source: trunk/src/gui/kernel/qwinnativepangesturerecognizer_win.cpp

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#include "private/qwinnativepangesturerecognizer_win_p.h"

#include "qevent.h"
#include "qgraphicsitem.h"
#include "qgesture.h"

#include "private/qgesture_p.h"
#include "private/qevent_p.h"
#include "private/qapplication_p.h"
#include "private/qwidget_p.h"

#ifndef QT_NO_GESTURES

QT_BEGIN_NAMESPACE

#if !defined(QT_NO_NATIVE_GESTURES)

QWinNativePanGestureRecognizer::QWinNativePanGestureRecognizer()
{
}

QGesture *QWinNativePanGestureRecognizer::create(QObject *target)
{
    if (!target)
        return new QPanGesture; // a special case
    if (!target->isWidgetType())
        return 0;
    if (qobject_cast<QGraphicsObject *>(target))
        return 0;

    QWidget *q = static_cast<QWidget *>(target);
    QWidgetPrivate *d = q->d_func();
    d->nativeGesturePanEnabled = true;
    d->winSetupGestures();

    return new QPanGesture;
}

QGestureRecognizer::Result QWinNativePanGestureRecognizer::recognize(QGesture *state,
                                                                     QObject *,
                                                                     QEvent *event)
{
    QPanGesture *q = static_cast<QPanGesture*>(state);
    QPanGesturePrivate *d = q->d_func();

    QGestureRecognizer::Result result = QGestureRecognizer::Ignore;
    if (event->type() == QEvent::NativeGesture) {
        QNativeGestureEvent *ev = static_cast<QNativeGestureEvent*>(event);
        switch(ev->gestureType) {
        case QNativeGestureEvent::GestureBegin:
            break;
        case QNativeGestureEvent::Pan:
            result = QGestureRecognizer::TriggerGesture;
            event->accept();
            break;
        case QNativeGestureEvent::GestureEnd:
            if (q->state() == Qt::NoGesture)
                return QGestureRecognizer::Ignore; // some other gesture has ended
            result = QGestureRecognizer::FinishGesture;
            break;
        default:
            return QGestureRecognizer::Ignore;
        }
        if (q->state() == Qt::NoGesture) {
            d->lastOffset = d->offset = QPointF();
            d->startPosition = ev->position;
        } else {
            d->lastOffset = d->offset;
            d->offset = QPointF(ev->position.x() - d->startPosition.x(),
                                ev->position.y() - d->startPosition.y());
        }
    }
    return result;
}

void QWinNativePanGestureRecognizer::reset(QGesture *state)
{
    QPanGesture *pan = static_cast<QPanGesture*>(state);
    QPanGesturePrivate *d = pan->d_func();

    d->lastOffset = d->offset = QPointF();
    d->startPosition = QPoint();
    d->acceleration = 0;

    QGestureRecognizer::reset(state);
}

#endif // QT_NO_NATIVE_GESTURES

QT_END_NAMESPACE

#endif // QT_NO_GESTURES