C++ TextTrack::Mode方法代码示例

void
TextTrackManager::HonorUserPreferencesForTrackSelection()
{
  if (performedTrackSelection) {
    return;
  }

  TextTrackKind ttKinds[] = { TextTrackKind::Captions,
                              TextTrackKind::Subtitles };

  // Steps 1 - 3: Perform automatic track selection for different TextTrack
  // Kinds.
  PerformTrackSelection(ttKinds, ArrayLength(ttKinds));
  PerformTrackSelection(TextTrackKind::Descriptions);
  PerformTrackSelection(TextTrackKind::Chapters);

  // Step 4: Set all TextTracks with a kind of metadata that are disabled
  // to hidden.
  for (uint32_t i = 0; i < mTextTracks->Length(); i++) {
    TextTrack* track = (*mTextTracks)[i];
    if (track->Kind() == TextTrackKind::Metadata && TrackIsDefault(track) &&
        track->Mode() == TextTrackMode::Disabled) {
      track->SetMode(TextTrackMode::Hidden);
    }
  }

  performedTrackSelection = true;
}

void
TextTrackManager::PopulatePendingList()
{
  uint32_t len = mTextTracks->Length();
  bool dummy;
  for (uint32_t index = 0; index < len; ++index) {
    TextTrack* ttrack = mTextTracks->IndexedGetter(index, dummy);
    if (ttrack && ttrack->Mode() != TextTrackMode::Disabled &&
        ttrack->ReadyState() == HTMLTrackElement::LOADING) {
      mPendingTextTracks->AddTextTrack(ttrack);
    }
  }
}

void
TextTrackManager::PopulatePendingList()
{
  uint32_t len = mTextTracks->Length();
  bool dummy;
  for (uint32_t index = 0; index < len; ++index) {
    TextTrack* ttrack = mTextTracks->IndexedGetter(index, dummy);
    if (ttrack && ttrack->Mode() != TextTrackMode::Disabled &&
        ttrack->ReadyState() == TextTrackReadyState::Loading) {
      mPendingTextTracks->AddTextTrack(ttrack,
                                       CompareTextTracks(mMediaElement));
    }
  }
}

// https://html.spec.whatwg.org/multipage/embedded-content.html#time-marches-on
void TextTrackManager::TimeMarchesOn() {
  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
  mTimeMarchesOnDispatched = false;

  CycleCollectedJSContext* context = CycleCollectedJSContext::Get();
  if (context && context->IsInStableOrMetaStableState()) {
    // FireTimeUpdate can be called while at stable state following a
    // current position change which triggered a state watcher in MediaDecoder
    // (see bug 1443429).
    // TimeMarchesOn() will modify JS attributes which is forbidden while in
    // stable state. So we dispatch a task to perform such operation later
    // instead.
    DispatchTimeMarchesOn();
    return;
  }
  WEBVTT_LOG("TimeMarchesOn");

  // Early return if we don't have any TextTracks or shutting down.
  if (!mTextTracks || mTextTracks->Length() == 0 || IsShutdown()) {
    return;
  }

  nsISupports* parentObject = mMediaElement->OwnerDoc()->GetParentObject();
  if (NS_WARN_IF(!parentObject)) {
    return;
  }
  nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(parentObject);

  if (mMediaElement &&
      (!(mMediaElement->GetPlayedOrSeeked()) || mMediaElement->Seeking())) {
    WEBVTT_LOG("TimeMarchesOn seeking or post return");
    return;
  }

  // Step 3.
  double currentPlaybackTime = mMediaElement->CurrentTime();
  bool hasNormalPlayback = !mHasSeeked;
  mHasSeeked = false;
  WEBVTT_LOG(
      "TimeMarchesOn mLastTimeMarchesOnCalled %lf currentPlaybackTime %lf "
      "hasNormalPlayback %d",
      mLastTimeMarchesOnCalled, currentPlaybackTime, hasNormalPlayback);

  // Step 1, 2.
  RefPtr<TextTrackCueList> currentCues = new TextTrackCueList(window);
  RefPtr<TextTrackCueList> otherCues = new TextTrackCueList(window);
  bool dummy;
  for (uint32_t index = 0; index < mTextTracks->Length(); ++index) {
    TextTrack* ttrack = mTextTracks->IndexedGetter(index, dummy);
    if (ttrack && ttrack->Mode() != TextTrackMode::Disabled) {
      // TODO: call GetCueListByTimeInterval on mNewCues?
      ttrack->GetCurrentCueList(currentCues);
    }
  }
  WEBVTT_LOGV("TimeMarchesOn currentCues %d", currentCues->Length());
  // Populate otherCues with 'non-active" cues.
  if (hasNormalPlayback) {
    if (currentPlaybackTime < mLastTimeMarchesOnCalled) {
      // TODO: Add log and find the root cause why the
      // playback position goes backward.
      mLastTimeMarchesOnCalled = currentPlaybackTime;
    }
    media::Interval<double> interval(mLastTimeMarchesOnCalled,
                                     currentPlaybackTime);
    otherCues = mNewCues->GetCueListByTimeInterval(interval);
    ;
  } else {
    // Seek case. Put the mLastActiveCues into otherCues.
    otherCues = mLastActiveCues;
  }
  for (uint32_t i = 0; i < currentCues->Length(); ++i) {
    TextTrackCue* cue = (*currentCues)[i];
    otherCues->RemoveCue(*cue);
  }
  WEBVTT_LOGV("TimeMarchesOn otherCues %d", otherCues->Length());
  // Step 4.
  RefPtr<TextTrackCueList> missedCues = new TextTrackCueList(window);
  if (hasNormalPlayback) {
    for (uint32_t i = 0; i < otherCues->Length(); ++i) {
      TextTrackCue* cue = (*otherCues)[i];
      if (cue->StartTime() >= mLastTimeMarchesOnCalled &&
          cue->EndTime() <= currentPlaybackTime) {
        missedCues->AddCue(*cue);
      }
    }
  }
  WEBVTT_LOGV("TimeMarchesOn missedCues %d", missedCues->Length());
  // Step 5. Empty now.
  // TODO: Step 6: fire timeupdate?

  // Step 7. Abort steps if condition 1, 2, 3 are satisfied.
  // 1. All of the cues in current cues have their active flag set.
  // 2. None of the cues in other cues have their active flag set.
  // 3. Missed cues is empty.
  bool c1 = true;
  for (uint32_t i = 0; i < currentCues->Length(); ++i) {
    if (!(*currentCues)[i]->GetActive()) {
      c1 = false;
      break;
//.........这里部分代码省略.........