;
  92   }
  93   mDocument = window->GetDoc();
  94   if (!mDocument) {
  95     return NS_ERROR_NOT_AVAILABLE;
  96   }
  97   return NS_OK;
  98 }
  99
 100 already_AddRefed<DocumentFragment> TextTrackCue::GetCueAsHTML() {
 101   // mDocument may be null during cycle collector shutdown.
 102   // See bug 941701.
 103   if (!mDocument) {
 104     return nullptr;
 105   }
 106
 107   if (!sParserWrapper) {
 108     nsresult rv;
 109     nsCOMPtr<nsIWebVTTParserWrapper> parserWrapper =
 110         do_CreateInstance(NS_WEBVTTPARSERWRAPPER_CONTRACTID, &rv);
 111     if (NS_FAILED(rv)) {
 112       return mDocument->CreateDocumentFragment();
 113     }
 114     sParserWrapper = parserWrapper;
 115     ClearOnShutdown(&sParserWrapper);
 116   }
 117
 118   nsPIDOMWindowInner* window = mDocument->GetInnerWindow();
 119   if (!window) {
 120     return mDocument->CreateDocumentFragment();
 121   }
 122
 123   RefPtr<DocumentFragment> frag;
 124   sParserWrapper->ConvertCueToDOMTree(window, this, getter_AddRefs(frag));
 125   if (!frag) {
 126     return mDocument->CreateDocumentFragment();
 127   }
 128   return frag.forget();
 129 }
 130
 131 void TextTrackCue::SetTrackElement(HTMLTrackElement* aTrackElement) {
 132   mTrackElement = aTrackElement;
 133 }
 134
 135 JSObject* TextTrackCue::WrapObject(JSContext* aCx,
 136                                    JS::Handle<JSObject*> aGivenProto) {
 137   return VTTCue_Binding::Wrap(aCx, this, aGivenProto);
 138 }
 139
 140 TextTrackRegion* TextTrackCue::GetRegion() { return mRegion; }
 141
 142 void TextTrackCue::SetRegion(TextTrackRegion* aRegion) {
 143   if (mRegion == aRegion) {
 144     return;
 145   }
 146   mRegion = aRegion;
 147   mReset = true;
 148 }
 149
 150 double TextTrackCue::ComputedLine() {
 151   // See spec https://w3c.github.io/webvtt/#cue-computed-line
 152   if (!mLineIsAutoKeyword && !mSnapToLines && (mLine < 0.0 || mLine > 100.0)) {
 153     return 100.0;
 154   } else if (!mLineIsAutoKeyword) {
 155     return mLine;
 156   } else if (mLineIsAutoKeyword && !mSnapToLines) {
 157     return 100.0;
 158   } else if (!mTrack || !mTrack->GetTextTrackList() ||
 159              !mTrack->GetTextTrackList()->GetMediaElement()) {
 160     return -1.0;
 161   }
 162
 163   RefPtr<TextTrackList> trackList = mTrack->GetTextTrackList();
 164   bool dummy;
 165   uint32_t showingTracksNum = 0;
 166   for (uint32_t idx = 0; idx < trackList->Length(); idx++) {
 167     RefPtr<TextTrack> track = trackList->IndexedGetter(idx, dummy);
 168     if (track->Mode() == TextTrackMode::Showing) {
 169       showingTracksNum++;
 170     }
 171
 172     if (mTrack == track) {
 173       break;
 174     }
 175   }
 176
 177   return (-1.0) * showingTracksNum;
 178 }
 179
 180 double TextTrackCue::ComputedPosition() {
 181   // See spec https://w3c.github.io/webvtt/#cue-computed-position
 182   if (!mPositionIsAutoKeyword) {
 183     return mPosition;
 184   } else if (mAlign == AlignSetting::Left) {
 185     return 0.0;
 186   } else if (mAlign == AlignSetting::Right) {
 187     return 100.0;
 188   }
 189   return 50.0;
 190 }
 191
 192 PositionAlignSetting TextTrackCue::ComputedPositionAlign() {
 193   // See spec https://w3c.github.io/webvtt/#cue-computed-position-alignment
 194   if (mPositionAlign != PositionAlignSetting::Auto) {
 195     return mPositionAlign;
 196   } else if (mAlign == AlignSetting::Left) {
 197     return PositionAlignSetting::Line_left;
 198   } else if (mAlign == AlignSetting::Right) {
 199     return PositionAlignSetting::Line_right;
 200   }
 201   return PositionAlignSetting::Center;
 202 }
 203
 204 void TextTrackCue::NotifyDisplayStatesChanged() {
 205   if (!mReset) {
 206     return;
 207   }
 208
 209   if (!mTrack || !mTrack->GetTextTrackList() ||
 210       !mTrack->GetTextTrackList()->GetMediaElement()) {
 211     return;
 212   }
 213
 214   mTrack->GetTextTrackList()
 215       ->GetMediaElement()
 216       ->NotifyCueDisplayStatesChanged();
 217 }
 218
 219 }  // namespace dom
 220 }  // namespace mozilla