How to catch Ctrl key release?

Question

I press the Ctrl key. My first function works fine:

void MainWindow::keyPressEvent(QKeyEvent *event){
    if(event->modifiers()==Qt::CTRL){               //RETURNS TRUE
        ui->widget->groupmaking=true;
    } }

In the second, i have troubles with checking what kind of key was released. (It was Ctrl)

void MainWindow::keyReleaseEvent(QKeyEvent *event){
    if(event->modifiers()==Qt::CTRL){               //RETURNS FALSE. WHY?
        ui->widget->groupmaking=false;
        ui->widget->groupexist=true;
    }
}

So, how to catch Ctrl release correctly ?

If you have found a solution, post it as an answer to your question, and eventually accept your own answer. — Kuba hasn't forgotten Monica, Dec 23 '13 at 15:35

score 5 · Accepted Answer · edited Oct 06 '17 at 15:37

5

The reason for such behavior is that there is no key modifier at the moment, when you get the key release event, because the Ctrl key is already released. The right way to perform such a check would be:

void keyReleaseEvent(QKeyEvent *event)
{
    if(event->key() == Qt::Key_Control) {
        [..]
    }
}

edited Oct 06 '17 at 15:37

Paul Roub

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answered Dec 23 '13 at 15:38

vahancho

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How to catch Ctrl key release?

1 Answers1