NSOutlineView Group spacing

Question

I'm working on a NSOutlineView (SourceList) and want the replace the current styling with my own to get a better look for my app. I've changed the default header and content cells with custom NSTableViewRows. This works fine. But now I can see a space between the groups. These space is about 9 Pixels and I want to remove it. But I don't know how. Changing the cell spacing didn't help and I didn't find anything in the developer reference to do that. Is there anybody who can give me a hint or a snippet? that would be great.

-----------------------
* Group 1
  - Item 1
  - Item 2
-----------------------
// this space should be changed
-----------------------
* Group 2
  - Item 3
  - Item 4
-----------------------

Thank you. Alex

Answer 1

This might be just a try to get to the problem, not an answer, but stackoverflow doesn't let me comment because of my reputation.

Anyway, I remember to had weird behavior of NSOutlineView in the past. Maybe the setFloatsGroupRows: will help you:

[myOutlineView setFloatsGroupRows:NO];

Please let me know.