Scene SwiftUI

Scene SwiftUI

  • WindowGroup
  • DocumentGroup (PlainText3, WikiPad) Separate DocumentGroup SwiftUI???


  • .commands scene modifier. Separate commands from app and scene. Use CommandMenu.swift.


  • How do menu commands access document? (Specific to DocumentGroup.)
  • How does app access file?

Active Document from Command Menu How do menu commands access document? (Specific to DocumentGroup.)

  1. FocusedValuesExtension: calculated document binding
  2. .focusedSceneValue(.document, file.$document) // Scene value equivalent of environment for values? (Found in App.swift, DocumentGroup scene, apply modifier to top level view.)
  3. @FocusedValue(.document) var focusedDocument // 4. Focused value-focused scene value bug. If in app file, causes debug layout errors and drawing issuses. If in menu commands file ok. (Found in CommandsMenu.swift.)

Document File Name DocumentGroup(newDocument: WikiPadDocument()) { file in

File name available as parameter in DocumentGroup function.

Scene Phases

  • active
  • background
  • inactive
  • default (unknown)


  • @Environment(.scenePhase) private var scenePhase



  • Uses AppDelegate and @NSApplicationDelgateAdaptor.
  • Uses environment property scenePhase and WindowGroup:Scene onChange(of: scenePhase).


System Where start-stop code? app delegate proxy? 1x launch Where wake-sleep code? scene phases? Nx, active-inactive (Both app and scene can be active. Where startup code? App property init.


  • Red (Close): close window (file close and file new window do not affect scene phase, or app phase.)

  • Yellow (Minimize): minimize to dock

  • Green (Maximize): full screen or maximize

  • Dock running apps (dot below) have toolbar, even if no windows. Dock selection causes app active. (But not scene active.)

Scene (Does not affect App)

  • Minimize (window minimize or yellow button) cause scene inactive, dock right section.
  • Restore (window diamond or dock right section) cause scene active. (Active window gets check. Inactive windows get diamond.)