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/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2001 Intersect Software Corporation
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/
package net.wotonomy.control;
import net.wotonomy.foundation.NSSelector;
/**
* A convenience observer for objects that do not or cannot subclass
* EODelayedObserver. EOObserverProxy will invoke an NSSelector on an object
* when it receives a subjectChanged message.
*
* @author michael@mpowers.net
* @author $Author: cgruber $
* @version $Revision: 893 $
*/
public class EOObserverProxy extends EODelayedObserver {
protected Object target;
protected NSSelector selector;
protected int priority;
/**
* Constructs an EODelayedObserver that will invoke the specified selector on
* the specified object, and will run at the specified priority.
*/
public EOObserverProxy(Object anObject, NSSelector aSelector, int aPriority) {
target = anObject;
selector = aSelector;
priority = aPriority;
}
/**
* Constructs an EODelayedObserver that will invoke the specified selector on
* the specified object, and will run at ObserverPriorityThird priority, which
* is the default.
*/
public EOObserverProxy(Object anObject, NSSelector aSelector) {
this(anObject, aSelector, ObserverPriorityThird);
}
/**
* Returns the priority of this observer in the queue. This implementation
* returns the priority specified in the constructor.
*/
public int priority() {
return priority;
}
/**
* Notifies observer that one or more objects that it is observing have changed.
* The observer should check all objects it is observing for changes.
*/
public void subjectChanged() {
try {
selector.invoke(target);
} catch (Exception exc) {
System.out.println("Error notifying observer: ");
exc.printStackTrace();
}
}
}
/*
* $Log$ Revision 1.1 2006/02/16 13:19:57 cgruber Check in all sources in
* eclipse-friendly maven-enabled packages.
*
* Revision 1.1 2001/10/22 21:55:32 mpowers This turns out to be a really useful
* class.
*
*
*/
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