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>{@link DialogImpl} is a basic implementation of {@link Dialog}.</p>
   *
   * @since 1.0.4
   */
  public final class DialogImpl implements Dialog {
  
  
      // ------------------------------------------------------ Instance Variables
  
  
      /***
       * <p>The class of a JavaBean to be instantiated as the initial
       * value of the <code>data</code> property of a newly instantiated
       * <code>DialogContext</code>.</p>
       */
      private Class dataClass = HashMap.class;
  
  
      /***
       * <p>Name of this {@link Dialog}.</p>
       */
      private String name = null;
  
  
      /***
       * <p>Name of the starting {@link State} for this {@link Dialog}.</p>
       */
      private String start = null;
  
  
      /***
       * <p>The {@link State}s owned by this {@link Dialog}, keyed by
       * identifier.</p>
       */
      private Map states = new HashMap();
  
  
      /***
       * <p>The global {@link Transition}s owned by this {@link Dialog}, keyed by
       * outcome.  Logic that performs transition management should first check
       * for a {@link Transition} associated with the origin {@link State}, then
       * consult the {@link Dialog} for a global definition.</p>
       */
      private Map transitions = new HashMap();
  
  
      // -------------------------------------------------------------- Properties
  
  
      /***
       * <p>Return the class of a JavaBean to be instantiated as the initial
       * value of the <code>data</code> property of a newly instantiated
       * <code>DialogContext</code>.</p>
       *
       * @return The JavaBean class whose instance becomes the <code>data</code>
       *         property of a new instance of this dialog
       */
      public Class getDataClass() {
  
          return this.dataClass;
  
      }
  
  
      /***
       * <p>Return the name of this {@link Dialog}.</p>
       *
       * @return The name of this {@link Dialog}
       */
      public String getName() {
  
          return this.name;
 
     }
 
 
     /***
      * <p>Return the name of the starting {@link State} for this
      * {@link Dialog}.</p>
      *
      * @return The starting state associated with this {@link Dialog}
      */
     public String getStart() {
 
         return this.start;
 
     }
 
 
     /***
      * <p>Return an <code>Iterator</code> over the names of {@link State}s
      * that are owned by this {@link Dialog}.  If there are no such
      * {@link State}s, an empty <code>Iterator</code> is returned.</p>
      *
      * @return An <code>Iterator</code> over all the {@link State}s in this
      *         {@link Dialog}
      */
     public Iterator getStateIds() {
 
         return this.states.keySet().iterator();
 
     }
 
 
     /***
      * <p>Return an <code>Iterator</code> over the logical outcomes of
      * global {@link Transition}s for this {@link Dialog}.  If there are
      * no such {@link Transition}s, an empty <code>Iterator</code> is
      * returned.</p>
      *
      * @return An <code>Iterator</code> over the logical outcomes of global
      *         {@link Transition}s for this {@link Dialog}
      */
     public Iterator getTransitionOutcomes() {
 
         return this.transitions.keySet().iterator();
 
     }
 
 
     // ---------------------------------------------------------- Public Methods
 
 
     /***
      * <p>Return the specified {@link State}, owned by this {@link Dialog},
      * if any.  Otherwise, return <code>null</code>.</p>
      *
      * @param id Identifier of the requested {@link State}
      * @return The {@link State} specified by the identifier, may be null
      */
     public State findState(String id) {
 
         return (State) states.get(id);
 
     }
 
 
     /***
      * <p>Return the global {@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 global {@link Transition} for the specified logical outcome
      */
     public Transition findTransition(String outcome) {
 
         return (Transition) transitions.get(outcome);
 
     }
 
 
     /***
      * <p>Render a printable version of this instance.</p>
      *
      * @return A printable version of this instance
      */
     public String toString() {
 
         return "Dialog[name=" + this.name + ",start=" + this.start + "]";
 
     }
 
 
     // --------------------------------------------------- Configuration Methods
 
 
     /***
      * <p>Add the specified {@link State} to the {@link State}s owned by
      * this {@link Dialog}.</p>
      *
      * @param state {@link State} to be added
      *
      * @exception IllegalArgumentException if there is already a {@link State}
      *  with the specified <code>id</code> owned by this {@link Dialog}
      */
     public void addState(State state) throws IllegalArgumentException {
 
         if (states.containsKey(state.getName())) {
             throw new IllegalArgumentException(state.getName());
         }
         states.put(state.getName(), state);
         if (state instanceof AbstractState) {
             ((AbstractState) state).setDialog(this);
         }
 
     }
 
 
     /***
      * <p>Add the specified {@link Transition} to the global {@link Transition}s
      * associated with this {@link Dialog}.</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>Return the data class name for the <code>data</code> property
      * of a newly instantiated <code>DialogContext</code>.</p>
      *
      * @return The fully qualified class name whose instance becomes the
      *         <code>data</code> property of a new instance of this dialog
      */
     public String getDataClassName() {
 
         return dataClass.getName();
 
     }
 
 
     /***
      * <p>Set the data class name for the <code>data</code> property
      * of a newly instantiated <code>DialogContext</code>.</p>
      *
      * @param dataClassName New data class name
      *
      * @exception Exception if the specified class name cannot be loaded
      */
     public void setDataClassName(String dataClassName) {
 
         ClassLoader loader = Thread.currentThread().getContextClassLoader();
         if (loader == null) {
             loader = DialogImpl.class.getClassLoader();
         }
         try {
             this.dataClass = loader.loadClass(dataClassName);
         } catch (RuntimeException e) {
             throw e;
         } catch (Exception e) {
             throw new IllegalArgumentException(e.toString());
         }
 
     }
 
 
     /***
      * <p>Set the name of this {@link Dialog}.</p>
      *
      * @param name New name
      */
     public void setName(String name) {
 
         this.name = name;
 
     }
 
 
     /***
      * <p>Set the name of the starting {@link State} for this
      * {@link Dialog}.</p>
      *
      * @param start Name of the starting {@link State}
      */
     public void setStart(String start) {
 
         this.start = start;
 
     }
 
 
     /***
      * <p>Remove the specified {@link State} from the {@link State}s owned by
      * this {@link Dialog}, if it is currently registered.  Otherwise,
      * do nothing.</p>
      *
      * @param state {@link State} to be removed
      */
     public void removeState(State state) {
 
         states.remove(state.getName());
         if (state instanceof AbstractState) {
             ((AbstractState) state).setDialog(null);
         }
 
     }
 
 
     /***
      * <p>Remove the specified {@link Transition} from the global
      * {@link Transition}s associated with this {@link Dialog}, 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());
 
     }
 
 
 }