How to visualize UITouch events on the iPhone/iPad

gistfile1.mm

/*
 * This bit of code is to visualize how touches works
 * so that we can use it to drag around objects on a screen.
 */
-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
	UITouch *touch = [touches anyObject];
	CGPoint touchPoint = [touch locationInView:self.view];
	NSLog(@"touchesBegan: X: %2.2f Y: %2.2f", touchPoint.x, touchPoint.y);
}

-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
	UITouch *touch = [touches anyObject];
	CGPoint touchPoint = [touch locationInView:self.view];
        
        // Some simple code to demonstrate that you can move a 
        // UIView (which you can customize beyond your wildest dreams :D)
        // around.
        [self moveBox:someViewName WithTouch:touch WithTouchPoint:touchPoint];
}

-(void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
	UITouch *touch = [touches anyObject];
	CGPoint touchPoint = [touch locationInView:self.view];	
	NSLog(@"touchesEnded: X: %2.2f Y: %2.2f", touchPoint.x, touchPoint.y);
}

#pragma mark -
#pragma mark Moving UIViews around
-(void) moveBox:(CustomViewName *)viewname WithTouch:(UITouch *)touch WithTouchPoint:(CGPoint)touchPoint {
	if (touch.view == viewname) {
		viewname.center = touchPoint;
		// TODO: Collision detection/handling code
                // This can get trickier.
	}
}