root/Source/core/html/track/TextTrackList.cpp

DEFINITIONS

1. m_asyncEventQueue
2. length
3. getTrackIndex
4. getTrackIndexRelativeToRenderedTracks
5. item
6. getTrackById
7. invalidateTrackIndexesAfterTrack
8. append
9. remove
10. removeAllInbandTracks
11. contains
12. interfaceName
13. executionContext
14. clearOwner
15. scheduleTrackEvent
16. scheduleAddTrackEvent
17. scheduleChangeEvent
18. scheduleRemoveTrackEvent
19. owner

/*
 * Copyright (C) 2011, 2012 Apple Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "core/html/track/TextTrackList.h"

#include "bindings/v8/ExceptionStatePlaceholder.h"
#include "core/events/GenericEventQueue.h"
#include "core/html/HTMLMediaElement.h"
#include "core/html/track/InbandTextTrack.h"
#include "core/html/track/LoadableTextTrack.h"
#include "core/html/track/TextTrack.h"
#include "core/html/track/TrackEvent.h"

using namespace WebCore;

TextTrackList::TextTrackList(HTMLMediaElement* owner)
    : m_owner(owner)
    , m_asyncEventQueue(GenericEventQueue::create(this))
{
    ScriptWrappable::init(this);
}

TextTrackList::~TextTrackList()
{
    ASSERT(!m_owner);

    m_asyncEventQueue->close();

    for (unsigned i = 0; i < length(); ++i) {
        item(i)->setTrackList(0);
    }
}

unsigned TextTrackList::length() const
{
    return m_addTrackTracks.size() + m_elementTracks.size() + m_inbandTracks.size();
}

int TextTrackList::getTrackIndex(TextTrack *textTrack)
{
    if (textTrack->trackType() == TextTrack::TrackElement)
        return static_cast<LoadableTextTrack*>(textTrack)->trackElementIndex();

    if (textTrack->trackType() == TextTrack::AddTrack)
        return m_elementTracks.size() + m_addTrackTracks.find(textTrack);

    if (textTrack->trackType() == TextTrack::InBand)
        return m_elementTracks.size() + m_addTrackTracks.size() + m_inbandTracks.find(textTrack);

    ASSERT_NOT_REACHED();

    return -1;
}

int TextTrackList::getTrackIndexRelativeToRenderedTracks(TextTrack *textTrack)
{
    // Calculate the "Let n be the number of text tracks whose text track mode is showing and that are in the media element's list of text tracks before track."
    int trackIndex = 0;

    for (size_t i = 0; i < m_elementTracks.size(); ++i) {
        if (!m_elementTracks[i]->isRendered())
            continue;

        if (m_elementTracks[i] == textTrack)
            return trackIndex;
        ++trackIndex;
    }

    for (size_t i = 0; i < m_addTrackTracks.size(); ++i) {
        if (!m_addTrackTracks[i]->isRendered())
            continue;

        if (m_addTrackTracks[i] == textTrack)
            return trackIndex;
        ++trackIndex;
    }

    for (size_t i = 0; i < m_inbandTracks.size(); ++i) {
        if (!m_inbandTracks[i]->isRendered())
            continue;

        if (m_inbandTracks[i] == textTrack)
            return trackIndex;
        ++trackIndex;
    }

    ASSERT_NOT_REACHED();

    return -1;
}

TextTrack* TextTrackList::item(unsigned index)
{
    // 4.8.10.12.1 Text track model
    // The text tracks are sorted as follows:
    // 1. The text tracks corresponding to track element children of the media element, in tree order.
    // 2. Any text tracks added using the addTextTrack() method, in the order they were added, oldest first.
    // 3. Any media-resource-specific text tracks (text tracks corresponding to data in the media
    // resource), in the order defined by the media resource's format specification.

    if (index < m_elementTracks.size())
        return m_elementTracks[index].get();

    index -= m_elementTracks.size();
    if (index < m_addTrackTracks.size())
        return m_addTrackTracks[index].get();

    index -= m_addTrackTracks.size();
    if (index < m_inbandTracks.size())
        return m_inbandTracks[index].get();

    return 0;
}

TextTrack* TextTrackList::getTrackById(const AtomicString& id)
{
    // 4.8.10.12.5 Text track API
    // The getTrackById(id) method must return the first TextTrack in the
    // TextTrackList object whose id IDL attribute would return a value equal
    // to the value of the id argument.
    for (unsigned i = 0; i < length(); ++i) {
        TextTrack* track = item(i);
        if (track->id() == id)
            return track;
    }

    // When no tracks match the given argument, the method must return null.
    return 0;
}

void TextTrackList::invalidateTrackIndexesAfterTrack(TextTrack* track)
{
    Vector<RefPtr<TextTrack> >* tracks = 0;

    if (track->trackType() == TextTrack::TrackElement) {
        tracks = &m_elementTracks;
        for (size_t i = 0; i < m_addTrackTracks.size(); ++i)
            m_addTrackTracks[i]->invalidateTrackIndex();
        for (size_t i = 0; i < m_inbandTracks.size(); ++i)
            m_inbandTracks[i]->invalidateTrackIndex();
    } else if (track->trackType() == TextTrack::AddTrack) {
        tracks = &m_addTrackTracks;
        for (size_t i = 0; i < m_inbandTracks.size(); ++i)
            m_inbandTracks[i]->invalidateTrackIndex();
    } else if (track->trackType() == TextTrack::InBand)
        tracks = &m_inbandTracks;
    else
        ASSERT_NOT_REACHED();

    size_t index = tracks->find(track);
    if (index == kNotFound)
        return;

    for (size_t i = index; i < tracks->size(); ++i)
        tracks->at(index)->invalidateTrackIndex();
}

void TextTrackList::append(PassRefPtr<TextTrack> prpTrack)
{
    RefPtr<TextTrack> track = prpTrack;

    if (track->trackType() == TextTrack::AddTrack)
        m_addTrackTracks.append(track);
    else if (track->trackType() == TextTrack::TrackElement) {
        // Insert tracks added for <track> element in tree order.
        size_t index = static_cast<LoadableTextTrack*>(track.get())->trackElementIndex();
        m_elementTracks.insert(index, track);
    } else if (track->trackType() == TextTrack::InBand) {
        // Insert tracks added for in-band in the media file order.
        size_t index = static_cast<InbandTextTrack*>(track.get())->inbandTrackIndex();
        m_inbandTracks.insert(index, track);
    } else
        ASSERT_NOT_REACHED();

    invalidateTrackIndexesAfterTrack(track.get());

    ASSERT(!track->trackList());
    track->setTrackList(this);

    scheduleAddTrackEvent(track.release());
}

void TextTrackList::remove(TextTrack* track)
{
    Vector<RefPtr<TextTrack> >* tracks = 0;

    if (track->trackType() == TextTrack::TrackElement) {
        tracks = &m_elementTracks;
    } else if (track->trackType() == TextTrack::AddTrack) {
        tracks = &m_addTrackTracks;
    } else if (track->trackType() == TextTrack::InBand) {
        tracks = &m_inbandTracks;
    } else {
        ASSERT_NOT_REACHED();
    }

    size_t index = tracks->find(track);
    if (index == kNotFound)
        return;

    invalidateTrackIndexesAfterTrack(track);

    ASSERT(track->trackList() == this);
    track->setTrackList(0);

    tracks->remove(index);

    scheduleRemoveTrackEvent(track);
}

void TextTrackList::removeAllInbandTracks()
{
    for (unsigned i = 0; i < m_inbandTracks.size(); ++i) {
        m_inbandTracks[i]->setTrackList(0);
    }
    m_inbandTracks.clear();
}

bool TextTrackList::contains(TextTrack* track) const
{
    const Vector<RefPtr<TextTrack> >* tracks = 0;

    if (track->trackType() == TextTrack::TrackElement)
        tracks = &m_elementTracks;
    else if (track->trackType() == TextTrack::AddTrack)
        tracks = &m_addTrackTracks;
    else if (track->trackType() == TextTrack::InBand)
        tracks = &m_inbandTracks;
    else
        ASSERT_NOT_REACHED();

    return tracks->find(track) != kNotFound;
}

const AtomicString& TextTrackList::interfaceName() const
{
    return EventTargetNames::TextTrackList;
}

ExecutionContext* TextTrackList::executionContext() const
{
    ASSERT(m_owner);
    return m_owner->executionContext();
}

void TextTrackList::clearOwner()
{
    m_owner = 0;
}

void TextTrackList::scheduleTrackEvent(const AtomicString& eventName, PassRefPtr<TextTrack> track)
{
    TrackEventInit initializer;
    initializer.track = track;
    initializer.bubbles = false;
    initializer.cancelable = false;

    m_asyncEventQueue->enqueueEvent(TrackEvent::create(eventName, initializer));
}

void TextTrackList::scheduleAddTrackEvent(PassRefPtr<TextTrack> track)
{
    // 4.8.10.12.3 Sourcing out-of-band text tracks
    // 4.8.10.12.4 Text track API
    // ... then queue a task to fire an event with the name addtrack, that does not
    // bubble and is not cancelable, and that uses the TrackEvent interface, with
    // the track attribute initialized to the text track's TextTrack object, at
    // the media element's textTracks attribute's TextTrackList object.
    scheduleTrackEvent(EventTypeNames::addtrack, track);
}

void TextTrackList::scheduleChangeEvent()
{
    // 4.8.10.12.1 Text track model
    // Whenever a text track that is in a media element's list of text tracks
    // has its text track mode change value, the user agent must run the
    // following steps for the media element:
    // ...
    // Fire a simple event named change at the media element's textTracks
    // attribute's TextTrackList object.

    EventInit initializer;
    initializer.bubbles = false;
    initializer.cancelable = false;

    m_asyncEventQueue->enqueueEvent(Event::create(EventTypeNames::change, initializer));
}

void TextTrackList::scheduleRemoveTrackEvent(PassRefPtr<TextTrack> track)
{
    // 4.8.10.12.3 Sourcing out-of-band text tracks
    // When a track element's parent element changes and the old parent was a
    // media element, then the user agent must remove the track element's
    // corresponding text track from the media element's list of text tracks,
    // and then queue a task to fire a trusted event with the name removetrack,
    // that does not bubble and is not cancelable, and that uses the TrackEvent
    // interface, with the track attribute initialized to the text track's
    // TextTrack object, at the media element's textTracks attribute's
    // TextTrackList object.
    scheduleTrackEvent(EventTypeNames::removetrack, track);
}

HTMLMediaElement* TextTrackList::owner() const
{
    return m_owner;
}