The observable design pattern is interesting to keep track of changes or events that happen in the context of an object, without having to alter the code of its class.
This class provides an implementation of the observable design pattern that can be used by other classes.
This package implements the observerable design pattern.
It defines an observer interface. This interface defines a function for observer classes that is called when the observed objects are updated.
There is also an observerable class that keeps track of all observer objects. It can add and remove observer objects, as well notify the observers when the observerable object is updated.