Iglistkit: Container size and section insets

[rnystrom]

It can be a little tricky dealing with insets and collectionContext.containerSize. The container width doesn't account for insets, so if you have the following setup:

• insets of 10, 10, 10, 10
• The width of the collection view is 320

If your size method looks like

- (CGSize)sizeForItemAtIndex:(NSInteger)index {
  return CGSizeMake(self.collectionContext.containerSize.width, 50);
}

UICollectionViewFlowLayout will error b/c the item width is 320 but layout adds left/right insets, making the total item width 340.

Maybe we should have a containerInsetSizeForSectionController: method that returns the container size minus insets?

[jessesquires]

what about collectionContext.insetContainerSize ?

[rnystrom]

@jessesquires only thing we have to add is the section controller b/c each section controller is responsible for their own inset property

[racer1988]

Can we verify this is correctly calculated on iOS 9?
Inset were applied incorrectly for me.
I noticed a issue some time ago but I don't have a phone with iOS 9 to reproduce at the moment.

[jessesquires]

@racer1988 -- this work hasn't been completed. do you want to submit a PR?

[racer1988]

@jessesquires If it is not done after the Christmas Holiday, I may try.
I am not a good OBJ-C programmer, I am Swift "onlyish"
but I will have a look if not done in some weeks.

Thanks! :D

[zhubofei]

@racer1988 Are you still interested in working on this one?

[racer1988]

@zhubofei Hi! I did not start, and I might not have the time for a while.
So if you want to take it, go on