net.eduvax.util

Interface Observer<T>

public interface Observer<T>

Alternate Observable/Observer utility. Improvements from standar Observer/Observable : - no more need send anonymous objects to be casted before use. - only implement interface, no more ineritance restictions. // Register an oberver to an observable. Observable observable; Observer observer; // ... observable.getObserverManager().add(observer); warning: ObserverManager is memory less. a newly registered observable will not recieve notification sent to manager before the registration. Only notification comming after full registration will be recieved (unless some side effect of multi-threading). warning: Java does not allow multiple inheritance of the same generic interface even using different type parameters (C# does). Since this interface only define one methode, there's a simple workaround :

 // can't declare:
 // public class BiObs implements Observe<A>, Observer<B>  
 // so doing this way :
 public class BiObs {
                private void aChanged(A a) {
                        // get changes of A.
                }
                private void bChanged(B b) {
                        // get changes of B.
                }
                private Observer<A> aObs;
                private Observer<B> bObs;
                public BiObs(A a,B b) {
                        aObs=new Observer<A>() {
                                public void observableChanged(A a) {
                                        aChanged(a)
                                }
                        }
                        bObs=new Observer<B>() {
                                public void observableChanged(B b) {
                                        bChanged(b)
                                }
                        }
                        a.getObsManager().add(aObs);
                        b.getObsManager().add(bObs);
                }
                public void dispose() {
                        a.getObsManager().remove(aObs);
                        b.getObsManager().remove(bObs);
                }
 }

Method Summary

Methods

Modifier and Type	Method and Description
void	observableChanged(T sender) Signal change of Observable.

Method Detail

observableChanged

void observableChanged(T sender)

Signal change of Observable.

Parameters:

sender - notification source.