Asks the delegate if a gesture recognizer should be required to fail by another gesture recognizer.
- iOS 7.0+
- tvOS 9.0+
true to set up a dynamic failure requirement between
other. The default implementation returns
gesture isn’t required to fail by
This method is called once per attempt to recognize, so failure requirements can be determined lazily and may be set up between recognizers across view hierarchies. Note that returning
true is guaranteed to set up the failure requirement; returning
false, on the other hand, isn’t guaranteed to prevent or remove a failure requirement because
other might make itself a failure requirement by using its own subclass or delegate methods.