reportbuilder/java/com/sun/star/report/ReportFunction.java

   1 /*************************************************************************
   2  *
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * Copyright 2000, 2010 Oracle and/or its affiliates.
   6  *
   7  * OpenOffice.org - a multi-platform office productivity suite
   8  *
   9  * This file is part of OpenOffice.org.
  10  *
  11  * OpenOffice.org is free software: you can redistribute it and/or modify
  12  * it under the terms of the GNU Lesser General Public License version 3
  13  * only, as published by the Free Software Foundation.
  14  *
  15  * OpenOffice.org is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU Lesser General Public License version 3 for more details
  19  * (a copy is included in the LICENSE file that accompanied this code).
  20  *
  21  * You should have received a copy of the GNU Lesser General Public License
  22  * version 3 along with OpenOffice.org.  If not, see
  23  * <http://www.openoffice.org/license.html>
  24  * for a copy of the LGPLv3 License.
  25  *
  26  ************************************************************************/
  27 package com.sun.star.report;
  28
  29 /**
  30  * Functions are statefull computation components.
  31  *
  32  * Functions are allowed to have a state, but are considered
  33  * immutable (the same is true for expressions). Functions are
  34  * allowed to update their state on every call to 'advance', which
  35  * signals, that the cursor has been moved.
  36  *
  37  * Functions have no way to 'reset' their state, if a reset is needed,
  38  * the report engine is urged to query a new instance from the ReportAddin.
  39  */
  40 public interface ReportFunction extends ReportExpression
  41 {
  42
  43     public ReportFunction advance(DataRow row);
  44 }