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#include "qstandardgestures.h"
#include "qstandardgestures_p.h"

#include <qabstractscrollarea.h>
#include <qscrollbar.h>
#include <private/qapplication_p.h>

QT_BEGIN_NAMESPACE

/*!
    \class QPanGesture
    \since 4.6

    \brief The QPanGesture class represents a Pan gesture,
    providing additional information related to panning.
*/

/*!
    Creates a new Pan gesture handler object and marks it as a child of \a
    parent.

    On some platform like Windows it's necessary to provide a non-null widget
    as \a parent to get native gesture support.
*/
QPanGesture::QPanGesture(QWidget *parent)
    : QGesture(*new QPanGesturePrivate, parent)
{
#ifdef Q_WS_WIN
    if (parent) {
        QApplicationPrivate* getQApplicationPrivateInternal();
        QApplicationPrivate *qAppPriv = getQApplicationPrivateInternal();
        qAppPriv->widgetGestures[parent].pan = this;
    }
#endif
}

/*! \internal */
bool QPanGesture::event(QEvent *event)
{
#ifdef Q_WS_WIN
    QApplicationPrivate* getQApplicationPrivateInternal();
    switch (event->type()) {
    case QEvent::ParentAboutToChange:
        if (QWidget *w = qobject_cast<QWidget*>(parent()))
            getQApplicationPrivateInternal()->widgetGestures[w].pan = 0;
        break;
    case QEvent::ParentChange:
        if (QWidget *w = qobject_cast<QWidget*>(parent()))
            getQApplicationPrivateInternal()->widgetGestures[w].pan = this;
        break;
    default:
        break;
    }
#endif
    return QObject::event(event);
}

/*! \internal */
bool QPanGesture::filterEvent(QEvent *event)
{
    Q_D(QPanGesture);
    if (!event->spontaneous())
        return false;
    const QTouchEvent *ev = static_cast<const QTouchEvent*>(event);
    if (event->type() == QEvent::TouchBegin) {
        d->touchPoints = ev->touchPoints();
        const QPoint p = ev->touchPoints().at(0).pos().toPoint();
        setStartPos(p);
        setLastPos(p);
        setPos(p);
        return false;
    } else if (event->type() == QEvent::TouchEnd) {
        if (state() != Qt::NoGesture) {
            setState(Qt::GestureFinished);
            setLastPos(pos());
            setPos(ev->touchPoints().at(0).pos().toPoint());
            emit triggered();
            emit finished();
        }
        setState(Qt::NoGesture);
        reset();
    } else if (event->type() == QEvent::TouchUpdate) {
        d->touchPoints = ev->touchPoints();
        QPointF pt = d->touchPoints.at(0).pos() - d->touchPoints.at(0).startPos();
        setLastPos(pos());
        setPos(ev->touchPoints().at(0).pos().toPoint());
        if (pt.x() > 10 || pt.y() > 10 || pt.x() < -10 || pt.y() < -10) {
            if (state() == Qt::NoGesture)
                setState(Qt::GestureStarted);
            else
                setState(Qt::GestureUpdated);
            emit triggered();
        }
    }
    return false;
}

/*! \internal */
void QPanGesture::reset()
{
    Q_D(QPanGesture);
    d->touchPoints.clear();
}

/*!
    \property QPanGesture::totalOffset

    Specifies a total pan offset since the start of the gesture.
*/
QSize QPanGesture::totalOffset() const
{
    QPoint pt = pos() - startPos();
    return QSize(pt.x(), pt.y());
}

/*!
    \property QPanGesture::lastOffset

    Specifies a pan offset since the last time the gesture was
    triggered.
*/
QSize QPanGesture::lastOffset() const
{
    QPoint pt = pos() - lastPos();
    return QSize(pt.x(), pt.y());
}

/*!
    \class QTapAndHoldGesture
    \since 4.6

    \brief The QTapAndHoldGesture class represents a Tap-and-Hold gesture,
    providing additional information.
*/

const int QTapAndHoldGesturePrivate::iterationCount = 40;
const int QTapAndHoldGesturePrivate::iterationTimeout = 50;

/*!
    Creates a new Tap and Hold gesture handler object and marks it as a child
    of \a parent.

    On some platforms like Windows there is a system-wide tap and hold gesture
    that cannot be overriden, hence the gesture might never trigger and default
    context menu will be shown instead.
*/
QTapAndHoldGesture::QTapAndHoldGesture(QWidget *parent)
    : QGesture(*new QTapAndHoldGesturePrivate, parent)
{
}

/*! \internal */
bool QTapAndHoldGesture::filterEvent(QEvent *event)
{
    Q_D(QTapAndHoldGesture);
    if (!event->spontaneous())
        return false;
    const QTouchEvent *ev = static_cast<const QTouchEvent*>(event);
    switch (event->type()) {
    case QEvent::TouchBegin: {
        if (d->timer.isActive())
            d->timer.stop();
        d->timer.start(QTapAndHoldGesturePrivate::iterationTimeout, this);
        const QPoint p = ev->touchPoints().at(0).pos().toPoint();
        setStartPos(p);
        setLastPos(p);
        setPos(p);
        break;
    }
    case QEvent::TouchUpdate:
        if (ev->touchPoints().size() != 1)
            reset();
        else if ((startPos() - ev->touchPoints().at(0).pos().toPoint()).manhattanLength() > 15)
            reset();
        break;
    case QEvent::TouchEnd:
        reset();
        break;
    default:
        break;
    }
    return false;
}

/*! \internal */
void QTapAndHoldGesture::timerEvent(QTimerEvent *event)
{
    Q_D(QTapAndHoldGesture);
    if (event->timerId() != d->timer.timerId())
        return;
    if (d->iteration == QTapAndHoldGesturePrivate::iterationCount) {
        d->timer.stop();
        setState(Qt::GestureFinished);
        emit triggered();
    } else {
        setState(Qt::GestureStarted);
        emit triggered();
    }
    ++d->iteration;
}

/*! \internal */
void QTapAndHoldGesture::reset()
{
    Q_D(QTapAndHoldGesture);
    if (state() != Qt::NoGesture)
        emit cancelled();
    setState(Qt::NoGesture);
    d->timer.stop();
    d->iteration = 0;
}

QT_END_NAMESPACE