qcombobox.cpp

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// Copyright (C) 2020 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
// Qt-Security score:significant reason:default
 
#include "qcombobox_p.h"
 
#include <qstylepainter.h>
#include <qpa/qplatformtheme.h>
#include <qpa/qplatformmenu.h>
#include <qpa/qplatformwindow.h>
#include <qpa/qplatformwindow_p.h>
 
#include <qlineedit.h>
#include <qapplication.h>
#include <qlistview.h>
#if QT_CONFIG(tableview)
#include <qtableview.h>
#endif
#include <qabstractitemdelegate.h>
#include <qmap.h>
#if QT_CONFIG(menu)
#include <qmenu.h>
#endif
#include <qevent.h>
#include <qlayout.h>
#include <qscrollbar.h>
#if QT_CONFIG(treeview)
#include <qtreeview.h>
#endif
#include <qheaderview.h>
#include <qmath.h>
#include <qmetaobject.h>
#if QT_CONFIG(proxymodel)
#include <qabstractproxymodel.h>
#endif
#include <qstylehints.h>
#include <private/qguiapplication_p.h>
#include <private/qhighdpiscaling_p.h>
#include <private/qapplication_p.h>
#include <private/qabstractitemmodel_p.h>
#include <private/qabstractscrollarea_p.h>
#include <private/qlineedit_p.h>
#if QT_CONFIG(completer)
#include <private/qcompleter_p.h>
#endif
#include <qdebug.h>
#if QT_CONFIG(effects)
# include <private/qeffects_p.h>
#endif
#include <private/qstyle_p.h>
 
#if QT_CONFIG(accessibility)
#include "qaccessible.h"
#endif
#include <QtWidgets/qstyleoption.h>
 
#include <QtGui/qstandarditemmodel.h>
#include <QtGui/qpainter.h>
 
#include <QtCore/qpointer.h>
 
#include <array>
#include <chrono>
 
QT_BEGIN_NAMESPACE
 
using namespace Qt::StringLiterals;
using namespace std::chrono_literals;
 
//
// QComboBoxListView
//
 
QComboBoxListView::QComboBoxListView(QComboBox *cmb) : combo(cmb)
{
    if (cmb)
        setScreen(cmb->screen());
}
 
QComboBoxListView::~QComboBoxListView()
    = default;
 
void QComboBoxListView::resizeEvent(QResizeEvent *event)
{
    resizeContents(viewport()->width(), contentsSize().height());
    QListView::resizeEvent(event);
}
 
void QComboBoxListView::initViewItemOption(QStyleOptionViewItem *option) const
{
    QListView::initViewItemOption(option);
    option->showDecorationSelected = true;
    if (combo)
        option->font = combo->font();
}
 
void QComboBoxListView::paintEvent(QPaintEvent *e)
{
    if (combo) {
        QStyleOptionComboBox opt;
        opt.initFrom(combo);
        opt.editable = combo->isEditable();
        if (combo->style()->styleHint(QStyle::SH_ComboBox_Popup, &opt, combo)) {
            //we paint the empty menu area to avoid having blank space that can happen when scrolling
            QStyleOptionMenuItem menuOpt;
            menuOpt.initFrom(this);
            menuOpt.palette = palette();
            menuOpt.state = QStyle::State_None;
            menuOpt.checkType = QStyleOptionMenuItem::NotCheckable;
            menuOpt.menuRect = e->rect();
            menuOpt.maxIconWidth = 0;
            menuOpt.reservedShortcutWidth = 0;
            QPainter p(viewport());
            combo->style()->drawControl(QStyle::CE_MenuEmptyArea, &menuOpt, &p, this);
        }
    }
    QListView::paintEvent(e);
}
 
//
// QComboBoxPrivateScroller
//
 
QComboBoxPrivateScroller::QComboBoxPrivateScroller(QAbstractSlider::SliderAction action,
                                                   QWidget *parent)
    : QWidget(parent),
      sliderAction(action)
{
    setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Fixed);
    setAttribute(Qt::WA_NoMousePropagation);
}
 
QComboBoxPrivateScroller::~QComboBoxPrivateScroller()
    = default;
 
QSize QComboBoxPrivateScroller::sizeHint() const
{
    return QSize(20, style()->pixelMetric(QStyle::PM_MenuScrollerHeight, nullptr, this));
}
 
void QComboBoxPrivateScroller::stopTimer()
{
    timer.stop();
}
 
void QComboBoxPrivateScroller::startTimer() {
    timer.start(100ms, this);
    fast = false;
}
 
void QComboBoxPrivateScroller::enterEvent(QEnterEvent *)
{
    startTimer();
}
 
void QComboBoxPrivateScroller::leaveEvent(QEvent *)
{
    stopTimer();
}
 
void QComboBoxPrivateScroller::timerEvent(QTimerEvent *e)
{
    if (e->matches(timer)) {
        emit doScroll(sliderAction);
        if (fast) {
            emit doScroll(sliderAction);
            emit doScroll(sliderAction);
        }
    }
}
 
void QComboBoxPrivateScroller::hideEvent(QHideEvent *)
{
    stopTimer();
}
 
void QComboBoxPrivateScroller::mouseMoveEvent(QMouseEvent *e)
{
    // Enable fast scrolling if the cursor is directly above or below the popup.
    const int mouseX = e->position().toPoint().x();
    const int mouseY = e->position().toPoint().y();
    const bool horizontallyInside = pos().x() < mouseX && mouseX < rect().right() + 1;
    const bool verticallyOutside = (sliderAction == QAbstractSlider::SliderSingleStepAdd) ?
                rect().bottom() + 1 < mouseY : mouseY < pos().y();
 
    fast = horizontallyInside && verticallyOutside;
}
 
void QComboBoxPrivateScroller::paintEvent(QPaintEvent *)
{
    QPainter p(this);
    QStyleOptionMenuItem menuOpt;
    menuOpt.initFrom(this);
    menuOpt.checkType = QStyleOptionMenuItem::NotCheckable;
    menuOpt.menuRect = rect();
    menuOpt.maxIconWidth = 0;
    menuOpt.reservedShortcutWidth = 0;
    menuOpt.menuItemType = QStyleOptionMenuItem::Scroller;
    if (sliderAction == QAbstractSlider::SliderSingleStepAdd)
        menuOpt.state |= QStyle::State_DownArrow;
    p.eraseRect(rect());
    style()->drawControl(QStyle::CE_MenuScroller, &menuOpt, &p);
}
 
QComboBoxPrivate::QComboBoxPrivate()
    : QWidgetPrivate(),
      shownOnce(false),
      duplicatesEnabled(false),
      frame(true),
      inserting(false),
      hidingPopup(false)
{
}
 
QComboBoxPrivate::~QComboBoxPrivate()
{
    disconnectModel();
#ifdef Q_OS_MACOS
    cleanupNativePopup();
#endif
}
 
//
// QComboMenuDelegate
//
 
QComboMenuDelegate::QComboMenuDelegate(QObject *parent, QComboBox *cmb)
    : QAbstractItemDelegate(parent), mCombo(cmb), pressedIndex(-1)
{
}
 
QComboMenuDelegate::~QComboMenuDelegate()
    = default;
 
void QComboMenuDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
                               const QModelIndex &index) const
{
    const QStyleOptionMenuItem opt = getStyleOption(option, index);
    painter->fillRect(option.rect, opt.palette.window());
    mCombo->style()->drawControl(QStyle::CE_MenuItem, &opt, painter, mCombo);
}
 
QSize QComboMenuDelegate::sizeHint(const QStyleOptionViewItem &option,
                                   const QModelIndex &index) const
{
    const QStyleOptionMenuItem opt = getStyleOption(option, index);
    return mCombo->style()->sizeFromContents(QStyle::CT_MenuItem, &opt,
                                             option.rect.size(), mCombo);
}
 
QStyleOptionMenuItem QComboMenuDelegate::getStyleOption(const QStyleOptionViewItem &option,
                                                        const QModelIndex &index) const
{
    QStyleOptionMenuItem menuOption;
 
    QPalette resolvedpalette = option.palette.resolve(QApplication::palette("QMenu"));
    QVariant value = index.data(Qt::ForegroundRole);
    if (value.canConvert<QBrush>()) {
        resolvedpalette.setBrush(QPalette::WindowText, qvariant_cast<QBrush>(value));
        resolvedpalette.setBrush(QPalette::ButtonText, qvariant_cast<QBrush>(value));
        resolvedpalette.setBrush(QPalette::Text, qvariant_cast<QBrush>(value));
    }
    menuOption.palette = resolvedpalette;
    menuOption.state = QStyle::State_None;
    if (mCombo->window()->isActiveWindow())
        menuOption.state = QStyle::State_Active;
    if ((option.state & QStyle::State_Enabled) && (index.model()->flags(index) & Qt::ItemIsEnabled))
        menuOption.state |= QStyle::State_Enabled;
    else
        menuOption.palette.setCurrentColorGroup(QPalette::Disabled);
    if (option.state & QStyle::State_Selected)
        menuOption.state |= QStyle::State_Selected;
    menuOption.checkType = QStyleOptionMenuItem::NonExclusive;
    // a valid checkstate means that the model has checkable items
    const QVariant checkState = index.data(Qt::CheckStateRole);
    if (!checkState.isValid()) {
        menuOption.checked = mCombo->currentIndex() == index.row();
    } else {
        menuOption.checked = qvariant_cast<int>(checkState) == Qt::Checked;
        menuOption.state |= qvariant_cast<int>(checkState) == Qt::Checked
                          ? QStyle::State_On : QStyle::State_Off;
    }
    if (QComboBoxDelegate::isSeparator(index))
        menuOption.menuItemType = QStyleOptionMenuItem::Separator;
    else
        menuOption.menuItemType = QStyleOptionMenuItem::Normal;
 
    const QVariant variant = index.data(Qt::DecorationRole);
    switch (variant.userType()) {
    case QMetaType::QIcon:
        menuOption.icon = qvariant_cast<QIcon>(variant);
        break;
    case QMetaType::QColor: {
        static QPixmap pixmap(option.decorationSize);
        pixmap.fill(qvariant_cast<QColor>(variant));
        menuOption.icon = pixmap;
        break; }
    default:
        menuOption.icon = qvariant_cast<QPixmap>(variant);
        break;
    }
    if (index.data(Qt::BackgroundRole).canConvert<QBrush>()) {
        menuOption.palette.setBrush(QPalette::All, QPalette::Window,
                                    qvariant_cast<QBrush>(index.data(Qt::BackgroundRole)));
    }
    menuOption.text = index.data(Qt::DisplayRole).toString().replace(u'&', "&&"_L1);
    menuOption.reservedShortcutWidth = 0;
    menuOption.maxIconWidth =  option.decorationSize.width() + 4;
    menuOption.menuRect = option.rect;
    menuOption.rect = option.rect;
 
    // Make sure fonts set on the model or on the combo box, in
    // that order, also override the font for the popup menu.
    QVariant fontRoleData = index.data(Qt::FontRole);
    if (fontRoleData.isValid()) {
        menuOption.font = qvariant_cast<QFont>(fontRoleData);
    } else if (mCombo->testAttribute(Qt::WA_SetFont)
            || mCombo->testAttribute(Qt::WA_MacSmallSize)
            || mCombo->testAttribute(Qt::WA_MacMiniSize)
            || mCombo->font() != qt_app_fonts_hash()->value("QComboBox", QFont())) {
        menuOption.font = mCombo->font();
    } else {
        menuOption.font = qt_app_fonts_hash()->value("QComboMenuItem", mCombo->font());
    }
 
    menuOption.fontMetrics = QFontMetrics(menuOption.font);
 
    return menuOption;
}
 
bool QComboMenuDelegate::editorEvent(QEvent *event, QAbstractItemModel *model,
                                     const QStyleOptionViewItem &option, const QModelIndex &index)
{
    Q_ASSERT(event);
    Q_ASSERT(model);
 
    // make sure that the item is checkable
    Qt::ItemFlags flags = model->flags(index);
    if (!(flags & Qt::ItemIsUserCheckable) || !(option.state & QStyle::State_Enabled)
        || !(flags & Qt::ItemIsEnabled))
        return false;
 
    // make sure that we have a check state
    const QVariant checkState = index.data(Qt::CheckStateRole);
    if (!checkState.isValid())
        return false;
 
    // make sure that we have the right event type
    if ((event->type() == QEvent::MouseButtonRelease)
        || (event->type() == QEvent::MouseButtonDblClick)
        || (event->type() == QEvent::MouseButtonPress)) {
        QMouseEvent *me = static_cast<QMouseEvent*>(event);
        if (me->button() != Qt::LeftButton)
            return false;
 
        if ((event->type() == QEvent::MouseButtonPress)
            || (event->type() == QEvent::MouseButtonDblClick)) {
            pressedIndex = index.row();
            return false;
        }
 
        if (index.row() != pressedIndex)
            return false;
        pressedIndex = -1;
 
    } else if (event->type() == QEvent::KeyPress) {
        if (static_cast<QKeyEvent*>(event)->key() != Qt::Key_Space
         && static_cast<QKeyEvent*>(event)->key() != Qt::Key_Select)
            return false;
    } else {
        return false;
    }
 
    // we don't support user-tristate items in QComboBox (not implemented in any style)
    Qt::CheckState newState = (static_cast<Qt::CheckState>(checkState.toInt()) == Qt::Checked)
                            ? Qt::Unchecked : Qt::Checked;
    return model->setData(index, newState, Qt::CheckStateRole);
}
 
//
// QComboBoxDelegate
//
 
QComboBoxDelegate::QComboBoxDelegate(QObject *parent, QComboBox *cmb)
    : QStyledItemDelegate(parent),
      mCombo(cmb)
{}
 
QComboBoxDelegate::~QComboBoxDelegate()
    = default;
 
bool QComboBoxDelegate::isSeparator(const QModelIndex &index)
{
    return index.data(Qt::AccessibleDescriptionRole).toString() == "separator"_L1;
}
 
void QComboBoxDelegate::setSeparator(QAbstractItemModel *model, const QModelIndex &index)
{
    // don't use u""_s; model (QtCore) may outlive QtWidgets DLL, alloc dynamically:
    static const QString sepString = "separator"_L1;
    model->setData(index, sepString, Qt::AccessibleDescriptionRole);
    if (QStandardItemModel *m = qobject_cast<QStandardItemModel*>(model))
        if (QStandardItem *item = m->itemFromIndex(index))
            item->setFlags(item->flags() & ~(Qt::ItemIsSelectable|Qt::ItemIsEnabled));
}
 
void QComboBoxDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
                              const QModelIndex &index) const
{
    if (isSeparator(index)) {
        QRect rect = option.rect;
        if (const QAbstractItemView *view = qobject_cast<const QAbstractItemView*>(option.widget))
            rect.setWidth(view->viewport()->width());
        QStyleOption opt;
        opt.rect = rect;
        mCombo->style()->drawPrimitive(QStyle::PE_IndicatorToolBarSeparator,
                                       &opt, painter, mCombo);
    } else {
        QStyledItemDelegate::paint(painter, option, index);
    }
}
 
QSize QComboBoxDelegate::sizeHint(const QStyleOptionViewItem &option,
                                  const QModelIndex &index) const
{
    if (isSeparator(index)) {
        const int pm = mCombo->style()->pixelMetric(QStyle::PM_DefaultFrameWidth, nullptr, mCombo);
        return QSize(pm, pm);
    }
    return QStyledItemDelegate::sizeHint(option, index);
}
 
 
#if QT_CONFIG(completer)
void QComboBoxPrivate::completerActivated(const QModelIndex &index)
{
    Q_Q(QComboBox);
#if QT_CONFIG(proxymodel)
    if (index.isValid() && q->completer()) {
        QAbstractProxyModel *proxy = qobject_cast<QAbstractProxyModel *>(q->completer()->completionModel());
        if (proxy) {
            const QModelIndex &completerIndex = proxy->mapToSource(index);
            int row = -1;
            if (completerIndex.model() == model) {
                row = completerIndex.row();
            } else {
                // if QCompleter uses a proxy model to host widget's one - map again
                QAbstractProxyModel *completerProxy = qobject_cast<QAbstractProxyModel *>(q->completer()->model());
                if (completerProxy && completerProxy->sourceModel() == model) {
                    row = completerProxy->mapToSource(completerIndex).row();
                } else {
                    QString match = q->completer()->model()->data(completerIndex).toString();
                    row = q->findText(match, matchFlags());
                }
            }
            q->setCurrentIndex(row);
            emitActivated(currentIndex);
        }
    }
#endif
}
#endif // QT_CONFIG(completer)
 
void QComboBoxPrivate::updateArrow(QStyle::StateFlag state)
{
    Q_Q(QComboBox);
    if (arrowState == state)
        return;
    arrowState = state;
    QStyleOptionComboBox opt;
    q->initStyleOption(&opt);
    q->update(q->rect());
}
 
void QComboBoxPrivate::modelReset()
{
    Q_Q(QComboBox);
    if (lineEdit) {
        lineEdit->setText(QString());
        updateLineEditGeometry();
    }
    trySetValidIndex();
    modelChanged();
    q->update();
}
 
void QComboBoxPrivate::modelDestroyed()
{
    model = QAbstractItemModelPrivate::staticEmptyModel();
}
 
void QComboBoxPrivate::trySetValidIndex()
{
    Q_Q(QComboBox);
    bool currentReset = false;
 
    const int rowCount = q->count();
    for (int pos = 0; pos < rowCount; ++pos) {
        const QModelIndex idx(model->index(pos, modelColumn, root));
        if (idx.flags() & Qt::ItemIsEnabled) {
            setCurrentIndex(idx);
            currentReset = true;
            break;
        }
    }
 
    if (!currentReset)
        setCurrentIndex(QModelIndex());
}
 
QRect QComboBoxPrivate::popupGeometry(const QPoint &globalPosition) const
{
    Q_Q(const QComboBox);
    return QStylePrivate::useFullScreenForPopup()
        ? QWidgetPrivate::screenGeometry(q, globalPosition)
        : QWidgetPrivate::availableScreenGeometry(q, globalPosition);
}
 
bool QComboBoxPrivate::updateHoverControl(const QPoint &pos)
{
 
    Q_Q(QComboBox);
    QRect lastHoverRect = hoverRect;
    QStyle::SubControl lastHoverControl = hoverControl;
    bool doesHover = q->testAttribute(Qt::WA_Hover);
    if (lastHoverControl != newHoverControl(pos) && doesHover) {
        q->update(lastHoverRect);
        q->update(hoverRect);
        return true;
    }
    return !doesHover;
}
 
QStyle::SubControl QComboBoxPrivate::newHoverControl(const QPoint &pos)
{
    Q_Q(QComboBox);
    QStyleOptionComboBox opt;
    q->initStyleOption(&opt);
    opt.subControls = QStyle::SC_All;
    hoverControl = q->style()->hitTestComplexControl(QStyle::CC_ComboBox, &opt, pos, q);
    hoverRect = (hoverControl != QStyle::SC_None)
                   ? q->style()->subControlRect(QStyle::CC_ComboBox, &opt, hoverControl, q)
                   : QRect();
    return hoverControl;
}
 
/*
    Computes a size hint based on the maximum width
    for the items in the combobox.
*/
int QComboBoxPrivate::computeWidthHint() const
{
    Q_Q(const QComboBox);
 
    int width = 0;
    const int count = q->count();
    const int iconWidth = q->iconSize().width() + 4;
    const QFontMetrics &fontMetrics = q->fontMetrics();
 
    for (int i = 0; i < count; ++i) {
        const int textWidth = fontMetrics.horizontalAdvance(q->itemText(i));
        if (q->itemIcon(i).isNull())
            width = (qMax(width, textWidth));
        else
            width = (qMax(width, textWidth + iconWidth));
    }
 
    QStyleOptionComboBox opt;
    q->initStyleOption(&opt);
    QSize tmp(width, 0);
    tmp = q->style()->sizeFromContents(QStyle::CT_ComboBox, &opt, tmp, q);
    return tmp.width();
}
 
QSize QComboBoxPrivate::recomputeSizeHint(QSize &sh) const
{
    Q_Q(const QComboBox);
    if (!sh.isValid()) {
        if (q->itemDelegate() && q->labelDrawingMode() == QComboBox::LabelDrawingMode::UseDelegate) {
            QStyleOptionViewItem option;
            initViewItemOption(&option);
            sh = q->itemDelegate()->sizeHint(option, currentIndex);
        }
 
        bool hasIcon = sizeAdjustPolicy == QComboBox::AdjustToMinimumContentsLengthWithIcon;
        int count = q->count();
        QSize iconSize = q->iconSize();
        const QFontMetrics &fm = q->fontMetrics();
 
        // text width
        if (&sh == &sizeHint || minimumContentsLength == 0) {
            switch (sizeAdjustPolicy) {
            case QComboBox::AdjustToContents:
            case QComboBox::AdjustToContentsOnFirstShow:
                if (count == 0) {
                    sh.rwidth() = 7 * fm.horizontalAdvance(u'x');
                } else {
                    for (int i = 0; i < count; ++i) {
                        if (!q->itemIcon(i).isNull()) {
                            hasIcon = true;
                            sh.setWidth(qMax(sh.width(), fm.boundingRect(q->itemText(i)).width() + iconSize.width() + 4));
                        } else {
                            sh.setWidth(qMax(sh.width(), fm.boundingRect(q->itemText(i)).width()));
                        }
                    }
                }
                break;
            case QComboBox::AdjustToMinimumContentsLengthWithIcon:
                ;
            }
        } else {
            for (int i = 0; i < count && !hasIcon; ++i)
                hasIcon = !q->itemIcon(i).isNull();
        }
        if (minimumContentsLength > 0) {
            auto r = qint64{minimumContentsLength} * fm.horizontalAdvance(u'X');
            if (hasIcon)
                r += iconSize.width() + 4;
            if (r <= QWIDGETSIZE_MAX) {
                sh.setWidth(qMax(sh.width(), int(r)));
            } else {
                qWarning("QComboBox: cannot take minimumContentsLength %d into account for sizeHint(), "
                         "since it causes the widget to be wider than QWIDGETSIZE_MAX. "
                         "Consider setting it to a less extreme value.",
                         minimumContentsLength);
            }
        }
        if (!placeholderText.isEmpty())
            sh.setWidth(qMax(sh.width(), fm.boundingRect(placeholderText).width()));
 
 
        // height
        sh.setHeight(qMax(qCeil(QFontMetricsF(fm).height()), 14) + 2);
        if (hasIcon) {
            sh.setHeight(qMax(sh.height(), iconSize.height() + 2));
        }
 
        // add style and strut values
        QStyleOptionComboBox opt;
        q->initStyleOption(&opt);
        sh = q->style()->sizeFromContents(QStyle::CT_ComboBox, &opt, sh, q);
    }
    return sh;
}
 
void QComboBoxPrivate::adjustComboBoxSize()
{
    viewContainer()->adjustSizeTimer.start(20, container);
}
 
void QComboBoxPrivate::updateLayoutDirection()
{
    Q_Q(const QComboBox);
    QStyleOptionComboBox opt;
    q->initStyleOption(&opt);
    Qt::LayoutDirection dir = Qt::LayoutDirection(
        q->style()->styleHint(QStyle::SH_ComboBox_LayoutDirection, &opt, q));
    if (lineEdit)
        lineEdit->setLayoutDirection(dir);
    if (container)
        container->setLayoutDirection(dir);
}
 
 
void QComboBoxPrivateContainer::timerEvent(QTimerEvent *timerEvent)
{
    if (timerEvent->timerId() == adjustSizeTimer.timerId()) {
        adjustSizeTimer.stop();
        if (combo->sizeAdjustPolicy() == QComboBox::AdjustToContents) {
            combo->updateGeometry();
            combo->adjustSize();
            combo->update();
        }
    }
}
 
void QComboBoxPrivateContainer::resizeEvent(QResizeEvent *e)
{
    QStyleOptionComboBox opt = comboStyleOption();
    if (combo->style()->styleHint(QStyle::SH_ComboBox_Popup, &opt, combo)) {
        QStyleOption myOpt;
        myOpt.initFrom(this);
        QStyleHintReturnMask mask;
        if (combo->style()->styleHint(QStyle::SH_Menu_Mask, &myOpt, this, &mask)) {
            setMask(mask.region);
        }
    } else {
        clearMask();
    }
    QFrame::resizeEvent(e);
}
 
void QComboBoxPrivateContainer::paintEvent(QPaintEvent *e)
{
    QStyleOptionComboBox cbOpt = comboStyleOption();
    if (combo->style()->styleHint(QStyle::SH_ComboBox_Popup, &cbOpt, combo)
            && mask().isEmpty()) {
        QStyleOption opt;
        opt.initFrom(this);
        QPainter p(this);
        style()->drawPrimitive(QStyle::PE_PanelMenu, &opt, &p, this);
    }
 
    QFrame::paintEvent(e);
}
 
QComboBoxPrivateContainer::QComboBoxPrivateContainer(QAbstractItemView *itemView, QComboBox *parent)
    : QFrame(parent, Qt::Popup), combo(parent)
{
    // we need the combobox and itemview
    Q_ASSERT(parent);
    Q_ASSERT(itemView);
 
    setAttribute(Qt::WA_WindowPropagation);
    setAttribute(Qt::WA_X11NetWmWindowTypeCombo);
 
    // setup container
    blockMouseReleaseTimer.setSingleShot(true);
 
    // we need a vertical layout
    QBoxLayout *layout =  new QBoxLayout(QBoxLayout::TopToBottom, this);
    layout->setSpacing(0);
    layout->setContentsMargins(QMargins());
 
    // set item view
    setItemView(itemView);
 
    // add scroller arrows if style needs them
    QStyleOptionComboBox opt = comboStyleOption();
    const bool usePopup = combo->style()->styleHint(QStyle::SH_ComboBox_Popup, &opt, combo);
    if (usePopup) {
        top = new QComboBoxPrivateScroller(QAbstractSlider::SliderSingleStepSub, this);
        bottom = new QComboBoxPrivateScroller(QAbstractSlider::SliderSingleStepAdd, this);
        top->hide();
        bottom->hide();
    } else {
        setLineWidth(1);
    }
 
    if (top) {
        layout->insertWidget(0, top);
        connect(top, &QComboBoxPrivateScroller::doScroll,
                this, &QComboBoxPrivateContainer::scrollItemView);
    }
    if (bottom) {
        layout->addWidget(bottom);
        connect(bottom, &QComboBoxPrivateScroller::doScroll,
                this, &QComboBoxPrivateContainer::scrollItemView);
    }
 
    // Some styles (Mac) have a margin at the top and bottom of the popup.
    layout->insertSpacing(0, 0);
    layout->addSpacing(0);
    updateStyleSettings();
}
 
QComboBoxPrivateContainer::~QComboBoxPrivateContainer()
{
    disconnect(view, &QAbstractItemView::destroyed,
               this, &QComboBoxPrivateContainer::viewDestroyed);
}
 
void QComboBoxPrivateContainer::scrollItemView(int action)
{
#if QT_CONFIG(scrollbar)
    if (view->verticalScrollBar())
        view->verticalScrollBar()->triggerAction(static_cast<QAbstractSlider::SliderAction>(action));
#endif
}
 
void QComboBoxPrivateContainer::hideScrollers()
{
    if (top)
        top->hide();
    if (bottom)
        bottom->hide();
}
 
/*
    Hides or shows the scrollers when we emulate a popupmenu
*/
void QComboBoxPrivateContainer::updateScrollers()
{
#if QT_CONFIG(scrollbar)
    if (!top || !bottom)
        return;
 
    if (isVisible() == false)
        return;
 
    QStyleOptionComboBox opt = comboStyleOption();
    if (combo->style()->styleHint(QStyle::SH_ComboBox_Popup, &opt, combo) &&
        view->verticalScrollBar()->minimum() < view->verticalScrollBar()->maximum()) {
 
        bool needTop = view->verticalScrollBar()->value()
                       > (view->verticalScrollBar()->minimum() + topMargin());
        bool needBottom = view->verticalScrollBar()->value()
                          < (view->verticalScrollBar()->maximum() - bottomMargin() - topMargin());
        if (needTop)
            top->show();
        else
            top->hide();
        if (needBottom)
            bottom->show();
        else
            bottom->hide();
    } else {
        top->hide();
        bottom->hide();
    }
#endif // QT_CONFIG(scrollbar)
}
 
/*
    Cleans up when the view is destroyed.
*/
void QComboBoxPrivateContainer::viewDestroyed()
{
    view = nullptr;
    setItemView(new QComboBoxListView());
}
 
/*
    Returns the item view used for the combobox popup.
*/
QAbstractItemView *QComboBoxPrivateContainer::itemView() const
{
    return view;
}
 
/*!
    \class QComboBoxPrivateContainer
    \inmodule QtWidgets
    \internal
*/
 
/*!
    Sets the item view to be used for the combobox popup.
*/
void QComboBoxPrivateContainer::setItemView(QAbstractItemView *itemView)
{
    Q_ASSERT(itemView);
 
    // clean up old one
    if (view) {
        view->removeEventFilter(this);
        view->viewport()->removeEventFilter(this);
#if QT_CONFIG(scrollbar)
        disconnect(view->verticalScrollBar(), &QScrollBar::valueChanged,
                   this, &QComboBoxPrivateContainer::updateScrollers);
        disconnect(view->verticalScrollBar(), &QScrollBar::rangeChanged,
                   this, &QComboBoxPrivateContainer::updateScrollers);
#endif
        disconnect(view, &QAbstractItemView::destroyed,
                   this, &QComboBoxPrivateContainer::viewDestroyed);
 
        if (isAncestorOf(view))
            delete view;
        view = nullptr;
    }
 
    // setup the item view
    view = itemView;
    view->setParent(this);
    view->setAttribute(Qt::WA_MacShowFocusRect, false);
    qobject_cast<QBoxLayout*>(layout())->insertWidget(top ? 2 : 0, view);
    view->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored);
    view->installEventFilter(this);
    view->viewport()->installEventFilter(this);
    view->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    QStyleOptionComboBox opt = comboStyleOption();
    const auto *style = combo->style();
    const bool usePopup = style->styleHint(QStyle::SH_ComboBox_Popup, &opt, combo);
#if QT_CONFIG(scrollbar)
    if (usePopup)
        view->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
#endif
    if (usePopup ||
        style->styleHint(QStyle::SH_ComboBox_ListMouseTracking_Current, &opt, combo) ||
        style->styleHint(QStyle::SH_ComboBox_ListMouseTracking_Active, &opt, combo)
        ) {
        view->setMouseTracking(true);
    }
    view->setSelectionMode(QAbstractItemView::SingleSelection);
    view->setFrameStyle(QFrame::NoFrame);
    view->setLineWidth(0);
    view->setEditTriggers(QAbstractItemView::NoEditTriggers);
#if QT_CONFIG(scrollbar)
    connect(view->verticalScrollBar(), &QScrollBar::valueChanged,
            this, &QComboBoxPrivateContainer::updateScrollers);
    connect(view->verticalScrollBar(), &QScrollBar::rangeChanged,
            this, &QComboBoxPrivateContainer::updateScrollers);
#endif
    connect(view, &QAbstractItemView::destroyed,
            this, &QComboBoxPrivateContainer::viewDestroyed);
}
 
/*!
    Returns the top/bottom vertical margin of the view.
*/
int QComboBoxPrivateContainer::topMargin() const
{
    if (const QListView *lview = qobject_cast<const QListView*>(view))
        return lview->spacing();
#if QT_CONFIG(tableview)
    if (const QTableView *tview = qobject_cast<const QTableView*>(view))
        return tview->showGrid() ? 1 : 0;
#endif
    return 0;
}
 
/*!
    Returns the spacing between the items in the view.
*/
int QComboBoxPrivateContainer::spacing() const
{
    QListView *lview = qobject_cast<QListView*>(view);
    if (lview)
        return 2 * lview->spacing(); // QListView::spacing is the padding around the item.
#if QT_CONFIG(tableview)
    QTableView *tview = qobject_cast<QTableView*>(view);
    if (tview)
        return tview->showGrid() ? 1 : 0;
#endif
    return 0;
}
 
void QComboBoxPrivateContainer::updateTopBottomMargin()
{
    if (!layout() || layout()->count() < 1)
        return;
 
    QBoxLayout *boxLayout = qobject_cast<QBoxLayout *>(layout());
    if (!boxLayout)
        return;
 
    const QStyleOptionComboBox opt = comboStyleOption();
    const auto *style = combo->style();
    const bool usePopup = style->styleHint(QStyle::SH_ComboBox_Popup, &opt, combo);
    const int margin = usePopup ? style->pixelMetric(QStyle::PM_MenuVMargin, &opt, combo) : 0;
 
    QSpacerItem *topSpacer = boxLayout->itemAt(0)->spacerItem();
    if (topSpacer)
        topSpacer->changeSize(0, margin, QSizePolicy::Minimum, QSizePolicy::Fixed);
 
    QSpacerItem *bottomSpacer = boxLayout->itemAt(boxLayout->count() - 1)->spacerItem();
    if (bottomSpacer && bottomSpacer != topSpacer)
        bottomSpacer->changeSize(0, margin, QSizePolicy::Minimum, QSizePolicy::Fixed);
 
    boxLayout->invalidate();
}
 
void QComboBoxPrivateContainer::updateStyleSettings()
{
    // add scroller arrows if style needs them
    QStyleOptionComboBox opt = comboStyleOption();
    const auto *style = combo->style();
    view->setMouseTracking(style->styleHint(QStyle::SH_ComboBox_ListMouseTracking_Current, &opt, combo) ||
                           style->styleHint(QStyle::SH_ComboBox_ListMouseTracking_Active, &opt, combo) ||
                           style->styleHint(QStyle::SH_ComboBox_Popup, &opt, combo));
    setFrameStyle(style->styleHint(QStyle::SH_ComboBox_PopupFrameStyle, &opt, combo));
    updateTopBottomMargin();
}
 
void QComboBoxPrivateContainer::changeEvent(QEvent *e)
{
    if (e->type() == QEvent::StyleChange)
        updateStyleSettings();
 
    QFrame::changeEvent(e);
}
 
 
bool QComboBoxPrivateContainer::eventFilter(QObject *o, QEvent *e)
{
    switch (e->type()) {
    case QEvent::ShortcutOverride: {
        QKeyEvent *keyEvent = static_cast<QKeyEvent*>(e);
        switch (keyEvent->key()) {
        case Qt::Key_Enter:
        case Qt::Key_Return:
            if (view->currentIndex().isValid() && view->currentIndex().flags().testFlag(Qt::ItemIsEnabled)) {
                combo->hidePopup();
                keyEvent->accept();
                emit itemSelected(view->currentIndex());
            }
            return true;
        case Qt::Key_Down:
            if (!(keyEvent->modifiers() & Qt::AltModifier))
                break;
            Q_FALLTHROUGH();
        case Qt::Key_F4:
            combo->hidePopup();
            keyEvent->accept();
            emit itemSelected(view->currentIndex());
            return true;
        default:
#if QT_CONFIG(shortcut)
            if (keyEvent->matches(QKeySequence::Cancel) && isVisible()) {
                keyEvent->accept();
                return true;
            }
#endif
            break;
        }
        break;
    }
    case QEvent::MouseMove:
        if (isVisible()) {
            QMouseEvent *m = static_cast<QMouseEvent *>(e);
            QWidget *widget = static_cast<QWidget *>(o);
            const QPointF vector = widget->mapToGlobal(m->position()) - initialClickPosition;
            if (vector.manhattanLength() > 9 && blockMouseReleaseTimer.isActive())
                blockMouseReleaseTimer.stop();
            if (combo->style()->styleHint(QStyle::SH_ComboBox_ListMouseTracking_Current, nullptr, combo)) {
                QModelIndex indexUnderMouse = view->indexAt(m->position().toPoint());
                if (indexUnderMouse.isValid()
                         && !QComboBoxDelegate::isSeparator(indexUnderMouse)) {
                    view->setCurrentIndex(indexUnderMouse);
                }
            }
        }
        break;
    case QEvent::MouseButtonPress:
        maybeIgnoreMouseButtonRelease = false;
        break;
    case QEvent::MouseButtonRelease: {
        bool ignoreEvent = maybeIgnoreMouseButtonRelease && popupTimer.elapsed() < QApplication::doubleClickInterval();
 
        QMouseEvent *m = static_cast<QMouseEvent *>(e);
        if (isVisible() && view->rect().contains(m->position().toPoint()) && view->currentIndex().isValid()
            && !blockMouseReleaseTimer.isActive() && !ignoreEvent
            && (view->currentIndex().flags().testFlag(Qt::ItemIsEnabled))
            && (view->currentIndex().flags().testFlag(Qt::ItemIsSelectable))) {
            combo->hidePopup();
            emit itemSelected(view->currentIndex());
            return true;
        }
        break;
    }
    default:
        break;
    }
    return QFrame::eventFilter(o, e);
}
 
void QComboBoxPrivateContainer::showEvent(QShowEvent *)
{
    combo->update();
}
 
void QComboBoxPrivateContainer::hideEvent(QHideEvent *)
{
    emit resetButton();
    combo->update();
#if QT_CONFIG(graphicsview)
    // QGraphicsScenePrivate::removePopup closes the combo box popup, it hides it non-explicitly.
    // Hiding/showing the QComboBox after this will unexpectedly show the popup as well.
    // Re-hiding the popup container makes sure it is explicitly hidden.
    if (QGraphicsProxyWidget *proxy = graphicsProxyWidget())
        proxy->hide();
#endif
}
 
void QComboBoxPrivateContainer::mousePressEvent(QMouseEvent *e)
{
 
    QStyleOptionComboBox opt = comboStyleOption();
    opt.subControls = QStyle::SC_All;
    opt.activeSubControls = QStyle::SC_ComboBoxArrow;
    QStyle::SubControl sc = combo->style()->hitTestComplexControl(QStyle::CC_ComboBox, &opt,
                                                           combo->mapFromGlobal(e->globalPosition()).toPoint(),
                                                           combo);
    if ((combo->isEditable() && sc == QStyle::SC_ComboBoxArrow)
        || (!combo->isEditable() && sc != QStyle::SC_None))
        setAttribute(Qt::WA_NoMouseReplay);
    combo->hidePopup();
}
 
void QComboBoxPrivateContainer::mouseReleaseEvent(QMouseEvent *e)
{
    Q_UNUSED(e);
    if (!blockMouseReleaseTimer.isActive()) {
        combo->hidePopup();
        emit resetButton();
    }
}
 
QStyleOptionComboBox QComboBoxPrivateContainer::comboStyleOption() const
{
    // ### This should use QComboBox's initStyleOption(), but it's protected
    // perhaps, we could cheat by having the QCombo private instead?
    QStyleOptionComboBox opt;
    opt.initFrom(combo);
    opt.subControls = QStyle::SC_All;
    opt.activeSubControls = QStyle::SC_None;
    opt.editable = combo->isEditable();
    return opt;
}
 
/*!
    \enum QComboBox::InsertPolicy
 
    This enum specifies what the QComboBox should do when a new string is
    entered by the user.
 
    \value NoInsert             The string will not be inserted into the combobox.
    \value InsertAtTop          The string will be inserted as the first item in the combobox.
    \value InsertAtCurrent      The current item will be \e replaced by the string.
    \value InsertAtBottom       The string will be inserted after the last item in the combobox.
    \value InsertAfterCurrent   The string is inserted after the current item in the combobox.
    \value InsertBeforeCurrent  The string is inserted before the current item in the combobox.
    \value InsertAlphabetically The string is inserted in the alphabetic order in the combobox.
*/
 
/*!
    \enum QComboBox::SizeAdjustPolicy
 
    This enum specifies how the size hint of the QComboBox should
    adjust when new content is added or content changes.
 
    \value AdjustToContents              The combobox will always adjust to the contents
    \value AdjustToContentsOnFirstShow   The combobox will adjust to its contents the first time it is shown.
    \value AdjustToMinimumContentsLengthWithIcon The combobox will adjust to \l minimumContentsLength plus space for an icon.
                                         For performance reasons use this policy on large models.
*/
 
/*!
    \fn void QComboBox::activated(int index)
 
    This signal is sent when the user chooses an item in the combobox.
    The item's \a index is passed. Note that this signal is sent even
    when the choice is not changed. If you need to know when the
    choice actually changes, use signal currentIndexChanged() or
    currentTextChanged().
*/
 
/*!
    \fn void QComboBox::textActivated(const QString &text)
    \since 5.14
 
    This signal is sent when the user chooses an item in the combobox.
    The item's \a text is passed. Note that this signal is sent even
    when the choice is not changed. If you need to know when the
    choice actually changes, use signal currentIndexChanged() or
    currentTextChanged().
*/
 
/*!
    \fn void QComboBox::highlighted(int index)
 
    This signal is sent when an item in the combobox popup list is
    highlighted by the user. The item's \a index is passed.
*/
 
/*!
    \fn void QComboBox::textHighlighted(const QString &text)
    \since 5.14
 
    This signal is sent when an item in the combobox popup list is
    highlighted by the user. The item's \a text is passed.
*/
 
/*!
    \fn void QComboBox::currentIndexChanged(int index)
    \since 4.1
 
    This signal is sent whenever the currentIndex in the combobox
    changes either through user interaction or programmatically. The
    item's \a index is passed or -1 if the combobox becomes empty or the
    currentIndex was reset.
*/
 
/*!
    \fn void QComboBox::currentTextChanged(const QString &text)
    \since 5.0
 
    This signal is emitted whenever currentText changes.
    The new value is passed as \a text.
 
    \note It is not emitted, if currentText remains the same,
    even if currentIndex changes.
*/
 
/*!
    Constructs a combobox with the given \a parent, using the default
    model QStandardItemModel.
*/
QComboBox::QComboBox(QWidget *parent)
    : QWidget(*new QComboBoxPrivate(), parent, { })
{
    Q_D(QComboBox);
    d->init();
}
 
/*!
  \internal
*/
QComboBox::QComboBox(QComboBoxPrivate &dd, QWidget *parent)
    : QWidget(dd, parent, { })
{
    Q_D(QComboBox);
    d->init();
}
 
/*!
    \class QComboBox
    \brief The QComboBox widget combines a button with a dropdown list.
 
    \ingroup basicwidgets
    \inmodule QtWidgets
 
    \table
       \row
          \li \image collapsed_combobox.png
              {Combo box with collapsed options list}
              \caption Collapsed QCombobox
          \li
              \image expanded_combobox.png
              {Combo box with expanded options list}
              \caption Expanded QCombobox
    \endtable
 
    \section1 Display Features
    A QComboBox is a compact way to present a list of options to the user.
 
    A combobox is a selection widget that shows the current item,
    and pops up a list of selectable items when clicked. Comboboxes can
    contain pixmaps as well as strings if the insertItem() and setItemText()
    functions are suitably overloaded.
 
    \section1 Editing Features
    A combobox may be editable, allowing the user to modify each item in the
    list. For editable comboboxes, the function clearEditText() is provided,
    to clear the displayed string without changing the combobox's
    contents.
 
    When the user enters a new string in an editable combobox, the
    widget may or may not insert it, and it can insert it in several
    locations. The default policy is \l InsertAtBottom but you can change
    this using setInsertPolicy().
 
    It is possible to constrain the input to an editable combobox
    using QValidator; see setValidator(). By default, any input is
    accepted.
 
    A combobox can be populated using the insert functions,
    insertItem() and insertItems() for example. Items can be
    changed with setItemText(). An item can be removed with
    removeItem() and all items can be removed with clear(). The text
    of the current item is returned by currentText(), and the text of
    a numbered item is returned with text(). The current item can be
    set with setCurrentIndex(). The number of items in the combobox is
    returned by count(); the maximum number of items can be set with
    setMaxCount(). You can allow editing using setEditable(). For
    editable comboboxes you can set auto-completion using
    setCompleter() and whether or not the user can add duplicates
    is set with setDuplicatesEnabled().
 
    \section1 Signals
    There are three signals emitted if the current item of a combobox
    changes: currentIndexChanged(), currentTextChanged(), and activated().
    currentIndexChanged() and currentTextChanged() are always emitted
    regardless if the change
    was done programmatically or by user interaction, while
    activated() is only emitted when the change is caused by user
    interaction. The highlighted() signal is emitted when the user
    highlights an item in the combobox popup list. All three signals
    exist in two versions, one with a QString argument and one with an
    \c int argument. If the user selects or highlights a pixmap, only
    the \c int signals are emitted. Whenever the text of an editable
    combobox is changed, the editTextChanged() signal is emitted.
 
    \section1 Model/View Framework
 
    QComboBox uses the \l{Model/View Programming}{model/view framework} for its
    popup list and to store its items. By default a QStandardItemModel stores
    the items and a QListView subclass displays the popuplist. You can access
    the model and view directly (with model() and view()), but QComboBox also
    provides functions to set and get item data, for example, setItemData() and
    itemText(). You can also set a new model and view (with setModel()
    and setView()). For the text and icon in the combobox label, the data in
    the model that has the Qt::DisplayRole and Qt::DecorationRole is used.
 
    \note You cannot alter the \l{QAbstractItemView::}{SelectionMode}
    of the view(), for example, by using
    \l{QAbstractItemView::}{setSelectionMode()}.
 
    \sa QLineEdit, QSpinBox, QRadioButton, QButtonGroup
*/
 
void QComboBoxPrivate::init()
{
    Q_Q(QComboBox);
#ifdef Q_OS_MACOS
    // On OS X, only line edits and list views always get tab focus. It's only
    // when we enable full keyboard access that other controls can get tab focus.
    // When it's not editable, a combobox looks like a button, and it behaves as
    // such in this respect.
    if (!q->isEditable())
        q->setFocusPolicy(Qt::TabFocus);
    else
#endif
        q->setFocusPolicy(Qt::WheelFocus);
 
    q->setSizePolicy(QSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed,
                                 QSizePolicy::ComboBox));
    setLayoutItemMargins(QStyle::SE_ComboBoxLayoutItem);
    q->setModel(new QStandardItemModel(0, 1, q));
    if (!q->isEditable())
        q->setAttribute(Qt::WA_InputMethodEnabled, false);
    else
        q->setAttribute(Qt::WA_InputMethodEnabled);
}
 
QComboBoxPrivateContainer* QComboBoxPrivate::viewContainer()
{
    if (container)
        return container;
 
    Q_Q(QComboBox);
    container = new QComboBoxPrivateContainer(new QComboBoxListView(q), q);
    disconnectModel();
    container->itemView()->setModel(model);
    connectModel();
    container->itemView()->setTextElideMode(Qt::ElideMiddle);
    updateDelegate(true);
    updateLayoutDirection();
    updateViewContainerPaletteAndOpacity();
    QObjectPrivate::connect(container, &QComboBoxPrivateContainer::itemSelected,
                            this, &QComboBoxPrivate::itemSelected);
    QObjectPrivate::connect(container->itemView()->selectionModel(),
                            &QItemSelectionModel::currentChanged,
                            this, &QComboBoxPrivate::emitHighlighted);
    QObjectPrivate::connect(container, &QComboBoxPrivateContainer::resetButton,
                            this, &QComboBoxPrivate::resetButton);
    return container;
}
 
 
void QComboBoxPrivate::resetButton()
{
    updateArrow(QStyle::State_None);
}
 
void QComboBoxPrivate::dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight)
{
    Q_Q(QComboBox);
    if (inserting || topLeft.parent() != root)
        return;
 
    if (sizeAdjustPolicy == QComboBox::AdjustToContents) {
        sizeHint = QSize();
        adjustComboBoxSize();
        q->updateGeometry();
    }
 
    if (currentIndex.row() >= topLeft.row() && currentIndex.row() <= bottomRight.row()) {
        const QString text = q->itemText(currentIndex.row());
        if (lineEdit) {
            lineEdit->setText(text);
            updateLineEditGeometry();
        } else {
            updateCurrentText(text);
        }
        q->update();
#if QT_CONFIG(accessibility)
        QAccessibleValueChangeEvent event(q, text);
        QAccessible::updateAccessibility(&event);
#endif
    }
}
 
void QComboBoxPrivate::rowsInserted(const QModelIndex &parent, int start, int end)
{
    Q_Q(QComboBox);
    if (inserting || parent != root)
        return;
 
    if (sizeAdjustPolicy == QComboBox::AdjustToContents) {
        sizeHint = QSize();
        adjustComboBoxSize();
        q->updateGeometry();
    }
 
    // set current index if combo was previously empty and there is no placeholderText
    if (start == 0 && (end - start + 1) == q->count() && !currentIndex.isValid() &&
        placeholderText.isEmpty()) {
#if QT_CONFIG(accessibility)
        // This might have been called by the model emitting rowInserted(), at which
        // point the view won't have updated the accessibility bridge yet about its new
        // dimensions. Do it now so that the change of the selection matches the row
        // indexes of the accessibility bridge's representation.
        if (container && container->itemView()) {
            QAccessibleTableModelChangeEvent event(container->itemView(),
                                                   QAccessibleTableModelChangeEvent::ModelReset);
            QAccessible::updateAccessibility(&event);
        }
#endif
        q->setCurrentIndex(0);
        // need to emit changed if model updated index "silently"
    } else if (currentIndex.row() != indexBeforeChange) {
        q->update();
        emitCurrentIndexChanged(currentIndex);
    }
}
 
void QComboBoxPrivate::updateIndexBeforeChange()
{
    indexBeforeChange = currentIndex.row();
}
 
void QComboBoxPrivate::rowsRemoved(const QModelIndex &parent, int /*start*/, int /*end*/)
{
    Q_Q(QComboBox);
    if (parent != root)
        return;
 
    if (sizeAdjustPolicy == QComboBox::AdjustToContents) {
        sizeHint = QSize();
        adjustComboBoxSize();
        q->updateGeometry();
    }
 
    // model has removed the last row
    if (model->rowCount(root) == 0) {
        setCurrentIndex(QModelIndex());
        return;
    }
 
    // model has changed the currentIndex
    if (currentIndex.row() != indexBeforeChange) {
        if (!currentIndex.isValid() && q->count()) {
            q->setCurrentIndex(qMin(q->count() - 1, qMax(indexBeforeChange, 0)));
            return;
        }
        if (lineEdit) {
            lineEdit->setText(q->itemText(currentIndex.row()));
            updateLineEditGeometry();
        }
        q->update();
        emitCurrentIndexChanged(currentIndex);
    }
}
 
 
void QComboBoxPrivate::updateViewContainerPaletteAndOpacity()
{
    if (!container)
        return;
    Q_Q(QComboBox);
    QStyleOptionComboBox opt;
    q->initStyleOption(&opt);
#if QT_CONFIG(menu)
    if (q->style()->styleHint(QStyle::SH_ComboBox_Popup, &opt, q)) {
        QMenu menu;
        menu.ensurePolished();
        container->setPalette(menu.palette());
        container->setWindowOpacity(menu.windowOpacity());
    } else
#endif
    {
        container->setPalette(q->palette());
        container->setWindowOpacity(1.0);
    }
    if (lineEdit)
        lineEdit->setPalette(q->palette());
}
 
void QComboBoxPrivate::updateFocusPolicy()
{
#ifdef Q_OS_MACOS
    Q_Q(QComboBox);
 
    // See comment in QComboBoxPrivate::init()
    if (q->isEditable())
        q->setFocusPolicy(Qt::WheelFocus);
    else
        q->setFocusPolicy(Qt::TabFocus);
#endif
}
 
/*!
    Initialize \a option with the values from this QComboBox. This method
    is useful for subclasses when they need a QStyleOptionComboBox, but don't want
    to fill in all the information themselves.
 
    \sa QStyleOption::initFrom()
*/
void QComboBox::initStyleOption(QStyleOptionComboBox *option) const
{
    if (!option)
        return;
 
    Q_D(const QComboBox);
    option->initFrom(this);
    option->editable = isEditable();
    option->frame = d->frame;
    if (hasFocus() && !option->editable)
        option->state |= QStyle::State_Selected;
    option->subControls = QStyle::SC_All;
    if (d->arrowState == QStyle::State_Sunken) {
        option->activeSubControls = QStyle::SC_ComboBoxArrow;
        option->state |= d->arrowState;
    } else {
        option->activeSubControls = d->hoverControl;
    }
    option->currentText = currentText();
    if (d->currentIndex.isValid()) {
        option->currentIcon = d->itemIcon(d->currentIndex);
        QVariant alignment = d->model->data(d->currentIndex, Qt::TextAlignmentRole);
        if (alignment.isValid())
            option->textAlignment = static_cast<Qt::Alignment>(alignment.toUInt());
    }
    option->iconSize = iconSize();
    if (d->container && d->container->isVisible())
        option->state |= QStyle::State_On;
}
 
void QComboBoxPrivate::initViewItemOption(QStyleOptionViewItem *option) const
{
    Q_Q(const QComboBox);
    q->view()->initViewItemOption(option);
    option->widget = q;
    option->index = currentIndex;
    option->text = q->currentText();
    option->icon = itemIcon(currentIndex);
}
 
void QComboBoxPrivate::updateLineEditGeometry()
{
    if (!lineEdit)
        return;
 
    Q_Q(QComboBox);
    QStyleOptionComboBox opt;
    q->initStyleOption(&opt);
    QRect editRect = q->style()->subControlRect(QStyle::CC_ComboBox, &opt,
                                                QStyle::SC_ComboBoxEditField, q);
    if (currentIndex.isValid() && !q->itemIcon(q->currentIndex()).isNull()) {
        QRect comboRect(editRect);
        editRect.setWidth(editRect.width() - q->iconSize().width() - 4);
        editRect = QStyle::alignedRect(q->layoutDirection(), Qt::AlignRight,
                                       editRect.size(), comboRect);
    }
    lineEdit->setGeometry(editRect);
}
 
Qt::MatchFlags QComboBoxPrivate::matchFlags() const
{
    // Base how duplicates are determined on the autocompletion case sensitivity
    Qt::MatchFlags flags = Qt::MatchFixedString;
#if QT_CONFIG(completer)
    if (!lineEdit->completer() || lineEdit->completer()->caseSensitivity() == Qt::CaseSensitive)
#endif
        flags |= Qt::MatchCaseSensitive;
    return flags;
}
 
 
void QComboBoxPrivate::editingFinished()
{
    Q_Q(QComboBox);
    if (!lineEdit)
        return;
    const auto leText = lineEdit->text();
    if (!leText.isEmpty() && itemText(currentIndex) != leText) {
#if QT_CONFIG(completer)
        const auto *leCompleter = lineEdit->completer();
        const auto *popup = leCompleter ? QCompleterPrivate::get(leCompleter)->popup : nullptr;
        if (popup && popup->isVisible()) {
            // QLineEdit::editingFinished() will be emitted before the code flow returns
            // to QCompleter::eventFilter(), where QCompleter::activated() may be emitted.
            // We know that the completer popup will still be visible at this point, and
            // that any selection should be valid.
            const QItemSelectionModel *selModel = popup->selectionModel();
            const QModelIndex curIndex = popup->currentIndex();
            const bool completerIsActive = selModel && selModel->selectedIndexes().contains(curIndex);
 
            if (completerIsActive)
                return;
        }
#endif
        const int index = q_func()->findText(leText, matchFlags());
        if (index != -1) {
            q->setCurrentIndex(index);
            emitActivated(currentIndex);
        }
    }
 
}
 
void QComboBoxPrivate::returnPressed()
{
    Q_Q(QComboBox);
 
    // The insertion code below does not apply when the policy is QComboBox::NoInsert.
    // In case a completer is installed, item activation via the completer is handled
    // in completerActivated(). Otherwise editingFinished() updates the current
    // index as appropriate.
    if (insertPolicy == QComboBox::NoInsert)
        return;
 
    if (lineEdit && !lineEdit->text().isEmpty()) {
        if (q->count() >= maxCount && !(this->insertPolicy == QComboBox::InsertAtCurrent))
            return;
        lineEdit->deselect();
        lineEdit->end(false);
        QString text = lineEdit->text();
        // check for duplicates (if not enabled) and quit
        int index = -1;
        if (!duplicatesEnabled) {
            index = q->findText(text, matchFlags());
            if (index != -1) {
                q->setCurrentIndex(index);
                emitActivated(currentIndex);
                return;
            }
        }
        switch (insertPolicy) {
        case QComboBox::InsertAtTop:
            index = 0;
            break;
        case QComboBox::InsertAtBottom:
            index = q->count();
            break;
        case QComboBox::InsertAtCurrent:
        case QComboBox::InsertAfterCurrent:
        case QComboBox::InsertBeforeCurrent:
            if (!q->count() || !currentIndex.isValid())
                index = 0;
            else if (insertPolicy == QComboBox::InsertAtCurrent)
                q->setItemText(q->currentIndex(), text);
            else if (insertPolicy == QComboBox::InsertAfterCurrent)
                index = q->currentIndex() + 1;
            else if (insertPolicy == QComboBox::InsertBeforeCurrent)
                index = q->currentIndex();
            break;
        case QComboBox::InsertAlphabetically:
            index = 0;
            for (int i = 0; i < q->count(); ++i, ++index) {
                if (text.toLower() < q->itemText(i).toLower())
                    break;
            }
            break;
        default:
            break;
        }
        if (index >= 0) {
            q->insertItem(index, text);
            q->setCurrentIndex(index);
            emitActivated(currentIndex);
        }
    }
}
 
void QComboBoxPrivate::itemSelected(const QModelIndex &item)
{
    Q_Q(QComboBox);
    if (item != currentIndex) {
        setCurrentIndex(item);
    } else if (lineEdit) {
        lineEdit->selectAll();
        lineEdit->setText(q->itemText(currentIndex.row()));
    }
    emitActivated(currentIndex);
}
 
void QComboBoxPrivate::emitActivated(const QModelIndex &index)
{
    Q_Q(QComboBox);
    if (!index.isValid())
        return;
    QString text(itemText(index));
    emit q->activated(index.row());
    emit q->textActivated(text);
}
 
void QComboBoxPrivate::emitHighlighted(const QModelIndex &index)
{
    Q_Q(QComboBox);
    if (!index.isValid())
        return;
    QString text(itemText(index));
    emit q->highlighted(index.row());
    emit q->textHighlighted(text);
}
 
void QComboBoxPrivate::emitCurrentIndexChanged(const QModelIndex &index)
{
    Q_Q(QComboBox);
    const QString text = itemText(index);
    emit q->currentIndexChanged(index.row());
    // signal lineEdit.textChanged already connected to signal currentTextChanged, so don't emit double here
    if (!lineEdit)
        updateCurrentText(text);
#if QT_CONFIG(accessibility)
    QAccessibleValueChangeEvent event(q, text);
    QAccessible::updateAccessibility(&event);
#endif
}
 
QString QComboBoxPrivate::itemText(const QModelIndex &index) const
{
    return index.isValid() ? model->data(index, itemRole()).toString() : QString();
}
 
int QComboBoxPrivate::itemRole() const
{
    return q_func()->isEditable() ? Qt::EditRole : Qt::DisplayRole;
}
 
/*!
    Destroys the combobox.
*/
QComboBox::~QComboBox()
{
    // ### check delegateparent and delete delegate if us?
    Q_D(QComboBox);
 
    QT_TRY {
        d->disconnectModel();
    } QT_CATCH(...) {
        ; // objects can't throw in destructor
    }
 
    // Dispose of container before QComboBox goes away. Close explicitly so that
    // update cycles back into the combobox (e.g. from accessibility when the
    // active window changes) are completed first.
    if (d->container) {
        d->container->close();
        delete d->container;
        d->container = nullptr;
    }
}
 
/*!
    \property QComboBox::maxVisibleItems
    \brief the maximum allowed size on screen of the combo box, measured in items
 
    By default, this property has a value of 10.
 
    \note This property is ignored for non-editable comboboxes in styles that returns
    true for QStyle::SH_ComboBox_Popup such as the Mac style or the Gtk+ Style.
*/
int QComboBox::maxVisibleItems() const
{
    Q_D(const QComboBox);
    return d->maxVisibleItems;
}
 
void QComboBox::setMaxVisibleItems(int maxItems)
{
    Q_D(QComboBox);
    if (Q_UNLIKELY(maxItems < 0)) {
        qWarning("QComboBox::setMaxVisibleItems: "
                 "Invalid max visible items (%d) must be >= 0", maxItems);
        return;
    }
    d->maxVisibleItems = maxItems;
}
 
/*!
    \property QComboBox::count
    \brief the number of items in the combobox.
 
    By default, for an empty combo box, this property has a value of 0.
*/
int QComboBox::count() const
{
    Q_D(const QComboBox);
    return d->model->rowCount(d->root);
}
 
/*!
    \property QComboBox::maxCount
    \brief the maximum number of items allowed in the combobox.
 
    \note If you set the maximum number to be less then the current
    amount of items in the combobox, the extra items will be
    truncated. This also applies if you have set an external model on
    the combobox.
 
    By default, this property's value is derived from the highest
    signed integer available (typically 2147483647).
*/
void QComboBox::setMaxCount(int max)
{
    Q_D(QComboBox);
    if (Q_UNLIKELY(max < 0)) {
        qWarning("QComboBox::setMaxCount: Invalid count (%d) must be >= 0", max);
        return;
    }
 
    const int rowCount = count();
    if (rowCount > max)
        d->model->removeRows(max, rowCount - max, d->root);
 
    d->maxCount = max;
}
 
int QComboBox::maxCount() const
{
    Q_D(const QComboBox);
    return d->maxCount;
}
 
/*!
    \property QComboBox::duplicatesEnabled
    \brief whether the user can enter duplicate items into the combobox.
 
    Note that it is always possible to programmatically insert duplicate items into the
    combobox.
 
    By default, this property is \c false (duplicates are not allowed).
*/
bool QComboBox::duplicatesEnabled() const
{
    Q_D(const QComboBox);
    return d->duplicatesEnabled;
}
 
void QComboBox::setDuplicatesEnabled(bool enable)
{
    Q_D(QComboBox);
    d->duplicatesEnabled = enable;
}
 
/*!  \fn int QComboBox::findText(const QString &text, Qt::MatchFlags flags = Qt::MatchExactly|Qt::MatchCaseSensitive) const
 
  Returns the index of the item containing the given \a text; otherwise
  returns -1.
 
  The \a flags specify how the items in the combobox are searched.
*/
 
/*!
  Returns the index of the item containing the given \a data for the
  given \a role; otherwise returns -1.
 
  The \a flags specify how the items in the combobox are searched.
*/
int QComboBox::findData(const QVariant &data, int role, Qt::MatchFlags flags) const
{
    Q_D(const QComboBox);
    QModelIndex start = d->model->index(0, d->modelColumn, d->root);
    const QModelIndexList result = d->model->match(start, role, data, 1, flags);
    if (result.isEmpty())
        return -1;
    return result.first().row();
}
 
/*!
    \property QComboBox::insertPolicy
    \brief the policy used to determine where user-inserted items should
    appear in the combobox.
 
    The default value is \l InsertAtBottom, indicating that new items will appear
    at the bottom of the list of items.
 
    \sa InsertPolicy
*/
 
QComboBox::InsertPolicy QComboBox::insertPolicy() const
{
    Q_D(const QComboBox);
    return d->insertPolicy;
}
 
void QComboBox::setInsertPolicy(InsertPolicy policy)
{
    Q_D(QComboBox);
    d->insertPolicy = policy;
}
 
/*!
    \property QComboBox::sizeAdjustPolicy
    \brief the policy describing how the size of the combobox changes
    when the content changes.
 
    The default value is \l AdjustToContentsOnFirstShow.
 
    \sa SizeAdjustPolicy
*/
 
QComboBox::SizeAdjustPolicy QComboBox::sizeAdjustPolicy() const
{
    Q_D(const QComboBox);
    return d->sizeAdjustPolicy;
}
 
void QComboBox::setSizeAdjustPolicy(QComboBox::SizeAdjustPolicy policy)
{
    Q_D(QComboBox);
    if (policy == d->sizeAdjustPolicy)
        return;
 
    d->sizeAdjustPolicy = policy;
    d->sizeHint = QSize();
    d->adjustComboBoxSize();
    updateGeometry();
}
 
/*!
    \property QComboBox::minimumContentsLength
    \brief the minimum number of characters that should fit into the combobox.
 
    The default value is 0.
 
    If this property is set to a positive value, the
    minimumSizeHint() and sizeHint() take it into account.
 
    \sa sizeAdjustPolicy
*/
int QComboBox::minimumContentsLength() const
{
    Q_D(const QComboBox);
    return d->minimumContentsLength;
}
 
void QComboBox::setMinimumContentsLength(int characters)
{
    Q_D(QComboBox);
    if (characters == d->minimumContentsLength || characters < 0)
        return;
 
    d->minimumContentsLength = characters;
 
    if (d->sizeAdjustPolicy == AdjustToContents
        || d->sizeAdjustPolicy == AdjustToMinimumContentsLengthWithIcon) {
        d->sizeHint = QSize();
        d->adjustComboBoxSize();
        updateGeometry();
    }
}
 
/*!
    \property QComboBox::iconSize
    \brief the size of the icons shown in the combobox.
 
    Unless explicitly set this returns the default value of the
    current style.  This size is the maximum size that icons can have;
    icons of smaller size are not scaled up.
*/
 
QSize QComboBox::iconSize() const
{
    Q_D(const QComboBox);
    if (d->iconSize.isValid())
        return d->iconSize;
 
    int iconWidth = style()->pixelMetric(QStyle::PM_SmallIconSize, nullptr, this);
    return QSize(iconWidth, iconWidth);
}
 
void QComboBox::setIconSize(const QSize &size)
{
    Q_D(QComboBox);
    if (size == d->iconSize)
        return;
 
    view()->setIconSize(size);
    d->iconSize = size;
    d->sizeHint = QSize();
    updateGeometry();
}
 
/*!
    \property QComboBox::placeholderText
    \brief Sets a \a placeholderText text shown when no valid index is set.
 
    The \a placeholderText will be shown when an invalid index is set. The
    text is not accessible in the dropdown list. When this function is called
    before items are added the placeholder text will be shown, otherwise you
    have to call setCurrentIndex(-1) programmatically if you want to show the
    placeholder text.
    Set an empty placeholder text to reset the setting.
 
    When the QComboBox is editable, use QLineEdit::setPlaceholderText()
    instead.
 
    \since 5.15
*/
void QComboBox::setPlaceholderText(const QString &placeholderText)
{
    Q_D(QComboBox);
    if (placeholderText == d->placeholderText)
        return;
 
    d->placeholderText = placeholderText;
    if (currentIndex() == -1) {
      if (d->placeholderText.isEmpty())
        setCurrentIndex(0);
      else
        update();
    } else {
      updateGeometry();
    }
}
 
QString QComboBox::placeholderText() const
{
    Q_D(const QComboBox);
    return d->placeholderText;
}
 
/*!
    \property QComboBox::editable
    \brief whether the combo box can be edited by the user.
 
    By default, this property is \c false. The effect of editing depends
    on the insert policy.
 
    \note When disabling the \a editable state, the validator and
    completer are removed.
 
    \sa InsertPolicy
*/
bool QComboBox::isEditable() const
{
    Q_D(const QComboBox);
    return d->lineEdit != nullptr;
}
 
/*! \internal
    update the default delegate
    depending on the style's SH_ComboBox_Popup hint, we use a different default delegate.
 
    but we do not change the delegate is the combobox use a custom delegate,
    unless \a force is set to true.
 */
void QComboBoxPrivate::updateDelegate(bool force)
{
    Q_Q(QComboBox);
    QStyleOptionComboBox opt;
    q->initStyleOption(&opt);
    if (q->style()->styleHint(QStyle::SH_ComboBox_Popup, &opt, q)) {
        if (force || qobject_cast<QComboBoxDelegate *>(q->itemDelegate()))
            q->setItemDelegate(new QComboMenuDelegate(q->view(), q));
    } else {
        if (force || qobject_cast<QComboMenuDelegate *>(q->itemDelegate()))
            q->setItemDelegate(new QComboBoxDelegate(q->view(), q));
    }
}
 
QIcon QComboBoxPrivate::itemIcon(const QModelIndex &index) const
{
    if (!index.isValid())
        return {};
    QVariant decoration = model->data(index, Qt::DecorationRole);
    if (decoration.userType() == QMetaType::QPixmap)
        return QIcon(qvariant_cast<QPixmap>(decoration));
    else
        return qvariant_cast<QIcon>(decoration);
}
 
void QComboBox::setEditable(bool editable)
{
    Q_D(QComboBox);
    if (isEditable() == editable)
        return;
 
    QStyleOptionComboBox opt;
    initStyleOption(&opt);
    if (editable) {
        if (style()->styleHint(QStyle::SH_ComboBox_Popup, &opt, this)) {
            d->viewContainer()->updateScrollers();
            view()->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
        }
        QLineEdit *le = new QLineEdit(this);
        le->setPalette(palette());
        setLineEdit(le);
    } else {
        if (style()->styleHint(QStyle::SH_ComboBox_Popup, &opt, this)) {
            d->viewContainer()->updateScrollers();
            view()->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
        }
        setAttribute(Qt::WA_InputMethodEnabled, false);
        d->lineEdit->hide();
        d->lineEdit->deleteLater();
        d->lineEdit = nullptr;
    }
 
    d->updateDelegate();
    d->updateFocusPolicy();
 
    d->viewContainer()->updateTopBottomMargin();
    if (!testAttribute(Qt::WA_Resized))
        adjustSize();
}
 
/*!
    Sets the line \a edit to use instead of the current line edit widget.
 
    The combo box takes ownership of the line edit.
 
    \note Since the combobox's line edit owns the QCompleter, any previous
    call to setCompleter() will no longer have any effect.
*/
void QComboBox::setLineEdit(QLineEdit *edit)
{
    Q_D(QComboBox);
    if (Q_UNLIKELY(!edit)) {
        qWarning("QComboBox::setLineEdit: cannot set a 0 line edit");
        return;
    }
 
    if (edit == d->lineEdit)
        return;
 
    edit->setText(currentText());
    delete d->lineEdit;
 
    d->lineEdit = edit;
#ifndef QT_NO_IM
    qt_widget_private(d->lineEdit)->inheritsInputMethodHints = 1;
#endif
    if (d->lineEdit->parent() != this)
        d->lineEdit->setParent(this);
    QObjectPrivate::connect(d->lineEdit, &QLineEdit::returnPressed,
                            d, &QComboBoxPrivate::returnPressed);
    QObjectPrivate::connect(d->lineEdit, &QLineEdit::editingFinished,
                            d, &QComboBoxPrivate::editingFinished);
    connect(d->lineEdit, &QLineEdit::textChanged, this, &QComboBox::editTextChanged);
    connect(d->lineEdit, &QLineEdit::textChanged, this, &QComboBox::currentTextChanged);
    QObjectPrivate::connect(d->lineEdit, &QLineEdit::cursorPositionChanged,
                            d, &QComboBoxPrivate::updateMicroFocus);
    QObjectPrivate::connect(d->lineEdit, &QLineEdit::selectionChanged,
                            d, &QComboBoxPrivate::updateMicroFocus);
    QObjectPrivate::connect(d->lineEdit->d_func()->control, &QWidgetLineControl::updateMicroFocus,
                            d, &QComboBoxPrivate::updateMicroFocus);
    d->lineEdit->setFrame(false);
    d->lineEdit->setContextMenuPolicy(Qt::NoContextMenu);
    d->updateFocusPolicy();
    d->lineEdit->setFocusProxy(this);
    d->lineEdit->setAttribute(Qt::WA_MacShowFocusRect, false);
 
#if QT_CONFIG(completer)
    // create a default completer
    if (!d->lineEdit->completer()) {
        QCompleter *completer = new QCompleter(d->model, d->lineEdit);
        completer->setCaseSensitivity(Qt::CaseInsensitive);
        completer->setCompletionMode(QCompleter::InlineCompletion);
        completer->setCompletionColumn(d->modelColumn);
        // sets up connections
        setCompleter(completer);
    }
#endif
 
    setAttribute(Qt::WA_InputMethodEnabled);
    d->updateLayoutDirection();
    d->updateLineEditGeometry();
    if (isVisible())
        d->lineEdit->show();
 
    update();
}
 
/*!
    Returns the line edit used to edit items in the combobox, or
    \nullptr if there is no line edit.
 
    Only editable combo boxes have a line edit.
*/
QLineEdit *QComboBox::lineEdit() const
{
    Q_D(const QComboBox);
    return d->lineEdit;
}
 
#ifndef QT_NO_VALIDATOR
/*!
    \fn void QComboBox::setValidator(const QValidator *validator)
 
    Sets the \a validator to use instead of the current validator.
 
    \note The validator is removed when the \l editable property becomes \c false.
*/
 
void QComboBox::setValidator(const QValidator *v)
{
    Q_D(QComboBox);
    if (d->lineEdit)
        d->lineEdit->setValidator(v);
}
 
/*!
    Returns the validator that is used to constrain text input for the
    combobox.
 
    \sa editable
*/
const QValidator *QComboBox::validator() const
{
    Q_D(const QComboBox);
    return d->lineEdit ? d->lineEdit->validator() : nullptr;
}
#endif // QT_NO_VALIDATOR
 
#if QT_CONFIG(completer)
 
/*!
    \fn void QComboBox::setCompleter(QCompleter *completer)
    \since 4.2
 
    Sets the \a completer to use instead of the current completer.
    If \a completer is \nullptr, auto completion is disabled.
 
    By default, for an editable combo box, a QCompleter that
    performs case insensitive inline completion is automatically created.
 
    \note The completer is removed when the \l editable property becomes \c false,
    or when the line edit is replaced by a call to setLineEdit().
    Setting a completer on a QComboBox that is not editable will be ignored.
*/
void QComboBox::setCompleter(QCompleter *c)
{
    Q_D(QComboBox);
    if (!d->lineEdit) {
        qWarning("Setting a QCompleter on non-editable QComboBox is not allowed.");
        return;
    }
    d->lineEdit->setCompleter(c);
    if (c) {
        QObjectPrivate::connect(c, QOverload<const QModelIndex &>::of(&QCompleter::activated),
                                d, &QComboBoxPrivate::completerActivated);
        c->setWidget(this);
    }
}
 
/*!
    \since 4.2
 
    Returns the completer that is used to auto complete text input for the
    combobox.
 
    \sa editable
*/
QCompleter *QComboBox::completer() const
{
    Q_D(const QComboBox);
    return d->lineEdit ? d->lineEdit->completer() : nullptr;
}
 
#endif // QT_CONFIG(completer)
 
/*!
    Returns the item delegate used by the popup list view.
 
    \sa setItemDelegate()
*/
QAbstractItemDelegate *QComboBox::itemDelegate() const
{
    return view()->itemDelegate();
}
 
/*!
    Sets the item \a delegate for the popup list view.
    The combobox takes ownership of the delegate.
 
    Any existing delegate will be removed, but not deleted. QComboBox
    does not take ownership of \a delegate.
 
    \warning You should not share the same instance of a delegate between comboboxes,
    widget mappers or views. Doing so can cause incorrect or unintuitive editing behavior
    since each view connected to a given delegate may receive the
    \l{QAbstractItemDelegate::}{closeEditor()} signal, and attempt to access, modify or
    close an editor that has already been closed.
 
    \sa itemDelegate()
*/
void QComboBox::setItemDelegate(QAbstractItemDelegate *delegate)
{
    if (Q_UNLIKELY(!delegate)) {
        qWarning("QComboBox::setItemDelegate: cannot set a 0 delegate");
        return;
    }
    view()->setItemDelegate(delegate);
}
 
/*!
    Returns the model used by the combobox.
*/
 
QAbstractItemModel *QComboBox::model() const
{
    Q_D(const QComboBox);
    if (d->model == QAbstractItemModelPrivate::staticEmptyModel()) {
        QComboBox *that = const_cast<QComboBox*>(this);
        that->setModel(new QStandardItemModel(0, 1, that));
    }
    return d->model;
}
 
/*!
    Sets the model to be \a model. \a model must not be \nullptr.
    If you want to clear the contents of a model, call clear().
 
    \note If the combobox is editable, then the \a model will also be
    set on the completer of the line edit.
 
    \sa clear() setCompleter()
*/
void QComboBox::setModel(QAbstractItemModel *model)
{
    Q_D(QComboBox);
 
    if (Q_UNLIKELY(!model)) {
        qWarning("QComboBox::setModel: cannot set a 0 model");
        return;
    }
 
    if (model == d->model)
        return;
 
#if QT_CONFIG(completer)
    if (d->lineEdit && d->lineEdit->completer())
        d->lineEdit->completer()->setModel(model);
#endif
    d->disconnectModel();
    if (d->model && d->model->QObject::parent() == this) {
        delete d->model;
        d->model = nullptr;
    }
 
    d->model = model;
 
    if (d->container) {
        d->container->itemView()->setModel(model);
        QObjectPrivate::connect(d->container->itemView()->selectionModel(),
                                &QItemSelectionModel::currentChanged,
                                d, &QComboBoxPrivate::emitHighlighted, Qt::UniqueConnection);
    }
 
    d->connectModel();
 
    setRootModelIndex(QModelIndex());
 
    d->trySetValidIndex();
    d->modelChanged();
}
 
void QComboBoxPrivate::connectModel()
{
    if (!model)
        return;
 
    modelConnections = {
        QObjectPrivate::connect(model, &QAbstractItemModel::dataChanged,
                                this, &QComboBoxPrivate::dataChanged),
        QObjectPrivate::connect(model, &QAbstractItemModel::rowsAboutToBeInserted,
                                this, &QComboBoxPrivate::updateIndexBeforeChange),
        QObjectPrivate::connect(model, &QAbstractItemModel::rowsInserted,
                                this, &QComboBoxPrivate::rowsInserted),
        QObjectPrivate::connect(model, &QAbstractItemModel::rowsAboutToBeRemoved,
                                this, &QComboBoxPrivate::updateIndexBeforeChange),
        QObjectPrivate::connect(model, &QAbstractItemModel::rowsRemoved,
                                this, &QComboBoxPrivate::rowsRemoved),
        QObjectPrivate::connect(model, &QObject::destroyed,
                                this, &QComboBoxPrivate::modelDestroyed),
        QObjectPrivate::connect(model, &QAbstractItemModel::modelAboutToBeReset,
                                this, &QComboBoxPrivate::updateIndexBeforeChange),
        QObjectPrivate::connect(model, &QAbstractItemModel::modelReset,
                                this, &QComboBoxPrivate::modelReset)
    };
}
 
void QComboBoxPrivate::disconnectModel()
{
    for (auto &connection : modelConnections)
        QObject::disconnect(connection);
}
 
/*!
    Returns the root model item index for the items in the combobox.
 
    \sa setRootModelIndex()
*/
 
QModelIndex QComboBox::rootModelIndex() const
{
    Q_D(const QComboBox);
    return QModelIndex(d->root);
}
 
/*!
    Sets the root model item \a index for the items in the combobox.
 
    \sa rootModelIndex()
*/
void QComboBox::setRootModelIndex(const QModelIndex &index)
{
    Q_D(QComboBox);
    if (d->root == index)
        return;
    d->root = QPersistentModelIndex(index);
    view()->setRootIndex(index);
    update();
}
 
/*!
    \property QComboBox::currentIndex
    \brief the index of the current item in the combobox.
 
    The current index can change when inserting or removing items.
 
    By default, for an empty combo box or a combo box in which no current
    item is set, this property has a value of -1.
*/
int QComboBox::currentIndex() const
{
    Q_D(const QComboBox);
    return d->currentIndex.row();
}
 
void QComboBox::setCurrentIndex(int index)
{
    Q_D(QComboBox);
    QModelIndex mi = index >= 0 ? d->model->index(index, d->modelColumn, d->root) : QModelIndex();
    d->setCurrentIndex(mi);
}
 
void QComboBox::setCurrentText(const QString &text)
{
    if (isEditable()) {
        setEditText(text);
    } else {
        const int i = findText(text);
        if (i > -1)
            setCurrentIndex(i);
    }
}
 
void QComboBoxPrivate::setCurrentIndex(const QModelIndex &mi)
{
    Q_Q(QComboBox);
 
    QModelIndex normalized = mi.sibling(mi.row(), modelColumn); // no-op if mi.column() == modelColumn
    if (!normalized.isValid())
        normalized = mi;    // Fallback to passed index.
 
    bool indexChanged = (normalized != currentIndex);
    if (indexChanged)
        currentIndex = QPersistentModelIndex(normalized);
    if (lineEdit) {
        const QString newText = itemText(normalized);
        if (lineEdit->text() != newText) {
            lineEdit->setText(newText); // may cause lineEdit -> nullptr (QTBUG-54191)
#if QT_CONFIG(completer)
            if (lineEdit && lineEdit->completer())
                lineEdit->completer()->setCompletionPrefix(newText);
#endif
        }
        updateLineEditGeometry();
    }
    // If the model was reset to an empty one, currentIndex will be invalidated
    // (because it's a QPersistentModelIndex), but the index change will never
    // be advertised. So an explicit check for this condition is needed.
    // The variable used for that check has to be reset when a previously valid
    // index becomes invalid.
    const bool modelResetToEmpty = !normalized.isValid() && indexBeforeChange != -1;
    if (modelResetToEmpty)
        indexBeforeChange = -1;
 
    if (indexChanged || modelResetToEmpty) {
        QItemSelectionModel::SelectionFlags selectionMode = QItemSelectionModel::ClearAndSelect;
        if (q->view()->selectionBehavior() == QAbstractItemView::SelectRows)
            selectionMode.setFlag(QItemSelectionModel::Rows);
        if (auto *model = q->view()->selectionModel())
            model->setCurrentIndex(currentIndex, selectionMode);
 
        q->update();
        emitCurrentIndexChanged(currentIndex);
    }
}
 
/*!
    \property QComboBox::currentText
    \brief the current text
 
    If the combo box is editable, the current text is the value displayed
    by the line edit. Otherwise, it is the value of the current item or
    an empty string if the combo box is empty or no current item is set.
 
    The setter setCurrentText() simply calls setEditText() if the combo box is editable.
    Otherwise, if there is a matching text in the list, currentIndex is set to the
    corresponding index.
 
    \sa editable, setEditText()
*/
QString QComboBox::currentText() const
{
    Q_D(const QComboBox);
    if (d->lineEdit)
        return d->lineEdit->text();
    if (d->currentIndex.isValid())
        return d->itemText(d->currentIndex);
    return {};
}
 
/*!
    \property QComboBox::currentData
    \brief the data for the current item
    \since 5.2
 
    By default, for an empty combo box or a combo box in which no current
    item is set, this property contains an invalid QVariant.
*/
QVariant QComboBox::currentData(int role) const
{
    Q_D(const QComboBox);
    return d->currentIndex.data(role);
}
 
/*!
    Returns the text for the given \a index in the combobox.
*/
QString QComboBox::itemText(int index) const
{
    Q_D(const QComboBox);
    QModelIndex mi = d->model->index(index, d->modelColumn, d->root);
    return d->itemText(mi);
}
 
/*!
    Returns the icon for the given \a index in the combobox.
*/
QIcon QComboBox::itemIcon(int index) const
{
    Q_D(const QComboBox);
    QModelIndex mi = d->model->index(index, d->modelColumn, d->root);
    return d->itemIcon(mi);
}
 
/*!
   Returns the data for the given \a role in the given \a index in the
   combobox, or an invalid QVariant if there is no data for this role.
*/
QVariant QComboBox::itemData(int index, int role) const
{
    Q_D(const QComboBox);
    QModelIndex mi = d->model->index(index, d->modelColumn, d->root);
    return d->model->data(mi, role);
}
 
/*!
  \fn void QComboBox::insertItem(int index, const QString &text, const QVariant &userData)
 
    Inserts the \a text and \a userData (stored in the Qt::UserRole)
    into the combobox at the given \a index.
 
    If the index is equal to or higher than the total number of items,
    the new item is appended to the list of existing items. If the
    index is zero or negative, the new item is prepended to the list
    of existing items.
 
  \sa insertItems()
*/
 
/*!
 
    Inserts the \a icon, \a text and \a userData (stored in the
    Qt::UserRole) into the combobox at the given \a index.
 
    If the index is equal to or higher than the total number of items,
    the new item is appended to the list of existing items. If the
    index is zero or negative, the new item is prepended to the list
    of existing items.
 
    \sa insertItems()
*/
void QComboBox::insertItem(int index, const QIcon &icon, const QString &text, const QVariant &userData)
{
    Q_D(QComboBox);
    int itemCount = count();
    index = qBound(0, index, itemCount);
    if (index >= d->maxCount)
        return;
 
    // For the common case where we are using the built in QStandardItemModel
    // construct a QStandardItem, reducing the number of expensive signals from the model
    if (QStandardItemModel *m = qobject_cast<QStandardItemModel*>(d->model)) {
        QStandardItem *item = new QStandardItem(text);
        if (!icon.isNull()) item->setData(icon, Qt::DecorationRole);
        if (userData.isValid()) item->setData(userData, Qt::UserRole);
        m->insertRow(index, item);
        ++itemCount;
    } else {
        d->inserting = true;
        if (d->model->insertRows(index, 1, d->root)) {
            QModelIndex item = d->model->index(index, d->modelColumn, d->root);
            if (icon.isNull() && !userData.isValid()) {
                d->model->setData(item, text, Qt::EditRole);
            } else {
                QMap<int, QVariant> values;
                if (!text.isNull()) values.insert(Qt::EditRole, text);
                if (!icon.isNull()) values.insert(Qt::DecorationRole, icon);
                if (userData.isValid()) values.insert(Qt::UserRole, userData);
                if (!values.isEmpty()) d->model->setItemData(item, values);
            }
            d->inserting = false;
            d->rowsInserted(d->root, index, index);
            ++itemCount;
        } else {
            d->inserting = false;
        }
    }
 
    if (itemCount > d->maxCount)
        d->model->removeRows(itemCount - 1, itemCount - d->maxCount, d->root);
}
 
/*!
    Inserts the strings from the \a list into the combobox as separate items,
    starting at the \a index specified.
 
    If the index is equal to or higher than the total number of items, the new items
    are appended to the list of existing items. If the index is zero or negative, the
    new items are prepended to the list of existing items.
 
    \sa insertItem()
    */
void QComboBox::insertItems(int index, const QStringList &list)
{
    Q_D(QComboBox);
    if (list.isEmpty())
        return;
    index = qBound(0, index, count());
    int insertCount = qMin(d->maxCount - index, list.size());
    if (insertCount <= 0)
        return;
    // For the common case where we are using the built in QStandardItemModel
    // construct a QStandardItem, reducing the number of expensive signals from the model
    if (QStandardItemModel *m = qobject_cast<QStandardItemModel*>(d->model)) {
        QList<QStandardItem *> items;
        items.reserve(insertCount);
        QStandardItem *hiddenRoot = m->invisibleRootItem();
        for (int i = 0; i < insertCount; ++i)
            items.append(new QStandardItem(list.at(i)));
        hiddenRoot->insertRows(index, items);
    } else {
        d->inserting = true;
        if (d->model->insertRows(index, insertCount, d->root)) {
            QModelIndex item;
            for (int i = 0; i < insertCount; ++i) {
                item = d->model->index(i+index, d->modelColumn, d->root);
                d->model->setData(item, list.at(i), Qt::EditRole);
            }
            d->inserting = false;
            d->rowsInserted(d->root, index, index + insertCount - 1);
        } else {
            d->inserting = false;
        }
    }
 
    int mc = count();
    if (mc > d->maxCount)
        d->model->removeRows(d->maxCount, mc - d->maxCount, d->root);
}
 
/*!
    \since 4.4
 
    Inserts a separator item into the combobox at the given \a index.
 
    If the index is equal to or higher than the total number of items, the new item
    is appended to the list of existing items. If the index is zero or negative, the
    new item is prepended to the list of existing items.
 
    \sa insertItem()
*/
void QComboBox::insertSeparator(int index)
{
    Q_D(QComboBox);
    int itemCount = count();
    index = qBound(0, index, itemCount);
    if (index >= d->maxCount)
        return;
    insertItem(index, QIcon(), QString());
    QComboBoxDelegate::setSeparator(d->model, d->model->index(index, 0, d->root));
}
 
/*!
    Removes the item at the given \a index from the combobox.
    This will update the current index if the index is removed.
 
    This function does nothing if \a index is out of range.
*/
void QComboBox::removeItem(int index)
{
    Q_D(QComboBox);
    if (index < 0 || index >= count())
        return;
    d->model->removeRows(index, 1, d->root);
}
 
/*!
    Sets the \a text for the item on the given \a index in the combobox.
*/
void QComboBox::setItemText(int index, const QString &text)
{
    Q_D(const QComboBox);
    QModelIndex item = d->model->index(index, d->modelColumn, d->root);
    if (item.isValid()) {
        d->model->setData(item, text, Qt::EditRole);
    }
}
 
/*!
    Sets the \a icon for the item on the given \a index in the combobox.
*/
void QComboBox::setItemIcon(int index, const QIcon &icon)
{
    Q_D(const QComboBox);
    QModelIndex item = d->model->index(index, d->modelColumn, d->root);
    if (item.isValid()) {
        d->model->setData(item, icon, Qt::DecorationRole);
    }
}
 
/*!
    Sets the data \a role for the item on the given \a index in the combobox
    to the specified \a value.
*/
void QComboBox::setItemData(int index, const QVariant &value, int role)
{
    Q_D(const QComboBox);
    QModelIndex item = d->model->index(index, d->modelColumn, d->root);
    if (item.isValid()) {
        d->model->setData(item, value, role);
    }
}
 
/*!
    Returns the list view used for the combobox popup.
*/
QAbstractItemView *QComboBox::view() const
{
    Q_D(const QComboBox);
    return const_cast<QComboBoxPrivate*>(d)->viewContainer()->itemView();
}
 
/*!
  Sets the view to be used in the combobox popup to the given \a
  itemView. The combobox takes ownership of the view.
 
  Note: If you want to use the convenience views (like QListWidget,
  QTableWidget or QTreeWidget), make sure to call setModel() on the
  combobox with the convenience widgets model before calling this
  function.
*/
void QComboBox::setView(QAbstractItemView *itemView)
{
    Q_D(QComboBox);
    if (Q_UNLIKELY(!itemView)) {
        qWarning("QComboBox::setView: cannot set a 0 view");
        return;
    }
 
    if (itemView->model() != d->model) {
        d->disconnectModel();
        itemView->setModel(d->model);
        d->connectModel();
    }
    d->viewContainer()->setItemView(itemView);
}
 
/*!
    \reimp
*/
QSize QComboBox::minimumSizeHint() const
{
    Q_D(const QComboBox);
    return d->recomputeSizeHint(d->minimumSizeHint);
}
 
/*!
    \reimp
 
    This implementation caches the size hint to avoid resizing when
    the contents change dynamically. To invalidate the cached value
    change the \l sizeAdjustPolicy.
*/
QSize QComboBox::sizeHint() const
{
    Q_D(const QComboBox);
    return d->recomputeSizeHint(d->sizeHint);
}
 
#ifdef Q_OS_MACOS
void QComboBoxPrivate::cleanupNativePopup()
{
    if (!m_platformMenu)
        return;
 
    m_platformMenu->setVisible(false);
    int count = int(m_platformMenu->tag());
    for (int i = 0; i < count; ++i)
        m_platformMenu->menuItemAt(i)->deleteLater();
 
    delete m_platformMenu;
    m_platformMenu = nullptr;
}
 
/*!
 * \internal
 *
 * Tries to show a native popup. Returns true if it could, false otherwise.
 *
 */
bool QComboBoxPrivate::showNativePopup()
{
    Q_Q(QComboBox);
 
    cleanupNativePopup();
 
    QPlatformTheme *theme = QGuiApplicationPrivate::instance()->platformTheme();
    m_platformMenu = theme->createPlatformMenu();
    if (!m_platformMenu)
        return false;
 
    int itemsCount = q->count();
    m_platformMenu->setTag(quintptr(itemsCount));
 
    QPlatformMenuItem *currentItem = nullptr;
    int currentIndex = q->currentIndex();
 
    for (int i = 0; i < itemsCount; ++i) {
        QPlatformMenuItem *item = theme->createPlatformMenuItem();
        QModelIndex rowIndex = model->index(i, modelColumn, root);
        QVariant textVariant = model->data(rowIndex, Qt::EditRole);
        item->setText(textVariant.toString());
        QVariant iconVariant = model->data(rowIndex, Qt::DecorationRole);
        const Qt::ItemFlags itemFlags = model->flags(rowIndex);
        if (iconVariant.canConvert<QIcon>())
            item->setIcon(iconVariant.value<QIcon>());
        item->setCheckable(true);
        item->setChecked(i == currentIndex);
        item->setEnabled(itemFlags & Qt::ItemIsEnabled);
        if (!currentItem || i == currentIndex)
            currentItem = item;
 
        IndexSetter setter = { i, q };
        QObject::connect(item, &QPlatformMenuItem::activated, q, setter);
 
        m_platformMenu->insertMenuItem(item, 0);
        m_platformMenu->syncMenuItem(item);
    }
 
    QWindow *tlw = q->window()->windowHandle();
    m_platformMenu->setFont(q->font());
    m_platformMenu->setMinimumWidth(q->rect().width());
    QPoint offset = QPoint(0, 7);
    if (q->testAttribute(Qt::WA_MacSmallSize))
        offset = QPoint(-1, 7);
    else if (q->testAttribute(Qt::WA_MacMiniSize))
        offset = QPoint(-2, 6);
 
    [[maybe_unused]] QPointer<QComboBox> guard(q);
    const QRect targetRect = QRect(tlw->mapFromGlobal(q->mapToGlobal(offset)), QSize());
    m_platformMenu->showPopup(tlw, QHighDpi::toNativePixels(targetRect, tlw), currentItem);
 
#ifdef Q_OS_MACOS
    if (guard) {
        // The Cocoa popup will swallow any mouse release event.
        // We need to fake one here to un-press the button.
        QMouseEvent mouseReleased(QEvent::MouseButtonRelease, q->pos(), q->mapToGlobal(QPoint(0, 0)),
                                Qt::LeftButton, Qt::MouseButtons(Qt::LeftButton), {});
        QCoreApplication::sendEvent(q, &mouseReleased);
    }
#endif
 
    return true;
}
 
#endif // Q_OS_MACOS
 
/*!
    Displays the list of items in the combobox. If the list is empty
    then no items will be shown.
 
    If you reimplement this function to show a custom pop-up, make
    sure you call hidePopup() to reset the internal state.
 
    \sa hidePopup()
*/
void QComboBox::showPopup()
{
    Q_D(QComboBox);
    if (count() <= 0)
        return;
 
    QStyle * const style = this->style();
    QStyleOptionComboBox opt;
    initStyleOption(&opt);
    const bool usePopup = style->styleHint(QStyle::SH_ComboBox_Popup, &opt, this);
 
#ifdef Q_OS_MACOS
    if (usePopup
        && (!d->container
            || (qobject_cast<QComboBoxListView*>(view())
                && qobject_cast<QComboMenuDelegate*>(view()->itemDelegate())))
        && style->styleHint(QStyle::SH_ComboBox_UseNativePopup, &opt, this)
        && d->showNativePopup())
        return;
#endif // Q_OS_MACOS
 
    QComboBoxPrivateContainer* container = d->viewContainer();
    QRect listRect(style->subControlRect(QStyle::CC_ComboBox, &opt,
                                         QStyle::SC_ComboBoxListBoxPopup, this));
    QRect screen = d->popupGeometry(mapToGlobal(listRect.topLeft()));
 
    QPoint below = mapToGlobal(listRect.bottomLeft());
    int belowHeight = screen.bottom() - below.y();
    QPoint above = mapToGlobal(listRect.topLeft());
    int aboveHeight = above.y() - screen.y();
    bool boundToScreen = !window()->testAttribute(Qt::WA_DontShowOnScreen);
    const auto listView = qobject_cast<QListView *>(d->viewContainer()->itemView());
 
    {
        int listHeight = 0;
        int count = 0;
        QStack<QModelIndex> toCheck;
        toCheck.push(view()->rootIndex());
#if QT_CONFIG(treeview)
        QTreeView *treeView = qobject_cast<QTreeView*>(view());
        if (treeView && treeView->header() && !treeView->header()->isHidden())
            listHeight += treeView->header()->height();
#endif
        while (!toCheck.isEmpty()) {
            QModelIndex parent = toCheck.pop();
            for (int i = 0, end = d->model->rowCount(parent); i < end; ++i) {
                if (listView && listView->isRowHidden(i))
                    continue;
                QModelIndex idx = d->model->index(i, d->modelColumn, parent);
                if (!idx.isValid())
                    continue;
                listHeight += view()->visualRect(idx).height();
#if QT_CONFIG(treeview)
                if (d->model->hasChildren(idx) && treeView && treeView->isExpanded(idx))
                    toCheck.push(idx);
#endif
                ++count;
                if (!usePopup && count >= d->maxVisibleItems) {
                    toCheck.clear();
                    break;
                }
            }
        }
        if (count > 1)
            listHeight += (count - 1) * container->spacing();
        listRect.setHeight(listHeight);
    }
 
    {
        // add the spacing for the grid on the top and the bottom;
        int heightMargin = container->topMargin()  + container->bottomMargin();
 
        // add the frame of the container
        const QMargins cm = container->contentsMargins();
        heightMargin += cm.top() + cm.bottom();
 
        //add the frame of the view
        const QMargins vm = view()->contentsMargins();
        heightMargin += vm.top() + vm.bottom();
        heightMargin += static_cast<QAbstractScrollAreaPrivate *>(QObjectPrivate::get(view()))->top;
        heightMargin += static_cast<QAbstractScrollAreaPrivate *>(QObjectPrivate::get(view()))->bottom;
 
        listRect.setHeight(listRect.height() + heightMargin);
    }
 
    // Add space for margin at top and bottom if the style wants it.
    if (usePopup)
        listRect.setHeight(listRect.height() + style->pixelMetric(QStyle::PM_MenuVMargin, &opt, this) * 2);
 
    // Make sure the popup is wide enough to display its contents.
    if (usePopup) {
        const int diff = d->computeWidthHint() - width();
        if (diff > 0)
            listRect.setWidth(listRect.width() + diff);
    }
 
    //we need to activate the layout to make sure the min/maximum size are set when the widget was not yet show
    container->layout()->activate();
    //takes account of the minimum/maximum size of the container
    listRect.setSize( listRect.size().expandedTo(container->minimumSize())
                      .boundedTo(container->maximumSize()));
 
    // make sure the widget fits on screen
    if (boundToScreen) {
        if (listRect.width() > screen.width() )
            listRect.setWidth(screen.width());
        if (mapToGlobal(listRect.bottomRight()).x() > screen.right()) {
            below.setX(screen.x() + screen.width() - listRect.width());
            above.setX(screen.x() + screen.width() - listRect.width());
        }
        if (mapToGlobal(listRect.topLeft()).x() < screen.x() ) {
            below.setX(screen.x());
            above.setX(screen.x());
        }
    }
 
    if (usePopup) {
        // Position horizontally.
        listRect.moveLeft(above.x());
 
        // Position vertically so the currently selected item lines up
        // with the combo box. In order to do that, make sure that the item
        // view is scrolled to the top first, otherwise calls to view()->visualRect()
        // will return the geometry the selected item had the last time the popup
        // was visible (and perhaps scrolled). And this will not match the geometry
        // it will actually have when we resize the container to fit all the items
        // further down in this function.
        view()->scrollToTop();
        const QRect currentItemRect = view()->visualRect(view()->currentIndex());
        const int offset = listRect.top() - currentItemRect.top();
        listRect.moveTop(above.y() + offset - listRect.top());
 
        // Clamp the listRect height and vertical position so we don't expand outside the
        // available screen geometry.This may override the vertical position, but it is more
        // important to show as much as possible of the popup.
        const int height = !boundToScreen ? listRect.height() : qMin(listRect.height(), screen.height());
        listRect.setHeight(height);
 
        if (boundToScreen) {
            if (listRect.top() < screen.top())
                listRect.moveTop(screen.top());
            if (listRect.bottom() > screen.bottom())
                listRect.moveBottom(screen.bottom());
        }
    } else if (!boundToScreen || listRect.height() <= belowHeight) {
        listRect.moveTopLeft(below);
    } else if (listRect.height() <= aboveHeight) {
        listRect.moveBottomLeft(above);
    } else if (belowHeight >= aboveHeight) {
        listRect.setHeight(belowHeight);
        listRect.moveTopLeft(below);
    } else {
        listRect.setHeight(aboveHeight);
        listRect.moveBottomLeft(above);
    }
 
    if (qApp) {
        QGuiApplication::inputMethod()->reset();
    }
 
    const QScrollBar *sb = view()->horizontalScrollBar();
    const auto needHorizontalScrollBar = [this, sb]{
        const Qt::ScrollBarPolicy policy = view()->horizontalScrollBarPolicy();
        return (policy == Qt::ScrollBarAsNeeded || policy == Qt::ScrollBarAlwaysOn)
               && sb->minimum() < sb->maximum();
    };
    const bool neededHorizontalScrollBar = needHorizontalScrollBar();
    if (neededHorizontalScrollBar)
        listRect.adjust(0, 0, 0, sb->height());
 
    // Hide the scrollers here, so that the listrect gets the full height of the container
    // If the scrollers are truly needed, the later call to container->updateScrollers()
    // will make them visible again.
    container->hideScrollers();
    container->setGeometry(listRect);
 
#ifndef Q_OS_MACOS
    const bool updatesEnabled = container->updatesEnabled();
#endif
 
#if QT_CONFIG(effects)
    bool scrollDown = (listRect.topLeft() == below);
    if (QApplication::isEffectEnabled(Qt::UI_AnimateCombo)
        && !style->styleHint(QStyle::SH_ComboBox_Popup, &opt, this) && !window()->testAttribute(Qt::WA_DontShowOnScreen))
        qScrollEffect(container, scrollDown ? QEffects::DownScroll : QEffects::UpScroll, 150);
#endif
 
// Don't disable updates on OS X. Windows are displayed immediately on this platform,
// which means that the window will be visible before the call to container->show() returns.
// If updates are disabled at this point we'll miss our chance at painting the popup
// menu before it's shown, causing flicker since the window then displays the standard gray
// background.
#ifndef Q_OS_MACOS
    container->setUpdatesEnabled(false);
#endif
 
    bool startTimer = !container->isVisible();
    container->raise();
    container->create();
    if (QWindow *containerWindow = qt_widget_private(container)->windowHandle(QWidgetPrivate::WindowHandleMode::TopLevel)) {
        QScreen *currentScreen = d->associatedScreen();
        if (currentScreen && !currentScreen->virtualSiblings().contains(containerWindow->screen())) {
            containerWindow->setScreen(currentScreen);
 
            // This seems to workaround an issue in xcb+multi GPU+multiscreen
            // environment where the window might not always show up when screen
            // is changed.
            container->hide();
        }
    }
 
#if QT_CONFIG(wayland)
    if (auto waylandWindow = dynamic_cast<QNativeInterface::Private::QWaylandWindow*>(container->windowHandle()->handle())) {
        const QRect popup(style->subControlRect(QStyle::CC_ComboBox, &opt,
                                         QStyle::SC_ComboBoxListBoxPopup, this));
        const QRect controlGeometry = QRect(mapTo(window(), popup.topLeft()), popup.size());
        waylandWindow->setParentControlGeometry(controlGeometry);
        waylandWindow->setExtendedWindowType(QNativeInterface::Private::QWaylandWindow::ComboBox);
    }
#endif
 
    container->show();
    if (!neededHorizontalScrollBar && needHorizontalScrollBar()) {
        listRect.adjust(0, 0, 0, sb->height());
        container->setGeometry(listRect);
    }
 
    container->updateScrollers();
    view()->setFocus();
 
    view()->scrollTo(view()->currentIndex(),
                     style->styleHint(QStyle::SH_ComboBox_Popup, &opt, this)
                             ? QAbstractItemView::PositionAtCenter
                             : QAbstractItemView::EnsureVisible);
 
#ifndef Q_OS_MACOS
    container->setUpdatesEnabled(updatesEnabled);
#endif
 
    container->update();
    if (startTimer) {
        container->popupTimer.start();
        container->maybeIgnoreMouseButtonRelease = true;
    }
}
 
/*!
    Hides the list of items in the combobox if it is currently visible
    and resets the internal state, so that if the custom pop-up was
    shown inside the reimplemented showPopup(), then you also need to
    reimplement the hidePopup() function to hide your custom pop-up
    and call the base class implementation to reset the internal state
    whenever your custom pop-up widget is hidden.
 
    \sa showPopup()
*/
void QComboBox::hidePopup()
{
    Q_D(QComboBox);
    if (d->hidingPopup)
        return;
    d->hidingPopup = true;
    // can't use QScopedValueRollback on a bitfield
    auto resetHidingPopup = qScopeGuard([d]{
        d->hidingPopup = false;
    });
 
    if (!d->container || !d->container->isVisible())
        return;
 
#if QT_CONFIG(effects)
    QItemSelectionModel *selectionModel = d->container->itemView()
                                        ? d->container->itemView()->selectionModel() : nullptr;
    // Flash selected/triggered item (if any) before hiding the popup.
    if (style()->styleHint(QStyle::SH_Menu_FlashTriggeredItem, nullptr, this) &&
        selectionModel && selectionModel->hasSelection()) {
        const QItemSelection selection = selectionModel->selection();
 
        QTimer::singleShot(0, d->container, [d, selection, selectionModel]{
            QSignalBlocker modelBlocker(d->model);
            QSignalBlocker viewBlocker(d->container->itemView());
            QSignalBlocker containerBlocker(d->container);
 
            // Deselect item and wait 60 ms.
            selectionModel->select(selection, QItemSelectionModel::Toggle);
            QTimer::singleShot(60, d->container, [d, selection, selectionModel]{
                QSignalBlocker modelBlocker(d->model);
                QSignalBlocker viewBlocker(d->container->itemView());
                QSignalBlocker containerBlocker(d->container);
                selectionModel->select(selection, QItemSelectionModel::Toggle);
                QTimer::singleShot(20, d->container, [d] {
                    d->doHidePopup();
                });
            });
        });
    } else
#endif // QT_CONFIG(effects)
    {
        d->doHidePopup();
    }
}
 
void QComboBoxPrivate::doHidePopup()
{
    if (container && container->isVisible())
        container->hide();
 
    resetButton();
}
 
void QComboBoxPrivate::updateCurrentText(const QString &text)
{
    if (text == currentText)
        return;
 
    currentText = text;
    emit q_func()->currentTextChanged(text);
}
 
/*!
    Clears the combobox, removing all items.
 
    Note: If you have set an external model on the combobox this model
    will still be cleared when calling this function.
*/
void QComboBox::clear()
{
    Q_D(QComboBox);
    d->model->removeRows(0, d->model->rowCount(d->root), d->root);
#if QT_CONFIG(accessibility)
    QAccessibleValueChangeEvent event(this, QString());
    QAccessible::updateAccessibility(&event);
#endif
}
 
/*!
    Clears the contents of the line edit used for editing in the combobox.
*/
void QComboBox::clearEditText()
{
    Q_D(QComboBox);
    if (d->lineEdit)
        d->lineEdit->clear();
#if QT_CONFIG(accessibility)
    QAccessibleValueChangeEvent event(this, QString());
    QAccessible::updateAccessibility(&event);
#endif
}
 
/*!
    Sets the \a text in the combobox's text edit.
*/
void QComboBox::setEditText(const QString &text)
{
    Q_D(QComboBox);
    if (d->lineEdit)
        d->lineEdit->setText(text);
#if QT_CONFIG(accessibility)
    QAccessibleValueChangeEvent event(this, text);
    QAccessible::updateAccessibility(&event);
#endif
}
 
/*!
    \reimp
*/
void QComboBox::focusInEvent(QFocusEvent *e)
{
    Q_D(QComboBox);
    update();
    if (d->lineEdit) {
        d->lineEdit->event(e);
#if QT_CONFIG(completer)
        if (d->lineEdit->completer())
            d->lineEdit->completer()->setWidget(this);
#endif
    }
}
 
/*!
    \reimp
*/
void QComboBox::focusOutEvent(QFocusEvent *e)
{
    Q_D(QComboBox);
    update();
    if (d->lineEdit)
        d->lineEdit->event(e);
}
 
/*! \reimp */
void QComboBox::changeEvent(QEvent *e)
{
    Q_D(QComboBox);
    switch (e->type()) {
    case QEvent::StyleChange:
        if (d->container)
            d->container->updateStyleSettings();
        d->updateDelegate();
 
#ifdef Q_OS_MACOS
    case QEvent::MacSizeChange:
#endif
        d->sizeHint = QSize(); // invalidate size hint
        d->minimumSizeHint = QSize();
        d->updateLayoutDirection();
        if (d->lineEdit)
            d->updateLineEditGeometry();
        d->setLayoutItemMargins(QStyle::SE_ComboBoxLayoutItem);
 
        if (e->type() == QEvent::MacSizeChange) {
            QPlatformTheme::Font f = QPlatformTheme::SystemFont;
            if (testAttribute(Qt::WA_MacSmallSize))
                f = QPlatformTheme::SmallFont;
            else if (testAttribute(Qt::WA_MacMiniSize))
                f = QPlatformTheme::MiniFont;
            if (const QFont *platformFont = QApplicationPrivate::platformTheme()->font(f)) {
                QFont f = font();
                f.setPointSizeF(platformFont->pointSizeF());
                setFont(f);
            }
        }
        // ### need to update scrollers etc. as well here
        break;
    case QEvent::EnabledChange:
        if (!isEnabled())
            hidePopup();
        break;
    case QEvent::PaletteChange: {
        d->updateViewContainerPaletteAndOpacity();
        break;
    }
    case QEvent::FontChange: {
        d->sizeHint = QSize(); // invalidate size hint
        d->viewContainer()->setFont(font());
        d->viewContainer()->itemView()->doItemsLayout();
        if (d->lineEdit)
            d->updateLineEditGeometry();
        break;
    }
    default:
        break;
    }
    QWidget::changeEvent(e);
}
 
/*!
    \reimp
*/
void QComboBox::resizeEvent(QResizeEvent *)
{
    Q_D(QComboBox);
    d->updateLineEditGeometry();
}
 
/*!
    \reimp
*/
void QComboBox::paintEvent(QPaintEvent *)
{
    Q_D(QComboBox);
    QStylePainter painter(this);
    painter.setPen(palette().color(QPalette::Text));
 
    // draw the combobox frame, focusrect and selected etc.
    QStyleOptionComboBox opt;
    initStyleOption(&opt);
    painter.drawComplexControl(QStyle::CC_ComboBox, opt);
 
    if (currentIndex() < 0 && !placeholderText().isEmpty()) {
        opt.palette.setBrush(QPalette::ButtonText, opt.palette.placeholderText());
        opt.currentText = placeholderText();
    }
 
    // draw contents
    if (itemDelegate() && labelDrawingMode() == QComboBox::LabelDrawingMode::UseDelegate) {
        QStyleOptionViewItem itemOption;
        d->initViewItemOption(&itemOption);
        itemOption.rect = style()->subControlRect(QStyle::CC_ComboBox, &opt,
                                                  QStyle::SC_ComboBoxEditField, this);
        itemDelegate()->paint(&painter, itemOption, d->currentIndex);
    } else {
        // draw the icon and text
        painter.drawControl(QStyle::CE_ComboBoxLabel, opt);
    }
}
 
/*!
    \reimp
*/
void QComboBox::showEvent(QShowEvent *e)
{
    Q_D(QComboBox);
    if (!d->shownOnce && d->sizeAdjustPolicy == QComboBox::AdjustToContentsOnFirstShow) {
        d->sizeHint = QSize();
        updateGeometry();
    }
    d->shownOnce = true;
    QWidget::showEvent(e);
}
 
/*!
    \reimp
*/
void QComboBox::hideEvent(QHideEvent *)
{
    hidePopup();
}
 
/*!
    \reimp
*/
bool QComboBox::event(QEvent *event)
{
    Q_D(QComboBox);
    switch(event->type()) {
    case QEvent::LayoutDirectionChange:
    case QEvent::ApplicationLayoutDirectionChange:
        d->updateLayoutDirection();
        d->updateLineEditGeometry();
        break;
    case QEvent::HoverEnter:
    case QEvent::HoverLeave:
    case QEvent::HoverMove:
        if (const QHoverEvent *he = static_cast<const QHoverEvent *>(event))
            d->updateHoverControl(he->position().toPoint());
        break;
    case QEvent::ShortcutOverride:
        if (d->lineEdit)
            return d->lineEdit->event(event);
        break;
    default:
        break;
    }
    return QWidget::event(event);
}
 
/*!
    \reimp
*/
void QComboBox::mousePressEvent(QMouseEvent *e)
{
    Q_D(QComboBox);
    if (!QGuiApplication::styleHints()->setFocusOnTouchRelease())
        d->showPopupFromMouseEvent(e);
}
 
void QComboBoxPrivate::showPopupFromMouseEvent(QMouseEvent *e)
{
    Q_Q(QComboBox);
    QStyleOptionComboBox opt;
    q->initStyleOption(&opt);
    QStyle::SubControl sc = q->style()->hitTestComplexControl(QStyle::CC_ComboBox, &opt, e->position().toPoint(), q);
 
    if (e->button() == Qt::LeftButton
            && !(sc == QStyle::SC_None && e->type() == QEvent::MouseButtonRelease)
            && (sc == QStyle::SC_ComboBoxArrow || !q->isEditable())
            && !viewContainer()->isVisible()) {
        if (sc == QStyle::SC_ComboBoxArrow)
            updateArrow(QStyle::State_Sunken);
        // We've restricted the next couple of lines, because by not calling
        // viewContainer(), we avoid creating the QComboBoxPrivateContainer.
        viewContainer()->initialClickPosition = q->mapToGlobal(e->position());
        QPointer<QComboBox> guard = q;
        q->showPopup();
        if (!guard)
            return;
        // The code below ensures that regular mousepress and pick item still works
        // If it was not called the viewContainer would ignore event since it didn't have
        // a mousePressEvent first.
        if (viewContainer()) {
            viewContainer()->blockMouseReleaseTimer.start(QApplication::doubleClickInterval());
            viewContainer()->maybeIgnoreMouseButtonRelease = false;
        }
    } else {
        e->ignore();
    }
}
 
/*!
    \reimp
*/
void QComboBox::mouseReleaseEvent(QMouseEvent *e)
{
    Q_D(QComboBox);
    d->updateArrow(QStyle::State_None);
    if (QGuiApplication::styleHints()->setFocusOnTouchRelease() && hasFocus())
        d->showPopupFromMouseEvent(e);
}
 
/*!
    \reimp
*/
void QComboBox::keyPressEvent(QKeyEvent *e)
{
    Q_D(QComboBox);
 
#if QT_CONFIG(completer)
    if (const auto *cmpltr = completer()) {
        const auto *popup = QCompleterPrivate::get(cmpltr)->popup;
        if (popup && popup->isVisible()) {
            // provide same autocompletion support as line edit
            d->lineEdit->event(e);
            return;
        }
    }
#endif
 
    enum Move { NoMove=0 , MoveUp , MoveDown , MoveFirst , MoveLast};
 
    Move move = NoMove;
    int newIndex = currentIndex();
 
    bool pressLikeButton = !d->lineEdit;
    auto key = e->key();
    if (pressLikeButton) {
        const auto buttonPressKeys = QGuiApplicationPrivate::platformTheme()
                                             ->themeHint(QPlatformTheme::ButtonPressKeys)
                                             .value<QList<Qt::Key>>();
        if (buttonPressKeys.contains(key)) {
            showPopup();
            return;
        }
    }
 
    switch (key) {
    case Qt::Key_Up:
        if (e->modifiers() & Qt::ControlModifier)
            break; // pass to line edit for auto completion
        Q_FALLTHROUGH();
    case Qt::Key_PageUp:
        move = MoveUp;
        break;
    case Qt::Key_Down:
        if (e->modifiers() & Qt::AltModifier) {
            showPopup();
            return;
        } else if (e->modifiers() & Qt::ControlModifier)
            break; // pass to line edit for auto completion
        Q_FALLTHROUGH();
    case Qt::Key_PageDown:
        move = MoveDown;
        break;
    case Qt::Key_Home:
        if (!d->lineEdit)
            move = MoveFirst;
        break;
    case Qt::Key_End:
        if (!d->lineEdit)
            move = MoveLast;
        break;
    case Qt::Key_F4:
        if (!e->modifiers()) {
            showPopup();
            return;
        }
        break;
    case Qt::Key_Enter:
    case Qt::Key_Return:
    case Qt::Key_Escape:
        if (!d->lineEdit)
            e->ignore();
        break;
    default:
#if QT_CONFIG(shortcut)
        if (d->container && d->container->isVisible() && e->matches(QKeySequence::Cancel)) {
            hidePopup();
            e->accept();
        }
#endif
 
        if (!d->lineEdit) {
            const auto text = e->text();
            if (!text.isEmpty() && text.at(0).isPrint())
                d->keyboardSearchString(text);
            else
                e->ignore();
        }
    }
 
    const int rowCount = count();
 
    if (move != NoMove) {
        e->accept();
        switch (move) {
        case MoveFirst:
            newIndex = -1;
            Q_FALLTHROUGH();
        case MoveDown:
            newIndex++;
            while (newIndex < rowCount && !(d->model->index(newIndex, d->modelColumn, d->root).flags() & Qt::ItemIsEnabled))
                newIndex++;
            break;
        case MoveLast:
            newIndex = rowCount;
            Q_FALLTHROUGH();
        case MoveUp:
            newIndex--;
            while ((newIndex >= 0) && !(d->model->flags(d->model->index(newIndex,d->modelColumn,d->root)) & Qt::ItemIsEnabled))
                newIndex--;
            break;
        default:
            e->ignore();
            break;
        }
 
        if (newIndex >= 0 && newIndex < rowCount && newIndex != currentIndex()) {
            setCurrentIndex(newIndex);
            d->emitActivated(d->currentIndex);
        }
    } else if (d->lineEdit) {
        d->lineEdit->event(e);
    }
}
 
 
/*!
    \reimp
*/
void QComboBox::keyReleaseEvent(QKeyEvent *e)
{
    Q_D(QComboBox);
    if (d->lineEdit)
        d->lineEdit->event(e);
    else
        QWidget::keyReleaseEvent(e);
}
 
/*!
    \reimp
*/
#if QT_CONFIG(wheelevent)
void QComboBox::wheelEvent(QWheelEvent *e)
{
    Q_D(QComboBox);
    QStyleOptionComboBox opt;
    initStyleOption(&opt);
    if (style()->styleHint(QStyle::SH_ComboBox_AllowWheelScrolling, &opt, this) &&
        !d->viewContainer()->isVisible()) {
        const int rowCount = count();
        int newIndex = currentIndex();
        int delta = e->angleDelta().y();
 
        if (delta > 0) {
            newIndex--;
            while ((newIndex >= 0) && !(d->model->flags(d->model->index(newIndex,d->modelColumn,d->root)) & Qt::ItemIsEnabled))
                newIndex--;
        } else if (delta < 0) {
            newIndex++;
            while (newIndex < rowCount && !(d->model->index(newIndex, d->modelColumn, d->root).flags() & Qt::ItemIsEnabled))
                newIndex++;
        }
 
        if (newIndex >= 0 && newIndex < rowCount && newIndex != currentIndex()) {
            setCurrentIndex(newIndex);
            d->emitActivated(d->currentIndex);
        }
        e->accept();
    } else {
        e->ignore();
    }
}
#endif
 
#ifndef QT_NO_CONTEXTMENU
/*!
    \reimp
*/
void QComboBox::contextMenuEvent(QContextMenuEvent *e)
{
    Q_D(QComboBox);
    if (d->lineEdit) {
        Qt::ContextMenuPolicy p = d->lineEdit->contextMenuPolicy();
        d->lineEdit->setContextMenuPolicy(Qt::DefaultContextMenu);
        d->lineEdit->event(e);
        d->lineEdit->setContextMenuPolicy(p);
    }
}
#endif // QT_NO_CONTEXTMENU
 
void QComboBoxPrivate::keyboardSearchString(const QString &text)
{
    // use keyboardSearch from the listView so we do not duplicate code
    QAbstractItemView *view = viewContainer()->itemView();
    view->setCurrentIndex(currentIndex);
    int currentRow = view->currentIndex().row();
    view->keyboardSearch(text);
    if (currentRow != view->currentIndex().row()) {
        setCurrentIndex(view->currentIndex());
        emitActivated(currentIndex);
    }
}
 
void QComboBoxPrivate::modelChanged()
{
    Q_Q(QComboBox);
 
    if (sizeAdjustPolicy == QComboBox::AdjustToContents) {
        sizeHint = QSize();
        adjustComboBoxSize();
        q->updateGeometry();
    }
}
 
/*!
    \reimp
*/
void QComboBox::inputMethodEvent(QInputMethodEvent *e)
{
    Q_D(QComboBox);
    if (d->lineEdit) {
        d->lineEdit->event(e);
    } else {
        if (!e->commitString().isEmpty())
            d->keyboardSearchString(e->commitString());
        else
            e->ignore();
    }
}
 
/*!
    \reimp
*/
QVariant QComboBox::inputMethodQuery(Qt::InputMethodQuery query) const
{
    Q_D(const QComboBox);
    if (d->lineEdit)
        return d->lineEdit->inputMethodQuery(query);
    return QWidget::inputMethodQuery(query);
}
 
/*!\internal
*/
QVariant QComboBox::inputMethodQuery(Qt::InputMethodQuery query, const QVariant &argument) const
{
    Q_D(const QComboBox);
    if (d->lineEdit)
        return d->lineEdit->inputMethodQuery(query, argument);
    return QWidget::inputMethodQuery(query);
}
 
/*!
    \fn void QComboBox::addItem(const QString &text, const QVariant &userData)
 
    Adds an item to the combobox with the given \a text, and
    containing the specified \a userData (stored in the Qt::UserRole).
    The item is appended to the list of existing items.
*/
 
/*!
    \fn void QComboBox::addItem(const QIcon &icon, const QString &text,
                                const QVariant &userData)
 
    Adds an item to the combobox with the given \a icon and \a text,
    and containing the specified \a userData (stored in the
    Qt::UserRole). The item is appended to the list of existing items.
*/
 
/*!
    \fn void QComboBox::addItems(const QStringList &texts)
 
    Adds each of the strings in the given \a texts to the combobox. Each item
    is appended to the list of existing items in turn.
*/
 
/*!
    \fn void QComboBox::editTextChanged(const QString &text)
 
    This signal is emitted when the text in the combobox's line edit
    widget is changed. The new text is specified by \a text.
*/
 
/*!
    \property QComboBox::frame
    \brief whether the combo box draws itself with a frame.
 
 
    If enabled (the default) the combo box draws itself inside a
    frame, otherwise the combo box draws itself without any frame.
*/
bool QComboBox::hasFrame() const
{
    Q_D(const QComboBox);
    return d->frame;
}
 
 
void QComboBox::setFrame(bool enable)
{
    Q_D(QComboBox);
    d->frame = enable;
    update();
    updateGeometry();
}
 
/*!
    \property QComboBox::modelColumn
    \brief the column in the model that is visible.
 
    If set prior to populating the combo box, the pop-up view will
    not be affected and will show the first column (using this property's
    default value).
 
    By default, this property has a value of 0.
 
    \note In an editable combobox, the visible column will also become
    the \l{QCompleter::completionColumn}{completion column}.
*/
int QComboBox::modelColumn() const
{
    Q_D(const QComboBox);
    return d->modelColumn;
}
 
void QComboBox::setModelColumn(int visibleColumn)
{
    Q_D(QComboBox);
    d->modelColumn = visibleColumn;
    QListView *lv = qobject_cast<QListView *>(d->viewContainer()->itemView());
    if (lv)
        lv->setModelColumn(visibleColumn);
#if QT_CONFIG(completer)
    if (d->lineEdit && d->lineEdit->completer())
        d->lineEdit->completer()->setCompletionColumn(visibleColumn);
#endif
    setCurrentIndex(currentIndex()); //update the text to the text of the new column;
}
 
/*!
    \enum QComboBox::LabelDrawingMode
    \since 6.9
 
    This enum specifies how the combobox draws its label.
 
    \value UseStyle The combobox uses the \l{QStyle}{style} to draw its label.
    \value UseDelegate The combobox uses the \l{itemDelegate()}{item delegate} to
           draw the label. Set a suitable item delegate when using this mode.
 
    \sa labelDrawingMode, {Books}{Books example}
*/
 
/*!
    \property QComboBox::labelDrawingMode
    \since 6.9
 
    \brief the mode used by the combobox to draw its label.
 
    The default value is \l{QComboBox::}{UseStyle}. When changing this property
    to UseDelegate, make sure to also set a suitable \l{itemDelegate()}{item delegate}.
    The default delegate depends on the style and might not be suitable for
    drawing the label.
 
    \sa {Books}{Books example}
*/
QComboBox::LabelDrawingMode QComboBox::labelDrawingMode() const
{
    Q_D(const QComboBox);
    return d->labelDrawingMode;
}
 
void QComboBox::setLabelDrawingMode(LabelDrawingMode drawingLabel)
{
    Q_D(QComboBox);
    if (d->labelDrawingMode != drawingLabel) {
        d->labelDrawingMode = drawingLabel;
        update();
    }
}
 
QT_END_NAMESPACE
 
#include "moc_qcombobox.cpp"
#include "moc_qcombobox_p.cpp"