shaking detection in iPhone application

Few days ago, I saw an iPhone application, which as an wallpaper type application and the image was changed when iPhone shaked.

Then I try to learn how iPhone detects shaking.
In the following I describe it:

UIResponder class has two delegate method which is called when iPhone is shaked. The methods are:

- (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event;
- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event;

The first method Tells the receiver that a motion event has begun.
The second method Tells the receiver that a motion event has ended.

->Note:
1. iPhone OS informs the first responder only when a motion event starts and when it ends; for example, it
doesn’t report individual shakes.

2. The receiving
object must be the first responder to receive motion events .

-> How we can use this methods in our app:

The UIView which you want to respond to shake, you have to subclass this view of a UIView, and you have to override the 3 methods:
- (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event{

NSLog(@" Shake Start");

/*
do what you want when shake start;
*/

}


- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event{

NSLog(@" Shake End");

/*
do what you want when shake End;
*/

}

- (BOOL)canBecomeFirstResponder{ return YES; }

and in your view controller class, always respond that view as a first responder.


You can download my demo project on iPhone shaking from here