2009/05/20 - Apache Shale has been retired.

 /*

  * Licensed to the Apache Software Foundation (ASF) under one or more

  * contributor license agreements.  See the NOTICE file distributed with

  * this work for additional information regarding copyright ownership.

  * The ASF licenses this file to you under the Apache License, Version 2.0

  * (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.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.apache.shale.dialog.basic.config;

 import java.util.HashMap;

 import java.util.Iterator;

 import java.util.Map;

 import org.apache.shale.dialog.basic.model.Dialog;

 import org.apache.shale.dialog.basic.model.State;

 import org.apache.shale.dialog.basic.model.Transition;

 /**

  * <p>Abstract base class for {@link State} definitions.  Each state is owned

  * by exactly one owning {@link Dialog}.  While an application

  * is running, {@link Dialog} (and the constituent {@link State}s and

  * other configuration information) is immutable, so that it may be

  * shared by multiple simultaneous paths of execution.</p>

  *

  * @since 1.0.4

  */

 public abstract class AbstractState implements State {

     // ------------------------------------------------------ Instance Variables

     /**

      * <p>The {@link Dialog} that owns this {@link State} instance.</p>

      */

     private Dialog dialog = null;

     /**

      * <p>The identifier of this {@link State}, which must be unique among

      * all {@link State}s within the owning {@link Dialog}.</p>

      */

     private String name = null;

     /**

      * <p>The {@link Transition}s owned by this {@link State}, keyed by

      * outcome.  <strong>FIXME</strong> - a different strategy will be needed

      * if {@link Transition}s become more complex and manage their own

      * criteria.</p>

      */

     private Map transitions = new HashMap();

     // -------------------------------------------------------------- Properties

     /**

      * {@inheritDoc}

      */

     public Dialog getDialog() {

         return this.dialog;

     }

     /**

      * {@inheritDoc}

      */

     public String getName() {

         return this.name;

     }

     /**

      * {@inheritDoc}

      */

     public Iterator getTransitionOutcomes() {

         return this.transitions.keySet().iterator();

     }

     // ---------------------------------------------------------- Public Methods

     /**

      * <p>Return the {@link Transition} for the specified logical outcome,

      * if any; otherwise, return <code>null</code>.</p>

      *

      * @param outcome Logical outcome for which to return a {@link Transition}

      * @return The matching {@link Transition}

      */

     public Transition findTransition(String outcome) {

         return (Transition) transitions.get(outcome);

     }

     // --------------------------------------------------- Configuration Methods

     /**

      * <p>Add the specified {@link Transition} to the {@link Transition}s owned

      * by this {@link State}.</p>

      *

      * @param transition {@link Transition} to be added

      *

      * @exception IllegalArgumentException if the specified {@link Transition}

      *  cannot be added to this {@link State}

      */

     public void addTransition(Transition transition) throws IllegalArgumentException {

         // FIXME - addTransition() - ignore duplicate outcomes for now

         transitions.put(transition.getOutcome(), transition);

     }

     /**

      * <p>Remove the specified {@link Transition} from the {@link Transition}s

      * owned by this {@link State}, if it is currently registered.  Otherwise,

      * do nothing.</p>

      *

      * @param transition {@link Transition} to be removed

      */

     public void removeTransition(Transition transition) {

         transitions.remove(transition.getOutcome());

     }

     /**

      * <p>Set the {@link Dialog} that owns this {@link State}.</p>

      *

      * @param dialog New owning {@link Dialog}

      */

     public void setDialog(Dialog dialog) {

         this.dialog = dialog;

     }

     /**

      * <p>Set the identifier of this {@link State}, which must be unique

      * among the {@link State}s owned by the same {@link Dialog}.</p>

      *

      * @param name New identifier

      */

     public void setName(String name) {

         this.name = name;

     }

 }