JavaFx: Method selectAll() just works by focus with keyboard

i use selectionAll() to select the whole text in my textfield but it just works when the focus comes from keyboard (like Tab).

If i click with my mouse in the textfield, it selects the text just for a very short moment. But it has to work like with the focus which comes from the keyboard.

flaschenPreis.focusedProperty().addListener(new ChangeListener<Boolean>() {
    public void changed(ObservableValue ov, Boolean t, Boolean t1) {

        if ( flaschenPreis.isFocused() && !flaschenPreis.getText().isEmpty()) {
            flaschenPreis.selectAll();
        }              
    }
});


literPreis.focusedProperty().addListener(new ChangeListener() {
    public void changed(ObservableValue ov, Object t, Object t1) {

        if (literPreis.isFocused() && !literPreis.getText().isEmpty()) {
            literPreis.selectAll();
        }
    }
});

flaschenPreis und literPreis are my textfields