Learning the Observer Pattern w/ Callbacks

Taking another look at how we can use the Observer Pattern in our application, but this time we will implement the pattern using call backs and events. The Observer pattern allows you to define a one-to-many relationship inside your application where the parent object (the one) has the ability to notify the child objects (the many) of any state change. You can utilize this pattern to make sure that a set of objects are keep in order when there behavior needs to change based on the state of your application.