I'm creating test Document based app with Xcode 11 and SwiftUI.
At first, I have thought that I have to add file picker dialog and open menu/button to my app. But it need not. The file picker dialog was shown automatically when the app launched. But there are no code in Main App, document struct, and ContentView. Nothing.
What is happening in App launching sequence? The SwiftUI or Cocoa Framework processes this sequence? If there are some help document, please let me know.
