SimpleController can be used as a controller according to the model-view-controller (M-V-C) paradigm. It provides an IdentityDictionary of actions, which are called whenever the attached model sends a notification by calling changed.
Creates a SimpleController instance with the model to be observed.
An object of any class
Register an action, which is called when the model invokes changed(what, moreArgs).
Action to register.
Remove a registered action.
Action to remove