Notes to understand problem
I have a group box with buttons and a label in a vertical-layout in a window.
The label is set to expanding according to window size.
How do I set the initial window to only display group-box(window is fixed around group box)
When I load an image to label the window size increases, displaying the label
the label size is set to image size(hence initially 0,0)
Since the image is scaled to label(checked property)
I dont need to worry of images smaller than window size.

Problem
how ever if the image is bigger than window size- I want it to maximise the screen
how do I set a maximum window size to fullscreen maximise(for any screen)

I know more or less, how to do it?
Just need some direction
& maybe sample code on comparing image sizes

or is there another way of hiding label & setting window size smaller until uploading image

Thnks