How to change a UICollectionViewListCell’s separator inset

This article covers beta technology and it's up to date for Xcode 12 beta 5

In WWDC2020's session Lists in UICollectionView a slide is shown where a UICollectionViewListCell's separator inset is updated by assigning a new leading anchor to separatorLayoutGuide.leadingAnchor.

Looking for a great mobile CI/CD solution that has tons of iOS-specific tools, smooth code signing, and even real device testing? Learn more about Bitrise’s iOS specific solutions.

This sponsored message helps keep the content on this site free. Please check out this sponsor as it directly supports me and this site.

Unfortunately, this doesn't work in when you try to do it.

To set the separator inset for a UICollectionViewListCell you can update the leading anchor constraint by overriding updateConstraints in a UICollectionViewListCell subclass. Setting the anchor in init will cause the system to override your custom anchor leaving you with the default inset.

override func updateConstraints() {
  super.updateConstraints()

  separatorLayoutGuide.leadingAnchor.constraint(equalTo: someOtherView.leadingAnchor, constant: 10).isActive = true
}

You can set the leadingAnchor constraint just like you would set any other constraint. In fact, you can even set the separator's trailingAnchor using the same method I just showed if you want to offset the seperator from the trailing edge of your content view.