SwiftUIKitView

Easily use UIKit views in SwiftUI.

• Convert UIView to SwiftUI View
• Create Xcode Previews from UIView elements
• SwiftUI functional updating UIView properties using a protocol with Associated Types.

You can read more about Getting started with UIKit in SwiftUI and visa versa.

Examples

Using SwiftUIKitView in Production Code

Using a UIKit view directly in SwiftUI for production code requires you to use:

UIViewContainer(<YOUR UIKit View>, layout: <YOUR LAYOUT PREFERENCE>)

This is to prevent a UIKit view from being redrawn on every SwiftUI view redraw.

import SwiftUI
import SwiftUIKitView

struct SwiftUIwithUIKitView: View {
    var body: some View {
        NavigationView {
            UIViewContainer(UILabel(), layout: .intrinsic) // <- This can be any `UIKit` view.
                .set(\.text, to: "Hello, UIKit!") // <- Use key paths for updates.
                .set(\.backgroundColor, to: UIColor(named: "swiftlee_orange"))
                .fixedSize()
                .navigationTitle("Use UIKit in SwiftUI")
        }
    }
}

Using SwiftUIKitView in Previews

Performance in Previews is less important, it's being redrawn either way.

Therefore, you can use the more convenient swiftUIView() modifier:

UILabel() // <- This is a `UIKit` view.
    .swiftUIView(layout: .intrinsic) // <- This is returning a SwiftUI `View`.

Creating a preview provider for a UIView looks as follows:

import SwiftUI
import SwiftUIKitView

struct UILabelExample_Preview: PreviewProvider {
    static var previews: some View {
        UILabel() // <- This is a `UIKit` view.
            .swiftUIView(layout: .intrinsic) // <- This is a SwiftUI `View`.
            .set(\.text, to: "Hello, UIKit!") // <- Use key paths for updates.
            .fixedSize() // <- Make sure the size is set
            .previewLayout(.sizeThatFits)
            .previewDisplayName("UILabel Preview Example")
    }
}

Which results in the following preview:

KeyPath updating

This framework also comes with a KeyPathReferenceWritable protocol that allows to update objects using functions and writable KeyPath references:

/// Defines a type that is configurable using reference writeable keypaths.
public protocol KeyPathReferenceWritable {
    associatedtype T
    associatedtype U
    
    func set<Value>(_ keyPath: ReferenceWritableKeyPath<T, Value>, to value: Value) -> U
}

public extension KeyPathReferenceWritable {
    func set<Value>(_ keyPath: ReferenceWritableKeyPath<Self, Value>, to value: Value) -> Self {
        self[keyPath: keyPath] = value
        return self
    }
}

/// Add inheritance for NSObject types to make the methods accessible for many default types.
extension NSObject: KeyPathReferenceWritable { }

This can be used as follows:

UILabel()
    .set(\.text, to: "Example")

And allows to easily build up SwiftUI style view configurations to keep the same readability when working in SwiftUI.

Installation

Swift Package Manager

The Swift Package Manager is a tool for automating the distribution of Swift code and is integrated into the swift compiler. It is in early development, but this SDK does support its use on supported platforms.

Once you have your Swift package set up, adding the SDK as a dependency is as easy as adding it to the dependencies value of your Package.swift.

dependencies: [
    .package(url: "https://github.com/AvdLee/SwiftUIKitView.git", .upToNextMajor(from: "2.0.0"))
]

Communication

• If you found a bug, open an issue.
• If you have a feature request, open an issue.
• If you want to contribute, submit a pull request.

License

SwiftUIKitView is available under the MIT license, and uses source code from open source projects. See the LICENSE file for more info.

Author

This project is originally created by Antoine van der Lee. I'm open for contributions of any kind to make this project even better.