qgraphicsitemanimation.cpp

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#include "qgraphicsitemanimation.h"

#ifndef QT_NO_GRAPHICSVIEW

#include "qgraphicsitem.h"

#include <QtCore/qtimeline.h>
#include <QtCore/qpoint.h>
#include <QtCore/qpointer.h>
#include <QtCore/qpair.h>
#include <QtGui/qmatrix.h>

QT_BEGIN_NAMESPACE

class QGraphicsItemAnimationPrivate
{
public:
    inline QGraphicsItemAnimationPrivate()
        : q(0), timeLine(0), item(0), step(0)
    { }

    QGraphicsItemAnimation *q;

    QPointer<QTimeLine> timeLine;
    QGraphicsItem *item;

    QPointF startPos;
    QMatrix startMatrix;

    qreal step;

    struct Pair {
        Pair(qreal a, qreal b) : step(a), value(b) {}
        bool operator <(const Pair &other) const
        { return step < other.step; }
        bool operator==(const Pair &other) const
        { return step == other.step; }
        qreal step;
        qreal value;
    };
    QList<Pair> xPosition;
    QList<Pair> yPosition;
    QList<Pair> rotation;
    QList<Pair> verticalScale;
    QList<Pair> horizontalScale;
    QList<Pair> verticalShear;
    QList<Pair> horizontalShear;
    QList<Pair> xTranslation;
    QList<Pair> yTranslation;

    qreal linearValueForStep(qreal step, QList<Pair> *source, qreal defaultValue = 0);
    void insertUniquePair(qreal step, qreal value, QList<Pair> *binList, const char* method);
};

qreal QGraphicsItemAnimationPrivate::linearValueForStep(qreal step, QList<Pair> *source, qreal defaultValue)
{
    if (source->isEmpty())
        return defaultValue;
    step = qMin<qreal>(qMax<qreal>(step, 0), 1);

    if (step == 1)
        return source->last().value;

    qreal stepBefore = 0;
    qreal stepAfter = 1;
    qreal valueBefore = source->first().step == 0 ? source->first().value : defaultValue;
    qreal valueAfter = source->last().value;

    // Find the closest step and value before the given step.
    for (int i = 0; i < source->size() && step >= source->at(i).step; ++i) {
        stepBefore = source->at(i).step;
        valueBefore = source->at(i).value;
    }

    // Find the closest step and value after the given step.
    for (int j = source->size() - 1; j >= 0 && step < source->at(j).step; --j) {
        stepAfter = source->at(j).step;
        valueAfter = source->at(j).value;
    }

    // Do a simple linear interpolation.
    return valueBefore + (valueAfter - valueBefore) * ((step - stepBefore) / (stepAfter - stepBefore));
}

void QGraphicsItemAnimationPrivate::insertUniquePair(qreal step, qreal value, QList<Pair> *binList, const char* method)
{
    if (step < 0.0 || step > 1.0) {
        qWarning("QGraphicsItemAnimation::%s: invalid step = %f", method, step);
        return;
    }

    Pair pair(step, value);

    QList<Pair>::iterator result = qBinaryFind(binList->begin(), binList->end(), pair);
    if (result != binList->end())
        result->value = value;
    else {
        *binList << pair;
        qSort(binList->begin(), binList->end());
    }
}

QGraphicsItemAnimation::QGraphicsItemAnimation(QObject *parent)
    : QObject(parent), d(new QGraphicsItemAnimationPrivate)
{
    d->q = this;
}

QGraphicsItemAnimation::~QGraphicsItemAnimation()
{
    delete d;
}

QGraphicsItem *QGraphicsItemAnimation::item() const
{
    return d->item;
}

void QGraphicsItemAnimation::setItem(QGraphicsItem *item)
{
    d->item = item;
    d->startPos = d->item->pos();
}

QTimeLine *QGraphicsItemAnimation::timeLine() const
{
    return d->timeLine;
}

void QGraphicsItemAnimation::setTimeLine(QTimeLine *timeLine)
{
    if (d->timeLine == timeLine)
        return;
    if (d->timeLine)
        delete d->timeLine;
    if (!timeLine)
        return;
    d->timeLine = timeLine;
    connect(timeLine, SIGNAL(valueChanged(qreal)), this, SLOT(setStep(qreal)));
}

QPointF QGraphicsItemAnimation::posAt(qreal step) const
{
    if (step < 0.0 || step > 1.0)
        qWarning("QGraphicsItemAnimation::posAt: invalid step = %f", step);

    return QPointF(d->linearValueForStep(step, &d->xPosition, d->startPos.x()),
                   d->linearValueForStep(step, &d->yPosition, d->startPos.y()));
}

void QGraphicsItemAnimation::setPosAt(qreal step, const QPointF &pos)
{
    d->insertUniquePair(step, pos.x(), &d->xPosition, "setPosAt");
    d->insertUniquePair(step, pos.y(), &d->yPosition, "setPosAt");
}

QList<QPair<qreal, QPointF> > QGraphicsItemAnimation::posList() const
{
    QList<QPair<qreal, QPointF> > list;
    for (int i = 0; i < d->xPosition.size(); ++i)
        list << QPair<qreal, QPointF>(d->xPosition.at(i).step, QPointF(d->xPosition.at(i).value, d->yPosition.at(i).value));

    return list;
}

QMatrix QGraphicsItemAnimation::matrixAt(qreal step) const
{
    if (step < 0.0 || step > 1.0)
        qWarning("QGraphicsItemAnimation::matrixAt: invalid step = %f", step);

    QMatrix matrix;
    if (!d->rotation.isEmpty())
        matrix.rotate(rotationAt(step));
    if (!d->verticalScale.isEmpty())
        matrix.scale(horizontalScaleAt(step), verticalScaleAt(step));
    if (!d->verticalShear.isEmpty())
        matrix.shear(horizontalShearAt(step), verticalShearAt(step));
    if (!d->xTranslation.isEmpty())
        matrix.translate(xTranslationAt(step), yTranslationAt(step));
    return matrix;
}

qreal QGraphicsItemAnimation::rotationAt(qreal step) const
{
    if (step < 0.0 || step > 1.0)
        qWarning("QGraphicsItemAnimation::rotationAt: invalid step = %f", step);

    return d->linearValueForStep(step, &d->rotation);
}

void QGraphicsItemAnimation::setRotationAt(qreal step, qreal angle)
{
    d->insertUniquePair(step, angle, &d->rotation, "setRotationAt");
}

QList<QPair<qreal, qreal> > QGraphicsItemAnimation::rotationList() const
{
    QList<QPair<qreal, qreal> > list;
    for (int i = 0; i < d->rotation.size(); ++i)
        list << QPair<qreal, qreal>(d->rotation.at(i).step, d->rotation.at(i).value);

    return list;
}

qreal QGraphicsItemAnimation::xTranslationAt(qreal step) const
{
    if (step < 0.0 || step > 1.0)
        qWarning("QGraphicsItemAnimation::xTranslationAt: invalid step = %f", step);

    return d->linearValueForStep(step, &d->xTranslation);
}

qreal QGraphicsItemAnimation::yTranslationAt(qreal step) const
{
    if (step < 0.0 || step > 1.0)
        qWarning("QGraphicsItemAnimation::yTranslationAt: invalid step = %f", step);

    return d->linearValueForStep(step, &d->yTranslation);
}

void QGraphicsItemAnimation::setTranslationAt(qreal step, qreal dx, qreal dy)
{
    d->insertUniquePair(step, dx, &d->xTranslation, "setTranslationAt");
    d->insertUniquePair(step, dy, &d->yTranslation, "setTranslationAt");
}

QList<QPair<qreal, QPointF> > QGraphicsItemAnimation::translationList() const
{
    QList<QPair<qreal, QPointF> > list;
    for (int i = 0; i < d->xTranslation.size(); ++i)
        list << QPair<qreal, QPointF>(d->xTranslation.at(i).step, QPointF(d->xTranslation.at(i).value, d->yTranslation.at(i).value));

    return list;
}

qreal QGraphicsItemAnimation::verticalScaleAt(qreal step) const
{
    if (step < 0.0 || step > 1.0)
        qWarning("QGraphicsItemAnimation::verticalScaleAt: invalid step = %f", step);

    return d->linearValueForStep(step, &d->verticalScale, 1);
}

qreal QGraphicsItemAnimation::horizontalScaleAt(qreal step) const
{
    if (step < 0.0 || step > 1.0)
        qWarning("QGraphicsItemAnimation::horizontalScaleAt: invalid step = %f", step);

    return d->linearValueForStep(step, &d->horizontalScale, 1);
}

void QGraphicsItemAnimation::setScaleAt(qreal step, qreal sx, qreal sy)
{
    d->insertUniquePair(step, sx, &d->horizontalScale, "setScaleAt");
    d->insertUniquePair(step, sy, &d->verticalScale, "setScaleAt");
}

QList<QPair<qreal, QPointF> > QGraphicsItemAnimation::scaleList() const
{
    QList<QPair<qreal, QPointF> > list;
    for (int i = 0; i < d->horizontalScale.size(); ++i)
        list << QPair<qreal, QPointF>(d->horizontalScale.at(i).step, QPointF(d->horizontalScale.at(i).value, d->verticalScale.at(i).value));

    return list;
}

qreal QGraphicsItemAnimation::verticalShearAt(qreal step) const
{
    if (step < 0.0 || step > 1.0)
        qWarning("QGraphicsItemAnimation::verticalShearAt: invalid step = %f", step);

    return d->linearValueForStep(step, &d->verticalShear, 0);
}

qreal QGraphicsItemAnimation::horizontalShearAt(qreal step) const
{
    if (step < 0.0 || step > 1.0)
        qWarning("QGraphicsItemAnimation::horizontalShearAt: invalid step = %f", step);

    return d->linearValueForStep(step, &d->horizontalShear, 0);
}

void QGraphicsItemAnimation::setShearAt(qreal step, qreal sh, qreal sv)
{
    d->insertUniquePair(step, sh, &d->horizontalShear, "setShearAt");
    d->insertUniquePair(step, sv, &d->verticalShear, "setShearAt");
}

QList<QPair<qreal, QPointF> > QGraphicsItemAnimation::shearList() const
{
    QList<QPair<qreal, QPointF> > list;
    for (int i = 0; i < d->horizontalShear.size(); ++i)
        list << QPair<qreal, QPointF>(d->horizontalShear.at(i).step, QPointF(d->horizontalShear.at(i).value, d->verticalShear.at(i).value));

    return list;
}

void QGraphicsItemAnimation::clear()
{
    d->xPosition.clear();
    d->yPosition.clear();
    d->rotation.clear();
    d->verticalScale.clear();
    d->horizontalScale.clear();
    d->verticalShear.clear();
    d->horizontalShear.clear();
    d->xTranslation.clear();
    d->yTranslation.clear();
}

void QGraphicsItemAnimation::setStep(qreal x)
{
    if (x < 0.0 || x > 1.0) {
        qWarning("QGraphicsItemAnimation::setStep: invalid step = %f", x);
        return;
    }

    beforeAnimationStep(x);

    d->step = x;
    if (d->item) {
        if (!d->xPosition.isEmpty() || !d->yPosition.isEmpty())
            d->item->setPos(posAt(x));
        if (!d->rotation.isEmpty()
            || !d->verticalScale.isEmpty()
            || !d->horizontalScale.isEmpty()
            || !d->verticalShear.isEmpty()
            || !d->horizontalShear.isEmpty()
            || !d->xTranslation.isEmpty()
            || !d->yTranslation.isEmpty()) {
            d->item->setMatrix(d->startMatrix * matrixAt(x));
        }
    }

    afterAnimationStep(x);
}

void QGraphicsItemAnimation::reset()
{
    if (!d->item)
        return;
    d->startPos = d->item->pos();
    d->startMatrix = d->item->matrix();
}

void QGraphicsItemAnimation::beforeAnimationStep(qreal step)
{
    Q_UNUSED(step);
}

void QGraphicsItemAnimation::afterAnimationStep(qreal step)
{
    Q_UNUSED(step);
}

QT_END_NAMESPACE

#endif // QT_NO_GRAPHICSVIEW