smcjavagenerator.java

SMC takes a state machine stored in a .sm file and generates a State pattern in twelve programming l

//
// The contents of this file are subject to the Mozilla Public
// License Version 1.1 (the "License"); you may not use this file
// except in compliance with the License. You may obtain a copy
// of the License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an
// "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
// implied. See the License for the specific language governing
// rights and limitations under the License.
//
// The Original Code is State Machine Compiler (SMC).
//
// The Initial Developer of the Original Code is Charles W. Rapp.
// Portions created by Charles W. Rapp are
// Copyright (C) 2005 - 2007. Charles W. Rapp.
// All Rights Reserved.
//
// Contributor(s):
//   Eitan Suez contributed examples/Ant.
//   (Name withheld) contributed the C# code generation and
//   examples/C#.
//   Francois Perrad contributed the Python code generation and
//   examples/Python.
//   Chris Liscio contributed the Objective-C code generation
//   and examples/ObjC.
//
// RCS ID
// $Id: SmcJavaGenerator.java,v 1.11 2008/03/21 14:03:16 fperrad Exp $
//
// CHANGE LOG
// (See the bottom of this file.)
//

package net.sf.smc;

import java.io.PrintStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * Visits the abstract syntax tree, emitting Java code.
 * @see SmcElement
 * @see SmcCodeGenerator
 * @see SmcVisitor
 *
 * @author <a href="mailto:[e-mail]">Charles Rapp</a>
 */

public final class SmcJavaGenerator
    extends SmcCodeGenerator
{
//---------------------------------------------------------------
// Member methods
//

    public SmcJavaGenerator(String srcfileBase)
    {
        super (srcfileBase, "{0}{1}Context.{2}", "java");
    } // end of SmcJavaGenerator(String)

    public void visit(SmcFSM fsm)
    {
        String rawSource = fsm.getSource();
        String packageName = fsm.getPackage();
        String context = fsm.getContext();
        String startState = fsm.getStartState();
        String accessLevel = fsm.getAccessLevel();
        List<SmcMap> maps = fsm.getMaps();
        List<SmcTransition> transitions;
        Iterator<SmcParameter> pit;
        String transName;
        String javaState;
        String separator;
        int index;
        List<SmcParameter> params;

        // If the access level has not been set, then the default
        // is "public".
        if (accessLevel == null || accessLevel.length() == 0)
        {
            accessLevel = "public";
        }
        // If the access level is package, change it to
        // /* package */
        else if (accessLevel.equals("package") == true)
        {
            accessLevel = "/* package */";
        }

        // Dump out the raw source code, if any.
        if (rawSource != null && rawSource.length() > 0)
        {
            _source.println(rawSource);
            _source.println();
        }

        // If a package has been specified, generate the
        // package statement now.
        if (packageName != null && packageName.length() > 0)
        {
            _source.print("package ");
            _source.print(packageName);
            _source.println(";");
            _source.println();
        }

        // Do user-specified imports now.
        for (String imp: fsm.getImports())
        {
            _source.print("import ");
            _source.print(imp);
            _source.println(";");
        }

        // If the -g option was specified, then import the
        // PrintStream class.
        if (Smc.isDebug() == true)
        {
            _source.println("import java.io.PrintStream;");
        }

        if (Smc.isReflection() == true)
        {
            _source.println("import java.util.HashMap;");
            _source.println("import java.util.Map;");
        }

        _source.println();

        // The context clas contains all the state classes as
        // inner classes, so generate the context first rather
        // than last.
        _source.print(accessLevel);
        _source.print(" final class ");
        _source.print(context);
        _source.println("Context");
        _source.println("    extends statemap.FSMContext");

        if (Smc.isSerial() == true)
        {
            _source.println(
                "    implements java.io.Serializable");
        }

        _source.println("{");
        _source.println(
            "//---------------------------------------------------------------");
        _source.println("// Member methods.");
        _source.println("//");
        _source.println();

        // Generate the context class' constructor.
        _source.print("    public ");
        _source.print(context);
        _source.print("Context(");
        _source.print(context);
        _source.println(" owner)");
        _source.println("    {");
        _source.println("        super();");
        _source.println();
        _source.println("        _owner = owner;");

        // The state name "map::state" must be changed to
        // "map.state".
        if ((index = startState.indexOf("::")) >= 0)
        {
            javaState =
                startState.substring(0, index) +
                "." +
                startState.substring(index + 2);
        }
        else
        {
            javaState = startState;
        }

        _source.print("        setState(");
        _source.print(javaState);
        _source.println(");");

        // Execute the start state's entry actions.
        _source.print("        ");
        _source.print(javaState);
        _source.println(".Entry(this);");

        _source.println("    }");
        _source.println();

        // Generate the second constructor which allows the
        // initial state to be dynamically set. Overrides the
        // %start specifier.
        _source.print("    public ");
        _source.print(context);
        _source.print("Context(");
        _source.print(context);
        _source.print(" owner, ");
        _source.print(context);
        _source.println("State initState)");
        _source.println("    {");
        _source.println("        super();");
        _source.println("        _owner = owner;");
        _source.println("        setState(initState);");
        _source.println("        initState.Entry(this);");
        _source.println("    }");
        _source.println();

        // Generate the default transition methods.
        // Get the transition list for the entire FSM.
        transitions = fsm.getTransitions();

        // Generate the transition methods.
        for (SmcTransition trans: transitions)
        {
            if (trans.getName().equals("Default") == false)
            {
                _source.print("    public ");

                // If the -sync flag was specified, then output
                // the "synchronized" keyword.
                if (Smc.isSynchronized() == true)
                {
                    _source.print("synchronized ");
                }

                _source.print("void ");
                _source.print(trans.getName());
                _source.print("(");

                params = trans.getParameters();
                for (pit = params.iterator(), separator = "";
                     pit.hasNext() == true;
                     separator = ", ")
                {
                    _source.print(separator);
                    (pit.next()).accept(this);
                }
                _source.println(")");
                _source.println("    {");

                // Save away the transition name in case it is
                // need in an UndefinedTransitionException.
                _source.print("        _transition = \"");
                _source.print(trans.getName());
                _source.println("\";");

                _source.print("        getState().");
                _source.print(trans.getName());
                _source.print("(this");

                for (pit = params.iterator();
                     pit.hasNext() == true;
                    )
                {
                    _source.print(", ");
                    _source.print((pit.next()).getName());
                }
                _source.println(");");
                _source.println("        _transition = \"\";");

                _source.println("        return;");
                _source.println("    }");
                _source.println();
            }
        }

        // If serialization is turned on, then generate a
        // setOwner method which allows the application class
        // to restore its ownership of the FSM.
        if (Smc.isSerial() == true)
        {
            // Also output the valueOf method in case developers
            // want to serialize manually.
            _source.print("    public ");
            _source.print(context);
            _source.println("State valueOf(int stateId)");
            _source.println(
                "        throws ArrayIndexOutOfBoundsException");
            _source.println("    {");
            _source.println(
                "        return (_States[stateId]);");
            _source.println("    }");
            _source.println();
        }

        // getState() method.
        _source.print("    public ");
        _source.print(context);
        _source.println("State getState()");
        _source.println(
            "        throws statemap.StateUndefinedException");
        _source.println("    {");
        _source.println("        if (_state == null)");
        _source.println("        {");
        _source.println(
            "            throw(");
        _source.println(
            "                new statemap.StateUndefinedException());");
        _source.println("        }");
        _source.println();
        _source.print("        return ((");
        _source.print(context);
        _source.println("State) _state);");
        _source.println("    }");
        _source.println();

        // getOwner() method.
        _source.print("    protected ");
        _source.print(context);
        _source.println(" getOwner()");
        _source.println("    {");
        _source.println("        return (_owner);");
        _source.println("    }");
        _source.println();

        // setOwner() method.
        _source.print("    public void setOwner(");
        _source.print(context);
        _source.println(" owner)");
        _source.println("    {");
        _source.println("        if (owner == null)");
        _source.println("        {");
        _source.println("            throw (");
        _source.println("                new NullPointerException(");
        _source.println("                    \"null owner\"));");
        _source.println("        }");
        _source.println("        else");
        _source.println("        {");
        _source.println("            _owner = owner;");
        _source.println("        }");
        _source.println();
        _source.println("        return;");
        _source.println("    }");
        _source.println();

        // If serialization is turned on, then output the
        // writeObject and readObject methods.
        if (Smc.isSerial() == true)
        {
            _source.print(
                "    private void writeObject(");
            _source.println(
                "java.io.ObjectOutputStream ostream)");
            _source.println(
                "        throws java.io.IOException");
            _source.println("    {");
            _source.println(
                "        int size =");
            _source.print("            ");
            _source.println(
                "(_stateStack == null ? 0 : _stateStack.size());");
            _source.println("        int i;");
            _source.println();
            _source.println(
                "        ostream.writeInt(size);");
            _source.println();
            _source.println(
                "        for (i = 0; i < size; ++i)");
            _source.println("        {");
            _source.println("            ostream.writeInt(");
            _source.print("                ((");
            _source.print(context);
            _source.println(
                "State) _stateStack.get(i)).getId());");
            _source.println("        }");
            _source.println();
            _source.println(
                "        ostream.writeInt(_state.getId());");
            _source.println();
            _source.println("        return;");
            _source.println("    }");
            _source.println();
            _source.print("    private void readObject(");
            _source.println(
                "java.io.ObjectInputStream istream)");
            _source.println(
                "        throws java.io.IOException");
            _source.println("    {");
            _source.println("        int size;");
            _source.println();
            _source.println("        size = istream.readInt();");
            _source.println();
            _source.println("        if (size == 0)");
            _source.println("        {");
            _source.println("            _stateStack = null;");
            _source.println("        }");
            _source.println("        else");
            _source.println("        {");
            _source.println("            int i;");
            _source.println();
            _source.println(
                "            _stateStack = new java.util.Stack();");
            _source.println();
            _source.println(
                "            for (i = 0; i < size; ++i)");
            _source.println("            {");
            _source.print(
                "                _stateStack.add(i, _States[");
            _source.println("istream.readInt()]);");
            _source.println("            }");
            _source.println("        }");
            _source.println();
            _source.println(
                "        _state = _States[istream.readInt()];");
            _source.println();
            _source.println("        return;");
            _source.println("    }");
            _source.println();
        }

        // Declare member data.
        _source.println(
            "//---------------------------------------------------------------");
        _source.println("// Member data.");
        _source.println("//");
        _source.println();
        _source.print("    transient private ");
        _source.print(context);
        _source.println(" _owner;");

        // If serialization support is on, then create the state
        // array.
        if (Smc.isSerial() == true)
        {
            Iterator<SmcMap> mit;
            SmcMap map;
            String mapName;
            Iterator<SmcState> stateIt;
            SmcState state;