KeyPressEvent and QLineEdit question

I have a clear "leUserInput" (a QLineEdit widget). When certain other conditions are met, I want to intercept a key stroke before it is displayed in the "leUserInput" to make changes to some "pushButton" options that were available before this key stroke.

Any help would be appreciated

If you're 100% sure this must happen before the key press event reaches line edit, reimplement QWidget::keyPressEvent() (or install an event filter). However, if you're happy with getting informed immediately afterwards, you could simply connect to QLineEdit::textChanged() or QLineEdit::textEdited().