SSSyncManager


1   /* $Id: SSSyncManager.java,v 1.6 2005/02/22 16:09:46 prasanth Exp $
2    *
3    * Tab Spacing = 4
4    *
5    * Copyright (c) 2005, The Pangburn Company and Prasanth R. Pasala.
6    * All rights reserved.
7    *
8    * Redistribution and use in source and binary forms, with or without
9    * modification, are permitted provided that the following conditions are met:
10   *
11   * Redistributions of source code must retain the above copyright notice, this
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32  
33   package com.nqadmin.swingSet.utils;
34  
35   import com.nqadmin.swingSet.datasources.*;
36   import java.sql.SQLException  ;
37   import com.nqadmin.swingSet.SSDBComboBox;
38   import com.nqadmin.swingSet.SSDataNavigator;
39   import javax.sql.RowSetListener  ;
40   import java.awt.event.ActionListener  ;
41   import java.awt.event.ActionEvent  ;
42   import javax.sql.RowSetEvent  ;
43  
44  /**
45   * SSSyncManager.java
46   *<p>
47   * SwingSet - Open Toolkit For Making Swing Controls Database-Aware
48   *<p><pre>
49   * Used to synchronize a data navigator and a navigation combo box.
50   *</pre><p>
51   * @author  $Author: prasanth $
52   * @version $Revision: 1.6 $
53   */
54  public class SSSyncManager {
55  
56      /**
57       * SSDBComboBox used for record navigation.
58       */
59      protected SSDBComboBox comboBox;
60  
61      /**
62       * SSDataNavigator to be synchronized with navigation combo box.
63       */
64      protected SSDataNavigator dataNavigator;
65  
66      /**
67       * SSRowSet navigated with data navigator and combo box.
68       */
69      protected SSRowSet rowset;
70  
71      /**
72       * SSRowSet column used as basis for synchronization.
73       */
74      protected String   columnName;
75  
76      /**
77       * Listener on combo box to detect combo-based navigations.
78       */
79      private final MyComboListener comboListener = new MyComboListener();
80  
81      /**
82       * Listener on SSRowSet to detect data navigator-based navigations.
83       */
84      private final MyRowSetListener rowsetListener = new MyRowSetListener();
85  
86      /**
87  
88       * Creates a SSSyncManager with the specified combo box and data navigator.
89       *
90       * @param _comboBox SSDBComboBox used for record navigation
91       * @param _dataNavigator    SSDataNavigator to be synchronized
92       * with navigation combo box
93       */
94      public SSSyncManager(SSDBComboBox _comboBox, SSDataNavigator _dataNavigator) {
95          comboBox = _comboBox;
96          dataNavigator = _dataNavigator;
97          rowset = dataNavigator.getSSRowSet();
98      }
99  
100     /**
101      * Sets column to be used as basis for synchronization.
102      *
103      * @param _columnName   SSRowSet column used as basis for synchronization.
104      */
105     public void setColumnName(String   _columnName) {
106         columnName = _columnName;
107     }
108 
109     /**
110      * Sets data navigator to be synchronized.
111      *
112      * @param _dataNavigator    data navigator to be synchronized
113      */
114     public void setDataNavigator(SSDataNavigator _dataNavigator) {
115         dataNavigator = _dataNavigator;
116         rowset = dataNavigator.getSSRowSet();
117     }
118 
119     /**
120      * Sets combo box to be synchronized.
121      *
122      * @param _comboBox combo box to be synchronized
123      */
124 
125     public void setComboBox(SSDBComboBox _comboBox) {
126         comboBox = _comboBox;
127     }
128 
129     /**
130      * Start synchronization between navigation components.
131      */
132     public void sync() {
133         addListeners();
134         adjustValue();
135     }
136 
137     /**
138      * Stop synchronization between navigation components.
139      */
140     public void async() {
141         removeListeners();
142     }
143 
144     /**
145      * Adds listeners to combo box & rowset.
146      */
147     private void addListeners() {
148         comboBox.addActionListener(comboListener);
149         dataNavigator.getSSRowSet().addRowSetListener(rowsetListener);
150     }
151 
152     /**
153      * Removes listeners from combo box & rowset.
154      */
155     private void removeListeners() {
156         comboBox.removeActionListener(comboListener);
157         dataNavigator.getSSRowSet().removeRowSetListener(rowsetListener);
158     }
159 
160     /**
161      *  Listener for rowset.
162      */
163     private class MyRowSetListener implements RowSetListener   {
164 
165         public void cursorMoved(RowSetEvent   rse) {
166             adjustValue();
167         }
168 
169         public void rowChanged(RowSetEvent   rse) {
170             adjustValue();
171         }
172 
173         public void rowSetChanged(RowSetEvent   rse) {
174             adjustValue();
175         }
176 
177     }
178 
179     /**
180 
181      * Method to update combo box based on rowset.
182      */
183     protected void adjustValue() {
184         comboBox.removeActionListener(comboListener);
185         try{
186             if(rowset != null & rowset.getRow() > 0){
187             // GET THE CURRENT VALUE FROM THE ROWSET.    
188                 String   currentRowValue = rowset.getString(columnName);
189             // CHECK IF THE COMBO BOX IS DISPLAYING THE SAME ONE.    
190                 if(comboBox.getSelectedStringValue() == null || !comboBox.getSelectedStringValue().equals(currentRowValue)){
191                 // IF NOT CHANGE THE SELECTION OF THE COMBO BOX.    
192                     comboBox.setSelectedStringValue(rowset.getString(columnName));
193                 }
194             } else {
195                 comboBox.setSelectedIndex(-1);
196             }
197         } catch(SQLException   se) {
198             se.printStackTrace();
199         }
200         comboBox.addActionListener(comboListener);
201     }
202 
203 
204     /**
205      *Listener for combo box to update data navigator when
206      * combo box-based navigation occurs.
207      */
208     private class MyComboListener implements ActionListener   {
209         //protected long id = -1;
210         protected String   id = "";
211 
212     // WHEN THERE IS A CHANGE IN THIS VALUE MOVE THE ROWSET SO THAT
213     // ITS POSITIONED AT THE RIGHT RECORD.
214         public void actionPerformed(ActionEvent   ae) {
215             try {
216 
217                 if(rowset == null || rowset.getRow() < 1 || comboBox.getSelectedIndex() == -1){
218                     return;
219                 }
220 
221                 //id = comboBox.getSelectedValue();
222                 id = comboBox.getSelectedStringValue();
223                 rowset.removeRowSetListener(rowsetListener);
224 
225             // UPDATE THE PRESENT ROW BEFORE MOVING TO ANOTHER ROW.
226                 dataNavigator.updatePresentRow();
227 
228                 //if(id != rowset.getLong(columnName)) {
229                 if(!id.equals(rowset.getString(columnName))) {
230 
231                     int index = comboBox.getSelectedIndex() + 1;
232                     rowset.absolute(index);
233                     int numRecords = comboBox.getItemCount();
234                     int count = 0;
235                     //while (id != rowset.getLong(columnName)) {
236                     while (!id.equals(rowset.getString(columnName))) {
237                         if (!rowset.next()) {
238                             rowset.beforeFirst();
239                             rowset.next();
240                         }
241 
242                         count++;
243 
244                         //number of items in combo is the number of records in resultset.
245                         //so if for some reason item is in combo but deleted in rowset
246                         //To avoid infinite loop in such scenario
247                         if (count > numRecords + 5) {
248                             //JOptionPane.showInternalMessageDialog(this,"Record deleted. Info the admin about this","Row not found",JOptionPane.OK_OPTION);
249                             break;
250                         }
251                     }
252                 }
253                 rowset.addRowSetListener(rowsetListener);
254 
255             } catch(SQLException   se) {
256                 se.printStackTrace();
257             }
258         }
259     } // private class MyComboListener implements ActionListener {
260 
261 } // end public class SSSyncManager {
262 
263 /*
264  * $Log: SSSyncManager.java,v $
265  * Revision 1.6  2005/02/22 16:09:46  prasanth
266  * In adjustValue while checking combo selection make sure the underlying value returned
267  * is not null. If the selected item is -1 the getSelectedStringValue will return null.
268  *
269  * Revision 1.5  2005/02/10 16:51:23  prasanth
270  * On rowset events checking if the combo box is displaying the right value
271  * or not. Changing the selection only if it is not displaying the right one.
272  *
273  * Revision 1.4  2005/02/10 03:36:08  yoda2
274  * JavaDoc cleanup and updated to support string columns used for synchronization (to match recent changes in SSDBComboBox).
275  *
276  * Revision 1.3  2005/02/05 15:06:56  yoda2
277  * Got rid of depreciated calls.
278  *
279  * Revision 1.2  2005/02/04 22:49:15  yoda2
280  * API cleanup & updated Copyright info.
281  *
282  * Revision 1.1  2005/01/03 19:53:43  prasanth
283  * Initial Commit.
284  *
285  */
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