I have horizontal list for which I'm implementing my own scrolling logic. I have the "touch and drag" scrolling working great, but I'm having trouble with the "flick" gesture. All the built in scrollable views have the feature that if you "flick" the view it scrolls faster or slower based on the intensity of the flick.
Does anyone has any suggestion how do that for my view?
What I'm doing right now is changing the UIView.center.x coordinate of my custom UIView to scroll it across the screen
I would strongly suggest you figure out how to make use of the built in UIScrollView class. Apple has invested a LOT of effort to make scrolling feel 'right'. You may be able to recreate some, or even all, of that feel, but it'll take a lot of work. Better to piggy back off of what's already been done.
If you want to implement your own scroll view, you'll have to make the view scroll based on the length of the sweeping distance and the speed at witch it went across the screen.
Taking these parameters as input and using simple geometry math you could calculate how much further the view should scroll after the sweep has ended(touchesEnded event).
Ofcourse this is not as simple as it sounds, making the flick gesture just feel right and natural is much harder.
If you really are set on doing this yourself, Drew McCormack has a great article on MacResearch where he explains some of the physics behind momentum-based scrolling. His implementation uses HTML, CSS, and JavaScript, but the core principles could be brought across to your custom UIView subclass.