UICollectionView - replicate Photos.app functionality

Question

I'm trying to create a UICollectionView that behaves like the photos.app on the iPad (pinch to group and expand).

How do you think photos.app is built?

• Is it one UICollectionView with one layout, and the pinch just does a batch update and moves cells in to sections?
• Or is it one UICollectionView with two different layout?
• Or the last option, could it be two UICollectionViews?

What do you think is the best approach?

Thanks

Answer 1

It is the second suggestion - two different layouts.

I'd recommend checking the almost identical example in iOS6 by Turorials book (paid content, but probably worth it in your case).

http://www.raywenderlich.com/store/ios-6-by-tutorials

Answer 2

In case you didn't buy the book yet, I also wrote a blog post about the basic idea (and some code for the flow layout subclass).

http://thyraz.tumblr.com/post/35135290759/stacklayout