How to make an iTunes like (playlists, library) left-sided (collapsible) navigation bar?

Question

I am talking about the navigation area on the left side of iTunes for Library and Playlists. I'm wondering if this is a built in class (which I couldn't find documented) or something custom implemented by Apple.

I'm working an a mac application where I want to include that type of navigation. I want to allow people to "fold" the categories up by using the triangles. Do I need to write a custom implementation of this, or can I use some control in Interface Builder or some open source library?

Thanks!

Answer 1

The bar is called a source list. In 10.5, you can use an NSTableView for this, as described here. Before 10.5, you'll have to resort to third-party implementations.

See also: "How would one implement a sidebar similar to Mail/iTunes/Finder/etc in Cocoa/IB?"

Answer 2

You can also use NSOutlineView, as shown in this example

Answer 3

Another example can be found in this blog article: Cocoa: Sidebar with Badges.