Hello, $username!

I have troubles with such easy feature:

Imagine, that we have layout with widget1 and widget2 on it - one under another, and after receiving some signal i want to have widget2 hidden with wrapping my program.

E.g. if i want widget1 to be 200x300, then after hiding the second one the app should be 200x300.

The only that was successful is appearing widget2 and unwrapping program, but after hiding it, all the widget1's stuff places was reordered, but the app was still large.

Any helloworld-like examples for this situation would be welcome =)

TIA, Eugene.