What should I return in eventFilter?

[qwe3]

Hi,

For example I have mainWindow and myTextEdit ( inherits QTextEdit ) on it. I install in mainWindow eventFilter for mainWindow and myTextEdit like this:

mainWindow constructor:
    textEdit = new MyTextEdit(this);
    textEdit->installEventFilter(this);
    installEventFilter(this);

And of course I have eventFilter in mainWindow:

bool MainWindow::eventFilter(QObject *object, QEvent *event)
{
    if( object == textEdit )
    {
        if(event->type() == QEvent::Type::KeyPress) 
        {
            qInfo()<<"some Text";
            event->ignore();
            return true;
        }
        else
        {
            return ...... // I don't know what I should return here
        }
    }
    else if(object == this)
    {
        if(event->type() == QEvent::Type::KeyPress) 
        {
            qInfo()<<"some Text";
            event->ignore();
            return true;
        }
        else
        {
            return QMainWindow::eventFilter(object, event);
        }
    }
}

In (object == this ( mainWindow )) I return "QMainWindow::eventFilter(object, event);" because MainWindow inherits QMainWindow, so I think I should return in (object == textEdit) "QTextEdit::eventFilter(object, event);". But I can't. I get errors:

1. call to non-static member function without an object argument
2. eventFilter is protected member of QAbstractScrollArea

[jsulm]

@qwe3 said in What should I return in eventFilter?:

QTextEdit::eventFilter(object, event);

Well, this of course cannot work because eventFilter is not static and MainWindow is not a subclass of QTextEdit.
You can simply return false, so it will go to your textEdit.
https://doc.qt.io/qt-5/qobject.html#eventFilter
"In your reimplementation of this function, if you want to filter the event out, i.e. stop it being handled further, return true; otherwise return false."

[eyllanesc]

@qwe3 use return QMainWindow::eventFilter(object, event);

[qwe3]

@jsulm @eyllanesc Thank you for replies.

@eyllanesc Why QMainWindow::eventFilter(object, event); ? I don' see link between QMainWindow and myTextEdit class.

[eyllanesc]

@qwe3 If you don't want to modify the behavior then just call the base class method.

[qwe3]

@eyllanesc But if I return QMainWindow::eventFilter(object, event);, other events than QEvent::Type::KeyPress will go to event() method of myTextEdit ?

[eyllanesc]

@qwe3 I do not understand you. If you already returned true in the event:

bool MainWindow::eventFilter(QObject *object, QEvent *event)
{
    if(event->type() == QEvent::Type::KeyPress) {
            qInfo()<<"some Text";
            event->ignore();
            return true;
     }
     return QMainWindow::eventFilter(object, event);
}

[qwe3]

@eyllanesc Ok, I understand :)