msystem.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.uml.sys;

import java.io.*;
import java.util.ArrayList;
import java.util.EmptyStackException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.swing.event.EventListenerList;

import org.tzi.use.gen.tool.GGenerator;
import org.tzi.use.uml.mm.MClass;
import org.tzi.use.uml.mm.MModel;
import org.tzi.use.uml.mm.MOperation;
import org.tzi.use.uml.mm.MPrePostCondition;
import org.tzi.use.uml.ocl.expr.Evaluator;
import org.tzi.use.uml.ocl.expr.Expression;
import org.tzi.use.uml.ocl.value.BooleanValue;
import org.tzi.use.uml.ocl.value.Value;
import org.tzi.use.uml.ocl.value.VarBindings;
import org.tzi.use.util.Log;
import org.tzi.use.util.UniqueNameGenerator;
import org.tzi.use.util.cmd.*;

/**
 * A system maintains a system state and provides functionality for
 * doing state transitions.
 *
 * @version     $ProjectVersion: 2-3-0-release.1 $
 * @author      Mark Richters 
 */
public final class MSystem {
    private MModel fModel;  // The model of this system. 
    private MSystemState fCurrentState; // The current system state. 
    private Map fObjects;   // (String -> MObject) The set of all objects
    private UniqueNameGenerator fUniqueNameGenerator; // creation of object names
    private CommandProcessor fCommandProcessor; // executing state change commands
    protected EventListenerList fListenerList = new EventListenerList();
    private List fOperationCallStack; // stack of active operations
    private VarBindings fVarBindings; // top-level variable bindings
    private GGenerator fGenerator;    // snapshot generator

    public MSystem(MModel model) {
        fModel = model;
        init();
    }

    private void init() {
        fObjects = new HashMap();
        fUniqueNameGenerator = new UniqueNameGenerator();
        fCommandProcessor = new CommandProcessor();
        fCurrentState = new MSystemState(fUniqueNameGenerator.generate("state#"), this);
        fOperationCallStack = new ArrayList();
        fVarBindings = new VarBindings();
        fGenerator = new GGenerator(this);
    }

    /**
     * Returns the current system state.
     */
    public MSystemState state() {
        return fCurrentState;
    }

    /**
     * Returns the system's model.
     */
    public MModel model() {
        return fModel;
    }

    /**
     * Returns the system's instance generator.
     */
    public GGenerator generator() {
        return fGenerator;
    }

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

    /**
     * Creates and adds a new object to the system. The name of the
     * object may be null in which case a unique name is automatically
     * generated.
     *
     * @return the created object.  
     */
    MObject createObject(MClass cls, String name) throws MSystemException {
        if (cls.isAbstract() )
            throw new MSystemException("The abstract class `" + cls.name() + 
                                       "' cannot be instantiated.");
    
        // create new object and initial state
        if (name == null ) {
            name = uniqueObjectNameForClass(cls.name());
        } else if (fObjects.containsKey(name) )
            throw new MSystemException("An object with name `" + name + 
                                       "' already exists.");
        
        MObject obj = new MObjectImpl(cls, name);
        addObject(obj);
        return obj;
    }

    void addObject(MObject obj) {
        fObjects.put(obj.name(), obj);
    }

    void deleteObject(MObject obj) {
        fObjects.remove(obj.name());
    }

    /**
     * Returns a unique name that can be used for a new object of the
     * given class.  
     */
    public String uniqueObjectNameForClass(String clsName) {
        return fUniqueNameGenerator.generate(clsName);
    }

    /**
     * Executes a state manipulation command.
     */
    public void executeCmd(MCmd cmd) throws MSystemException {
        Log.trace(this, "executing command: " + cmd);
        try {
            fCommandProcessor.execute(cmd);
            fireStateChanged(cmd, false);
        } catch (CommandFailedException ex) {
            throw new MSystemException(ex.getMessage());
        }
    }

    /**
     * Undoes the last state manipulation command.
     */
    public void undoCmd() throws MSystemException {
        Log.trace(this, "undoing last command");
        try {
            MCmd cmd = (MCmd) fCommandProcessor.undoLast();
            fireStateChanged(cmd, true);
        } catch (CannotUndoException ex) {
            throw new MSystemException(ex.getMessage());
        }
    }

    /** 
     * Returns the name of the next command that can be undone.
     *
     * @return null, if there is no command for undo.
     */
    public String nextUndoableCmdName() {
        Command cmd = fCommandProcessor.nextUndoableCmd();
        String name = null;
        if (cmd != null )
            name = cmd.name();
        return name;
    }

    /**
     * Writes a sequence of commands that can be read and executed by
     * the USE shell to reproduce the same effects of all command
     * executed so far.  
     */
    public void writeUSEcmds(PrintWriter out) 
        throws IOException 
    {
        Iterator cmdIter = fCommandProcessor.commands().iterator();
        while (cmdIter.hasNext() ) {
            MCmd cmd = (MCmd) cmdIter.next();
            Log.trace(this, cmd.getUSEcmd());
            out.println(cmd.getUSEcmd());
        }
    }

    /**
     * Returns the number of commands executed so far.
     */
    public int numExecutedCmds() {
        return fCommandProcessor.commands().size();
    }

    /**
     * Returns the list of commands executed so far.
     *
     * @return List(MCmd)
     */
    public List commands() {
        return fCommandProcessor.commands();
    }

    /**
     * Resets the system to its initial state.
     */
    public void reset() {
        init();
    }

    /**
     * Simulate entry of an operation. The preconditions of the
     * operation are checked with the current state. If all