Relative sizing of widgets with a maximum size limit in Qt Creator

[kpks]

Hi,
I am struggling to design my UI with Qt Creator 2.8.1.

I have multiple windows with multiple panels.

The first window has 3 panels, 1 with a login/view button, 2 giving instructions and 3 serving as an application log.

How do I fix it so that panel 1 and 3 are small, with a limitation on the maximum possible button size while
Panel 3 is relatively small.

I want my panels to expand with the window size but only upto a limit.

I could figure this out if I can generate C++ code from the creator, this qml is very confusing.

Thanks!