Delay on tap gestures and pop alert vibration - ios

Question

I'm getting a lot of delay in an app that needs to feel more instant.
I've got a simple app that toggles left and right. It's a seesaw and when one end is up, the other is down. Your supposed to use two fingers and tap on the screen like your just fidgeting with it. It supposed to be an aid to ADHD.
I've got two large images for left and right state. I've got a gesture recognized on the image and I check the coordinates of the tap to determine if you tapped the right side to go down or the left. I'm also using AudioServicesPlayAlertSound to cause a small pop vibrate on touch begin in an effort to give a bit of a feedback stimulus to the user.
In my tests, if I tap rapidly it seems I get a backlog of taps on the toggle. The vibrations happen way after the tap is over, so it feels useless. Sometimes the UI image gets backlogged just switching between images.
override func viewDidLoad() {
super.viewDidLoad()
let imageView = Seesaw
let tapGestureRecognizer = UILongPressGestureRecognizer(target:self, action: #selector(SeesawViewController.tapped));
tapGestureRecognizer.minimumPressDuration = 0
imageView?.addGestureRecognizer(tapGestureRecognizer)
imageView?.isUserInteractionEnabled = true
}
func tapped(touch: UITapGestureRecognizer) {
if touch.state == .began {
if(vibrateOn){
AudioServicesPlaySystemSound(1520)
}
let tapLocation = touch.location(in: Seesaw)
if(tapLocation.y > Seesaw.frame.height/2){
print("Go Down")
Seesaw.image = UIImage(named:"Down Seesaw");
seesawUp = false
} else if (tapLocation.y < Seesaw.frame.height/2){
print("Go Up");
Seesaw.image = UIImage(named:"Up Seesaw");
seesawUp = true
}
}
}
Another idea - would it be faster to implement this as a button? Are gesture recognizers just slow? Are the way I'm drawing the image states consuming the wrong type processing power?

Answer 1

Sems like you made mistake in your code. You want to create tap recognizer, but you created UILongPressGestureRecognizer
Please change line from
let tapGestureRecognizer = UILongPressGestureRecognizer(target:self, action: #selector(SeesawViewController.tapped))
to
let tapGestureRecognizer = UITapGestureRecognizer(target:self, action: #selector(SeesawViewController.tapped))
Or you may add transparent button and put your code to its handler
// onDown will fired when user touched button(not tapped)
button.addTarget(self, action: #selector(onDown), for: .touchDown)