Checkbox in a header cell in QTableView

Question

I want to have a simple column header with a checkbox that selects/ deselects all rows in a QTableView. Clicking the check box in the header causes either to select or desel

Answer 1

Here is a bit modified/fixed (checkbox was displayed as disabled and redrawing didn't work) code from the link in the accepted answer.

.h

class CheckBoxHeader : public QHeaderView
{
    Q_OBJECT

public:
    CheckBoxHeader(Qt::Orientation orientation, QWidget* parent = 0);

    bool isChecked() const { return isChecked_; }
    void setIsChecked(bool val);

signals:
    void checkBoxClicked(bool state);

protected:
    void paintSection(QPainter* painter, const QRect& rect, int logicalIndex) const;

    void mousePressEvent(QMouseEvent* event);

private:
    bool isChecked_;

    void redrawCheckBox();
};

.cpp

#include "CheckBoxHeader.h"

CheckBoxHeader::CheckBoxHeader(Qt::Orientation orientation, QWidget* parent /*= 0*/)
    : QHeaderView(orientation, parent)
{
    isChecked_ = true;
}

void CheckBoxHeader::paintSection(QPainter* painter, const QRect& rect, int logicalIndex) const
{
    painter->save();
    QHeaderView::paintSection(painter, rect, logicalIndex);  
    painter->restore();
    if (logicalIndex == 0)
    {
        QStyleOptionButton option;

        option.rect = QRect(1,3,20,20);

        option.state = QStyle::State_Enabled | QStyle::State_Active;

        if (isChecked_)
            option.state |= QStyle::State_On;
        else
            option.state |= QStyle::State_Off;
        option.state |= QStyle::State_Off;

        style()->drawPrimitive(QStyle::PE_IndicatorCheckBox, &option, painter);
    }
}

void CheckBoxHeader::mousePressEvent(QMouseEvent* event)
{
    setIsChecked(!isChecked());

    emit checkBoxClicked(isChecked());
}

void CheckBoxHeader::redrawCheckBox()
{
    viewport()->update();
}

void CheckBoxHeader::setIsChecked(bool val)
{
    if (isChecked_ != val)
    {
        isChecked_ = val;

        redrawCheckBox();
    }
}

usage

CheckBoxHeader* header = new CheckBoxHeader(Qt::Horizontal, &table);
table.setHorizontalHeader(header);
// handle signal if needed (to set checkboxes in all rows, etc.)
//connect(header, &CheckBoxHeader::checkBoxClicked, this, &MyForm::on_header_checkBoxClicked);