activeAppearance
A property that indicates whether a scene has an active appearance.
Declaration
var activeAppearance: UIUserInterfaceActiveAppearance { get }Discussion
activeAppearance describes whether a scene is frontmost; it doesn’t describe a scene’s life-cycle state. A scene that isn’t frontmost can remain in the UIScene.ActivationState.foregroundActive activation state as long as it can still receive user interaction. Its activation state changes to UIScene.ActivationState.foregroundInactive only when a system interruption takes over interaction. This can happen because of Control Center, an alert, Siri, App Switcher, or another app’s window covering it in windowed apps. Use UIScene.ActivationState to decide when to save view state, and use activeAppearance to detect when a scene is no longer frontmost.
Because activeAppearance belongs to a scene’s trait collection, each scene has its own value, even in apps that support multiple scenes. To detect when a scene becomes frontmost, register for changes to this trait by calling registerForTraitChanges(_:handler:) on the window scene, or on any view or view controller in its hierarchy.
In Mac apps built with Mac Catalyst, Stage Manager on iPad, and a windowed app on iPad, the value is .active when the window is focused (the key window) and .inactive when it isn’t. A window that another app’s window covers keeps an .active appearance as long as it remains the focused window.
In iOS and in a full-screen app on iPad, the value reflects whether the app itself is in the foreground (.active) or not (.inactive).
See Also
Retrieving interface-related traits
userInterfaceStyleUIUserInterfaceStyleuserInterfaceIdiomUIUserInterfaceIdiomuserInterfaceLevelUIUserInterfaceLevellayoutDirectionUITraitEnvironmentLayoutDirectionresolvesNaturalAlignmentWithBaseWritingDirectionaccessibilityContrastUIAccessibilityContrastlegibilityWeightUILegibilityWeightUIUserInterfaceActiveAppearancetoolbarItemPresentationSize