/*
    * Copyright (c) 2001-2004,
    * RedVerst Group, ISP RAS http://www.ispras.ru
    * All rights reserved.
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions are met:
    *
    * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * 3. The names "ATP", "TreeDL", "RedVerst", "ISP RAS"
   *    may not be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package com.unitesk.atp.dynattrs;
  
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Map;
  import java.util.Set;
  
  /***
   * The implementation of {@link Attributed} interface that stores attributes
   * in {@link Map}.
   *
   * @author <A href="mailto:demakov@ispras.ru">Alexey Demakov</A>
   * @version $Id: MapAttributed.java,v 1.2 2005/08/02 06:04:29 all-x Exp $
   */
  public class MapAttributed extends IndexedAttributedImpl
  {
      /***
       * Class constructor with the default map created by {@link #createMap()}.
       */
      public MapAttributed()
      {
      }
  
      /***
       * Class constructor with the specified map.
       *
       * @param  map      The map to store attributes.
       *                  This map should support optional operations:
       *                  {@link Map#put(Object,Object)}, {@link Map#remove(Object)}.
       * @throws NullPointerException
       *                  If <code>map</code> is <code>null</code>.
       */
      public MapAttributed( Map map )
      {
          if( map == null )
          {
              throw new NullPointerException();
          }
          this.map = map;
      }
  
      /***
       * {@inheritDoc}
       */
      public boolean hasAttribute( String name )
      {
          /*
           * If map allows null key we should throw NullPointerException.
           */
          if( name == null )
          {
              throw new AttributeException( this, name );
          }
          if( map == null ) return false;
          return map.containsKey( name );
      }
  
      /***
       * Always returns <code>true</code> - attributes of this class
       * may be created dynamically.
       */
      public boolean isAttrCreatable()
      {
          return true;
      }
  
      /***
       * All existent attributes may be removed dynamically.
      */
     public boolean isRemovable( String name )
     {
         if( !hasAttribute( name ) )
         {
             throw new AttributeException( this, name );
         }
         return true;
     }
 
     /***
      * Always returns <code>true</code> - all attributes of this class
      * are writable.
      */
     public boolean isWritable( String name )
     {
         if( !hasAttribute( name ) )
         {
             throw new AttributeException( this, name );
         }
         return true;
     }
 
 //------------------------------------------------------------------------------
 
     /***
      * {@inheritDoc}
      */
     public void addAttribute( String name, Object value )
     {
         if( hasAttribute( name ) )
         {
             throw new AttributeException( this, name );
         }
         if( map == null ) createMap();
         map.put( name, value );
     }
 
     /***
      * {@inheritDoc}
      */
     public void removeAttribute( String name )
     {
         /*
          * If map allows null key we should throw NullPointerException.
          */
         if( name == null )
         {
             throw new AttributeException( this, null );
         }
         
         if( map == null ) return;
 
         map.remove( name );
     }
 
 //------------------------------------------------------------------------------
 
     /***
      * {@inheritDoc}
      */
     public Object getAttribute( String name )
     {
         if( !hasAttribute( name ) )
         {
             throw new AttributeException( this, name );
         }
         // (map == null) => !hasAttribute( name )
         return map.get( name );
     }
 
     /***
      * {@inheritDoc}
      */
     public void setAttribute( String name, Object value )
     {
         if( !hasAttribute( name ) )
         {
             throw new AttributeException( this, name );
         }
         // (map == null) => !hasAttribute( name )
         map.put( name, value );
     }
 
 //------------------------------------------------------------------------------
 
     /***
      * {@inheritDoc}
      */
     public Set/*String*/ getAttributeNames()
     {
         if( map == null ) return new HashSet/*String*/();
         return map.keySet();
     }
 
 //------------------------------------------------------------------------------
 // implementation
     
     /***
      * Creates default map instance.
      */
     protected void createMap()
     {
         map = new HashMap/*String,Object*/();
     }
     
     private Map/*String,Object*/ map = null;
 }