iphone - How to access to app default gesture recognizers -

i have created simple single view application , added 1 button view. next used next code determine subviews , it's gesture recognizers:

-(void) debug:(uiview*) view{     for(uigesturerecognizer* g in view.gesturerecognizers)     {         nslog(@"base view gr=%@ gr_view=%@",nsstringfromclass ([g class]),g.view);     }     (uiview* sub in view.subviews) {          nslog(@"%@.subview=%@",nsstringfromclass ([view class]),nsstringfromclass ([sub class]));          for(uigesturerecognizer* g in sub.gesturerecognizers)         {             nslog(@"          | gr=%@ gr_view=%@",nsstringfromclass ([g class]),g.view);         }         [self debug:sub];     } } 

but log shows no 1 gesture recognizer in existing view , it's subviews. wold have access default app gesture recognizers, how can this?