org.bs.mdi
Interface ActionObservable

All Known Subinterfaces:

RootView, View

All Known Implementing Classes:

Data, SwingRootView, SwingView

public interface ActionObservable

An interface for objects that can be observed by an ActionObserver.

Method Summary

void	addObserver(ActionObserver observer) Registers this observer so that it will receive notification messages.
int	countObservers() Counts all registered observers.
boolean	isObserver(ActionObserver observer) Determines if the given observer is currently observing this object.
void	notifyObservers(Action action, boolean undo) Notifies the observers about an action which has been recently performed.
void	removeObserver(ActionObserver observer) Un-registers this observer so that it will not receive notifications any longer.

Method Detail

addObserver

public void addObserver(ActionObserver observer)

Registers this observer so that it will receive notification messages.

Parameters:

observer - the observer to be registered

removeObserver

public void removeObserver(ActionObserver observer)

Un-registers this observer so that it will not receive notifications any longer.

Parameters:

observer - the observer to be un-registered

countObservers

public int countObservers()

Counts all registered observers.

Returns:

the number of registered observers.

isObserver

public boolean isObserver(ActionObserver observer)

Determines if the given observer is currently observing this object.

Parameters:

observer - the observer

Returns:

true if the observer is currently observing this object, false otherwise

notifyObservers

public void notifyObservers(Action action,
                            boolean undo)

Notifies the observers about an action which has been recently performed. Note that the implementation may use threading to deliver the notification messages.

Parameters:

action - the action which has been performed

undo - true if the action has been undone, false otherwise