NSButtonCell NSSwitchButton doesn't display checked box - objective-c

Question

The NSButtonCell from the code bellow works fine, but it doesn't visualy display the check icon when clicked. Any ideas why?
- (NSCell *)outlineView:(NSOutlineView *)outlineView dataCellForTableColumn:(NSTableColumn *)tableColumn item:(id)item {
if ([[tableColumn identifier] isEqualToString:#"select"]) {
NSButtonCell *cell = [[NSButtonCell alloc]init];
[cell setButtonType:NSSwitchButton];
[cell setTarget:self];
[cell setAction:#selector(checkboxChanged:)];
[cell setTitle:#""];
return cell;
} else {
NSCell *cell = [tableColumn dataCell];
return cell;
}
}
Here is the action code:
- (IBAction)checkboxChanged:(id)sender {
NSButtonCell *aCell = [[sender tableColumnWithIdentifier:#"select"]
dataCellForRow:[sender selectedRow]];
if ([aCell state] == NSOnState) {
NSLog(#"ON");
[aCell setState:NSOffState];
} else {
NSLog(#"OFF");
[aCell setState:NSOnState];
}
}

Answer 1

I'm not sure why your first solution didn't work—maybe you didn't have your delegate hooked up? Note that the data source and the delegate are two separate things.
The method you implemented in your answer, which is a data source, is not the proper place to do that. The data source, and particularly numberOfRowsInTableView: and tableView:objectValueForTableColumn:row:, should only return the content being presented, not create view/cell objects.
I recommend creating and configuring the NSButtonCell in your xib, if you have one, or in the same place where you create your table view and its columns—that's also the correct place to set each column's cell.

Answer 2

I solved this problem by changing the above code from the NSOutlineView delegate method outlineView: dataCellForTableColumn:item: to the delegate method outlineView: objectValueForTableColumn: byItem:
Like so:
- (id)outlineView:(NSOutlineView *)outlineView objectValueForTableColumn:(NSTableColumn *)tableColumn byItem:(id)item {
if ([[tableColumn identifier] isEqualToString:#"select"]) {
NSButtonCell* cell = [tableColumn dataCell];
[cell setSelectable:YES];
[cell setEnabled:YES];
[cell setTransparent:NO];
[cell setButtonType:NSSwitchButton];
[cell setTarget:self];
[cell setAction:#selector(checkboxChanged:)];
[cell setTitle:#""];
return cell;
}
return nil;
}
And now it works perfectly.