On January 30, 2010,
in iPhone Programming Tutorials,
by Sushant
Detecting Pinch is pretty easy. First, when the gesture begins, we check to make sure there are two touches,because pinches are two-finger gestures. If there are two , we store the distance between them. Then as the gesture progresses, we keep checking the distance between the user’s fingers, and if the distance increases or discreases more than a certain amount , we know there’s been a pinch.
