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**
** Copyright (C) 2017 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 "qquickcheckbox_p.h"
#include "qquickabstractbutton_p_p.h"

#include <QtGui/qpa/qplatformtheme.h>

QT_BEGIN_NAMESPACE

/*!
    \qmltype CheckBox
    \inherits AbstractButton
    \instantiates QQuickCheckBox
    \inqmlmodule QtQuick.Controls
    \since 5.7
    \ingroup qtquickcontrols2-buttons
    \brief Check button that can be toggled on or off.

    \image qtquickcontrols2-checkbox.gif

    CheckBox presents an option button that can be toggled on (checked) or
    off (unchecked). Check boxes are typically used to select one or more
    options from a set of options. For larger sets of options, such as those
    in a list, consider using \l CheckDelegate instead.

    CheckBox inherits its API from \l AbstractButton. For instance, the
    state of the checkbox can be set with the \l {AbstractButton::}{checked} property.

    In addition to the checked and unchecked states, there is a third state:
    partially checked. The partially checked state can be enabled using the
    \l tristate property. This state indicates that the regular checked/unchecked
    state can not be determined; generally because of other states that affect
    the checkbox. This state is useful when several child nodes are selected
    in a treeview, for example.

    \code
    ColumnLayout {
        CheckBox {
            checked: true
            text: qsTr("First")
        }
        CheckBox {
            text: qsTr("Second")
        }
        CheckBox {
            checked: true
            text: qsTr("Third")
        }
    }
    \endcode

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

class QQuickCheckBoxPrivate : public QQuickAbstractButtonPrivate
{
    Q_DECLARE_PUBLIC(QQuickCheckBox)

public:
    QQuickCheckBoxPrivate()
        : tristate(false),
          checkState(Qt::Unchecked)
    {
    }

    bool tristate;
    Qt::CheckState checkState;
};

QQuickCheckBox::QQuickCheckBox(QQuickItem *parent)
    : QQuickAbstractButton(*(new QQuickCheckBoxPrivate), parent)
{
    setCheckable(true);
}

/*!
    \qmlproperty bool QtQuick.Controls::CheckBox::tristate

    This property holds whether the checkbox is a tri-state checkbox.

    In the animation below, the first checkbox is tri-state:

    \image qtquickcontrols2-checkbox-tristate.gif

    The default is \c false, i.e., the checkbox has only two states.
*/
bool QQuickCheckBox::isTristate() const
{
    Q_D(const QQuickCheckBox);
    return d->tristate;
}

void QQuickCheckBox::setTristate(bool tristate)
{
    Q_D(QQuickCheckBox);
    if (d->tristate == tristate)
        return;

    d->tristate = tristate;
    emit tristateChanged();
}

/*!
    \qmlproperty enumeration QtQuick.Controls::CheckBox::checkState

    This property holds the check state of the checkbox.

    Available states:
    \value Qt.Unchecked The checkbox is unchecked.
    \value Qt.PartiallyChecked The checkbox is partially checked. This state is only used when \l tristate is enabled.
    \value Qt.Checked The checkbox is checked.

    \sa tristate, {AbstractButton::checked}{checked}
*/
Qt::CheckState QQuickCheckBox::checkState() const
{
    Q_D(const QQuickCheckBox);
    return d->checkState;
}

void QQuickCheckBox::setCheckState(Qt::CheckState state)
{
    Q_D(QQuickCheckBox);
    if (d->checkState == state)
        return;

    if (!d->tristate && state == Qt::PartiallyChecked)
        setTristate(true);

    bool wasChecked = isChecked();
    d->checked = state != Qt::Unchecked;
    d->checkState = state;
    emit checkStateChanged();
    if (d->checked != wasChecked)
        emit checkedChanged();
}

QFont QQuickCheckBox::defaultFont() const
{
    return QQuickControlPrivate::themeFont(QPlatformTheme::CheckBoxFont);
}

void QQuickCheckBox::buttonChange(ButtonChange change)
{
    if (change == ButtonCheckedChange)
        setCheckState(isChecked() ? Qt::Checked : Qt::Unchecked);
    else
        QQuickAbstractButton::buttonChange(change);
}

void QQuickCheckBox::nextCheckState()
{
    Q_D(QQuickCheckBox);
    if (d->tristate)
        setCheckState(static_cast<Qt::CheckState>((d->checkState + 1) % 3));
    else
        QQuickAbstractButton::nextCheckState();
}

#if QT_CONFIG(accessibility)
QAccessible::Role QQuickCheckBox::accessibleRole() const
{
    return QAccessible::CheckBox;
}
#endif

QT_END_NAMESPACE
