weird bug or feature?

FROM : William Squires
DATE : Sun Jun 22 17:41:44 2008

Okay, here's a strange UI glitch. I have an Xcode project in which 
I have a "to-do" list (the challenge in Chapter 6 of the new 
Hillegaas book). I've sprinkled NSLog() calls into my methods in 
AppController, so I can see what's going on. I build and run, then 
add a few items - all okay so far; they appear in the NSTableView. If 
I hover the mouse over the content region of the NSTableVIew, a 
spurious tableView:objectValueForColumn:row shows up in the console 
log (note that I'm not clicking on anything, just hovering the mouse 
over the NSTableView) about once every few seconds. Bug or feature? I 
would expect a delegate for mousing over, but not 
tableView:objectValueForColumn:row!