[Gambas-user] Fitting a preview into a fixed area

[Rolf-Werner Eilert]

I am showing a pdf preview. There are landscape and portrait pdfs, and 
some are A4, some are A3...

Instead of following the size, I would like to fit them into a fixed, 
square preview area, i. e. the A3 ones would have to be shown smaller, 
but the aspect ratio must be kept of course, not stretched.

Is there any automatic property, or how would you make it fit?

Thanks for your ideas

Rolf