Double clicking on headers of NSOutlineView is triggering double-click method?

Question

I've a set a double-click action for my NSOutlineView, everything is working well:every time I double click on a row in the table, the correct method is invoked.

However, the same method is invoked when I double click on the header of a column (let's say to change the sort order). I've never noticed this behaviour before, how could I disable it?

Answer 1

What about checking the clickedRow?

[self.outlineView clickedRow]