keyPressEvent not being called...

[bruceariggs]

I have a class that doesn't seem to override the keyPressEvent properly, or at least, the function isn't getting called.

It inherits from QDialog

class SelectionDialog : public QDialog

class SelectionDialog : public QDialog

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As a public function, it has:

void keyPressEvent( QKeyEvent* event );

void keyPressEvent( QKeyEvent* event );

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Which is defined as:

void SelectionDialog::keyPressEvent( QKeyEvent* event )
{
    switch( event->key() )
    {
        case Qt::Key_Up:
        {
            upClicked();
            break;
        }
        case Qt::Key_Down:
        {
            downClicked();
            break;
        }
        default:
        {
            QDialog::keyPressEvent( event );
            break;
        }
    };
}

void SelectionDialog::keyPressEvent( QKeyEvent* event )
{
    switch( event->key() )
    {
        case Qt::Key_Up:
        {
            upClicked();
            break;
        }
        case Qt::Key_Down:
        {
            downClicked();
            break;
        }
        default:
        {
            QDialog::keyPressEvent( event );
            break;
        }
    };
}

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In the constructor of my class, I do this

setFocusPolicy( Qt::StrongFocus );
    setFocus( Qt::PopupFocusReason );
    setEnabled( true );

setFocusPolicy( Qt::StrongFocus );
    setFocus( Qt::PopupFocusReason );
    setEnabled( true );

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Yet when this dialog box launches in the program, no amount of key presses gets me into this function.
What am I missing or doing wrong?

[wysota]

The dialog has to get focus when it is shown and not when it is constructed. Only visible components can have focus.

#include <QtGui>
 
class Widget : public QWidget {
public:
  Widget() : QWidget() { setFocusPolicy(Qt::StrongFocus); }
protected:
  void keyPressEvent(QKeyEvent *ke) {
    qDebug() << ke->key();
  }
};
 
 
int main(int argc, char **argv) {
  QApplication app(argc, argv);
  Widget w;
  w.show(); // gets focus automatically since is the only widget shown
  return app.exec();
}

#include <QtGui>

class Widget : public QWidget {
public:
  Widget() : QWidget() { setFocusPolicy(Qt::StrongFocus); }
protected:
  void keyPressEvent(QKeyEvent *ke) {
    qDebug() << ke->key();
  }
};


int main(int argc, char **argv) {
  QApplication app(argc, argv);
  Widget w;
  w.show(); // gets focus automatically since is the only widget shown
  return app.exec();
}

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[bruceariggs]

Hey Wysota,

Thanks for the response, but now I have a question about how that can be done.

I display my QDialog by calling exec(), which displays the dialog to the screen, how can I call setFocus() on the Dialog if exec() is what both shows, executes, and closes the window after OK or Cancel is clicked?

SelectionDialog* dialog = new SelectionDialog();
 
// Too early to set focus?
 
if( dialog->exec() ) // handles the show and execution
{
    // Too late to set focus?
}

SelectionDialog* dialog = new SelectionDialog();

// Too early to set focus?

if( dialog->exec() ) // handles the show and execution
{
    // Too late to set focus?
}

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[wysota]

If the dialog doesn't get focus automatically (look out, if there is a default button on the dialog, this button will steal the focus!), you can reimplement showEvent() for the dialog and set focus from within there.