Chapter #10. Don't Invent New, Arbitrary Controls
This could be:
An isometric pseudo-3D wheel to choose the color of your car
A volume dial that you must click and drag up-and-down to "rotate"
A button you must click and hold for a few seconds to indicate that you really want to do this action
Just don't invent them. As designers, we already have a rich palette of existing controls to choose from. If you're thinking about making a new UI control, please stop and think about how hard it will be for users to learn yet another interface pattern. I promise you this—there's already a way to do what you want to do.
However, every now and thn, something new comes along that is genuinely an advance in UI. Back in 2008, Loren Brichter made a Twitter app called Tweetie, with a unique pull-to-refresh interaction. Pulling the view down would show "release to refresh" and releasing would show a spinner. The pull-to-refresh interaction went on to be included in Twitter, which bought Tweetie, and then in iOS...