Performance problem with horizontal UIPicker

[SirDuke]

I needed a horizontal scrolling view, something like the UIPickerView (but horizontal). So I decided to make it myself. The view I build scrolls with swipes, has momentum and scales its contents accordingly. On the simulator it works fine. The only problem it has is that its performance on the iPhone is too jerky.

In general I made a class that takes an Array of strings and creates a set of UILabels using those strings. Then it places them on a UIView that the user can scroll.

I am attaching a ready-to-run project below in case someone can see what I am doing wrong and if there is something that would justify such a glitchy performance. I am assuming it might be the way I am handling touches, since there seems to be a delay (like half a second) every time the user starts to swipe.
Also in case someone finds it helpful and would like to use it.

http://locus-delicti.com/files/HScroller.zip

If you can't see a problem in the code, maybe you can suggest some similar component that someone else has made... I've seen horizontal scrollers a lot on the AppStore...

[pcooperllan]

Hi,
I was just wondering if you were able to solve this, and if so if you could share the solution?

Thanks,
Paul

[SirDuke]

Hi pcooperllan,

in the end I used a UIScrollView. Simple as that. I created a very wide UIScrollView to hold all of my content and then on the "viewDidScroll" method, I took care of resizing my view's content according to my needs. The performance is fine in all devices with 2 of those UIScrollViews on the screen, each one holding about 800 subviews.

If you need to create something significantly larger, make sure you also hide/show your subviews when they are not showing to improve performance even more, or even to release them from memory (following the UITableViewCell's reusability paradigm).

[pcooperllan]

Thanks for answering, I'll have a go at writing something with the UIScrollView.

I hope I'm not asking too much, but I don't suppose that you have any sample code which would illustrate how you achieved the UIScrollView based horizontal picker?

Thanks again,
Paul

[rocotilos]

I am also using horizontal pickerview. But i didnt make any kind of class. I just apply transform on it and each of the items in it when showing the picker. works ok for me.