I have an UIView subclass with its layout in a .xib
file. I set the size to freeform and the dimensions to something like 200 x 300.
How can I set different dimensions for iPad so the "View as" option correctly show a preview of how it would look like?
Or, can this be achieved in a different way? Maybe using a storyboard instead of a xib file?
Certainly, you can make it compatible with Auto Layout and you can use IBDesignable to do visual layout in Interface Builder.
I have a couple examples - including loading custom views from XIB files - here: https://github.com/DonMag/IBDesignInspect
Similar kind of feature I did last week. I had an xib file and that I was using as a collectionView item. Through interface builder it cannot be differed. I achieved this programmatically. You can change the size of UIView as required.
Let me know if you have any query.