001 /** 002 * ========================================= 003 * LibFormula : a free Java formula library 004 * ========================================= 005 * 006 * Project Info: http://reporting.pentaho.org/libformula/ 007 * 008 * (C) Copyright 2006-2007, by 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 * ------------ 027 * $Id: NullFunctionDescription.java 3521 2007-10-16 10:55:14Z tmorgner $ 028 * ------------ 029 * (C) Copyright 2006-2007, by Pentaho Corporation. 030 */ 031 032 package org.jfree.formula.function.userdefined; 033 034 import org.jfree.formula.function.AbstractFunctionDescription; 035 import org.jfree.formula.function.FunctionCategory; 036 import org.jfree.formula.typing.Type; 037 import org.jfree.formula.typing.coretypes.AnyType; 038 039 /** 040 * Creation-Date: 04.11.2006, 18:28:55 041 * 042 * @author Thomas Morgner 043 */ 044 public class NullFunctionDescription extends AbstractFunctionDescription 045 { 046 public NullFunctionDescription() 047 { 048 super("org.jfree.formula.function.userdefined.Null-Function"); 049 } 050 051 public int getParameterCount() 052 { 053 return 0; 054 } 055 056 public boolean isInfiniteParameterCount() 057 { 058 return false; 059 } 060 061 public Type getParameterType(final int position) 062 { 063 return AnyType.TYPE; 064 } 065 066 public Type getValueType() 067 { 068 return AnyType.TYPE; 069 } 070 071 /** 072 * Defines, whether the parameter at the given position is mandatory. A 073 * mandatory parameter must be filled in, while optional parameters need not 074 * to be filled in. 075 * 076 * @return 077 */ 078 public boolean isParameterMandatory(final int position) 079 { 080 return false; 081 } 082 083 /** 084 * Returns the default value for an optional parameter. If the value returned 085 * here is null, then this either means, that the parameter is mandatory or 086 * that the default value is computed by the expression itself. 087 * 088 * @param position 089 * @return 090 */ 091 public Object getDefaultValue(final int position) 092 { 093 return null; 094 } 095 096 public FunctionCategory getCategory() 097 { 098 return UserDefinedFunctionCategory.CATEGORY; 099 } 100 101 }