session.java

UML设计测试工具

/*
 * USE - UML based specification environment
 * Copyright (C) 1999-2004 Mark Richters, University of Bremen
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* $ProjectHeader: use 2-3-0-release.1 Mon, 12 Sep 2005 20:18:33 +0200 green $ */

package org.tzi.use.main;

import java.util.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.event.EventListenerList;

import org.tzi.use.uml.sys.MCmd;
import org.tzi.use.uml.sys.MSystem;

/**
 * A session manages a system and its model. System and model may
 * change during a session. Interested listeners are then notified.
 *
 * @version     $ProjectVersion: 2-3-0-release.1 $
 * @author      Mark Richters 
 */
public class Session {
    private MSystem fSystem;
    private EventListenerList fListenerList;

    /**
     * Event triggered when a command has been executed.
     */
    public class ExecutedCmd extends EventObject {
        private MCmd fCmd;
        public ExecutedCmd(Object source, MCmd cmd) {
            super(source);
            fCmd = cmd;
        }
        public MCmd cmd() {
            return fCmd;
        }
    }

    public interface ExecutedCmdListener extends EventListener {
        void executedCmd(Session.ExecutedCmd event);
    }

    public Session() {
        fListenerList = new EventListenerList();
    }

    /** 
     * Set application state for new system. The system parameter may
     * be null.
     */
    public void setSystem(MSystem system) {
        fSystem = system;
        fireStateChanged();
    }

    /** 
     * Returns true if we have a system.
     */
    public boolean hasSystem() {
        return fSystem != null;
    }

    public void executedCmd(MCmd cmd) {
        fireExecutedCmd(cmd);
    }

    /**
     * Resets the system to its initial state.
     */
    public void reset() {
        if (fSystem != null ) {
            fSystem.reset();
            fireStateChanged();
        }
    }

    /** 
     * Returns the current system. 
     *
     * @throws IllegalStateException if no system available
     */
    public MSystem system() {
        if (fSystem == null )
            throw new IllegalStateException("no system");
        return fSystem;
    }

    public void addChangeListener(ChangeListener l) {
        fListenerList.add(ChangeListener.class, l);
    }
    
    public void removeChangeListener(ChangeListener l) {
        fListenerList.remove(ChangeListener.class, l);
    }

    public void addExecutedCmdListener(ExecutedCmdListener l) {
        fListenerList.add(ExecutedCmdListener.class, l);
    }

    public void removeExecutedCmdListener(ExecutedCmdListener l) {
        fListenerList.remove(ExecutedCmdListener.class, l);
    }
    
    /**
     * Notify all listeners that have registered interest for
     * notification on this event type.  
     */
    private void fireStateChanged() {
        // Guaranteed to return a non-null array
        Object[] listeners = fListenerList.getListenerList();
        // Process the listeners last to first, notifying
        // those that are interested in this event
        ChangeEvent event = null;
        for (int i = listeners.length-2; i >= 0; i -= 2) {
            if (listeners[i] == ChangeListener.class ) {
                if (event == null )
                    event = new ChangeEvent(this);
                ((ChangeListener) listeners[i+1]).stateChanged(event);

                // System.out.println("Notifying: " + ((ChangeListener) listeners[i+1]).getClass());
            }          
        }
    }

    /**
     * Notify all listeners that have registered interest for
     * notification on this event type.  
     */
    private void fireExecutedCmd(MCmd cmd) {
        // Guaranteed to return a non-null array
        Object[] listeners = fListenerList.getListenerList();
        // Process the listeners last to first, notifying
        // those that are interested in this event
        ExecutedCmd event = null;
        for (int i = listeners.length-2; i >= 0; i -= 2) {
            if (listeners[i] == ExecutedCmdListener.class ) {
                if (event == null )
                    event = new ExecutedCmd(this, cmd);
                ((ExecutedCmdListener) listeners[i+1]).executedCmd(event);
            }          
        }
    }

}