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: FlowController.java 2725 2007-04-01 18:49:29Z taqua $
027     * ------------
028     * (C) Copyright 2000-2005, by Object Refinery Limited.
029     * (C) Copyright 2005-2007, by Pentaho Corporation.
030     */
031    package org.jfree.report.flow;
032    
033    import org.jfree.report.DataSourceException;
034    import org.jfree.report.ReportDataFactoryException;
035    import org.jfree.report.data.ExpressionSlot;
036    import org.jfree.report.data.GlobalMasterRow;
037    import org.jfree.report.data.PrecomputedValueRegistry;
038    
039    /**
040     * A flow-controller is an immutable object. Whenever an method, that may change
041     * the internal state of the controller, is invoked, a new instance of the
042     * controller is returned.
043     *
044     * @author Thomas Morgner
045     */
046    public interface FlowController
047    {
048      public FlowController performOperation(FlowControlOperation operation)
049          throws DataSourceException;
050    
051      public GlobalMasterRow getMasterRow();
052    
053      public ReportContext getReportContext();
054    
055      public String getExportDescriptor();
056    
057      public boolean isAdvanceRequested();
058    
059      public FlowController performQuery(final String query)
060          throws ReportDataFactoryException, DataSourceException;
061    
062      public FlowController performSubReportQuery(final String query,
063                                                  final ParameterMapping[] inputParameters,
064                                                  final ParameterMapping[] outputParameters)
065          throws ReportDataFactoryException, DataSourceException;
066    
067      /**
068       * Activates expressions that compute running values. This does not activate
069       * precomputed expressions.
070       *
071       * @param expressions
072       * @return
073       * @throws DataSourceException
074       */
075      public FlowController activateExpressions(final ExpressionSlot[] expressions)
076          throws DataSourceException;
077    
078      /**
079       * Returns the current expression slots of all currently active expressions.
080       * (Maybe we should limit the access to the name and value of the expression
081       * instead?)
082       *
083       * @return
084       * @throws DataSourceException
085       */
086      public ExpressionSlot[] getActiveExpressions () throws DataSourceException;
087    
088      public FlowController deactivateExpressions() throws DataSourceException;
089    
090      public ReportJob getReportJob();
091    
092      public FlowController performReturnFromQuery() throws DataSourceException;
093    
094      public FlowController createPrecomputeInstance () throws DataSourceException;
095    
096      public PrecomputedValueRegistry getPrecomputedValueRegistry();
097    }