Source/core/animation/Player.cpp

/*
 * Copyright (C) 2013 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
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 * notice, this list of conditions and the following disclaimer.
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 * in the documentation and/or other materials provided with the
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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#include "config.h"
#include "core/animation/Player.h"

#include "core/animation/DocumentTimeline.h"
#include "core/animation/TimedItem.h"

namespace WebCore {

namespace {

double effectiveTime(double time) { return isNull(time) ? 0 : time; }

} // namespace

PassRefPtr<Player> Player::create(DocumentTimeline& timeline, TimedItem* content)
{
    return adoptRef(new Player(timeline, content));
}

Player::Player(DocumentTimeline& timeline, TimedItem* content)
    : m_pauseStartTime(nullValue())
    , m_playbackRate(1)
    , m_timeDrift(0)
    , m_startTime(effectiveTime(timeline.currentTime()))
    , m_content(content)
    , m_timeline(timeline)
    , m_isPausedForTesting(false)
{
    ASSERT(m_startTime >= 0);
    if (m_content)
        m_content->attach(this);
    update();
}

Player::~Player()
{
    if (m_content)
        m_content->detach();
}

double Player::currentTimeBeforeDrift() const
{
    return (effectiveTime(m_timeline.currentTime()) - m_startTime) * m_playbackRate;
}

double Player::pausedTimeDrift() const
{
    ASSERT(pausedInternal());
    return currentTimeBeforeDrift() - m_pauseStartTime;
}

double Player::timeDrift() const
{
    return pausedInternal() ? pausedTimeDrift() : m_timeDrift;
}

double Player::currentTime() const
{
    return currentTimeBeforeDrift() - timeDrift();
}

bool Player::update(double* timeToEffectChange, bool* didTriggerStyleRecalc)
{
    if (!m_content) {
        if (timeToEffectChange)
            *timeToEffectChange = std::numeric_limits<double>::infinity();
        if (didTriggerStyleRecalc)
            *didTriggerStyleRecalc = false;
        return false;
    }

    double newTime = isNull(m_timeline.currentTime()) ? nullValue() : currentTime();
    bool didTriggerStyleRecalcLocal = m_content->updateInheritedTime(newTime);
    if (timeToEffectChange)
        *timeToEffectChange = m_content->timeToEffectChange();
    if (didTriggerStyleRecalc)
        *didTriggerStyleRecalc = didTriggerStyleRecalcLocal;
    return m_content->isCurrent() || m_content->isInEffect();
}

void Player::cancel()
{
    if (!m_content)
        return;

    ASSERT(m_content->player() == this);
    m_content->detach();
    m_content = 0;
}

void Player::setCurrentTime(double seekTime)
{
    if (pausedInternal())
        m_pauseStartTime = seekTime;
    else
        m_timeDrift = currentTimeBeforeDrift() - seekTime;

    update();
}

void Player::pauseForTesting()
{
    ASSERT(!paused());
    m_isPausedForTesting = true;
    setPausedImpl(true);
}

void Player::setPaused(bool newValue)
{
    ASSERT(!m_isPausedForTesting);
    setPausedImpl(newValue);
}

void Player::setPausedImpl(bool newValue)
{
    if (pausedInternal() == newValue)
        return;

    if (newValue)
        m_pauseStartTime = currentTime();
    else {
        m_timeDrift = pausedTimeDrift();
        m_pauseStartTime = nullValue();
    }
}

void Player::setPlaybackRate(double newRate)
{
    double previousTime = currentTime();
    m_playbackRate = newRate;
    setCurrentTime(previousTime);
}

} // namespace