I have a view which contains another view on the top part, which I'm using to show some basic information. It has about 40% of the total view height. Below that "header" view, I'm using a UICollectionView which is scrollable. Now I've added a UIRefreshControl to my UICollectionView, but refreshing does never occur, because the user can't pull down the UICollectionView that far. When I reduce the height of the top view, it starts working because there's enough space to pull the collectionview down then.
Here's how I'm adding the refreshControl:
self.matchDetailRefreshControl = UIRefreshControl()
self.matchDetailRefreshControl.addTarget(self, action: #selector(MatchDetailViewController.fetchAll), forControlEvents: .ValueChanged)
self.collectionView!.addSubview(self.matchDetailRefreshControl)
self.collectionView!.alwaysBounceVertical = true
Have a look at this screenshot for reference:

As you can see, the UIRefreshControl doesn't get fully filled, while my finger is already at the bottom of the screen.
How can I fix that?