// ****** 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