Sizing Things Equally in SwiftUI

Using Preferences we can communicate data, such as the actual size of a view, to any ancestor view. By taking advantage of the reduce function required by the PreferenceKey protocol, we can combine multiple values in whatever way suits our needs. In this episode we will use this technique to size a bunch of sibling views equally by collecting the biggest width and then pushing this value down to subviews with some parent state.

This is a companion discussion topic for the original entry at