Based on the Sidebar tutorial we can add a DisclosureGroup one.

New SwiftUI features are coming, some of them are supported only on the latest macOS .e.g. Table. It might be worth considering to introduce some kind of "flag/badge" which would shows where that feature is available.

Tutorial about how to add Preference window to a SwiftUI macOS app.

Simple (Table)[https://developer.apple.com/documentation/swiftui/table] demo, which is similar to NSTableView maybe the functionalities are less but better than using List.

Congrats, this side is great and exactly what I am looking for, working with Swift and macOS!

Suggestion: I try to find samples to understand the 'rubber band' functionality used in conjunction with e.g.: @IBAction func related to radio buttons.

Well, it is a personal challenge I am having right now: Four text fields should be evaluated by its content. In order to calculate mathematical results, the button should be deactivated, till all inputs are valid or at least meaningful.
If all four text fields are filled accordingly, the -button should become activated.

Maybe you could provide me a hint where to start and I would try to submit this course with a pull request?

Happy hackin'
LoetLuemmel!

The Finder sidebar has a default width that hugs its content (180 pt on my machine) and a minimum width of ~ 112 pt. Is it possible to implement Finder sidebar behavior with SwiftUI? (Custom default/initial width, snap to default width)

Or more simply, customizing the initial width to something other than 140 pt would be a great start too!

Need to add a .gitignore file to the repository instead of assuming people have one installed on their system. This will prevent contributors from submitting files that don't need to be in version control.