CheckboxDelegate Class Reference

Detailed Description

CheckboxDelegate modifies a model view to display boolean values as checkboxes.

Important: the column on which this delegate is set (QAbstractItemView::setItemDelegateForColumn()) must not have the flags Qt::ItemIsEditable or Qt::ItemIsUserCheckable set in the model.

Definition at line 17 of file CheckboxDelegate.h.

#include <CheckboxDelegate.h>

Inheritance diagram for CheckboxDelegate:

Collaboration diagram for CheckboxDelegate:

Public Member Functions
	CheckboxDelegate (QObject *parent=nullptr)
	Constructor.
void	paint (QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const override
	Paints a checkbox. This overrides the default painting of a combo box.
bool	editorEvent (QEvent *event, QAbstractItemModel *model, const QStyleOptionViewItem &option, const QModelIndex &index) override
	Handles the click events and sets the model data.
QSize	sizeHint (const QStyleOptionViewItem &option, const QModelIndex &index) const override

Private Member Functions
QRect	checkboxRect (const QStyleOptionViewItem &viewItemStyleOptions) const

Constructor & Destructor Documentation

CheckboxDelegate()

CheckboxDelegate::CheckboxDelegate ( QObject * parent = nullptr )

explicit

Constructor.

Definition at line 14 of file CheckboxDelegate.cpp.

: QItemDelegate(parent) {}

Member Function Documentation

checkboxRect()

QRect CheckboxDelegate::checkboxRect ( const QStyleOptionViewItem & viewItemStyleOptions ) const

private

Definition at line 92 of file CheckboxDelegate.cpp.

{
    QStyleOptionButton styleOptionButton;
    QRect rect = QApplication::style()->subElementRect(
        QStyle::SE_CheckBoxIndicator, &styleOptionButton);
    QPoint point(viewItemStyleOptions.rect.x() +
                     viewItemStyleOptions.rect.width() / 2 - rect.width() / 2,
                 viewItemStyleOptions.rect.y() +
                     viewItemStyleOptions.rect.height() / 2 -
                     rect.height() / 2);
    return QRect(point, rect.size());
}

Referenced by editorEvent(), paint(), and sizeHint().

editorEvent()

bool CheckboxDelegate::editorEvent ( QEvent * event, QAbstractItemModel * model, const QStyleOptionViewItem & option, const QModelIndex & index )

override

Handles the click events and sets the model data.

Definition at line 46 of file CheckboxDelegate.cpp.

{
    Q_UNUSED(option);
 
    if ((event->type() == QEvent::MouseButtonRelease) ||
        (event->type() == QEvent::MouseButtonDblClick))
    {
        auto* mouse_event = static_cast<QMouseEvent*>(event);
        if (mouse_event->button() != Qt::LeftButton ||
            !checkboxRect(option).contains(mouse_event->pos()))
        {
            return false;
        }
        if (event->type() == QEvent::MouseButtonDblClick)
        {
            return true;
        }
    }
    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;
    }
 
    bool checked = index.model()->data(index, Qt::DisplayRole).toBool();
    return model->setData(index, !checked, Qt::EditRole);
}

References checkboxRect().

paint()

void CheckboxDelegate::paint ( QPainter * painter, const QStyleOptionViewItem & option, const QModelIndex & index ) const

override

Paints a checkbox. This overrides the default painting of a combo box.

Definition at line 16 of file CheckboxDelegate.cpp.

{
    if (index.isValid())
    {
        bool checked = index.model()->data(index, Qt::DisplayRole).toBool();
 
        QStyleOptionButton styleOptionButton;
        styleOptionButton.state |= QStyle::State_Enabled;
        if (checked)
        {
            styleOptionButton.state |= QStyle::State_On;
        }
        else
        {
            styleOptionButton.state |= QStyle::State_Off;
        }
 
        styleOptionButton.rect = this->checkboxRect(option);
 
        QApplication::style()->drawControl(QStyle::CE_CheckBox,
                                           &styleOptionButton, painter);
    }
    else
    {
        QItemDelegate::paint(painter, option, index);
    }
}

References checkboxRect().

sizeHint()

QSize CheckboxDelegate::sizeHint ( const QStyleOptionViewItem & option, const QModelIndex & index ) const

override

Definition at line 83 of file CheckboxDelegate.cpp.

{
    Q_UNUSED(index);
 
    QRect rect = checkboxRect(option);
    return QSize(rect.width(), rect.height());
}

References checkboxRect().

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The documentation for this class was generated from the following files:

• CheckboxDelegate.h
• CheckboxDelegate.cpp