Center the main window of an app in Mac Catalyst

Question

It is possible to set the position on the screen of the app's main Window in UIWindowScene?

I want to center the window of my Mac Catalyst app every time the user open it (instead of appearing in the last position before the app was closed)

I believe that this fact greatly affects the usability of an application and I do not see information on the Internet.

Answer 1

As of iOS 16, you can use UIWindowScene requestGeometryUpdate(_:errorHandler:)

I would add the following to your main window scene's root view controller:

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    if #available(macCatalyst 16.0, *) {
        if let winScene = self.view.window?.windowScene {
            // Calculate the new window frame
            // This takes the existing window size and position and centers it on the screen
            let screen = winScene.screen.bounds
            var frame = winScene.effectiveGeometry.systemFrame
            frame.origin.x = (screen.width - frame.width) / 2
            frame.origin.y = (screen.height - frame.height) / 2

            // Now request the new frame
            winScene.requestGeometryUpdate(.Mac(systemFrame: frame))
        }
    }
}