Source for org.jfree.formula.function.information.HasChangedFunctionDescription

   1: /**
   2:  * =========================================
   3:  * LibFormula : a free Java formula library
   4:  * =========================================
   5:  *
   6:  * Project Info:  http://reporting.pentaho.org/libformula/
   7:  *
   8:  * (C) Copyright 2006-2007, by 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:  * ------------
  27:  * $Id: HasChangedFunctionDescription.java,v 1.4 2007/04/01 13:51:52 taqua Exp $
  28:  * ------------
  29:  * (C) Copyright 2006-2007, by Pentaho Corporation.
  30:  */
  31: 
  32: package org.jfree.formula.function.information;
  33: 
  34: import org.jfree.formula.function.AbstractFunctionDescription;
  35: import org.jfree.formula.function.FunctionCategory;
  36: import org.jfree.formula.typing.Type;
  37: import org.jfree.formula.typing.coretypes.LogicalType;
  38: import org.jfree.formula.typing.coretypes.TextType;
  39: 
  40: /**
  41:  * Creation-Date: 31.10.2006, 17:41:12
  42:  *
  43:  * @author Thomas Morgner
  44:  */
  45: public class HasChangedFunctionDescription extends AbstractFunctionDescription
  46: {
  47:   public HasChangedFunctionDescription()
  48:   {
  49:     super("org.jfree.formula.function.information.HasChanged-Function");
  50:   }
  51: 
  52:   public Type getValueType()
  53:   {
  54:     return LogicalType.TYPE;
  55:   }
  56: 
  57:   public int getParameterCount()
  58:   {
  59:     return 1;
  60:   }
  61: 
  62:   public boolean isInfiniteParameterCount()
  63:   {
  64:     return true;
  65:   }
  66: 
  67:   public Type getParameterType(int position)
  68:   {
  69:     return TextType.TYPE;
  70:   }
  71: 
  72:   /**
  73:    * Defines, whether the parameter at the given position is mandatory. A
  74:    * mandatory parameter must be filled in, while optional parameters need not
  75:    * to be filled in.
  76:    *
  77:    * @return false
  78:    */
  79:   public boolean isParameterMandatory(int position)
  80:   {
  81:     return false;
  82:   }
  83: 
  84:   /**
  85:    * Returns the default value for an optional parameter. If the value returned
  86:    * here is null, then this either means, that the parameter is mandatory or
  87:    * that the default value is computed by the expression itself.
  88:    *
  89:    * @param position
  90:    * @return null.
  91:    */
  92:   public Object getDefaultValue(int position)
  93:   {
  94:     return null;
  95:   }
  96: 
  97:   public boolean isVolatile()
  98:   {
  99:     return true;
 100:   }
 101: 
 102:   public FunctionCategory getCategory()
 103:   {
 104:     return InformationFunctionCategory.CATEGORY;
 105:   }
 106: }