Disable KeyEvent for "unneeded QWidget?

Question

I have a QDockWidget in my Mainwindow with a QTableWidget and two QPushbuttons. Of course, I can click the buttons with my mouse, but I want also to "click" them with left- and right-arrow-key.

It nearly works perfect. But before they are clicked via key, it seems like the focus jumps to the right/left of the QTableWidget (the items in it, it goes through all columns).

Is it possible that I have the KeyPressEvents only for the buttons in the QDockWidget?

Answer 1

You can use an event filter like this:

class Filter : public QObject
{
public:
    bool eventFilter(QObject * o, QEvent * e)
    {
        if(e->type() == QEvent::KeyPress)
        {
            QKeyEvent * event = static_cast<QKeyEvent *>(e);
            if((event->key() == Qt::Key_Left) || (event->key() == Qt::Key_Right))
            {
                //do what you want ...
                return true;
            }
        }
        return QObject::eventFilter(o, e);
    }
};

keep an instance of the filter class in your main window class:

private:
    Filter filter;

then install it in your widgets, e.g. in your main window class constructor:

//...
installEventFilter(&filter); //in the main window itself
ui->dockWidget->installEventFilter(&filter);
ui->tableWidget->installEventFilter(&filter);
ui->pushButton->installEventFilter(&filter);
//etc ...

You may want to check for modifiers (e.g. Ctrl key), to preserve the standard behaviour of the arrow keys:

//...
if(event->modifiers() == Qt::CTRL) //Ctrl key is also pressed
{
        if((event->key() == Qt::Key_Left) || (event->key() == Qt::Key_Right))
        {

//...