Protocol

WKInterfaceObjectRepresentable

A view that represents a WatchKit interface object.

Declaration

protocol WKInterfaceObjectRepresentable where Self.Body == Never

Overview

Use a WKInterfaceObjectRepresentable instance to create and manage a WKInterfaceObject in your SwiftUI interface. Adopt this protocol in one of your app's custom instances, and use its methods to create, update, and tear down your interface object. The creation and update processes parallel the behavior of SwiftUI views, and you use them to configure your interface object with your app's current state information. Use the teardown process to remove your interface object cleanly from your SwiftUI. For example, you might use the teardown process to notify other parts of your app that the interface object is disappearing.

To add your interface object into your SwiftUI interface, create your UIViewRepresentable instance and add it to your SwiftUI interface. The system calls the methods of your representable instance at appropriate times to create and update the interface object.

The system doesn't automatically communicate changes occurring within your interface object to other parts of your SwiftUI interface. When you want your interface object to coordinate with other SwiftUI views, you must provide a Coordinator instance to facilitate those interactions. For example, you use a coordinator to forward target-action and delegate messages from your interface object to any SwiftUI views.

Topics

Creating and Updating the Interface Object

func makeWKInterfaceObject(context: Self.Context) -> Self.WKInterfaceObjectType

Creates a WatchKit interface object and configures its initial state.

Required.

func updateWKInterfaceObject(Self.WKInterfaceObjectType, context: Self.Context)

Updates the presented WatchKit interface object (and its coordinator) to the latest configuration.

Required.

struct WKInterfaceObjectRepresentableContext

Contextual information about the state of the system that you use to create and update your WatchKit interface object.

Cleaning Up the Interface Object

static func dismantleWKInterfaceObject(Self.WKInterfaceObjectType, coordinator: Self.Coordinator)

Cleans up the presented WatchKit interface object (and its coordinator) in anticipation of their removal.

Required. Default implementation provided.

Providing a Custom Coordinator Object

func makeCoordinator() -> Self.Coordinator

Creates the custom instance that you use to communicate changes from your interface object to other parts of your SwiftUI interface.

Required. Default implementation provided.

associatedtype Coordinator

A type to coordinate with the WatchKit interface object.

Required.

associatedtype WKInterfaceObjectType

The type of WatchKit interface object to be presented.

Required.

Relationships

Inherits From

See Also

WatchKit Hosting

class WKHostingController

A WatchKit interface controller that hosts a SwiftUI view hierarchy.

class WKUserNotificationHostingController

A WatchKit user notification interface controller that hosts a SwiftUI view hierarchy.

enum DigitalCrownRotationalSensitivity

The amount of Digital Crown rotation needed to move between two integer numbers.