Question

I need to traverse a viewcontroller’s view hierarchy what font is being used. Is there a generic way to determine if the view (and subclass of view) supports fonts? I do not want to do a huge if-then-else:

if ([[view isKindOfClass: [UILabel class]) {
  // Do stuff
} else if ([[view isKindOfClass: [UITextField class]) {
  // Do stuff
} etc. ...

due to the maintenance issue. I prefer to have a method such as

if ([view canPerform: @selector(getFont:)]) {
  // Do stuff
}

but this does not work as one might hope.

Answer 1

You may use the respondsToSelector method, inherited from NSObject.

if( [ view respondsToSelector: @selector( font ) ] ) {}

Or

if( [ view respondsToSelector: @selector( setFont: ) ] ) {}