makeBody(configuration:)

Creates a view that represents the body of a toggle.

Declaration

@ViewBuilder @MainActor @preconcurrency func makeBody(configuration: Self.Configuration) -> Self.Body

Parameters

configuration:
The properties of the toggle, including a label and a binding to the toggle’s state.

Return Value

A view that has behavior and appearance that enables it to function as a Toggle.

Discussion

Implement this method when you define a custom toggle style that conforms to the ToggleStyle protocol. Use the configuration input — a ToggleStyleConfiguration instance — to access the toggle’s label and state. Return a view that has the appearance and behavior of a toggle. For example you can create a toggle that displays a label and a circle that’s either empty or filled with a checkmark:

struct ChecklistToggleStyle: ToggleStyle {
    func makeBody(configuration: Configuration) -> some View {
        Button {
            configuration.isOn.toggle()
        } label: {
            HStack {
                Image(systemName: configuration.isOn
                        ? "checkmark.circle.fill"
                        : "circle")
                configuration.label
            }
        }
        .tint(.primary)
        .buttonStyle(.borderless)
    }
}

The ChecklistToggleStyle toggle style provides a way to both observe and modify the toggle state: the circle fills for the on state, and users can tap or click the toggle to change the state. By using a customized Button to compose the toggle’s body, SwiftUI automatically provides the behaviors that users expect from a control that has button-like characteristics.

You can present a collection of toggles that use this style in a stack:

[Image]

When updating a view hierarchy, the system calls your implementation of the makeBody(configuration:) method for each Toggle instance that uses the associated style.

Modify the current style

Rather than create an entirely new style, you can alternatively modify a toggle’s current style. Use the init(_:) initializer inside the makeBody(configuration:) method to create and modify a toggle based on a configuration value. For example, you can create a style that adds padding and a red border to the current style:

struct RedBorderToggleStyle: ToggleStyle {
    func makeBody(configuration: Configuration) -> some View {
        Toggle(configuration)
            .padding()
            .border(.red)
    }
}

If you create a redBorder static variable from this style, you can apply the style to toggles that already use another style, like the built-in switch and button styles:

Toggle("Switch", isOn: $isSwitchOn)
    .toggleStyle(.redBorder)
    .toggleStyle(.switch)

Toggle("Button", isOn: $isButtonOn)
    .toggleStyle(.redBorder)
    .toggleStyle(.button)

Both toggles appear with the usual styling, each with a red border: