How to draw your own NSTabView tabs?

Question

I want to draw my own tabs for NSTabViewItems. My Tabs should look different and start in the top left corner and not centered.

How can I do this?

Answer 1

NSTabView isn't the most customizable class in Cocoa, but it is possible to subclass it and do your own drawing. You won't use much functionality from the superclass besides maintaining a collection of tab view items, and you'll end up implementing a number of NSView and NSResponder methods to get the drawing and event handling working correctly.

It might be best to look at one of the free or open source tab bar controls first, I've used PSMTabBarControl in the past, and it was much easier than implementing my own tab view subclass (which is what it was replacing).