[PyQt] Organize the components in window (Qt-Designer)

[Alfredo Junior]

Hi
I'm creating a Mame(mamedev.org) Front-end in PyQt4 and using Qt-Designer to build my windows.
This (Qt-Designer) is a little bit new to me and I have a problem to manage the layout components in the window.
As you can see in a video below, I can't organize the components into the window.
http://vimeo.com/39561463
I don't know how to do, because the vertical/horizontal layout there are not some property as max. size, for example.
I'm not sure if by the video I came to my goal to show you the exactly that I need.
Thanks for advance.

Junix