UICollectionView: add spacing between header and items - ios

Question

I want to add some spacing between my header and the actual items, which currently look like this:
func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
// Create header
switch kind{
case UICollectionElementKindSectionHeader:
let headerView = iconCollectionView.dequeueReusableSupplementaryViewOfKind(kind, withReuseIdentifier: "customIconHeaderView", forIndexPath: indexPath) as! CustonIconHeaderView
headerView.setUp() //add whatever into the view
return headerView
default:
assert(false, "Unexpected element kind")
}
}

Answer 1

You are basically talking about adding a top margin to the collection view section, for that you would set top inset for the section. To do it in code, implement insetForSectionAtIndex:
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAtIndex section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: 10.0, left: 1.0, bottom: 1.0, right: 1.0)
}
If you don't want to implement the insetForSectionAtIndex, you could also do something like this in an appropriate method e.g. viewDidLoad:
let layout = collectionView.collectionViewLayout as! UICollectionViewFlowLayout
layout.sectionInset = UIEdgeInsets(top: 10.0, left: 1.0, bottom: 1.0, right: 1.0)
In Interface Builder, Select collection view and change the value for Section Insets -> Top as shown in the image below:
NOTE: This only works if you are using Flow Layout.

Answer 2

One way you can do is to increase your header container's heigh using
collectionView(_:layout:referenceSizeForHeaderInSection:)
Example:
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
return CGSize(width: 0, height: yourHeaderContentHeight + yourHeaderMarginToCell)
}
Edit:
func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
let headerView = collectionView.dequeueReusableSupplementaryViewOfKind(UICollectionElementKindSectionHeader, withReuseIdentifier: "YourID", forIndexPath: indexPath)
let yourCustomView = UIView(frame: CGRect(x: 0, y: 0, width: yourHeaderWidth, height: yourHeaderHeight))
headerView.addSubview(yourCustomView)
return headerView
}
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
return CGSize(width: yourHeaderWidth, height: yourHeaderHeight + yourHeaderMargin)
}