I meant to say -touchesMoved instead of -touchesBegan below. - Carl On Oct 3, 2013, at 12:47 PM, Carl Hoefs <newsli...@autonomy.caltech.edu> wrote:
> iOS 6.1.3 & 7.0.2, newb! > > I'm seeing an unacceptable lag in my iOS app on drag touches, from when a > finger is dragged across the screen to when my code updates the screen. I > can't figure out what is causing the lag. > > Here's my setup. I have a -touchesBegan:withEvent: method in my view > controller that gets invoked via callback from the GUI when a finger touch > occurs. My code displays a tiny dot on the GUI beneath the user's fingertip > that is supposed to track with the user's touch in real time. > > -(void) -touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event > { > CGPoint apoint=[[touches anyObject] locationInView:[self view]]; > [layer setPosition:apoint]; > } > > The 'layer' variable is defined as: > > CALayer *layer=[[CALayer alloc]init]; > [layer setDelegate:self]; > [layer setBounds:CGRectMake(0,0,5,5)]; // a tiny "dot" > > This all works well except when the user makes large, sweeping touches (say > dragging a fingertip across the entire screen). In this case, the update > drawing of the dot lags a second or two behind, which is unacceptable. > > So I'm wondering how to handle this. FWIW, adding a [super > touchesBegan:touches withEvent:event] to the above callback method didn't > change the behavior. > > - Carl > > _______________________________________________ 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