[Gambas-bugtracker] Bug #2728: Gambas Button: No Background and Border Control with QT5

[bugtracker at gambaswiki.org]

http://gambaswiki.org/bugtracker/edit?object=BUG.2728&from=L21haW4-

Comment #5 by Benoît MINISINI:

Buttons are native control, so the way they look entirely depends on the underlying toolkit and the widget theme in use. Gambas has no control on it.

And yes, some widget themes sometimes ignore the background color when drawing a button.

As GTK+3 implements a theming engine based on CSS, defining a background color should always work. But you don't have any guarantee, as it's done by adding custom CSS on the widget theme CSS.