One of the things that sets the iPhone’s user interface apart from the competition is Apple’s incredible attention to detail. This attention does not only extend to every single pixel on the screen but, perhaps even more important, also to gesture recognition: the standard iOS controls do a lot of smart things in order to identify the gesture the user intended to make and to allow multiple gestures to be executed at the same time if appropriate.
For example, scroll views must distinguish between a simple tap and the beginning of a swipe gesture. Similarly, the built-in map view control allows pinching and scrolling in one simultaneous gesture (put two fingers on the screen and you can switch seamlessly between pinching and scrolling without having to “restart” the gesture).
Half-assed Gesture Recognition Is Not Good Enough
We should set ourselves the same high standards for our own apps. In this article, I would like to show you an example where the half-assed implementation of gesture recognition seems to work well enough at first glance. But as the user continues to use the app, they quickly stumble upon little irritations, small annoyances in the user interface that they perhaps cannot even pinpoint but notice nevertheless. And while these irritations do not seem to be a big deal to many developers, I want to show you how getting rid of them can improve the user experience tremendously.