Alternative iOS layouts for portrait and landscape using just one .xib file

Question

Using interface builder in xcode and just one .xib file, how can I create alternate layouts when rotating between landscape and portrait orientations?

See di

Answer 1

I like @MeXx's solution, but it has the overhead of keeping two different view hierarchies in memory. Also, if any subview has state (e.g. color) that changes, you'll need to map that across when you switch hierarchies.

Another solution might be to use auto-layout and swap the constraints for each subview for each orientation. This would work best if you have a 1:1 mapping between subviews in both orientations.

Understandably you want to use IB to visually define the layout for each orientation. Under my plan you'd have to do what @MeXx prescribes, but then create a mechanism to store both sets of constraints once the nib was loaded (awakeFromNib) and re-apply the correct set on layout (viewWillLayoutSubviews). You could throw away the secondary view hierarchy once you scraped and stored its constraints. (Since constraints are view-specific you'd likely be creating new constraints to apply to the actual subviews).

Sorry I don't have any code. It's just a plan at this stage.

Final note - this would all be easier with a xib than a storyboard since in a storyboard it's painful to describe views that live outside of a view controller's main view (which is desirable since otherwise its a PITA to edit). Blach!