Actually I think I may have answered my own question: calling dequeueNotificationsMatching immediately before posting a new notification seems to do the trick. This seems like a reasonable and logical way of achieving what I want. Can anyone see any problem with doing that?
On 6 May 2015, at 11:54, Jonathan Taylor <jonathan.tay...@glasgow.ac.uk> wrote: > I am trying to work out whether there are any rules that define which of > multiple NSNotifications combined using coalescing actually get through to > the receivers, and preferably a way of controlling that behaviour. This > becomes relevant if for example there is different UserInfo associated with > each object. I can’t find any specific statement about what the behaviour is > under these circumstances. > > A concrete example: frames are received from a video camera, and a > notification (with coalescing) is sent when each one arrives (with a pointer > to the actual frame object in the user data of the NSNotification). Listeners > may wish to update their own displayed image if spare cycles are available. > However a quick experiment suggests that the EARLIEST-posted notification is > the one that survives coalescing. That means that receivers are acting on > stale information. No doubt there are some different circumstances where it > might make sense to keep the earliest-posted notification, but in this case > I’d definitely like the most-recently posted to make it through. > > I can think of several ways of achieving what I want with the help of > additional code, but is there any way I can get the NSNotification > infrastructure to behave the way I want (coalescing keeps the most > recently-posted notification and discards older ones)? > > Thanks for any suggestions! > Jonny. _______________________________________________ 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
