NEW: Start my new Ultimate Portfolio App course with a free Hacking with Swift+ trial! >>

How to control layout priority using layoutPriority()

Paul Hudson    @twostraws   

Updated for Xcode 12.5

SwiftUI’s layoutPriority() modifier lets us request that certain views should be given more room on the screen when space is limited. All views have a layout priority of 0 by default, but if you’re finding one particular view is squashed you can ask it to be given a higher priority using layoutPriority().

As an example, here are two pieces of text laid out side by side:

struct ContentView: View {
    var body: some View {
        HStack {
            Text("The rain Spain falls mainly on the Spaniards.")
            Text("Knowledge is power, France is bacon.")
        }
    }
}

Both text strings are long enough that they will wrap across two lines on an iPhone, and SwiftUI will try to size them fairly so they each get a fair amount of space depending on their length.

We can use the layoutPriority() modifier to change this by making one of the two strings more important. SwiftUI will calculate the minimum amount of space required for the low-priority text view, then offer the remaining space to the higher-priority text so it can take up as much as it wants.

Here’s how that looks:

struct ContentView: View {
    var body: some View {
        HStack {
            Text("The rain Spain falls mainly on the Spaniards.")
            Text("Knowledge is power, France is bacon.")
                .layoutPriority(1)
        }
    }
}

Obviously the result of that depends on what size screen you’re using, but it’s likely the higher-priority text view won’t use all the available space it was offered, and so the remainder will be given to the lower-priority text view to use.

Hacking with Swift is sponsored by Emerge

SPONSORED Emerge helps iOS devs write better, smaller apps by profiling binary size on each pull request and surfacing insights and suggestions. Companies using Emerge have reduced the size of their apps by up to 50% in just the first day. Built by a team with years of experience reducing app size at Airbnb.

Set up a demo!

Sponsor Hacking with Swift and reach the world's largest Swift community!

Similar solutions…

BUY OUR BOOKS
Buy Pro Swift Buy Swift Design Patterns Buy Testing Swift Buy Hacking with iOS Buy Swift Coding Challenges Buy Swift on Sundays Volume One Buy Server-Side Swift (Vapor Edition) Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Advanced iOS Volume Three Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with macOS Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Server-Side Swift (Kitura Edition) Buy Beyond Code

Was this page useful? Let us know!

 
Unknown user

You are not logged in

Log in or create account
 

Link copied to your pasteboard.