Question

I’d like to disable cut and/or paste in the menubar at runtime, in my ObjC app. I know that that’s possible in iOS using
-(BOOL)canPerformAction:(SEL)aSelector withSender:(id)sender

Is there anything similar for MacOS?

Thank you

Answer 1

There is the NSUserInterfaceValidations Protocol, a generic protocol for validating items. You simply implement the validateUserInterfaceItem: method and return NO to disable the action.

- (BOOL)validateUserInterfaceItem:(id < NSValidatedUserInterfaceItem >)anItem {
    if([anItem action] == @selector(cut:) ||
       [anItem action] == @selector(copy:) ||
       [anItem action] == @selector(paste:)) return NO;
    return [self respondsToSelector:[anItem action]];
}

There is also a NSMenuValidation Protocol, which performs the same function but is used only to validate menu items, instead of all interface items. If you don’t implement it, the system will fall back to the standard validation instead.