Delegate should not commit on error in editor

Hi,

I'm trying to implement a delegate with a custom editor. This editor can validate its content and return True / False on invalid text input.
I need to block the commit somehow if an error occurs, but I'm unable to do this.

I tried implementing eventFilter and throw away the Key_RETURN and Key_ENTER event if the editor contains errors, but the delegate will still accept the input and save the content to the model.
I also tried implementing commitData but this seems to be called after the editor is closed.

Is there a way to make sure I can only close the editor / delegate if there are no input errors?

Right now the validation is a custom funktion isValid(), that simply checks the inputs of both QLineEdit widgets and returns true / false.
I could write this as a QValidator I guess if neccessary, but I hoped there would be another way to handle this topic.

I think that QValidator exists for this reason. If the input isn't acceptable, it won't let you leave the editor unless you cancel.

Delegates can be tricky. I ran into a problem like this, using an editable combo box in a table, and finally had to abandon the editing capability because I couldn't find a straightforward way to make it work and didn't want to waste more time on it. It has been a while, but I think my problem was similar to yours - I couldn't prevent the return or tab keys from moving focus and closing the editor when the content was invalid.