Boxlayout Draw All Widget In The Corner

I'm trying to draw different widget in a box layout. But if I try to draw some class, which extend widget, implemented by myself, the BoxLayout draw everything in the low left corn

Solution 1:

Widget:Button:

That's putting a Button inside a Widget - not extending anything. However, Widget has no layout functionality and does not place its children anywhere - so they show up at (0, 0).

Here's an example of extending a class in kv:

<MyButton@Button>:
    text: 'a'BoxLayout:
    MyButton