howto detect the modifier key on mouse click in QT

Question

I searched for hours but I found nothing about that.

I have a qtablewidget and by pressing CTRL while clicking on a column header a would like to mark the whole column content. To get the column index is not the problem: there is a sectionPressed signal which gives me the current index I clicked. Can anybody help?

Answer 1

The state of the keyboard modifier keys can be found by calling the modifiers() function, inherited from QInputEvent.

http://doc.qt.nokia.com/4.6/qmouseevent.html

Answer 2

this is really annoying, I have to install an eventFilter and remove the sectionPressed handler

ui->tableWidget->horizontalHeader()->viewport()->installEventFilter(this);

Within the eventFilter I can check wether a key was pressed like so

bool MainWindow::eventFilter(QObject *object, QEvent *event)
{
    if(event->type() == QEvent::MouseButtonPress)
    {
        if(Qt::ControlModifier == QApplication::keyboardModifiers())
        {
            QMouseEvent *mouseEvent = static_cast<QMouseEvent *>(event);
            if(mouseEvent)
            {
                if(mouseEvent->button()== Qt::LeftButton)
                {
                    ui->tableWidget->selectColumn(ui->tableWidget->itemAt(mouseEvent->pos())->column());
                    return true;
                }
            }
        }
    }

    return QWidget::eventFilter(object,event);
}

Answer 3

Try QApplication::keyboardModifiers() which is always available.