root/Source/core/animation/DocumentTimeline.cpp

DEFINITIONS

1. create
2. m_document
3. createAnimationPlayer
4. play
5. wake
6. serviceAnimations
7. setZeroTime
8. wakeAfter
9. cancelWake
10. serviceOnNextFrame
11. currentTime
12. currentTime
13. effectiveTime
14. pauseAnimationsForTesting
15. setOutdatedAnimationPlayer
16. numberOfActiveAnimationsForTesting
17. detachFromDocument

/*
 * Copyright (C) 2013 Google 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:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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 THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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#include "config.h"
#include "core/animation/DocumentTimeline.h"

#include "core/animation/ActiveAnimations.h"
#include "core/animation/AnimationClock.h"
#include "core/dom/Document.h"
#include "core/frame/FrameView.h"
#include "core/page/Page.h"
#include "platform/TraceEvent.h"

namespace WebCore {

// This value represents 1 frame at 30Hz plus a little bit of wiggle room.
// TODO: Plumb a nominal framerate through and derive this value from that.
const double DocumentTimeline::s_minimumDelay = 0.04;


PassRefPtr<DocumentTimeline> DocumentTimeline::create(Document* document, PassOwnPtr<PlatformTiming> timing)
{
    return adoptRef(new DocumentTimeline(document, timing));
}

DocumentTimeline::DocumentTimeline(Document* document, PassOwnPtr<PlatformTiming> timing)
    : m_zeroTime(nullValue())
    , m_document(document)
{
    if (!timing)
        m_timing = adoptPtr(new DocumentTimelineTiming(this));
    else
        m_timing = timing;

    ASSERT(document);
}

DocumentTimeline::~DocumentTimeline()
{
    for (HashSet<AnimationPlayer*>::iterator it = m_players.begin(); it != m_players.end(); ++it)
        (*it)->timelineDestroyed();
}

AnimationPlayer* DocumentTimeline::createAnimationPlayer(TimedItem* child)
{
    RefPtr<AnimationPlayer> player = AnimationPlayer::create(*this, child);
    AnimationPlayer* result = player.get();
    m_players.add(result);
    setOutdatedAnimationPlayer(result);
    return result;
}

AnimationPlayer* DocumentTimeline::play(TimedItem* child)
{
    if (!m_document)
        return 0;
    AnimationPlayer* player = createAnimationPlayer(child);
    player->setStartTime(effectiveTime());
    return player;
}

void DocumentTimeline::wake()
{
    m_timing->serviceOnNextFrame();
}

void DocumentTimeline::serviceAnimations(AnimationPlayer::UpdateReason reason)
{
    TRACE_EVENT0("webkit", "DocumentTimeline::serviceAnimations");

    m_timing->cancelWake();
    m_hasOutdatedAnimationPlayer = false;

    double timeToNextEffect = std::numeric_limits<double>::infinity();
    Vector<AnimationPlayer*> players;
    for (HashSet<RefPtr<AnimationPlayer> >::iterator it = m_playersNeedingUpdate.begin(); it != m_playersNeedingUpdate.end(); ++it)
        players.append(it->get());

    std::sort(players.begin(), players.end(), AnimationPlayer::hasLowerPriority);

    for (size_t i = 0; i < players.size(); ++i) {
        AnimationPlayer* player = players[i];
        if (player->update(reason))
            timeToNextEffect = std::min(timeToNextEffect, player->timeToEffectChange());
        else
            m_playersNeedingUpdate.remove(player);
    }

    ASSERT(!m_playersNeedingUpdate.isEmpty() || timeToNextEffect == std::numeric_limits<double>::infinity());
    if (timeToNextEffect < s_minimumDelay)
        m_timing->serviceOnNextFrame();
    else if (timeToNextEffect != std::numeric_limits<double>::infinity())
        m_timing->wakeAfter(timeToNextEffect - s_minimumDelay);

    ASSERT(!m_hasOutdatedAnimationPlayer);
}

void DocumentTimeline::setZeroTime(double zeroTime)
{
    ASSERT(isNull(m_zeroTime));
    m_zeroTime = zeroTime;
    ASSERT(!isNull(m_zeroTime));
    serviceAnimations(AnimationPlayer::UpdateOnDemand);
}

void DocumentTimeline::DocumentTimelineTiming::wakeAfter(double duration)
{
    m_timer.startOneShot(duration, FROM_HERE);
}

void DocumentTimeline::DocumentTimelineTiming::cancelWake()
{
    m_timer.stop();
}

void DocumentTimeline::DocumentTimelineTiming::serviceOnNextFrame()
{
    if (m_timeline->m_document && m_timeline->m_document->view())
        m_timeline->m_document->view()->scheduleAnimation();
}

double DocumentTimeline::currentTime(bool& isNull)
{
    if (!m_document) {
        isNull = true;
        return std::numeric_limits<double>::quiet_NaN();
    }
    double result = m_document->animationClock().currentTime() - m_zeroTime;
    isNull = std::isnan(result);
    return result;
}

double DocumentTimeline::currentTime()
{
    bool isNull;
    return currentTime(isNull);
}

double DocumentTimeline::effectiveTime()
{
    double time = currentTime();
    return std::isnan(time) ? 0 : time;
}

void DocumentTimeline::pauseAnimationsForTesting(double pauseTime)
{
    for (HashSet<RefPtr<AnimationPlayer> >::iterator it = m_playersNeedingUpdate.begin(); it != m_playersNeedingUpdate.end(); ++it)
        (*it)->pauseForTesting(pauseTime);
    serviceAnimations(AnimationPlayer::UpdateOnDemand);
}

void DocumentTimeline::setOutdatedAnimationPlayer(AnimationPlayer* player)
{
    m_playersNeedingUpdate.add(player);
    m_hasOutdatedAnimationPlayer = true;
    if (m_document && m_document->page() && !m_document->page()->animator().isServicingAnimations())
        m_timing->serviceOnNextFrame();
}

size_t DocumentTimeline::numberOfActiveAnimationsForTesting() const
{
    if (isNull(m_zeroTime))
        return 0;
    // Includes all players whose directly associated timed items
    // are current or in effect.
    if (isNull(m_zeroTime))
        return 0;
    size_t count = 0;
    for (HashSet<RefPtr<AnimationPlayer> >::iterator it = m_playersNeedingUpdate.begin(); it != m_playersNeedingUpdate.end(); ++it) {
        const TimedItem* timedItem = (*it)->source();
        if ((*it)->hasStartTime())
            count += (timedItem && (timedItem->isCurrent() || timedItem->isInEffect()));
    }
    return count;
}

void DocumentTimeline::detachFromDocument() {
    // FIXME: DocumentTimeline should keep Document alive.
    m_document = 0;
}

} // namespace