[objc] 제스쳐, 싱글탭 더블탭 동시에, gesture, single tap, double tap

// ****** gesture recognizers ******

{   // single tap    
    UITapGestureRecognizer *single_tap_recognizer;

    single_tap_recognizer = [[[UITapGestureRecognizer alloc] 
                    initWithTarget : table_view_controller  
                    action         : @selector(upper_button_view_tapped:)]
                    autorelease];

    [single_tap_recognizer setNumberOfTouchesRequired : 1];
    [u_buttons_view addGestureRecognizer : single_tap_recognizer];


    // double tap 
    UITapGestureRecognizer *double_tap_recognizer;

    double_tap_recognizer = [[[UITapGestureRecognizer alloc] 
                     initWithTarget : table_view_controller  
                     action         : @selector
                              (upper_button_view_double_tapped:)]
                     autorelease];        

    [double_tap_recognizer setNumberOfTouchesRequired : 2];

    [single_tap_recognizer requireGestureRecognizerToFail : double_tap_recognizer]; 

    [u_buttons_view addGestureRecognizer : double_tap_recognizer];

http://stackoverflow.com/questions/8876202/uitapgesturerecognizer-single-tap-and-double-tap