qcheckbox.cpp

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// Copyright (C) 2016 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 "qcheckbox.h"
#include "qapplication.h"
#include "qbitmap.h"
#include "qicon.h"
#include "qstylepainter.h"
#include "qstyle.h"
#include "qstyleoption.h"
#include "qevent.h"
#if QT_CONFIG(accessibility)
#include "qaccessible.h"
#endif
 
#include "private/qabstractbutton_p.h"
 
QT_BEGIN_NAMESPACE
 
class QCheckBoxPrivate : public QAbstractButtonPrivate
{
    Q_DECLARE_PUBLIC(QCheckBox)
public:
    QCheckBoxPrivate()
        : QAbstractButtonPrivate(QSizePolicy::CheckBox), tristate(false), noChange(false),
          hovering(true), publishedState(Qt::Unchecked) {}
 
    uint tristate : 1;
    uint noChange : 1;
    uint hovering : 1;
    Qt::CheckState publishedState : 2;
 
    void init();
};
 
 
void QCheckBoxPrivate::init()
{
    Q_Q(QCheckBox);
    q->setCheckable(true);
    q->setMouseTracking(true);
    q->setForegroundRole(QPalette::WindowText);
    q->setAttribute(Qt::WA_MacShowFocusRect);
    setLayoutItemMargins(QStyle::SE_CheckBoxLayoutItem);
}
 
void QCheckBox::initStyleOption(QStyleOptionButton *option) const
{
    if (!option)
        return;
    Q_D(const QCheckBox);
    option->initFrom(this);
    if (d->down)
        option->state |= QStyle::State_Sunken;
    if (d->tristate && d->noChange)
        option->state |= QStyle::State_NoChange;
    else
        option->state |= d->checked ? QStyle::State_On : QStyle::State_Off;
    if (testAttribute(Qt::WA_Hover) && underMouse()) {
        option->state.setFlag(QStyle::State_MouseOver, d->hovering);
    }
    option->text = d->text;
    option->icon = d->icon;
    option->iconSize = iconSize();
}
 
QCheckBox::QCheckBox(QWidget *parent)
    : QAbstractButton (*new QCheckBoxPrivate, parent)
{
    Q_D(QCheckBox);
    d->init();
}
 
QCheckBox::QCheckBox(const QString &text, QWidget *parent)
    : QCheckBox(parent)
{
    setText(text);
}
 
QCheckBox::~QCheckBox()
{
}
 
void QCheckBox::setTristate(bool y)
{
    Q_D(QCheckBox);
    d->tristate = y;
}
 
bool QCheckBox::isTristate() const
{
    Q_D(const QCheckBox);
    return d->tristate;
}
 
 
Qt::CheckState QCheckBox::checkState() const
{
    Q_D(const QCheckBox);
    if (d->tristate &&  d->noChange)
        return Qt::PartiallyChecked;
    return d->checked ? Qt::Checked : Qt::Unchecked;
}
 
void QCheckBox::setCheckState(Qt::CheckState state)
{
    Q_D(QCheckBox);
#if QT_CONFIG(accessibility)
    bool noChange = d->noChange;
#endif
    if (state == Qt::PartiallyChecked) {
        d->tristate = true;
        d->noChange = true;
    } else {
        d->noChange = false;
    }
    d->blockRefresh = true;
    setChecked(state != Qt::Unchecked);
    d->blockRefresh = false;
    d->refresh();
    if (state != d->publishedState) {
        d->publishedState = state;
        emit stateChanged(state);
    }
 
#if QT_CONFIG(accessibility)
    if (noChange != d->noChange) {
        QAccessible::State s;
        s.checkStateMixed = true;
        QAccessibleStateChangeEvent event(this, s);
        QAccessible::updateAccessibility(&event);
    }
#endif
}
 
 
QSize QCheckBox::sizeHint() const
{
    Q_D(const QCheckBox);
    if (d->sizeHint.isValid())
        return d->sizeHint;
    ensurePolished();
    QFontMetrics fm = fontMetrics();
    QStyleOptionButton opt;
    initStyleOption(&opt);
    QSize sz = style()->itemTextRect(fm, QRect(), Qt::TextShowMnemonic, false,
                                     text()).size();
    if (!opt.icon.isNull())
        sz = QSize(sz.width() + opt.iconSize.width() + 4, qMax(sz.height(), opt.iconSize.height()));
    d->sizeHint = style()->sizeFromContents(QStyle::CT_CheckBox, &opt, sz, this);
    return d->sizeHint;
}
 
 
QSize QCheckBox::minimumSizeHint() const
{
    return sizeHint();
}
 
void QCheckBox::paintEvent(QPaintEvent *)
{
    QStylePainter p(this);
    QStyleOptionButton opt;
    initStyleOption(&opt);
    p.drawControl(QStyle::CE_CheckBox, opt);
}
 
void QCheckBox::mouseMoveEvent(QMouseEvent *e)
{
    Q_D(QCheckBox);
    if (testAttribute(Qt::WA_Hover)) {
        bool hit = false;
        if (underMouse())
            hit = hitButton(e->position().toPoint());
 
        if (hit != d->hovering) {
            update(rect());
            d->hovering = hit;
        }
    }
 
    QAbstractButton::mouseMoveEvent(e);
}
 
 
bool QCheckBox::hitButton(const QPoint &pos) const
{
    QStyleOptionButton opt;
    initStyleOption(&opt);
    return style()->subElementRect(QStyle::SE_CheckBoxClickRect, &opt, this).contains(pos);
}
 
void QCheckBox::checkStateSet()
{
    Q_D(QCheckBox);
    d->noChange = false;
    Qt::CheckState state = checkState();
    if (state != d->publishedState) {
        d->publishedState = state;
        emit stateChanged(state);
    }
}
 
void QCheckBox::nextCheckState()
{
    Q_D(QCheckBox);
    if (d->tristate)
        setCheckState((Qt::CheckState)((checkState() + 1) % 3));
    else {
        QAbstractButton::nextCheckState();
        QCheckBox::checkStateSet();
    }
}
 
bool QCheckBox::event(QEvent *e)
{
    Q_D(QCheckBox);
    if (e->type() == QEvent::StyleChange
#ifdef Q_OS_MAC
            || e->type() == QEvent::MacSizeChange
#endif
            )
        d->setLayoutItemMargins(QStyle::SE_CheckBoxLayoutItem);
    return QAbstractButton::event(e);
}
 
 
 
QT_END_NAMESPACE
 
#include "moc_qcheckbox.cpp"