Xcode iOS push down button and drag then up on a second button

Question

Lets say I wan\'t to add 1 to an integer. This will only be done when I push down on a UIButton and then release my finger on another UIButton.

Answer 1

Do the following for the first UIButton in the ViewDidLoad method

    [button1 addTarget:self action:@selector(dragMoving:withEvent: )
              forControlEvents: UIControlEventTouchDragInside | UIControlEventTouchDragOutside];

    [button1 addTarget:self action:@selector(dragEnded:withEvent: )
              forControlEvents: UIControlEventTouchUpInside |
     UIControlEventTouchUpOutside];

In the dragMoving method

- (void)dragMoving:(UIControl *)c withEvent:event{

    NSSet* touches = [event allTouches];
    UITouch *touch = [touches anyObject];
    CGPoint currentPoint = [touch locationInView:[button2 superview]];


        if ( CGRectContainsPoint(button2.frame, currentPoint) ) {
            NSLog(@"over second button); 
        } 
    }

As for the dragEnded method:

- (void) dragEnded:(UIControl *)c withEvent:event{

    NSSet* touches = [event allTouches];
    UITouch *touch = [touches anyObject];
    CGPoint currentPoint = [touch locationInView:[self.button1 superview]];
        if ( CGRectContainsPoint(button2.frame, currentPoint) ) {
            NSLog(@"ended on button 2");
            //add 1 to the integer


        }
    else {
        NSLog(@"not on button 2");
    }
}