A Boolean value that indicates whether the receiver has any actions to redo.
- iOS 3.0+
- macOS 10.0+
- tvOS 9.0+
- watchOS 2.0+
true if the receiver has any actions to redo, otherwise
Because any undo operation registered clears the redo stack, this method posts an
NSUndo to allow clients to apply their pending operations before testing the redo stack.