On Thu, Jan 22, 2009 at 7:34 PM, Quincey Morris <quinceymor...@earthlink.net> wrote: > On Jan 22, 2009, at 14:55, John Mikros wrote: > >> I'm working on a Cocoa application which does all of its work within an >> NSTimer callback that is called regularly. Events are handled normally >> within a Cocoa run loop. >> >> However, there are times when within the callback, the code enters an >> inner loop, and will not exit until some user action is performed. >> I'm trying to force the run loop to pump events within this inner loop, >> but I can't seem to ever get it to work. > > I use, from the timer callback: > >> NSEvent *event; >> while (event = [NSApp nextEventMatchingMask: NSAnyEventMask >> untilDate: nil inMode: NSEventTrackingRunLoopMode dequeue: YES]) >> [NSApp sendEvent: event]; > > > I don't know if this is officially blessed or not, but it certainly seems to > work just fine. > > In the places I've done this, I was only really interested in making the > mouse and keyboard work, hence NSEventTrackingRunLoopMode. You could use the > default run loop mode instead, I guess.
Yes, this is fine, and supported. It's a common way of implementing mouse tracking instead of relying on the stateless mouseDragged: method. The reason you have to do this and can't just run the runloop is because the event loop is actually a separate concept from the runloop. It's a bit confusing because the event loop is implemented using the runloop, but if you just run the runloop on the main thread, events won't get processed. You have to explicitly run this in order to get them to be processed. Note that using the default runloop mode with this is generally a bad idea. By running in the default mode you allow *everything* else to run, which means that some other code might decide that *it* wants an inner event loop as well. If you then want to quit before that other code has finished, tough cookies. Much better to control things more tightly by using a different runloop mode. Mike _______________________________________________ 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: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
