NSViewController extension for fetching a window title's NSTextField

NSViewController+NSTextField.swift

extension NSViewController {

    var titlebarTextField: NSTextField? {
        // NSTitlebarContainerView
        guard let titlebarContainerView = view.superview?.subviews
            .first(where: { $0.className.hasSuffix("ContainerView") })
            else { return nil }

        // NSTitlebarView
        guard let titlebarView = titlebarContainerView.subviews
            .first(where: { $0.className.hasSuffix("TitlebarView") }) as? NSVisualEffectView
            else { return nil }

        // NSTextField
        return titlebarView.subviews
            .first(where: { $0 is NSTextField }) as? NSTextField
    }

}