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/*
 * Copyright 2000,2005 wingS development team.
 *
 * This file is part of wingS (http://wingsframework.org).
 *
 * wingS 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.
 *
 * Please see COPYING for the complete licence.
 */
package org.wings;

import javax.swing.*;
import java.beans.PropertyChangeListener;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;

/**
 */
abstract class AbstractActionPropertyChangeListener implements PropertyChangeListener {
    private static ReferenceQueue queue;
    private WeakReference target;
    private Action action;

    AbstractActionPropertyChangeListener(SComponent c, Action a) {
        super();
        setTarget(c);
        this.action = a;
    }

    public void setTarget(SComponent c) {
        if (queue == null) {
            queue = new ReferenceQueue();
        }

        OwnedWeakReference r;
        while ((r = (OwnedWeakReference) queue.poll()) != null) {
            AbstractActionPropertyChangeListener oldPCL =
                    (AbstractActionPropertyChangeListener) r.getOwner();
            Action oldAction = oldPCL.action;
            if (oldAction != null)
                oldAction.removePropertyChangeListener(oldPCL);
        }
        this.target = new OwnedWeakReference(c, queue, this);
    }

    public SComponent getTarget() {
        return (SComponent) this.target.get();
    }

    public Action getAction() {
        return action;
    }

    private static class OwnedWeakReference extends WeakReference {
        private Object owner;

        OwnedWeakReference(Object target, ReferenceQueue queue, Object owner) {
            super(target, queue);
            this.owner = owner;
        }

        public Object getOwner() {
            return owner;
        }
    }
}