On Fri, Oct 17, 2008 at 2:33 PM, James Walker <[EMAIL PROTECTED]> wrote: > I'd like to be notified when the mouse button has been released after some > live tracking of a slider. I can probably do it by subclassing NSSlider and > NSSliderCell, for instance overriding [NSCell > stopTracking:at:inView:mouseIsUp:], but is there an easier way?
There is indeed. Write your action like this: - (IBAction)sliderMoved:(id)sender { SEL trackingEndedSelector = @selector(sliderEnded:); [NSObject cancelPreviousPerformRequestsWithTarget:self selector:trackingEndedSelector object:sender]; [self performSelector:trackingEndedSelector withObject:sender afterDelay:0.0]; // do whatever you want to do during tracking here } - (void)sliderEnded:(id)sender { // do whatever you want to do when tracking ends here } It may not be immediately obvious why this works. Delayed performs happen in the default runloop mode (unless you specify otherwise using the variant that has modes: at the end). Event tracking happens in a special event tracking runloop mode. So the delayed perform won't happen until the user lets go of the mouse button. To keep these delayed performs from piling up, this method first cancels any previous ones before scheduling the new one. An alternate method would be to have some sort of flag that guarantees you only schedule one, but this way is simpler and doesn't require a flag. This technique works for any control that uses the event tracking mode, such as continuous buttons, menus, and other such things, but it's most commonly used for sliders. 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 [EMAIL PROTECTED]