Observer pattern

An example of observer pattern

The observer pattern allows to decouple the GUI elements (control and view) from the data model. All views are automatically synchronized through notify()/update()

Example:
iw1 = interval_window();
iw2 = interval_window_flow();
iv = interval_view();

i1 = interval(2,8,6);

i1.attach_observer(iw1);
i1.attach_observer(iw2);
i1.attach_observer(iv);