defaultValue

Declaration

static var defaultValue: Self.Value { get }

Discussion

Implement the defaultValue property for a type that conforms to the LayoutValueKey protocol. For example, you can create a Flexibility layout value that defaults to nil:

private struct Flexibility: LayoutValueKey {
    static let defaultValue: CGFloat? = nil
}

The type that you declare for the defaultValue sets the layout key’s Value associated type. The Swift compiler infers the key’s associated type in the above example as an optional CGFloat.

Any view that you don’t explicitly set a value for uses the default value. Override the default value for a view using the layoutValue(key:value:) modifier.

See Also

Providing a default value

• Value