/*

  * $Source$

  * $Revision$

  *

  * Copyright (C) 2000 William Chesters

  *

  * Part of Melati (http://melati.org), a framework for the rapid

  * development of clean, maintainable web applications.

  *

  * Melati is free software; Permission is granted to copy, distribute

  * and/or modify this software under the terms either:

  *

  * a) the GNU General Public License as published by the Free Software

  *    Foundation; either version 2 of the License, or (at your option)

  *    any later version,

  *

  *    or

  *

  * b) any version of the Melati Software License, as published

  *    at http://melati.org

  *

  * You should have received a copy of the GNU General Public License and

  * the Melati Software License along with this program;

  * if not, write to the Free Software Foundation, Inc.,

  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the

  * GNU General Public License and visit http://melati.org to obtain the

  * Melati Software License.

  *

  * Feel free to contact the Developers of Melati (http://melati.org),

  * if you would like to work out a different arrangement than the options

  * outlined here.  It is our intention to allow Melati to be used by as

  * wide an audience as possible.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * Contact details for copyright holder:

  *

  *     William Chesters <williamc At paneris.org>

  *     http://paneris.org/~williamc

  *     Obrechtstraat 114, 2517VX Den Haag, The Netherlands

  */

 package org.melati.poem;

 import java.util.Hashtable;

 /**

  * The quality of being searchable:

  *  <tt>yes</tt>, <tt>no</tt> or <tt>primary</tt>.

  */

 public final class Searchability {

   /** The Id of the Searchability. */

   public final Integer index;

   /** Its name. */

   private final String name;

   /** Constructor. */

   private Searchability(int index, String name) {

     this.index = new Integer(index);

     this.name = name;

   }

   /**

    * The column is the only one in the table for which a

    * special widget is provided to enter a search value.

    * <p>

    * There is at most one such column per table.

    * The user is able to select matching rows without

    * popping up a search criteria dialogue window.

    */

   public static final Searchability primary;

   /**

    * The column is searchable so that the user is able

    * to enter search criteria for it included along

    * with others when searching for rows.

    * <p>

    * Currently the search criteria for a column consist

    * of at most one non-null value.

    */

   public static final Searchability yes;

   /**

    * The column is not searchable so the user will not

    * be given the opportunity to enter search criteria

    * for it.

    */

   public static final Searchability no;

   private static int n = 0;

   private static final Searchability[] searchabilities =

     { primary = new Searchability(n++, "primary"),

       yes = new Searchability(n++, "yes"),

       no = new Searchability(n++, "no") };

   private static final Hashtable<String, Searchability> searchabilityOfName = new Hashtable<String, Searchability>();

   static {

     for (int i = 0; i < searchabilities.length; ++i)

       searchabilityOfName.put(searchabilities[i].name, searchabilities[i]);

   }

   /**

    * @param index key

    * @return the selected Searchability

    */

   public static Searchability forIndex(int index) {

     return searchabilities[index];

   }

   /**

    * @return the number of Searchabilities

    */

   public static int count() {

     return searchabilities.length;

   }

  /**

   * Thrown when an invalid {@link Searchability} level is specified, 

   * by a typing mistake in the DSD for example.

   */

   public static class NameUnrecognisedException

       extends PoemException {

     private static final long serialVersionUID = 1L;

     /** The name of the requested Searchability. */

     public String name;

     /** Constructor. */

     public NameUnrecognisedException(String name) {

       this.name = name;

     }

     /**

      * {@inheritDoc}

      */

     public String getMessage() {

       return

         "No searchability level found which goes by the name `" + name + "'";

     }

   }

   /**

    * Throws NameUnrecognisedException if not found.

    *  

    * @param name String name of Searchability

    * @return the Searchability 

    */

   public static Searchability named(String name) {

     Searchability it = (Searchability)searchabilityOfName.get(name);

     if (it == null)

       throw new NameUnrecognisedException(name);

     return it;

   }

   /** 

    * @return the name and index

    * {@inheritDoc}

    * @see java.lang.Object#toString()

    */

   public String toString() {

     return name + "/" + index;

   }

   /**

    * @return the index

    */

   public Integer getIndex() {

     return index;

   }

   /**

    * @return the Name

    */

   public String getName() {

     return name;

   }

 }