1 /*
   2  * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package javax.swing.event;
  26 
  27 import javax.swing.RowSorter;
  28 
  29 /**
  30  * <code>RowSorterEvent</code> provides notification of changes to
  31  * a <code>RowSorter</code>.  Two types of notification are possible:
  32  * <ul>
  33  * <li><code>Type.SORT_ORDER_CHANGED</code>: indicates the sort order has
  34  *     changed.  This is typically followed by a notification of:
  35  * <li><code>Type.SORTED</code>: indicates the contents of the model have
  36  *     been transformed in some way.  For example, the contents may have
  37  *     been sorted or filtered.
  38  * </ul>
  39  *
  40  * @see javax.swing.RowSorter
  41  * @since 1.6
  42  */
  43 public class RowSorterEvent extends java.util.EventObject {
  44     private Type type;
  45     private int[] oldViewToModel;
  46 
  47     /**
  48      * Enumeration of the types of <code>RowSorterEvent</code>s.
  49      *
  50      * @since 1.6
  51      */
  52     public enum Type {
  53         /**
  54          * Indicates the sort order has changed.
  55          */
  56         SORT_ORDER_CHANGED,
  57 
  58         /**
  59          * Indicates the contents have been newly sorted or
  60          * transformed in some way.
  61          */
  62         SORTED
  63     }
  64 
  65     /**
  66      * Creates a <code>RowSorterEvent</code> of type
  67      * <code>SORT_ORDER_CHANGED</code>.
  68      *
  69      * @param source the source of the change
  70      * @throws IllegalArgumentException if <code>source</code> is
  71      *         <code>null</code>
  72      */
  73     public RowSorterEvent(RowSorter source) {
  74         this(source, Type.SORT_ORDER_CHANGED, null);
  75     }
  76 
  77     /**
  78      * Creates a <code>RowSorterEvent</code>.
  79      *
  80      * @param source the source of the change
  81      * @param type the type of event
  82      * @param previousRowIndexToModel the mapping from model indices to
  83      *        view indices prior to the sort, may be <code>null</code>
  84      * @throws IllegalArgumentException if source or <code>type</code> is
  85      *         <code>null</code>
  86      */
  87     public RowSorterEvent(RowSorter source, Type type,
  88                           int[] previousRowIndexToModel) {
  89         super(source);
  90         if (type == null) {
  91             throw new IllegalArgumentException("type must be non-null");
  92         }
  93         this.type = type;
  94         this.oldViewToModel = previousRowIndexToModel;
  95     }
  96 
  97     /**
  98      * Returns the source of the event as a <code>RowSorter</code>.
  99      *
 100      * @return the source of the event as a <code>RowSorter</code>
 101      */
 102     public RowSorter getSource() {
 103         return (RowSorter)super.getSource();
 104     }
 105 
 106     /**
 107      * Returns the type of event.
 108      *
 109      * @return the type of event
 110      */
 111     public Type getType() {
 112         return type;
 113     }
 114 
 115     /**
 116      * Returns the location of <code>index</code> in terms of the
 117      * model prior to the sort.  This method is only useful for events
 118      * of type <code>SORTED</code>.  This method will return -1 if the
 119      * index is not valid, or the locations prior to the sort have not
 120      * been provided.
 121      *
 122      * @param index the index in terms of the view
 123      * @return the index in terms of the model prior to the sort, or -1 if
 124      *         the location is not valid or the mapping was not provided.
 125      */
 126     public int convertPreviousRowIndexToModel(int index) {
 127         if (oldViewToModel != null && index >= 0 &&
 128                 index < oldViewToModel.length) {
 129             return oldViewToModel[index];
 130         }
 131         return -1;
 132     }
 133 
 134     /**
 135      * Returns the number of rows before the sort.  This method is only
 136      * useful for events of type <code>SORTED</code> and if the
 137      * last locations have not been provided will return 0.
 138      *
 139      * @return the number of rows in terms of the view prior to the sort
 140      */
 141     public int getPreviousRowCount() {
 142         return (oldViewToModel == null) ? 0 : oldViewToModel.length;
 143     }
 144 }