<img src="./Logo.png" width="128">

Transmission

Transmission aims to improve SwiftUI view presentations and transitions. It does this by bridging UIKit presentation APIs to a SwiftUI API so you can use presentation controllers, interactive transitions and more.

Built using Engine

See Also

• Turbocharger
• Ignition

Preview

https://github.com/user-attachments/assets/5b323b24-6697-4b66-aef0-d7b085b17d79

Requirements

• Deployment target: iOS 13.0, macOS 10.15, tvOS 13.0, or watchOS 6.0
• Xcode 16.4+

Installation

Xcode Projects

Select File -> Swift Packages -> Add Package Dependency and enter https://github.com/nathantannar4/Transmission.

Swift Package Manager Projects

You can add Transmission as a package dependency in your Package.swift file:

let package = Package(
    //...
    dependencies: [
        .package(url: "https://github.com/nathantannar4/Transmission"),
    ],
    targets: [
        .target(
            name: "YourPackageTarget",
            dependencies: [
                .product(name: "Transmission", package: "Transmission"),
            ],
            //...
        ),
        //...
    ],
    //...
)

Introduction to Transmission

For some sample code to get started with Transmission, build and run the included "Example" project.

PresentationLink

@available(iOS 14.0, *)
public struct PresentationLinkTransition {

    public static var `default`: PresentationLinkTransition

    public static let sheet: PresentationLinkTransition
    public static let currentContext: PresentationLinkTransition
    public static let fullscreen: PresentationLinkTransition
    public static let popover: PresentationLinkTransition
    public static let slide: PresentationLinkTransition
    public static let card: PresentationLinkTransition
    @available(iOS 18.0, *)
    public static let zoom: PresentationLinkTransition
    public static let matchedGeometry: PresentationLinkTransition
    public static let toast: PresentationLinkTransition
    
    public static func custom<T: PresentationLinkTransitionRepresentable>(_ transition: T) -> PresentationLinkTransition
}

@available(iOS 15.0, *)
extension SheetTransitionOptions.Detent {
    
    /// Creates a large detent.
    public static let large: Detent

    /// Creates a medium detent.
    public static let medium: Detent

    /// Creates a detent with an auto-resolved height of the views ideal size.
    public static let ideal: Detent

    /// Creates a detent with a constant height.
    public static func constant(_ identifier: Identifier, height: CGFloat) -> Detent
    
    /// Creates a detent that's height is lazily resolved.
    public static func custom(
        _ identifier: Identifier,
        resolver: @escaping (ResolutionContext) -> CGFloat?
    ) -> Detent
}

/// A protocol that defines a custom transition for a ``PresentationLinkTransition``
///
/// > Tip: Use ``PresentationController`` or ``InteractivePresentationController``
///
@available(iOS 14.0, *)
public protocol PresentationLinkTransitionRepresentable {

    typealias Context = PresentationLinkTransitionRepresentableContext
    associatedtype UIPresentationControllerType: UIPresentationController

    /// The presentation controller to use for the transition.
    func makeUIPresentationController(
        presented: UIViewController,
        presenting: UIViewController?,
        source: UIViewController,
        context: Context
    ) -> UIPresentationControllerType

    func updateUIPresentationController(
        presentationController: UIPresentationControllerType,
        context: Context
    )
}

/// A coordinator that can be used to programatically dismiss a view.
///
/// See Also:
///  - ``PresentationLink``
///  - ``WindowLink``
///
@available(iOS 14.0, *)
@frozen
public struct PresentationCoordinator {

    public var isPresented: Bool
    public weak var sourceView: UIView?

    public func dismiss(count: Int, animation: Animation? = .default)
    
    public func dismiss(count: Int, transaction: Transaction)
}

@available(iOS 14.0, *)
extension EnvironmentValues {
    public var presentationCoordinator: PresentationCoordinator { get }
}

/// A button that presents a destination view in a new `UIViewController`.
///
/// The destination view is presented with the provided `transition`.
/// By default, the ``PresentationLinkTransition/default`` transition is used.
///
/// See Also:
///  - ``PresentationSourceViewLink``
///  - ``PresentationLinkTransition``
///  - ``PresentationLinkModifier``
///  - ``TransitionReader``
///
/// > Tip: You can implement custom transitions with a `UIPresentationController` and/or
/// `UIViewControllerInteractiveTransitioning` with the ``PresentationLinkTransition/custom(_:)``
///  transition.
///
@available(iOS 14.0, *)
@frozen
public struct PresentationLink<
    Label: View,
    Destination: View
>: View {

    public init(
        transition: PresentationLinkTransition = .default,
        @ViewBuilder destination: () -> Destination,
        @ViewBuilder label: () -> Label
    )

    public init(
        transition: PresentationLinkTransition,
        isPresented: Binding<Bool>,
        @ViewBuilder destination: () -> Destination,
        @ViewBuilder label: () -> Label
    )
}

@available(iOS 14.0, *)
extension PresentationLink {

    public init<ViewController: UIViewController>(
        transition: PresentationLinkTransition,
        destination: @escaping () -> ViewController,
        @ViewBuilder label: () -> Label
    )

    public init<ViewController: UIViewController>(
        transition: PresentationLinkTransition,
        isPresented: Binding<Bool>,
        destination: @escaping () -> ViewController,
        @ViewBuilder label: () -> Label
    )
}

@available(iOS 14.0, *)
extension View {

    public func presentation<Destination: View>(
        transition: PresentationLinkTransition = .default,
        isPresented: Binding<Bool>,
        @ViewBuilder destination: () -> Destination
    ) -> some View

    public func presentation<T, Destination: View>(
        _ value: Binding<T?>,
        transition: PresentationLinkTransition = .default,
        @ViewBuilder destination: (Binding<T>) -> Destination
    ) -> some View
}

TransitionReader

/// A container view that defines its content as a function of its hosting view's
/// `UIViewControllerTransitionCoordinator` transition progress.
///
/// > Tip: Use a ``TransitionReader`` to build interactive presentation and dismissal
/// transitions
/// 
public struct TransitionReader<Content: View>: View {
    public struct Proxy {
        /// The progress state of the transition from 0 to 1 where 1 is fully presented
        public var progress: CGFloat

        public var isPresented: Bool
    }

    public init(@ViewBuilder content: @escaping (Proxy) -> Content)
}

DestinationLink

/// The transition and presentation style for a ``DestinationLink`` or ``DestinationLinkModifier``.
@available(iOS 14.0, *)
public struct DestinationLinkTransition: Sendable {

    public static let `default`: DestinationLinkTransition

    @available(iOS 18.0, *)
    public static let zoom: DestinationLinkTransition

    public static func custom<T: DestinationLinkTransitionRepresentable>(_ transition: T) -> DestinationLinkTransition
}

/// A protocol that defines a custom transition for a ``DestinationLinkTransition``
@available(iOS 14.0, *)
@MainActor @preconcurrency
public protocol DestinationLinkTransitionRepresentable {

    typealias Context = DestinationLinkTransitionRepresentableContext

    /// The interaction controller to use for the transition presentation.
    ///
    /// > Note: This protocol implementation is optional and defaults to `nil`
    ///
    @MainActor @preconcurrency func navigationController(
        _ navigationController: UINavigationController,
        interactionControllerFor animationController: UIViewControllerAnimatedTransitioning,
        context: Context
    ) -> UIViewControllerInteractiveTransitioning?

    /// The animation controller to use for the transition presentation.
    @MainActor @preconcurrency func navigationController(
        _ navigationController: UINavigationController,
        animationControllerFor operation: UINavigationController.Operation,
        from fromVC: UIViewController,
        to toVC: UIViewController,
        context: Context
    ) -> UIViewControllerAnimatedTransitioning?
}

/// A coordinator that can be used to programatically dismiss a view.
///
/// See Also:
///  - ``DestinationLink``
///
@available(iOS 14.0, *)
@frozen
public struct DestinationCoordinator {
    public var isPresented: Bool

    public func pop(count: Int, animation: Animation? = .default)
    
    public func pop(count: Int, transaction: Transaction)
}

@available(iOS 14.0, *)
extension EnvironmentValues {
    public var destinationCoordinator: DestinationCoordinator { get }
}

/// A button that pushes a destination view in a new `UIViewController`.
///
/// The destination view is presented with the provided `transition`.
/// By default, the ``DestinationLinkTransition/default`` transition is used.
///
/// See Also:
///  - ``DestinationLinkModifier``
///  - ``DestinationLinkTransition``
///  - ``DestinationSourceViewLink``
///  - ``TransitionReader``
///
/// > Tip: You can implement custom transitions with the ``DestinationLinkTransition/custom(_:)``
///  transition.
///
@available(iOS 14.0, *)
@frozen
public struct DestinationLink<
    Label: View,
    Destination: View
>: View {

    public init(
        transition: DestinationLinkTransition = .default,
        @ViewBuilder destination: () -> Destination,
        @ViewBuilder label: () -> Label
    )

    public init(
        transition: DestinationLinkTransition,
        isPres