Paged Collection View
This project is an implementation of a paged collection view that allows for a peek of the next and previous pages, as per a bet between myself and Jake MacMullin (@jmacmullin), discussed in Mobile Couch #45.
- Collection view must display cells on the pages to either side of the current page.
- Paging must behave as per the built-in implementation triggered by the paging boolean.
- Must be a pure collection view. No additional scroll views or custom views are allowed.
- Code is allowed, but cannot be a hack.
Scrollview content insets, as found in iOS 7 and up, allow for content to appear outside of the content area (so it can appear underneath translucent bars, but not be blocked by them), but don't affect the built-in paging code: page size is still considered to be the same as the frame of the collection view.
My solution is to use content insets to adjust the page size, and reimplement a very simple paging mechanism (with the built in version turned off). The benefit of this solution is that it can be applied to anything that uses a scrollview where you want paging and a preview of content on other pages: paging controllers, collection views, table views, etc.
My opinion is that this should be the default behaviour of paging: that the page size is affected by the content insets. The existing implementation is useless as it causes content to be inaccessible. As such, I've filed a radar (19075189), which you can read and duplicate if you so choose: openradar.appspot.com/radar?id=6358822092275712
I have no idea if Apple will respond to this. Don't hold your breath.
Released as Public Domain
This is a simple solution to a long-term problem. I claim no copyright on it, but also take no liability for any consequence of using it, nor do I offer any support for issues you come across.