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 3048 2007-07-28 18:02:42Z tmorgner $
027: * ------------
028: * (C) Copyright 2000-2005, by Object Refinery Limited.
029: * (C) Copyright 2005-2007, by Pentaho Corporation.
030: */package org.jfree.report.flow.layoutprocessor;
031:
032: import org.jfree.report.DataSourceException;
033: import org.jfree.report.ReportDataFactoryException;
034: import org.jfree.report.ReportProcessingException;
035: import org.jfree.report.flow.FlowController;
036: import org.jfree.report.flow.ReportTarget;
037:
038: /**
039: * The layout controller iterates over the report layout. It uses a flow
040: * controller to query the data.
041: *
042: * @author Thomas Morgner
043: */
044: public interface LayoutController extends Cloneable {
045: /**
046: * Retrieves the parent of this layout controller. This allows childs to query
047: * their context.
048: *
049: * @return the layout controller's parent to <code>null</code> if there is no
050: * parent.
051: */
052: public LayoutController getParent();
053:
054: /**
055: * Initializes the layout controller. This method is called exactly once. It
056: * is the creators responsibility to call this method.
057: * <p/>
058: * Calling initialize after the first advance must result in a
059: * IllegalStateException.
060: *
061: * @param node the currently processed object or layout node.
062: * @param flowController the current flow controller.
063: * @param parent the parent layout controller that was responsible for
064: * instantiating this controller.
065: * @throws DataSourceException if there was a problem reading data from
066: * the datasource.
067: * @throws ReportProcessingException if there was a general problem during
068: * the report processing.
069: * @throws ReportDataFactoryException if a query failed.
070: */
071: public void initialize(final Object node,
072: final FlowController flowController,
073: final LayoutController parent) throws DataSourceException,
074: ReportDataFactoryException, ReportProcessingException;
075:
076: /**
077: * Advances the processing position.
078: *
079: * @param target the report target that receives generated events.
080: * @return the new layout controller instance representing the new state.
081: *
082: * @throws DataSourceException if there was a problem reading data from
083: * the datasource.
084: * @throws ReportProcessingException if there was a general problem during
085: * the report processing.
086: * @throws ReportDataFactoryException if a query failed.
087: */
088: public LayoutController advance(ReportTarget target)
089: throws DataSourceException, ReportDataFactoryException,
090: ReportProcessingException;
091:
092: /**
093: * Checks, whether the layout controller would be advanceable. If this method
094: * returns true, it is generally safe to call the 'advance()' method.
095: *
096: * @return true, if the layout controller is advanceable, false otherwise.
097: */
098: public boolean isAdvanceable();
099:
100: /**
101: * Joins with a delegated process flow. This is generally called from a child
102: * flow and should *not* (I mean it!) be called from outside. If you do,
103: * you'll suffer.
104: *
105: * @param flowController the flow controller of the parent.
106: * @return the joined layout controller that incorperates all changes from
107: * the delegate.
108: */
109: public LayoutController join(FlowController flowController)
110: throws DataSourceException, ReportDataFactoryException,
111: ReportProcessingException;
112:
113: /**
114: * Creates a copy of this layout controller.
115: *
116: * @return a copy.
117: */
118: public Object clone();
119:
120: /**
121: * Derives a copy of this controller that is suitable to perform a
122: * precomputation. The returned layout controller must be independent from
123: * the it's anchestor controller.
124: *
125: * @param fc a new flow controller for the precomputation.
126: * @return a copy that is suitable for precomputation.
127: */
128: public LayoutController createPrecomputeInstance(FlowController fc);
129:
130: public FlowController getFlowController();
131:
132: public Object getNode();
133: }
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