Module ballworld_inherit

Package provided.util.dispatcher

Interface IDispatcher<TMsg>

Type Parameters:

TMsg - The type of message to send to all the observers.

All Known Implementing Classes:

ADispatcher, ParallelDispatcher, SequentialDispatcher

public interface IDispatcher<TMsg>

Top-level abstraction of a Dispatcher which is the Observable in the Observer-Observable Design Pattern without the requirement to set the state before sending a message to the observers. A Dispatcher sends IMsg-type messages to all its observers which therefore must be capable of receiving and processing those messages, i.e. are IObserver<TMSg>. To maximally decouple an application from the randomizer's implementation any variable representing a randomizer should be typed to this interface, not to any concrete implementation. For example: IDispatcher<Graphics> myDispatcher = new SequentialDispatcher<Graphics>()

Author:

swong

Method Summary

Modifier and Type	Method	Description
boolean	addObserver(IObserver<TMsg> obs)	Add an observer to the dispatcher.
java.util.Set<IObserver<TMsg>>	getAllObservers()	Get a COPY of the set of all the observers currently in the dispatcher.
java.util.Set<IObserver<TMsg>>	removeAllObservers()	Removes all the observers currently in the dispatcher
IObserver<TMsg>	removeObserver(IObserver<TMsg> obs)	Remove an observer from the dispatcher.
void	updateAll(TMsg msg)	Send the given message to all the observers in the dispatcher

Method Detail

addObserver

boolean addObserver(IObserver<TMsg> obs)

Add an observer to the dispatcher. If the observer is already in the dispatcher, as determined by the comparison (equals()) process, the dispatcher is NOT mutated and false is returned.

Parameters:

obs - The IObserver to add

Returns:

true if the given observer was not already in the dispatcher, false otherwise.

Throws:

java.lang.ClassCastException - If the observer cannot be properly compared against the existing observers

java.lang.NullPointerException - If the supplied value is null

removeObserver

IObserver<TMsg> removeObserver(IObserver<TMsg> obs)

Remove an observer from the dispatcher. The dispatcher does not make any assumptions that the observer being removed is identically the same object as that it was requested to remove via the input parameter. The returned object is the object that was internally held by the dispatcher.

Parameters:

obs - The IObserver to add

Returns:

The observer that was removed or null if it was not found.

getAllObservers

java.util.Set<IObserver<TMsg>> getAllObservers()

Get a COPY of the set of all the observers currently in the dispatcher. This is a shallow copy, so the observers themselves are not copied.

Returns:

A set of IObservers

removeAllObservers

java.util.Set<IObserver<TMsg>> removeAllObservers()

Removes all the observers currently in the dispatcher

Returns:

A COPY of the set of IObservers in the dispatcher before they were all removed.

updateAll

void updateAll(TMsg msg)

Send the given message to all the observers in the dispatcher

Parameters:

msg - The IMsg to send to all the observers