Source for org.jfree.report.flow.layoutprocessor.LayoutController

   1: /**
   2:  * ========================================
   3:  * JFreeReport : a free Java report library
   4:  * ========================================
   5:  *
   6:  * Project Info:  http://reporting.pentaho.org/
   7:  *
   8:  * (C) Copyright 2000-2007, by Object Refinery Limited, Pentaho Corporation and Contributors.
   9:  *
  10:  * This library is free software; you can redistribute it and/or modify it under the terms
  11:  * of the GNU Lesser General Public License as published by the Free Software Foundation;
  12:  * either version 2.1 of the License, or (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
  15:  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  16:  * See the GNU Lesser General Public License for more details.
  17:  *
  18:  * You should have received a copy of the GNU Lesser General Public License along with this
  19:  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20:  * Boston, MA 02111-1307, USA.
  21:  *
  22:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
  23:  * in the United States and other countries.]
  24:  *
  25:  * ------------
  26:  * $Id: LayoutController.java 2725 2007-04-01 18:49:29Z taqua $
  27:  * ------------
  28:  * (C) Copyright 2000-2005, by Object Refinery Limited.
  29:  * (C) Copyright 2005-2007, by Pentaho Corporation.
  30:  */
  31: package org.jfree.report.flow.layoutprocessor;
  32: 
  33: import org.jfree.report.DataSourceException;
  34: import org.jfree.report.ReportDataFactoryException;
  35: import org.jfree.report.ReportProcessingException;
  36: import org.jfree.report.flow.FlowController;
  37: import org.jfree.report.flow.ReportTarget;
  38: 
  39: /**
  40:  * The layout controller iterates over the report layout. It uses a flow
  41:  * controller to query the data.
  42:  *
  43:  * @author Thomas Morgner
  44:  */
  45: public interface LayoutController extends Cloneable
  46: {
  47:   /**
  48:    * Retrieves the parent of this layout controller. This allows childs to query
  49:    * their context.
  50:    *
  51:    * @return the layout controller's parent to <code>null</code> if there is no
  52:    * parent.
  53:    */
  54:   public LayoutController getParent();
  55: 
  56:   /**
  57:    * Initializes the layout controller. This method is called exactly once. It
  58:    * is the creators responsibility to call this method.
  59:    * <p/>
  60:    * Calling initialize after the first advance must result in a
  61:    * IllegalStateException.
  62:    *
  63:    * @param node           the currently processed object or layout node.
  64:    * @param flowController the current flow controller.
  65:    * @param parent         the parent layout controller that was responsible for
  66:    *                       instantiating this controller.
  67:    * @throws DataSourceException        if there was a problem reading data from
  68:    *                                    the datasource.
  69:    * @throws ReportProcessingException  if there was a general problem during
  70:    *                                    the report processing.
  71:    * @throws ReportDataFactoryException if a query failed.
  72:    */
  73:   public void initialize(final Object node,
  74:                          final FlowController flowController,
  75:                          final LayoutController parent)
  76:       throws DataSourceException, ReportDataFactoryException,
  77:       ReportProcessingException;
  78: 
  79:   /**
  80:    * Advances the processing position.
  81:    *
  82:    * @param target the report target that receives generated events.
  83:    * @return the new layout controller instance representing the new state.
  84:    *
  85:    * @throws DataSourceException        if there was a problem reading data from
  86:    *                                    the datasource.
  87:    * @throws ReportProcessingException  if there was a general problem during
  88:    *                                    the report processing.
  89:    * @throws ReportDataFactoryException if a query failed.
  90:    */
  91:   public LayoutController advance(ReportTarget target)
  92:       throws DataSourceException, ReportDataFactoryException,
  93:       ReportProcessingException;
  94: 
  95:   /**
  96:    * Checks, whether the layout controller would be advanceable. If this method
  97:    * returns true, it is generally safe to call the 'advance()' method.
  98:    *
  99:    * @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: }