title: Sidebar in macOS app in Swift
body: <p>I'm trying to learn Swift and macOS app development by building various little apps for myself taking inspiration from other apps that are out there. I'd like to try to replicate the look and feel of the sidebar in Things 3 but I'm coming unstuck... I currently have a Split View but don't know where to go from there.</p>
  
  <p><a href="https://i.stack.imgur.com/3RNAj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3RNAj.png" alt="Things 3 screenshot"></a></p>
  
  <p>I've had a look at using NSOutlineView and thought about NSStackView, but I'm not really sure what the best way to go about it is. I've been trying to poke around with <a href="https://developer.apple.com/library/content/samplecode/SidebarDemo/Introduction/Intro.html" rel="nofollow noreferrer">https://developer.apple.com/library/content/samplecode/SidebarDemo/Introduction/Intro.html</a> but to no avail. I'd ideally like to be able to implement this myself without using third party frameworks since I'm trying to learn the language.</p>
  
  <p>Thanks in advance!</p>