Changes

In the chapter entitled [[Detecting iOS 4 iPad Touch Screen Gesture Motions (Xcode 4)|Detecting iOS 4 iPad Touch Screen Gesture Motions]] we looked at how to track the motion of contact with the iPad screen. The techniques used in that chapter did little more than track the coordinates of the user’s finger on the device display. Whilst this is useful in some situations, in most applications it is more probable that an application will need to respond to very specific gesture motions. In fact, there are a range of gestures that users are will already be familiar with based on experience with other iPad applications. The swiping of a finger across the screen might, for example, be required slide a new view onto the display or to turn the page of a virtual book. Similarly, a pinching motion is typically used in iPad applications to enlarge or reduce an image or to zoom in and out of text.