qquickswitch.cpp

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// Copyright (C) 2017 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 "qquickswitch_p.h"
#include "qquickabstractbutton_p_p.h"
 
#include <QtGui/qstylehints.h>
#include <QtGui/qguiapplication.h>
#include <QtQuick/private/qquickwindow_p.h>
#include <QtQuick/private/qquickevents_p_p.h>
 
QT_BEGIN_NAMESPACE
 
 
class QQuickSwitchPrivate : public QQuickAbstractButtonPrivate
{
    Q_DECLARE_PUBLIC(QQuickSwitch)
 
public:
    qreal positionAt(const QPointF &point) const;
 
    bool canDrag(const QPointF &movePoint) const;
    bool handleMove(const QPointF &point, ulong timestamp) override;
    bool handleRelease(const QPointF &point, ulong timestamp) override;
 
    QPalette defaultPalette() const override { return QQuickTheme::palette(QQuickTheme::Switch); }
 
    qreal position = 0;
};
 
qreal QQuickSwitchPrivate::positionAt(const QPointF &point) const
{
    Q_Q(const QQuickSwitch);
    qreal pos = 0.0;
    if (indicator)
        pos = indicator->mapFromItem(q, point).x() / indicator->width();
    if (q->isMirrored())
        return 1.0 - pos;
    return pos;
}
 
bool QQuickSwitchPrivate::canDrag(const QPointF &movePoint) const
{
    // don't start dragging the handle unless the initial press was at the indicator,
    // or the drag has reached the indicator area. this prevents unnatural jumps when
    // dragging far outside the indicator.
    const qreal pressPos = positionAt(pressPoint);
    const qreal movePos = positionAt(movePoint);
    return (pressPos >= 0.0 && pressPos <= 1.0) || (movePos >= 0.0 && movePos <= 1.0);
}
 
bool QQuickSwitchPrivate::handleMove(const QPointF &point, ulong timestamp)
{
    Q_Q(QQuickSwitch);
    QQuickAbstractButtonPrivate::handleMove(point, timestamp);
    if (q->keepMouseGrab() || q->keepTouchGrab())
        q->setPosition(positionAt(point));
    return true;
}
 
bool QQuickSwitchPrivate::handleRelease(const QPointF &point, ulong timestamp)
{
    Q_Q(QQuickSwitch);
    QQuickAbstractButtonPrivate::handleRelease(point, timestamp);
    q->setKeepMouseGrab(false);
    q->setKeepTouchGrab(false);
    return true;
}
 
QQuickSwitch::QQuickSwitch(QQuickItem *parent)
    : QQuickAbstractButton(*(new QQuickSwitchPrivate), parent)
{
    Q_D(QQuickSwitch);
    d->keepPressed = true;
    setCheckable(true);
}
 
qreal QQuickSwitch::position() const
{
    Q_D(const QQuickSwitch);
    return d->position;
}
 
void QQuickSwitch::setPosition(qreal position)
{
    Q_D(QQuickSwitch);
    position = qBound<qreal>(0.0, position, 1.0);
    if (qFuzzyCompare(d->position, position))
        return;
 
    d->position = position;
    emit positionChanged();
    emit visualPositionChanged();
}
 
qreal QQuickSwitch::visualPosition() const
{
    Q_D(const QQuickSwitch);
    if (isMirrored())
        return 1.0 - d->position;
    return d->position;
}
 
void QQuickSwitch::mouseMoveEvent(QMouseEvent *event)
{
    Q_D(QQuickSwitch);
    if (!keepMouseGrab()) {
        const QPointF movePoint = event->position();
        if (d->canDrag(movePoint))
            setKeepMouseGrab(QQuickWindowPrivate::dragOverThreshold(movePoint.x() - d->pressPoint.x(), Qt::XAxis, event));
    }
    QQuickAbstractButton::mouseMoveEvent(event);
}
 
#if QT_CONFIG(quicktemplates2_multitouch)
void QQuickSwitch::touchEvent(QTouchEvent *event)
{
    Q_D(QQuickSwitch);
    if (!keepTouchGrab() && event->type() == QEvent::TouchUpdate) {
        for (const QTouchEvent::TouchPoint &point : event->points()) {
            if (point.id() != d->touchId || point.state() != QEventPoint::Updated)
                continue;
            if (d->canDrag(point.position()))
                setKeepTouchGrab(QQuickWindowPrivate::dragOverThreshold(point.position().x() - d->pressPoint.x(), Qt::XAxis, &point));
        }
    }
    QQuickAbstractButton::touchEvent(event);
}
#endif
 
void QQuickSwitch::mirrorChange()
{
    QQuickAbstractButton::mirrorChange();
    emit visualPositionChanged();
}
 
void QQuickSwitch::nextCheckState()
{
    Q_D(QQuickSwitch);
    if (keepMouseGrab() || keepTouchGrab()) {
        d->toggle(d->position > 0.5);
        // the checked state might not change => force a position update to
        // avoid that the handle is left somewhere in the middle (QTBUG-57944)
        setPosition(d->checked ? 1.0 : 0.0);
    } else {
        QQuickAbstractButton::nextCheckState();
    }
}
 
void QQuickSwitch::buttonChange(ButtonChange change)
{
    Q_D(QQuickSwitch);
    if (change == ButtonCheckedChange)
        setPosition(d->checked ? 1.0 : 0.0);
    else
        QQuickAbstractButton::buttonChange(change);
}
 
QFont QQuickSwitch::defaultFont() const
{
    return QQuickTheme::font(QQuickTheme::Switch);
}
 
QT_END_NAMESPACE
 
#include "moc_qquickswitch_p.cpp"