Source for org.jfree.report.modules.misc.tablemodel.SubSetTableModel

   1: /**
   2:  * ========================================
   3:  * JFreeReport : a free Java report library
   4:  * ========================================
   5:  *
   6:  * Project Info:  http://reporting.pentaho.org/
   7:  *
   8:  * (C) Copyright 2000-2007, by Object Refinery Limited, Pentaho Corporation and Contributors.
   9:  *
  10:  * This library is free software; you can redistribute it and/or modify it under the terms
  11:  * of the GNU Lesser General Public License as published by the Free Software Foundation;
  12:  * either version 2.1 of the License, or (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
  15:  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  16:  * See the GNU Lesser General Public License for more details.
  17:  *
  18:  * You should have received a copy of the GNU Lesser General Public License along with this
  19:  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20:  * Boston, MA 02111-1307, USA.
  21:  *
  22:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
  23:  * in the United States and other countries.]
  24:  *
  25:  * ------------
  26:  * $Id: SubSetTableModel.java 2725 2007-04-01 18:49:29Z taqua $
  27:  * ------------
  28:  * (C) Copyright 2000-2005, by Object Refinery Limited.
  29:  * (C) Copyright 2005-2007, by Pentaho Corporation.
  30:  */
  31: 
  32: package org.jfree.report.modules.misc.tablemodel;
  33: 
  34: import java.util.ArrayList;
  35: import javax.swing.event.TableModelEvent;
  36: import javax.swing.event.TableModelListener;
  37: import javax.swing.table.TableModel;
  38: 
  39: /**
  40:  * A TableModel that proxies an other tablemodel and cuts rows from the start and/or the
  41:  * end of the other tablemodel.
  42:  *
  43:  * @author Thomas Morgner
  44:  */
  45: public class SubSetTableModel implements TableModel
  46: {
  47:   /**
  48:    * A helper class, that translates tableevents received from the wrapped table model and
  49:    * forwards them with changed indices to the registered listeners.
  50:    */
  51:   private final class TableEventTranslator implements TableModelListener
  52:   {
  53:     /**
  54:      * the registered listeners.
  55:      */
  56:     private final ArrayList listeners;
  57: 
  58:     /**
  59:      * Default Constructor.
  60:      */
  61:     private TableEventTranslator ()
  62:     {
  63:       listeners = new ArrayList();
  64:     }
  65: 
  66:     /**
  67:      * This fine grain notification tells listeners the exact range of cells, rows, or
  68:      * columns that changed. The received rows are translated to fit the external
  69:      * tablemodel size.
  70:      *
  71:      * @param e the event, that should be translated.
  72:      */
  73:     public void tableChanged (final TableModelEvent e)
  74:     {
  75:       int firstRow = e.getFirstRow();
  76:       if (e.getFirstRow() > 0)
  77:       {
  78:         firstRow -= getStart();
  79:       }
  80: 
  81:       int lastRow = e.getLastRow();
  82:       if (lastRow > 0)
  83:       {
  84:         lastRow -= getStart();
  85:         lastRow -= (getEnclosedModel().getRowCount() - getEnd());
  86:       }
  87:       final int type = e.getType();
  88:       final int column = e.getColumn();
  89: 
  90:       final TableModelEvent event =
  91:               new TableModelEvent(SubSetTableModel.this, firstRow, lastRow, column, type);
  92: 
  93:       for (int i = 0; i < listeners.size(); i++)
  94:       {
  95:         final TableModelListener l = (TableModelListener) listeners.get(i);
  96:         l.tableChanged(event);
  97:       }
  98:     }
  99: 
 100:     /**
 101:      * Adds the TableModelListener to this Translator.
 102:      *
 103:      * @param l the tablemodel listener
 104:      */
 105:     protected void addTableModelListener (final TableModelListener l)
 106:     {
 107:       listeners.add(l);
 108:     }
 109: 
 110:     /**
 111:      * Removes the TableModelListener from this Translator.
 112:      *
 113:      * @param l the tablemodel listener
 114:      */
 115:     protected void removeTableModelListener (final TableModelListener l)
 116:     {
 117:       listeners.remove(l);
 118:     }
 119:   }
 120: 
 121:   /**
 122:    * the row that should be the first row.
 123:    */
 124:   private int start;
 125: 
 126:   /**
 127:    * the row that should be the last row.
 128:    */
 129:   private int end;
 130: 
 131:   /**
 132:    * the model.
 133:    */
 134:   private TableModel model;
 135: 
 136:   /**
 137:    * the event translator.
 138:    */
 139:   private TableEventTranslator eventHandler;
 140: 
 141:   /**
 142:    * Creates a new SubSetTableModel, the start and the end parameters define the new
 143:    * tablemodel row count. The parameter <code>start</code> must be a positive integer and
 144:    * denotes the number or rows removed from the start of the tablemodel. <code>end</code>
 145:    * is the number of the last translated row. Any row after <code>end</code> is ignored.
 146:    * End must be greater or equal the given start row.
 147:    *
 148:    * @param start the number of rows that should be removed.
 149:    * @param end   the last row.
 150:    * @param model the wrapped model
 151:    * @throws NullPointerException     if the given model is null
 152:    * @throws IllegalArgumentException if start or end are invalid.
 153:    */
 154:   public SubSetTableModel (final int start, final int end, final TableModel model)
 155:   {
 156:     if (start < 0)
 157:     {
 158:       throw new IllegalArgumentException("Start < 0");
 159:     }
 160:     if (end <= start)
 161:     {
 162:       throw new IllegalArgumentException("end < start");
 163:     }
 164:     if (model == null)
 165:     {
 166:       throw new NullPointerException();
 167:     }
 168:     if (end >= model.getRowCount())
 169:     {
 170:       throw new IllegalArgumentException("End >= Model.RowCount");
 171:     }
 172: 
 173:     this.start = start;
 174:     this.end = end;
 175:     this.model = model;
 176:     this.eventHandler = new TableEventTranslator();
 177:   }
 178: 
 179:   /**
 180:    * Translates the given row to fit for the wrapped tablemodel.
 181:    *
 182:    * @param rowIndex the original row index.
 183:    * @return the translated row index.
 184:    */
 185:   private int getClientRowIndex (final int rowIndex)
 186:   {
 187:     return rowIndex + start;
 188:   }
 189: 
 190:   /**
 191:    * Returns the number of rows in the model. A <code>JTable</code> uses this method to
 192:    * determine how many rows it should display.  This method should be quick, as it is
 193:    * called frequently during rendering.
 194:    *
 195:    * @return the number of rows in the model
 196:    *
 197:    * @see #getColumnCount
 198:    */
 199:   public int getRowCount ()
 200:   {
 201:     final int rowCount = model.getRowCount();
 202:     return rowCount - start - (rowCount - end);
 203:   }
 204: 
 205:   /**
 206:    * Returns the number of columns in the model. A <code>JTable</code> uses this method to
 207:    * determine how many columns it should create and display by default.
 208:    *
 209:    * @return the number of columns in the model
 210:    *
 211:    * @see #getRowCount
 212:    */
 213:   public int getColumnCount ()
 214:   {
 215:     return model.getColumnCount();
 216:   }
 217: 
 218:   /**
 219:    * Returns the name of the column at <code>columnIndex</code>.  This is used to
 220:    * initialize the table's column header name.  Note: this name does not need to be
 221:    * unique; two columns in a table can have the same name.
 222:    *
 223:    * @param columnIndex the index of the column
 224:    * @return the name of the column
 225:    */
 226:   public String getColumnName (final int columnIndex)
 227:   {
 228:     return model.getColumnName(columnIndex);
 229:   }
 230: 
 231:   /**
 232:    * Returns the most specific superclass for all the cell values in the column.  This is
 233:    * used by the <code>JTable</code> to set up a default renderer and editor for the
 234:    * column.
 235:    *
 236:    * @param columnIndex the index of the column
 237:    * @return the base ancestor class of the object values in the model.
 238:    */
 239:   public Class getColumnClass (final int columnIndex)
 240:   {
 241:     return model.getColumnClass(columnIndex);
 242:   }
 243: 
 244:   /**
 245:    * Returns true if the cell at <code>rowIndex</code> and <code>columnIndex</code> is
 246:    * editable.  Otherwise, <code>setValueAt</code> on the cell will not change the value
 247:    * of that cell.
 248:    *
 249:    * @param rowIndex    the row whose value to be queried
 250:    * @param columnIndex the column whose value to be queried
 251:    * @return true if the cell is editable
 252:    *
 253:    * @see #setValueAt
 254:    */
 255:   public boolean isCellEditable (final int rowIndex, final int columnIndex)
 256:   {
 257:     return model.isCellEditable(getClientRowIndex(rowIndex), columnIndex);
 258:   }
 259: 
 260:   /**
 261:    * Returns the value for the cell at <code>columnIndex</code> and
 262:    * <code>rowIndex</code>.
 263:    *
 264:    * @param rowIndex    the row whose value is to be queried
 265:    * @param columnIndex the column whose value is to be queried
 266:    * @return the value Object at the specified cell
 267:    */
 268:   public Object getValueAt (final int rowIndex, final int columnIndex)
 269:   {
 270:     return model.getValueAt(getClientRowIndex(rowIndex), columnIndex);
 271:   }
 272: 
 273:   /**
 274:    * Sets the value in the cell at <code>columnIndex</code> and <code>rowIndex</code> to
 275:    * <code>aValue</code>.
 276:    *
 277:    * @param aValue      the new value
 278:    * @param rowIndex    the row whose value is to be changed
 279:    * @param columnIndex the column whose value is to be changed
 280:    * @see #getValueAt
 281:    * @see #isCellEditable
 282:    */
 283:   public void setValueAt (final Object aValue, final int rowIndex, final int columnIndex)
 284:   {
 285:     model.setValueAt(aValue, getClientRowIndex(rowIndex), columnIndex);
 286:   }
 287: 
 288:   /**
 289:    * Adds a listener to the list that is notified each time a change to the data model
 290:    * occurs.
 291:    *
 292:    * @param l the TableModelListener
 293:    */
 294:   public void addTableModelListener (final TableModelListener l)
 295:   {
 296:     eventHandler.addTableModelListener(l);
 297:   }
 298: 
 299:   /**
 300:    * Removes a listener from the list that is notified each time a change to the data
 301:    * model occurs.
 302:    *
 303:    * @param l the TableModelListener
 304:    */
 305:   public void removeTableModelListener (final TableModelListener l)
 306:   {
 307:     eventHandler.removeTableModelListener(l);
 308:   }
 309: 
 310:   /**
 311:    * Returns the enclosed tablemodel, which is wrapped by this subset table model.
 312:    *
 313:    * @return the enclosed table model, never null.
 314:    */
 315:   protected TableModel getEnclosedModel ()
 316:   {
 317:     return model;
 318:   }
 319: 
 320:   /**
 321:    * Returns the start row that should be mapped to row 0 of this model.
 322:    *
 323:    * @return the first row that should be visible.
 324:    */
 325:   protected int getStart ()
 326:   {
 327:     return start;
 328:   }
 329: 
 330:   /**
 331:    * Returns the last row that should be visible.
 332:    *
 333:    * @return the number of the last row.
 334:    */
 335:   protected int getEnd ()
 336:   {
 337:     return end;
 338:   }
 339: }