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

I very much got stuck on this - and posted NSTabView with background color - as the PSMTabBarControl is now out of date also posted https://github.com/dirkx/CustomizableTabView/blob/master/CustomizableTabView/CustomizableTabView.m