Detect 3 fingers touch in the whole app without affecting the subviews - ios

Question

I am making an iPad app where you can swipe/pan with 3 fingers at any time on the whole screen (cancel action)
It's working with a UISwipeGestureRecognizer or UIPanGestureRecognizer but the subviews underneath my fingers (for instance a UITableView or UIScrollview) received the touch and moves. Which I don't want.
My idea was to put a transparent UIView on top of the whole app that will forward touches to the other views or not. I tried something with hitTest but I think I didn't understand it well since the return number of touches isn't right and takes time...
Thanks a lot if you can help me with that :)
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
if (event.type == UIEventTypeTouches) {
if (event.allTouches.count >= 2) {
return self;
}
}
return [super hitTest:point withEvent:event];
}

Answer 1

I think you must use the
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
delegate of UIGestureRecognizer to define which gestures is valid in the same time.
E.g:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
NSLog(#"gestRecogn: %# otherGestRec: %#",[[gestureRecognizer class] className],[[otherGestureRecognizer class] className]);
if ([[[gestureRecognizer class] className] isEqualToString:#"UIScrollViewPanGestureRecognizer"] && [[[otherGestureRecognizer class] className] isEqualToString:#"UILongPressGestureRecognizer"]) {
return FALSE;
}
if ([[[gestureRecognizer class] className] isEqualToString:#"UILongPressGestureRecognizer"] && [[[otherGestureRecognizer class] className] isEqualToString:#"UIScrollViewPanGestureRecognizer"]) {
return FALSE;
}
return TRUE;
}