Source for org.jfree.report.expressions.formula.sys.AttrFunctionDescription

   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: AttrFunctionDescription.java 3525 2007-10-16 11:43:48Z tmorgner $
  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.expressions.formula.sys;
  33: 
  34: import org.jfree.formula.function.AbstractFunctionDescription;
  35: import org.jfree.formula.function.FunctionCategory;
  36: import org.jfree.formula.function.userdefined.UserDefinedFunctionCategory;
  37: import org.jfree.formula.typing.Type;
  38: import org.jfree.formula.typing.coretypes.AnyType;
  39: import org.jfree.formula.typing.coretypes.TextType;
  40: 
  41: /**
  42:  * Creation-Date: 29.11.2006, 18:04:18
  43:  *
  44:  * @author Thomas Morgner
  45:  */
  46: public class AttrFunctionDescription extends AbstractFunctionDescription
  47: {
  48:   public AttrFunctionDescription()
  49:   {
  50:     super("org.jfree.report.expressions.formula.sys.Attr-Function");
  51:   }
  52: 
  53:   public int getParameterCount()
  54:   {
  55:     return 1;
  56:   }
  57: 
  58:   public boolean isInfiniteParameterCount()
  59:   {
  60:     return false;
  61:   }
  62: 
  63:   public Type getParameterType(final int position)
  64:   {
  65:     return TextType.TYPE;
  66:   }
  67: 
  68:   public Type getValueType()
  69:   {
  70:     return AnyType.TYPE;
  71:   }
  72: 
  73:   /**
  74:    * Defines, whether the parameter at the given position is mandatory. A
  75:    * mandatory parameter must be filled in, while optional parameters need not
  76:    * to be filled in.
  77:    *
  78:    * @return
  79:    */
  80:   public boolean isParameterMandatory(final int position)
  81:   {
  82:     if (position == 0)
  83:     {
  84:       return true;
  85:     }
  86:     return false;
  87:   }
  88: 
  89:   /**
  90:    * Returns the default value for an optional parameter. If the value returned
  91:    * here is null, then this either means, that the parameter is mandatory or
  92:    * that the default value is computed by the expression itself.
  93:    *
  94:    * @param position
  95:    * @return
  96:    */
  97:   public Object getDefaultValue(final int position)
  98:   {
  99:     return null;
 100:   }
 101: 
 102:   public FunctionCategory getCategory()
 103:   {
 104:     return UserDefinedFunctionCategory.CATEGORY;
 105:   }
 106: 
 107: }