C++ WillBeHeapVector::contains方法代码示例

void CueTimeline::updateActiveCues(double movieTime)
{
    // 4.8.10.8 Playing the media resource

    //  If the current playback position changes while the steps are running,
    //  then the user agent must wait for the steps to complete, and then must
    //  immediately rerun the steps.
    if (ignoreUpdateRequests())
        return;

    HTMLMediaElement& mediaElement = this->mediaElement();

    // https://html.spec.whatwg.org/#time-marches-on

    // 1 - Let current cues be a list of cues, initialized to contain all the
    // cues of all the hidden, showing, or showing by default text tracks of the
    // media element (not the disabled ones) whose start times are less than or
    // equal to the current playback position and whose end times are greater
    // than the current playback position.
    CueList currentCues;

    // The user agent must synchronously unset [the text track cue active] flag
    // whenever ... the media element's readyState is changed back to HAVE_NOTHING.
    if (mediaElement.readyState() != HTMLMediaElement::HAVE_NOTHING && mediaElement.webMediaPlayer())
        currentCues = m_cueTree.allOverlaps(m_cueTree.createInterval(movieTime, movieTime));

    CueList previousCues;
    CueList missedCues;

    // 2 - Let other cues be a list of cues, initialized to contain all the cues
    // of hidden, showing, and showing by default text tracks of the media
    // element that are not present in current cues.
    previousCues = m_currentlyActiveCues;

    // 3 - Let last time be the current playback position at the time this
    // algorithm was last run for this media element, if this is not the first
    // time it has run.
    double lastTime = m_lastUpdateTime;
    double lastSeekTime = mediaElement.lastSeekTime();

    // 4 - If the current playback position has, since the last time this
    // algorithm was run, only changed through its usual monotonic increase
    // during normal playback, then let missed cues be the list of cues in other
    // cues whose start times are greater than or equal to last time and whose
    // end times are less than or equal to the current playback position.
    // Otherwise, let missed cues be an empty list.
    if (lastTime >= 0 && lastSeekTime < movieTime) {
        CueList potentiallySkippedCues =
            m_cueTree.allOverlaps(m_cueTree.createInterval(lastTime, movieTime));

        for (CueInterval cue : potentiallySkippedCues) {
            // Consider cues that may have been missed since the last seek time.
            if (cue.low() > std::max(lastSeekTime, lastTime) && cue.high() < movieTime)
                missedCues.append(cue);
        }
    }

    m_lastUpdateTime = movieTime;

    // 5 - If the time was reached through the usual monotonic increase of the
    // current playback position during normal playback, and if the user agent
    // has not fired a timeupdate event at the element in the past 15 to 250ms
    // and is not still running event handlers for such an event, then the user
    // agent must queue a task to fire a simple event named timeupdate at the
    // element. (In the other cases, such as explicit seeks, relevant events get
    // fired as part of the overall process of changing the current playback
    // position.)
    if (!mediaElement.seeking() && lastSeekTime < lastTime)
        mediaElement.scheduleTimeupdateEvent(true);

    // Explicitly cache vector sizes, as their content is constant from here.
    size_t currentCuesSize = currentCues.size();
    size_t missedCuesSize = missedCues.size();
    size_t previousCuesSize = previousCues.size();

    // 6 - If all of the cues in current cues have their text track cue active
    // flag set, none of the cues in other cues have their text track cue active
    // flag set, and missed cues is empty, then abort these steps.
    bool activeSetChanged = missedCuesSize;

    for (size_t i = 0; !activeSetChanged && i < previousCuesSize; ++i) {
        if (!currentCues.contains(previousCues[i]) && previousCues[i].data()->isActive())
            activeSetChanged = true;
    }

    for (CueInterval currentCue : currentCues) {
        // Notify any cues that are already active of the current time to mark
        // past and future nodes. Any inactive cues have an empty display state;
        // they will be notified of the current time when the display state is
        // updated.
        if (currentCue.data()->isActive())
            currentCue.data()->updatePastAndFutureNodes(movieTime);
        else
            activeSetChanged = true;
    }

    if (!activeSetChanged)
        return;

    // 7 - If the time was reached through the usual monotonic increase of the
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