Returns a Boolean value indicating whether this object can become the first responder.
- iOS 10.0+
- tvOS 10.0+
true if the receiver can become the first responder or
false if it cannot.
This method returns
false by default. Subclasses must override this method and return
true to be able to become first responder.
Do not call this method on a view that is not currently in the active view hierarchy. The result is undefined.