package com.explosion.utilities;
   
   
   /* =============================================================================
    *       
    *     Copyright 2004 Stephen Cowx
    *
    *     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 java.io.Serializable;
  import java.util.ArrayList;
  import java.util.List;
  
  import javax.swing.AbstractListModel;
  import javax.swing.MutableComboBoxModel;
  
  /***
   * @author Stephen
   * Created on Apr 17, 2004
   * Changes the Sun DefaultComboBoxModel to work with Lists instead of Lists
   */
  public class ListComboBoxModel extends AbstractListModel implements MutableComboBoxModel, Serializable {
      List objects;
      Object selectedObject;
  
      /***
       * Constructs an empty NewComboBoxModel object.
       */
      public ListComboBoxModel() {
          objects = new ArrayList();
      }
  
      /***
       * Constructs a NewComboBoxModel object initialized with
       * an array of objects.
       *
       * @param items  an array of Object objects
       */
      public ListComboBoxModel(final Object items[]) {
          objects = new ArrayList();
          
          int i,c;
          for ( i=0,c=items.length;i<c;i++ )
              objects.add(items[i]);
  
          if ( getSize() > 0 ) {
              selectedObject = getElementAt( 0 );
          }
      }
  
      /***
       * Constructs a NewComboBoxModel object initialized with
       * a vector.
       *
       * @param v  a List object ...
       */
      public ListComboBoxModel(List l) {
          objects = l;
  
          if ( getSize() > 0 ) {
              selectedObject = getElementAt( 0 );
          }
      }
  
      // implements javax.swing.ComboBoxModel
      /***
       * Set the value of the selected item. The selected item may be null.
       * <p>
       * @param anObject The combo box value or null for no selection.
       */
      public void setSelectedItem(Object anObject) {
          if ((selectedObject != null && !selectedObject.equals( anObject )) ||
  	    selectedObject == null && anObject != null) {
  	    selectedObject = anObject;
  	    fireContentsChanged(this, -1, -1);
          }
      }
  
      // implements javax.swing.ComboBoxModel
      public Object getSelectedItem() {
          return selectedObject;
      }
  
      // implements javax.swing.ListModel
      public int getSize() {
          return objects.size();
      }
 
     // implements javax.swing.ListModel
     public Object getElementAt(int index) {
         if ( index >= 0 && index < objects.size() )
             return objects.get(index);
         else
             return null;
     }
 
     /***
      * Returns the index-position of the specified object in the list.
      *
      * @param anObject  
      * @return an int representing the index position, where 0 is 
      *         the first position
      */
     public int getIndexOf(Object anObject) {
         return objects.indexOf(anObject);
     }
 
     // implements javax.swing.MutableComboBoxModel
     public void addElement(Object anObject) {
         objects.add(anObject);
         fireIntervalAdded(this,objects.size()-1, objects.size()-1);
         if ( objects.size() == 1 && selectedObject == null && anObject != null ) {
             setSelectedItem( anObject );
         }
     }
 
     // implements javax.swing.MutableComboBoxModel
     public void insertElementAt(Object anObject,int index) {
         objects.add(index, anObject);
         fireIntervalAdded(this, index, index);
     }
 
     // implements javax.swing.MutableComboBoxModel
     public void removeElementAt(int index) {
         if ( getElementAt( index ) == selectedObject ) {
             if ( index == 0 ) {
                 setSelectedItem( getSize() == 1 ? null : getElementAt( index + 1 ) );
             }
             else {
                 setSelectedItem( getElementAt( index - 1 ) );
             }
         }
 
         objects.remove(index);
 
         fireIntervalRemoved(this, index, index);
     }
 
     // implements javax.swing.MutableComboBoxModel
     public void removeElement(Object anObject) {
         int index = objects.indexOf(anObject);
         if ( index != -1 ) {
             removeElementAt(index);
         }
     }
 
     /***
      * Empties the list.
      */
     public void removeAllElements() {
         if ( objects.size() > 0 ) {
             int firstIndex = 0;
             int lastIndex = objects.size() - 1;
             objects.clear();
 	    selectedObject = null;
             fireIntervalRemoved(this, firstIndex, lastIndex);
         } else {
 	    selectedObject = null;
 	}
     }
 }