🎭 Gala - SwiftGit

SwiftUI

🎭 Gala

August 2, 2025

Gala is a Swift Package Manager project for macOS, iOS, tvOS, and watchOS to help you create SwiftUI preview variants.

Say for instance you want to render your preview in both light and dark mode, you can use NightAndDay:


                                              
                                                static var previews: some View {

NightAndDay {

ContentView()

}

}

Without Gala, this would have to be written as


                                              
                                                static var previews: some View {

Group {

ContentView()

.environment(\.colorScheme, .light)
ContentView()

.environment(\.colorScheme, .dark)

}

}


                                              
                                                static var previews: some View {

ForEach(ColorScheme.allCases, id: \.self) { scheme in

ContentView()

}

}

However, Gala doesn’t stop there. It also offers a few other “attribute iterators”:

ContentSizeCategories
HorizontalSizeClasses
LayoutDirections
LegibilityWeights
VerticalSizeClasses

Just substitute them in for NightAndDay:


                                              
                                                static var previews: some View {

LayoutDirections {

ContentView()

}

}

Layouts

In addition, you can iterate over a given set of layouts as follows:


                                              
                                                static var previews: some View {

Layouts([.fixed(width: 200, height: 150), .sizeThatFits, .device]) {

ContentView()

}

}

This is convenient if you have a set of frames you want to set your view up with.

Devices

You can also pass in a set of devices to the Device iterator:


                                              
                                                static var previews: some View {

Devices([.iPhoneX, .iPhone11]) {

ContentView()

}

}

Thanks to autocompletion you don’t have to remember the precise names. Please note that particular care has been taken to transform Apple’s fantastic product names into identifiers. For instance:

iPadPro9·7inch
iPhoneXʀ
appleWatchSeries5﹘40mm

Thanks to Swift’s support of unicode identifiers you can use these (and thanks to autocomplete you can actually enter them 😅).

You can also use Devices.iPhones (iPads, watches, tvs) to preview all of them:


                                              
                                                static var previews: some View {

Devices(.iPhones) {

ContentView()

}

}

GitHub

View Github