package org.apache.ojb.otm.states;
   
   /* Copyright 2003-2005 The Apache Software Foundation
    *
    * Licensed 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.
   */
  
  import org.apache.ojb.broker.util.ObjectModification;
  
  /**
   * Represents the state of object.
   */
  public abstract class State implements ObjectModification
  {
      public static final State TRANSIENT = new Transient();
  
      public static final State PERSISTENT_CLEAN = new PersistentClean();
  
      public static final State PERSISTENT_DIRTY = new PersistentDirty();
  
      public static final State PERSISTENT_NEW = new PersistentNew();
  
      public static final State PERSISTENT_DELETED = new PersistentDeleted();
  
      public static final State PERSISTENT_NEW_DELETED = new PersistentNewDeleted();
  
      public static final State HOLLOW = new Hollow();
  
      //-------------- State transitions --------------------
  
      /**
       * Describes the state transition when object is gotten from the cache
       * or is loaded from database (once per transaction).
       */
      public State getObject()
              throws IllegalObjectStateException
      {
          throw new IllegalObjectStateException(this + " during getObject");
      }
  
      /**
       * Describes the state transition when user modifies object
       */
      public State markDirty()
              throws IllegalObjectStateException
      {
          throw new IllegalObjectStateException(this + " during markDirty()");
      }
  
      /**
       * Describes the state transition on makePersistent()
       */
      public State makePersistent()
              throws IllegalObjectStateException
      {
          throw new IllegalObjectStateException(this + " during makePersistent()");
      }
  
      /**
       * Describes the state transition on deletePersistent()
       */
      public State deletePersistent()
              throws IllegalObjectStateException
      {
          throw new IllegalObjectStateException(this + " during deletePersistent()");
      }
  
      /**
       * Describes the state transition on commit()
       */
      public State commit()
              throws IllegalObjectStateException
      {
          throw new IllegalObjectStateException(this + " during commit()");
      }
  
      /**
       * Describes the state transition on rollback()
       */
      public State rollback()
              throws IllegalObjectStateException
      {
          throw new IllegalObjectStateException(this + " during rollback()");
      }
  
      /**
       * Describes the state transition on refresh()
       */
      public State refresh()
             throws IllegalObjectStateException
     {
         return this;
     }
 
 
     //-------------- State semantics --------------------
 
     /**
      * returns true is this state requires INSERT
      */
     public boolean needsInsert()
     {
         return false;
     }
 
     /**
      * returns true is this state requires UPDATE
      */
     public boolean needsUpdate()
     {
         return false;
     }
 
     /**
      * returns true is this state requires DELETE
      */
     public boolean needsDelete()
     {
         return false;
     }
 
     /**
      * returns true is this state means that the object has been deleted
      */
     public boolean isDeleted()
     {
         return false;
     }
 
 }