Adds a button with the given text (or a stock button, if button_text
is a stock ID) and sets things up so that clicking the button will emit
the "response" signal with the given response_id. The button is appended
to the end of the info bars's action area. The button widget is
returned, but usually you don't need it.
Since 2.18
Adds a button with the given text (or a stock button, if button_text is a stock ID) and sets things up so that clicking the button will emit the "response" signal with the given response_id. The button is appended to the end of the info bars's action area. The button widget is returned, but usually you don't need it. Since 2.18