NSArrayController issue

FROM : Måns Severin
DATE : Thu May 01 23:09:50 2008

Hi,

I've been working with an NSArrayController containing CoreData entity 
objects.
I've created a segmented control for cycling through these object 
(similar to Safari's Back/Forward buttons).
For some reason, after calling the NSArrayController methods 
selectNext: and selectPrevious: from my controller object, the 
canSelectNext and canSelectPrevious controller keys doesn't reflect 
the new selection.

In the code i provide I have a stepProjects: action called from the 
segmented control (oStepper), it calls the oProjectsController to 
select next/previous records. It then updates the UI which sets 
enabled flags for the segments in the segment control. Problem is,
canSelectPrevious and canSelectNext does not return correct value even 
if the array controller has selected the first or last element. If I 
instead of the [self updateUI] call create an NSTimer object, which in 
turn does an updateUI call after a 0.2 second delay, I get a correct 
update of the segment control.

Is there some kind of delegate / observer method of the 
NSArrayController to see when it is done changing selection?

I wouldn't have had this problem if I could bind the segments directly 
in Interface Builder, but I am not able to do that.
Anyone have had the same issue?

Best Regards
Måns Severin


Code Listing:

- (void)updateUI
{
   [self updateStepper];
}

- (IBAction)stepProjects:(id)sender
{
   switch ( [oStepper selectedSegment] )
   {
       case 0:
           [oProjectsController selectPrevious:self];
           break;
           
       case 1:
           [oProjectsController selectNext:self];
           break;
   }
   
   [self updateUI];
}

- (void)updateStepper
{
   [oStepper setEnabled:[oProjectsController canSelectPrevious] 
forSegment:0];
   [oStepper setEnabled:[oProjectsController canSelectNext] forSegment:1];
}_______________________________________________

Cocoa-dev mailing list (<email_removed>)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/<email_removed>

This email sent to <email_removed>