001 /**
002 * ========================================
003 * JFreeReport : a free Java report library
004 * ========================================
005 *
006 * Project Info: http://reporting.pentaho.org/
007 *
008 * (C) Copyright 2000-2007, by Object Refinery Limited, Pentaho Corporation and Contributors.
009 *
010 * This library is free software; you can redistribute it and/or modify it under the terms
011 * of the GNU Lesser General Public License as published by the Free Software Foundation;
012 * either version 2.1 of the License, or (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
015 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
016 * See the GNU Lesser General Public License for more details.
017 *
018 * You should have received a copy of the GNU Lesser General Public License along with this
019 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
020 * Boston, MA 02111-1307, USA.
021 *
022 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
023 * in the United States and other countries.]
024 *
025 * ------------
026 * $Id: AttrFunctionDescription.java,v 1.3 2007/04/01 18:49:25 taqua Exp $
027 * ------------
028 * (C) Copyright 2000-2005, by Object Refinery Limited.
029 * (C) Copyright 2005-2007, by Pentaho Corporation.
030 */
031
032 package org.jfree.report.expressions.formula.sys;
033
034 import org.jfree.formula.function.AbstractFunctionDescription;
035 import org.jfree.formula.function.FunctionCategory;
036 import org.jfree.formula.function.userdefined.UserDefinedFunctionCategory;
037 import org.jfree.formula.typing.Type;
038 import org.jfree.formula.typing.coretypes.AnyType;
039 import org.jfree.formula.typing.coretypes.TextType;
040
041 /**
042 * Creation-Date: 29.11.2006, 18:04:18
043 *
044 * @author Thomas Morgner
045 */
046 public class AttrFunctionDescription extends AbstractFunctionDescription
047 {
048 public AttrFunctionDescription()
049 {
050 super("org.jfree.report.expressions.formula.sys.Attr-Function");
051 }
052
053 public int getParameterCount()
054 {
055 return 1;
056 }
057
058 public boolean isInfiniteParameterCount()
059 {
060 return false;
061 }
062
063 public Type getParameterType(int position)
064 {
065 return TextType.TYPE;
066 }
067
068 public Type getValueType()
069 {
070 return AnyType.TYPE;
071 }
072
073 /**
074 * Defines, whether the parameter at the given position is mandatory. A
075 * mandatory parameter must be filled in, while optional parameters need not
076 * to be filled in.
077 *
078 * @return
079 */
080 public boolean isParameterMandatory(int position)
081 {
082 if (position == 0)
083 {
084 return true;
085 }
086 return false;
087 }
088
089 /**
090 * Returns the default value for an optional parameter. If the value returned
091 * here is null, then this either means, that the parameter is mandatory or
092 * that the default value is computed by the expression itself.
093 *
094 * @param position
095 * @return
096 */
097 public Object getDefaultValue(int position)
098 {
099 return null;
100 }
101
102 public FunctionCategory getCategory()
103 {
104 return UserDefinedFunctionCategory.CATEGORY;
105 }
106
107 }