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: LayoutController.java,v 1.9 2007/04/01 18:49:26 taqua Exp $
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.layoutprocessor;
032
033 import org.jfree.report.DataSourceException;
034 import org.jfree.report.ReportDataFactoryException;
035 import org.jfree.report.ReportProcessingException;
036 import org.jfree.report.flow.FlowController;
037 import org.jfree.report.flow.ReportTarget;
038
039 /**
040 * The layout controller iterates over the report layout. It uses a flow
041 * controller to query the data.
042 *
043 * @author Thomas Morgner
044 */
045 public interface LayoutController extends Cloneable
046 {
047 /**
048 * Retrieves the parent of this layout controller. This allows childs to query
049 * their context.
050 *
051 * @return the layout controller's parent to <code>null</code> if there is no
052 * parent.
053 */
054 public LayoutController getParent();
055
056 /**
057 * Initializes the layout controller. This method is called exactly once. It
058 * is the creators responsibility to call this method.
059 * <p/>
060 * Calling initialize after the first advance must result in a
061 * IllegalStateException.
062 *
063 * @param node the currently processed object or layout node.
064 * @param flowController the current flow controller.
065 * @param parent the parent layout controller that was responsible for
066 * instantiating this controller.
067 * @throws DataSourceException if there was a problem reading data from
068 * the datasource.
069 * @throws ReportProcessingException if there was a general problem during
070 * the report processing.
071 * @throws ReportDataFactoryException if a query failed.
072 */
073 public void initialize(final Object node,
074 final FlowController flowController,
075 final LayoutController parent)
076 throws DataSourceException, ReportDataFactoryException,
077 ReportProcessingException;
078
079 /**
080 * Advances the processing position.
081 *
082 * @param target the report target that receives generated events.
083 * @return the new layout controller instance representing the new state.
084 *
085 * @throws DataSourceException if there was a problem reading data from
086 * the datasource.
087 * @throws ReportProcessingException if there was a general problem during
088 * the report processing.
089 * @throws ReportDataFactoryException if a query failed.
090 */
091 public LayoutController advance(ReportTarget target)
092 throws DataSourceException, ReportDataFactoryException,
093 ReportProcessingException;
094
095 /**
096 * Checks, whether the layout controller would be advanceable. If this method
097 * returns true, it is generally safe to call the 'advance()' method.
098 *
099 * @return true, if the layout controller is advanceable, false otherwise.
100 */
101 public boolean isAdvanceable();
102
103 /**
104 * Joins with a delegated process flow. This is generally called from a child
105 * flow and should *not* (I mean it!) be called from outside. If you do,
106 * you'll suffer.
107 *
108 * @param flowController the flow controller of the parent.
109 * @return the joined layout controller that incorperates all changes from
110 * the delegate.
111 */
112 public LayoutController join(FlowController flowController)
113 throws DataSourceException, ReportDataFactoryException,
114 ReportProcessingException;
115
116 /**
117 * Creates a copy of this layout controller.
118 *
119 * @return a copy.
120 */
121 public Object clone();
122
123 /**
124 * Derives a copy of this controller that is suitable to perform a
125 * precomputation. The returned layout controller must be independent from
126 * the it's anchestor controller.
127 *
128 * @param fc a new flow controller for the precomputation.
129 * @return a copy that is suitable for precomputation.
130 */
131 public LayoutController createPrecomputeInstance(FlowController fc);
132
133 public FlowController getFlowController();
134 public Object getNode();
135 }