On 10 Sep 2012, at 11:40, Motti Shneor <su...@bezeqint.net> wrote: > Thanks everyone. You are ALL right in your comments, and still my problem > persists. > > In reality, I have at least 6 external "triggers" or state-changes that > determine (in a quite complicated way) whether or not I should observe that > attribute. > > The (rather wise!) suggestion to start my key-path at self, and so avoid the > need to watch for representedObject changes could cure one of the 6. Still I > have the other 5... > > My question is general. Supposedly I could NOT start observing once, and stop > it once. Reasons: > 1. There are many instances of that NSViewController > 2. This observation is quite frequent in time (could reach 100 times a second) > 3. The code to filter-out unwanted value-changes is CPU intensive. > (Accounting for 5 orthogonal conditions, upon which I should actually do > something with the attribute change) > > So - I'd rather REMOVE the observation when I don't need it.
How much measurement have you done on this? In my experience, often the act of setting up or tearing down an observation is more time-consuming than leaving it running. Once the observation is in place, it's a fairly passive system. _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
