Source for org.jfree.report.data.PrecomputedValueRegistry

   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: PrecomputedValueRegistry.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.data;
  33: 
  34: /**
  35:  * Expression precomputation processes the report in a parallel process to
  36:  * retrieve the final value of an function. The final value of an expression
  37:  * is the value the expression would return before it goes out of scope.
  38:  *
  39:  * Precomputation can be generally considered expensive, so it should be done
  40:  * only once. During the precomputation run, no output is generated at all.
  41:  * Only named data-row expressions can be precomputed.
  42:  *
  43:  * @author Thomas Morgner
  44:  */
  45: public interface PrecomputedValueRegistry
  46: {
  47:   public void startElement (PrecomputeNodeKey element);
  48:   public void finishElement (PrecomputeNodeKey element);
  49:   public PrecomputeNode currentNode ();
  50: 
  51:   public void addFunction(final String name, final Object value);
  52: 
  53:   public void startElementPrecomputation(final PrecomputeNodeKey element);
  54: 
  55:   public void finishElementPrecomputation(final PrecomputeNodeKey element);
  56: }