NSOutlineView with source highlighting not retreating to the second level

Question

I had a very strange problem:

I have an NSOutlineView set to NSTableViewSelectionHighlightStyleSourceList . Under certain conditions, the second level has no indentation and is displayed at the same level as the root node.

I believe this is because the first level should be "group." However, at 10.8 everything is indented by default. I just caught this when testing on 10.7. It looks like this change has changed in versions.

The second level is not indented if:

• on Mac OS X 10.7 Lion (always the same behavior)
• OR only 10.8 if I implement - (BOOL)outlineView:(NSOutlineView *)outlineView isGroupItem:(id)item to return NO

How can I make each level fall back, as one would expect for a hierarchical layout and maintain the style of the original list?

Unexpected indentation:

Answer 1

Indentation only seems to start at level 3. So, to get around this, you need to add a node that wraps all your current root nodes. This root node will be very similar to the default OSX group node:

Not perfect, depending on your user interface, but better than using the usual NSOutlineView style.

If you do not want to show the root title, you can use outlineView:heightOfRowByItem: to set the height to 0 .