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**
** Copyright (C) 2016 The Qt Company Ltd.
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** This file is part of the Qt Quick Templates 2 module of the Qt Toolkit.
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****************************************************************************/

#include "qquickswitch_p.h"
#include "qquickabstractbutton_p_p.h"

#include <QtQuick/private/qquickwindow_p.h>
#include <QtQuick/private/qquickevents_p_p.h>

QT_BEGIN_NAMESPACE

/*!
    \qmltype Switch
    \inherits AbstractButton
    \instantiates QQuickSwitch
    \inqmlmodule QtQuick.Controls
    \since 5.7
    \ingroup qtquickcontrols2-buttons
    \brief An option button that can be toggled on or off.

    \image qtquickcontrols2-switch.gif

    Switch is an option button that can be dragged or toggled on (checked) or
    off (unchecked). Switches are typically used to select between two states.

    \table
    \row \li \image qtquickcontrols2-switch-normal.png
         \li A switch in its normal state.
    \row \li \image qtquickcontrols2-switch-checked.png
         \li A switch that is checked.
    \row \li \image qtquickcontrols2-switch-focused.png
         \li A switch that has active focus.
    \row \li \image qtquickcontrols2-switch-disabled.png
         \li A switch that is disabled.
    \endtable

    \code
    ColumnLayout {
        Switch {
            text: qsTr("Wi-Fi")
        }
        Switch {
            text: qsTr("Bluetooth")
        }
    }
    \endcode

    \sa {Customizing Switch}, {Button Controls}
*/

class QQuickSwitchPrivate : public QQuickAbstractButtonPrivate
{
    Q_DECLARE_PUBLIC(QQuickSwitch)

public:
    QQuickSwitchPrivate() : position(0) { }

    void updatePosition();
    qreal positionAt(const QPoint &point) const;

    bool handleMousePressEvent(QQuickItem *child, QMouseEvent *event);
    bool handleMouseMoveEvent(QQuickItem *child, QMouseEvent *event);
    bool handleMouseReleaseEvent(QQuickItem *child, QMouseEvent *event);
    bool handleMouseUngrabEvent(QQuickItem *child);

    qreal position;
    QPoint pressPoint;
};

void QQuickSwitchPrivate::updatePosition()
{
    Q_Q(QQuickSwitch);
    q->setPosition(checked ? 1.0 : 0.0);
}

qreal QQuickSwitchPrivate::positionAt(const QPoint &point) const
{
    Q_Q(const QQuickSwitch);
    qreal pos = point.x() / indicator->width();
    if (q->isMirrored())
        return 1.0 - pos;
    return pos;
}

bool QQuickSwitchPrivate::handleMousePressEvent(QQuickItem *child, QMouseEvent *event)
{
    Q_Q(QQuickSwitch);
    Q_UNUSED(child);
    pressPoint = event->pos();
    q->setPressed(true);
    event->accept();
    return true;
}

bool QQuickSwitchPrivate::handleMouseMoveEvent(QQuickItem *child, QMouseEvent *event)
{
    Q_Q(QQuickSwitch);
    if (!child->keepMouseGrab())
        child->setKeepMouseGrab(QQuickWindowPrivate::dragOverThreshold(event->pos().x() - pressPoint.x(), Qt::XAxis, event));
    if (child->keepMouseGrab()) {
        q->setPosition(positionAt(event->pos()));
        event->accept();
    }
    return true;
}

bool QQuickSwitchPrivate::handleMouseReleaseEvent(QQuickItem *child, QMouseEvent *event)
{
    Q_Q(QQuickSwitch);
    pressPoint = QPoint();
    q->setPressed(false);
    if (child->keepMouseGrab()) {
        bool wasChecked = checked;
        q->setChecked(position > 0.5);
        q->setPosition(checked ? 1.0 : 0.0);
        child->setKeepMouseGrab(false);
        if (wasChecked != checked)
            emit q->clicked();
        event->accept();
    } else {
        q->toggle();
        emit q->clicked();
        event->accept();
    }
    return true;
}

bool QQuickSwitchPrivate::handleMouseUngrabEvent(QQuickItem *child)
{
    Q_Q(QQuickSwitch);
    Q_UNUSED(child);
    pressPoint = QPoint();
    q->setChecked(position > 0.5);
    q->setPosition(checked ? 1.0 : 0.0);
    q->setPressed(false);
    return true;
}

QQuickSwitch::QQuickSwitch(QQuickItem *parent) :
    QQuickAbstractButton(*(new QQuickSwitchPrivate), parent)
{
    setCheckable(true);
    setFiltersChildMouseEvents(true);
    QObjectPrivate::connect(this, &QQuickAbstractButton::checkedChanged, d_func(), &QQuickSwitchPrivate::updatePosition);
}

/*!
    \qmlproperty real QtQuick.Controls::Switch::position
    \readonly

    \input includes/qquickswitch.qdocinc position
*/
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();
}

/*!
    \qmlproperty real QtQuick.Controls::Switch::visualPosition
    \readonly

    \input includes/qquickswitch.qdocinc visualPosition
*/
qreal QQuickSwitch::visualPosition() const
{
    Q_D(const QQuickSwitch);
    if (isMirrored())
        return 1.0 - d->position;
    return d->position;
}

void QQuickSwitch::mirrorChange()
{
    QQuickAbstractButton::mirrorChange();
    emit visualPositionChanged();
}

bool QQuickSwitch::childMouseEventFilter(QQuickItem *child, QEvent *event)
{
    Q_D(QQuickSwitch);
    if (child == indicator()) {
        switch (event->type()) {
        case QEvent::MouseButtonPress:
            return d->handleMousePressEvent(child, static_cast<QMouseEvent *>(event));
        case QEvent::MouseMove:
            return d->handleMouseMoveEvent(child, static_cast<QMouseEvent *>(event));
        case QEvent::MouseButtonRelease:
            return d->handleMouseReleaseEvent(child, static_cast<QMouseEvent *>(event));
        case QEvent::UngrabMouse:
            return d->handleMouseUngrabEvent(child);
        default:
            return false;
        }
    }
    return false;
}

QT_END_NAMESPACE