qquicksmoothedanimation.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qquicksmoothedanimation_p.h"
#include "qquicksmoothedanimation_p_p.h"
 
#include "qquickanimation_p_p.h"
#include "private/qcontinuinganimationgroupjob_p.h"
 
#include <qmath.h>
#include <qqmlproperty.h>
#include <private/qqmlproperty_p.h>
 
#include <private/qqmlglobal_p.h>
 
#include <QtCore/qdebug.h>
 
 
#define DELAY_STOP_TIMER_INTERVAL 32
 
QT_BEGIN_NAMESPACE
 
 
QSmoothedAnimationTimer::QSmoothedAnimationTimer(QSmoothedAnimation *animation, QObject *parent)
    : QTimer(parent)
    , m_animation(animation)
{
    connect(this, SIGNAL(timeout()), this, SLOT(stopAnimation()));
}
 
QSmoothedAnimationTimer::~QSmoothedAnimationTimer()
{
}
 
void QSmoothedAnimationTimer::stopAnimation()
{
    m_animation->stop();
}
 
QSmoothedAnimation::QSmoothedAnimation(QQuickSmoothedAnimationPrivate *priv)
    : QAbstractAnimationJob(), to(0), velocity(200), userDuration(-1), maximumEasingTime(-1),
      reversingMode(QQuickSmoothedAnimation::Eased), initialVelocity(0),
      trackVelocity(0), initialValue(0), invert(false), finalDuration(-1), lastTime(0),
      skipUpdate(false), delayedStopTimer(new QSmoothedAnimationTimer(this)), animationTemplate(priv)
{
    delayedStopTimer->setInterval(DELAY_STOP_TIMER_INTERVAL);
    delayedStopTimer->setSingleShot(true);
}
 
QSmoothedAnimation::~QSmoothedAnimation()
{
    delete delayedStopTimer;
    if (animationTemplate) {
        if (target.object()) {
            auto it = animationTemplate->activeAnimations.constFind(target);
            if (it != animationTemplate->activeAnimations.cend() && it.value() == this)
                animationTemplate->activeAnimations.erase(it);
        } else {
            //target is no longer valid, need to search linearly
            for (auto it = animationTemplate->activeAnimations.cbegin(); it != animationTemplate->activeAnimations.cend(); ++it) {
                if (it.value() == this) {
                    animationTemplate->activeAnimations.erase(it);
                    break;
                }
            }
        }
    }
}
 
void QSmoothedAnimation::restart()
{
    initialVelocity = trackVelocity;
    if (isRunning())
        init();
    else
        start();
}
 
void QSmoothedAnimation::prepareForRestart()
{
    initialVelocity = trackVelocity;
    if (isRunning()) {
        //we are joining a new wrapper group while running, our times need to be restarted
        skipUpdate = true;
        init();
        lastTime = 0;
    } else {
        skipUpdate = false;
        //we'll be started when the group starts, which will force an init()
    }
}
 
void QSmoothedAnimation::updateState(QAbstractAnimationJob::State newState, QAbstractAnimationJob::State /*oldState*/)
{
    if (newState == QAbstractAnimationJob::Running)
        init();
}
 
void QSmoothedAnimation::delayedStop()
{
    if (!delayedStopTimer->isActive())
        delayedStopTimer->start();
}
 
int QSmoothedAnimation::duration() const
{
    return -1;
}
 
bool QSmoothedAnimation::recalc()
{
    s = to - initialValue;
    vi = initialVelocity;
 
    s = (invert? -1.0: 1.0) * s;
 
    if (userDuration >= 0 && velocity > 0) {
        tf = s / velocity;
        if (tf > (userDuration / 1000.)) tf = (userDuration / 1000.);
    } else if (userDuration >= 0) {
        tf = userDuration / 1000.;
    } else if (velocity > 0) {
        tf = s / velocity;
    } else {
        return false;
    }
 
    finalDuration = qCeil(tf * 1000.0);
 
    if (maximumEasingTime == 0) {
        a = 0;
        d = 0;
        tp = 0;
        td = tf;
        vp = velocity;
        sp = 0;
        sd = s;
    } else if (maximumEasingTime != -1 && tf > (maximumEasingTime / 1000.)) {
        qreal met = maximumEasingTime / 1000.;
        /*       tp|       |td
         * vp_      _______
         *         /       \
         * vi_    /         \
         *                   \
         *                    \   _ 0
         *       |ta|      |ta|
         */
        qreal ta = met / 2.;
        a = (s - (vi * tf - 0.5 * vi * ta)) / (tf * ta - ta * ta);
 
        vp = vi + a * ta;
        d = vp / ta;
        tp = ta;
        sp = vi * ta + 0.5 * a * tp * tp;
        sd = sp + vp * (tf - 2 * ta);
        td = tf - ta;
    } else {
        qreal c1 = 0.25 * tf * tf;
        qreal c2 = 0.5 * vi * tf - s;
        qreal c3 = -0.25 * vi * vi;
 
        qreal a1 = (-c2 + qSqrt(c2 * c2 - 4 * c1 * c3)) / (2. * c1);
 
        qreal tp1 = 0.5 * tf - 0.5 * vi / a1;
        qreal vp1 = a1 * tp1 + vi;
 
        qreal sp1 = 0.5 * a1 * tp1 * tp1 + vi * tp1;
 
        a = a1;
        d = a1;
        tp = tp1;
        td = tp1;
        vp = vp1;
        sp = sp1;
        sd = sp1;
    }
    return true;
}
 
qreal QSmoothedAnimation::easeFollow(qreal time_seconds)
{
    qreal value;
    if (time_seconds < tp) {
        trackVelocity = vi + time_seconds * a;
        value = 0.5 * a * time_seconds * time_seconds + vi * time_seconds;
    } else if (time_seconds < td) {
        time_seconds -= tp;
        trackVelocity = vp;
        value = sp + time_seconds * vp;
    } else if (time_seconds < tf) {
        time_seconds -= td;
        trackVelocity = vp - time_seconds * a;
        value = sd - 0.5 * d * time_seconds * time_seconds + vp * time_seconds;
    } else {
        trackVelocity = 0;
        value = s;
        delayedStop();
    }
 
    // to normalize 's' between [0..1], divide 'value' by 's'
    return value;
}
 
void QSmoothedAnimation::updateCurrentTime(int t)
{
    if (skipUpdate) {
        skipUpdate = false;
        return;
    }
 
    if (!isRunning() && !isPaused()) // This can happen if init() stops the animation in some cases
        return;
 
    qreal time_seconds = qreal(t - lastTime) / 1000.;
 
    qreal value = easeFollow(time_seconds);
    value *= (invert? -1.0: 1.0);
    QQmlPropertyPrivate::write(target, initialValue + value,
                                       QQmlPropertyData::BypassInterceptor
                                       | QQmlPropertyData::DontRemoveBinding);
}
 
void QSmoothedAnimation::init()
{
    if (velocity == 0) {
        stop();
        return;
    }
 
    if (delayedStopTimer->isActive())
        delayedStopTimer->stop();
 
    initialValue = target.read().toReal();
    lastTime = this->currentTime();
 
    if (to == initialValue) {
        stop();
        return;
    }
 
    bool hasReversed = trackVelocity != 0. &&
                      ((!invert) == ((initialValue - to) > 0));
 
    if (hasReversed) {
        switch (reversingMode) {
            default:
            case QQuickSmoothedAnimation::Eased:
                initialVelocity = -trackVelocity;
                break;
            case QQuickSmoothedAnimation::Sync:
                QQmlPropertyPrivate::write(target, to,
                                                   QQmlPropertyData::BypassInterceptor
                                                   | QQmlPropertyData::DontRemoveBinding);
                trackVelocity = 0;
                stop();
                return;
            case QQuickSmoothedAnimation::Immediate:
                initialVelocity = 0;
                break;
        }
    }
 
    trackVelocity = initialVelocity;
 
    invert = (to < initialValue);
 
    if (!recalc()) {
        QQmlPropertyPrivate::write(target, to,
                                           QQmlPropertyData::BypassInterceptor
                                           | QQmlPropertyData::DontRemoveBinding);
        stop();
        return;
    }
}
 
void QSmoothedAnimation::debugAnimation(QDebug d) const
{
    d << "SmoothedAnimationJob(" << Qt::hex << (const void *) this << Qt::dec << ")" << "duration:" << userDuration
      << "velocity:" << velocity << "target:" << target.object() << "property:" << target.name()
      << "to:" << to << "current velocity:" << trackVelocity;
}
 
QQuickSmoothedAnimation::QQuickSmoothedAnimation(QObject *parent)
: QQuickNumberAnimation(*(new QQuickSmoothedAnimationPrivate), parent)
{
}
 
QQuickSmoothedAnimationPrivate::QQuickSmoothedAnimationPrivate()
    : anim(new QSmoothedAnimation)
{
}
 
QQuickSmoothedAnimationPrivate::~QQuickSmoothedAnimationPrivate()
{
    typedef QHash<QQmlProperty, QSmoothedAnimation* >::iterator ActiveAnimationsHashIt;
 
    delete anim;
    for (ActiveAnimationsHashIt it = activeAnimations.begin(), end = activeAnimations.end(); it != end; ++it)
        it.value()->clearTemplate();
}
 
void QQuickSmoothedAnimationPrivate::updateRunningAnimations()
{
    for (QSmoothedAnimation *ease : std::as_const(activeAnimations)) {
        ease->maximumEasingTime = anim->maximumEasingTime;
        ease->reversingMode = anim->reversingMode;
        ease->velocity = anim->velocity;
        ease->userDuration = anim->userDuration;
        ease->init();
    }
}
 
QAbstractAnimationJob* QQuickSmoothedAnimation::transition(QQuickStateActions &actions,
                                               QQmlProperties &modified,
                                               TransitionDirection direction,
                                               QObject *defaultTarget)
{
    Q_UNUSED(direction);
    Q_D(QQuickSmoothedAnimation);
 
    const QQuickStateActions dataActions = QQuickPropertyAnimation::createTransitionActions(actions, modified, defaultTarget);
 
    QContinuingAnimationGroupJob *wrapperGroup = new QContinuingAnimationGroupJob();
 
    if (!dataActions.isEmpty()) {
        QSet<QAbstractAnimationJob*> anims;
        for (int i = 0; i < dataActions.size(); i++) {
            QSmoothedAnimation *ease;
            bool isActive;
            if (!d->activeAnimations.contains(dataActions[i].property)) {
                ease = new QSmoothedAnimation(d);
                d->activeAnimations.insert(dataActions[i].property, ease);
                ease->target = dataActions[i].property;
                isActive = false;
            } else {
                ease = d->activeAnimations.value(dataActions[i].property);
                isActive = true;
            }
            wrapperGroup->appendAnimation(initInstance(ease));
 
            ease->to = dataActions[i].toValue.toReal();
 
            // copying public members from main value holder animation
            ease->maximumEasingTime = d->anim->maximumEasingTime;
            ease->reversingMode = d->anim->reversingMode;
            ease->velocity = d->anim->velocity;
            ease->userDuration = d->anim->userDuration;
 
            ease->initialVelocity = ease->trackVelocity;
 
            if (isActive)
                ease->prepareForRestart();
            anims.insert(ease);
        }
 
        const auto copy = d->activeAnimations;
        for (QSmoothedAnimation *ease : copy) {
            if (!anims.contains(ease)) {
                ease->clearTemplate();
                d->activeAnimations.remove(ease->target);
            }
        }
    }
    return wrapperGroup;
}
 
QQuickSmoothedAnimation::ReversingMode QQuickSmoothedAnimation::reversingMode() const
{
    Q_D(const QQuickSmoothedAnimation);
    return (QQuickSmoothedAnimation::ReversingMode) d->anim->reversingMode;
}
 
void QQuickSmoothedAnimation::setReversingMode(ReversingMode m)
{
    Q_D(QQuickSmoothedAnimation);
    if (d->anim->reversingMode == m)
        return;
 
    d->anim->reversingMode = m;
    emit reversingModeChanged();
    d->updateRunningAnimations();
}
 
int QQuickSmoothedAnimation::duration() const
{
    Q_D(const QQuickSmoothedAnimation);
    return d->anim->userDuration;
}
 
void QQuickSmoothedAnimation::setDuration(int duration)
{
    Q_D(QQuickSmoothedAnimation);
    if (duration != -1)
        QQuickNumberAnimation::setDuration(duration);
    if(duration == d->anim->userDuration)
        return;
    d->anim->userDuration = duration;
    d->updateRunningAnimations();
}
 
qreal QQuickSmoothedAnimation::velocity() const
{
    Q_D(const QQuickSmoothedAnimation);
    return d->anim->velocity;
}
 
void QQuickSmoothedAnimation::setVelocity(qreal v)
{
    Q_D(QQuickSmoothedAnimation);
    if (d->anim->velocity == v)
        return;
 
    d->anim->velocity = v;
    emit velocityChanged();
    d->updateRunningAnimations();
}
 
int QQuickSmoothedAnimation::maximumEasingTime() const
{
    Q_D(const QQuickSmoothedAnimation);
    return d->anim->maximumEasingTime;
}
 
void QQuickSmoothedAnimation::setMaximumEasingTime(int v)
{
    Q_D(QQuickSmoothedAnimation);
    if(v == d->anim->maximumEasingTime)
        return;
    d->anim->maximumEasingTime = v;
    emit maximumEasingTimeChanged();
    d->updateRunningAnimations();
}
 
QT_END_NAMESPACE
 
#include "moc_qquicksmoothedanimation_p_p.cpp"
 
#include "moc_qquicksmoothedanimation_p.cpp"