Forms - How to center all ?

[arfgh]

Hey guys !

i need your help to find a way to do this. I have a big shape that is surrounding all the controls i use in the form.
Because i always use the window mode, i centered the whole design with margins in the 4 sides.
But when i use the maximize window, or i use the fullscreen mode, all keep on that absolute position, and because actually we all use big screen resolutions, we obtain a wide empty area in the right and/or in the down parts.

When we use Base Reports, they get very well centered in the middle, and the resolution we use doesnt matters. Just the same is what i want to do in forms.

So, is there a good way to detect the maximize window and fullscreen mode, and by the way obtain the inner window resolution to proceed to do a centering ? I remember from other languages that exist controls that are owners for all the controls into it, example the famous 'frame'. With that frame we only need to move the frame position to move all at once. But i dont know here in AOO and its api.

thx in advance !!