content: /* ========================================================================
   * JCommon : a free general purpose class library for the Java(tm) platform
   * ========================================================================
   *
   * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
   * 
   * Project Info:  http://www.jfree.org/jcommon/index.html
   *
   * This library is free software; you can redistribute it and/or modify it 
   * under the terms of the GNU Lesser General Public License as published by 
   * the Free Software Foundation; either version 2.1 of the License, or 
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but 
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
   * USA.  
   *
   * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
   * in the United States and other countries.]
   * 
   * ------------------------
   * RootXmlWriteHandler.java
   * ------------------------
   * (C) Copyright 2002-2005, by Object Refinery Limited.
   *
   * Original Author:  Peter Becker;
   * Contributor(s):   -;
   *
   * $Id: RootXmlWriteHandler.java,v 1.5 2005/10/18 13:35:06 mungady Exp $
   *
   * Changes
   * -------
   * 23-Dec-2003 : Added missing Javadocs (DG);
   *
   */
  package org.jfree.xml.writer;
  
  import java.awt.BasicStroke;
  import java.awt.Color;
  import java.awt.Font;
  import java.awt.GradientPaint;
  import java.awt.Insets;
  import java.awt.Paint;
  import java.awt.RenderingHints;
  import java.awt.Stroke;
  import java.awt.geom.Point2D;
  import java.awt.geom.Rectangle2D;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Stack;
  import java.util.Vector;
  
  import org.jfree.util.ObjectUtilities;
  import org.jfree.xml.util.ManualMappingDefinition;
  import org.jfree.xml.util.MultiplexMappingDefinition;
  import org.jfree.xml.util.MultiplexMappingEntry;
  import org.jfree.xml.util.ObjectFactory;
  import org.jfree.xml.util.SimpleObjectFactory;
  import org.jfree.xml.writer.coretypes.BasicStrokeWriteHandler;
  import org.jfree.xml.writer.coretypes.ColorWriteHandler;
  import org.jfree.xml.writer.coretypes.FontWriteHandler;
  import org.jfree.xml.writer.coretypes.GenericWriteHandler;
  import org.jfree.xml.writer.coretypes.GradientPaintWriteHandler;
  import org.jfree.xml.writer.coretypes.InsetsWriteHandler;
  import org.jfree.xml.writer.coretypes.ListWriteHandler;
  import org.jfree.xml.writer.coretypes.Point2DWriteHandler;
  import org.jfree.xml.writer.coretypes.Rectangle2DWriteHandler;
  import org.jfree.xml.writer.coretypes.RenderingHintsWriteHandler;
  
  /**
   * A root handler for writing objects to XML format.
   */
  public abstract class RootXmlWriteHandler {
  
      /** A map containg the manual mappings. */
      private SimpleObjectFactory classToHandlerMapping;
  
      /**
       * Creates a new RootXmlWrite handler with the default mappings enabled.
       */
      public RootXmlWriteHandler() {
          this.classToHandlerMapping = new SimpleObjectFactory();
  
          // set up handling for Paint objects
          final MultiplexMappingEntry[] paintEntries = new MultiplexMappingEntry[2];
          paintEntries[0] = new MultiplexMappingEntry("color", Color.class.getName());
          paintEntries[1] = new MultiplexMappingEntry("gradientPaint", GradientPaint.class.getName());
          addMultiplexMapping(Paint.class, "type", paintEntries);
          addManualMapping(GradientPaint.class, GradientPaintWriteHandler.class);
          addManualMapping(Color.class, ColorWriteHandler.class);
  
          // set up handling for Point2D objects
          final MultiplexMappingEntry[] point2DEntries = new MultiplexMappingEntry[2];
          point2DEntries[0] = new MultiplexMappingEntry("float", Point2D.Float.class.getName());
          point2DEntries[1] = new MultiplexMappingEntry("double", Point2D.Double.class.getName());
          addMultiplexMapping(Point2D.class, "type", point2DEntries);
          addManualMapping(Point2D.Float.class, Point2DWriteHandler.class);
          addManualMapping(Point2D.Double.class, Point2DWriteHandler.class);
  
          // set up handling for Stroke objects
          final MultiplexMappingEntry[] strokeEntries = new MultiplexMappingEntry[1];
          strokeEntries[0] = new MultiplexMappingEntry("basic", BasicStroke.class.getName());
          addMultiplexMapping(Stroke.class, "type", strokeEntries);
          addManualMapping(BasicStroke.class, BasicStrokeWriteHandler.class);
  
          // set up handling for Rectangle2D objects
          final MultiplexMappingEntry[] rectangle2DEntries = new MultiplexMappingEntry[2];
          rectangle2DEntries[0] = new MultiplexMappingEntry(
              "float", Rectangle2D.Float.class.getName()
          );
          rectangle2DEntries[1] = new MultiplexMappingEntry(
              "double", Rectangle2D.Double.class.getName()
          );
          addMultiplexMapping(Rectangle2D.class, "type", rectangle2DEntries);
          addManualMapping(Rectangle2D.Float.class, Rectangle2DWriteHandler.class);
          addManualMapping(Rectangle2D.Double.class, Rectangle2DWriteHandler.class);
  
          // set up handling for List objects
          final MultiplexMappingEntry[] listEntries = new MultiplexMappingEntry[4];
          listEntries[0] = new MultiplexMappingEntry("array-list", ArrayList.class.getName());
          listEntries[1] = new MultiplexMappingEntry("linked-list", LinkedList.class.getName());
          listEntries[2] = new MultiplexMappingEntry("vector", Vector.class.getName());
          listEntries[3] = new MultiplexMappingEntry("stack", Stack.class.getName());
          addMultiplexMapping(List.class, "type", listEntries);
          addManualMapping(LinkedList.class, ListWriteHandler.class);
          addManualMapping(Vector.class, ListWriteHandler.class);
          addManualMapping(ArrayList.class, ListWriteHandler.class);
          addManualMapping(Stack.class, ListWriteHandler.class);
  
          // handle all other direct mapping types
          addManualMapping(RenderingHints.class, RenderingHintsWriteHandler.class);
          addManualMapping(Insets.class, InsetsWriteHandler.class);
          addManualMapping(Font.class, FontWriteHandler.class);
      }
  
      /**
       * Returns the object factory.
       * 
       * @return the object factory.
       */
      protected abstract ObjectFactory getFactoryLoader();
  
      /**
       * Adds a new manual mapping to this handler.
       *
       * This method provides support for the manual mapping. The manual mapping
       * will become active before the multiplexers were queried. This facility
       * could be used to override the model definition.
       *
       * @param classToWrite the class, which should be handled
       * @param handler the write handler implementation for that class.
       */
      protected void addManualMapping(final Class classToWrite, final Class handler) {
          if (handler == null) {
              throw new NullPointerException("handler must not be null.");
          }
          if (classToWrite == null) {
              throw new NullPointerException("classToWrite must not be null.");
          }
          if (!XmlWriteHandler.class.isAssignableFrom(handler)) {
              throw new IllegalArgumentException("The given handler is no XmlWriteHandler.");
          }
  
          this.classToHandlerMapping.addManualMapping
              (new ManualMappingDefinition(classToWrite, null, handler.getName()));
      }
  
      /**
       * Adds a multiplex mapping.
       * 
       * @param baseClass  the base class.
       * @param typeAttr  the type attribute.
       * @param mdef  the mapping entries.
       */
      protected void addMultiplexMapping(final Class baseClass,
                                         final String typeAttr,
                                         final MultiplexMappingEntry[] mdef) {
          
          this.classToHandlerMapping.addMultiplexMapping(
              new MultiplexMappingDefinition(baseClass, typeAttr, mdef)
          );
          
      }
  
      /**
       * Tries to find the mapping for the given class. This will first check
       * the manual mapping and then try to use the object factory to resolve
       * the class parameter into a write handler.
       *
       * @param classToWrite the class for which to find a handler.
       * @return the write handler, never null.
       * @throws XMLWriterException if no handler could be found for the given class.
       */
      protected XmlWriteHandler getMapping(final Class classToWrite) throws XMLWriterException {
  
          if (classToWrite == null) {
              throw new NullPointerException("ClassToWrite is null.");
          }
  
          // search direct matches, first the direct definitions ...
          ManualMappingDefinition manualMapping =
              this.classToHandlerMapping.getManualMappingDefinition(classToWrite);
          if (manualMapping == null) {
              // search the manual mappings from the xml file.
              manualMapping = getFactoryLoader().getManualMappingDefinition(classToWrite);
          }
          if (manualMapping != null) {
              return loadHandlerClass(manualMapping.getWriteHandler());
          }
  
  
          // multiplexer definitions can be safely ignored here, as they are used to
          // map parent classes to more specific child classes. In this case, we already
          // know the child class and can look up the handler directly.
  
          // of course we have to check for multiplexers later, so that we can apply
          // the mutiplex-attributes.
  
          // and finally try the generic handler matches ...
          if (this.classToHandlerMapping.isGenericHandler(classToWrite)) {
              return new GenericWriteHandler(
                  this.classToHandlerMapping.getFactoryForClass(classToWrite)
              );
          }
          if (getFactoryLoader().isGenericHandler(classToWrite)) {
              return new GenericWriteHandler(getFactoryLoader().getFactoryForClass(classToWrite));
          }
  
          throw new XMLWriterException("Unable to handle " + classToWrite);
      }
  
      /**
       * Writes the given object with the specified tagname. This method will
       * do nothing, if the given object is null.
       *
       * @param tagName  the tagname for the xml-element containing the object
       * definition. The tagname must not be null.
       * @param object  the object which should be written.
       * @param baseClass  the base class.
       * @param writer  the xml writer used to write the content, never null.
       * 
       * @throws IOException if an IOException occures.
       * @throws XMLWriterException if an object model related error occures during
       * the writing.
       */
      public void write(final String tagName, final Object object, final Class baseClass, final XMLWriter writer)
          throws IOException, XMLWriterException {
          if (object == null) {
              return;
          }
          if (tagName == null) {
              throw new NullPointerException("RootXmlWriteHandler.write(..) : tagName is null");
          }
          if (writer == null) {
              throw new NullPointerException("RootXmlWriteHandler.write(..) : writer is null");
          }
          if (!baseClass.isInstance(object)) {
              throw new ClassCastException("Object is no instance of " + baseClass);
          }
          final Class classToWrite = object.getClass();
          final XmlWriteHandler handler = getMapping(classToWrite);
          handler.setRootHandler(this);
  
          String attributeName = null;
          String attributeValue = null;
  
          // find multiplexer for this class...
          MultiplexMappingDefinition mplex =
              getFactoryLoader().getMultiplexDefinition(baseClass);
          if (mplex == null) {
              mplex = this.classToHandlerMapping.getMultiplexDefinition(baseClass);
          }
          if (mplex != null) {
              final MultiplexMappingEntry entry =
                  mplex.getEntryForClass(classToWrite.getName());
              if (entry != null) {
                  attributeName = mplex.getAttributeName();
                  attributeValue = entry.getAttributeValue();
              }
              else {
                  throw new XMLWriterException(
                      "Unable to find child mapping for multiplexer " 
                      + baseClass + " to child " + classToWrite
                  );
              }
          }
  
          handler.write(tagName, object, writer, attributeName, attributeValue);
          writer.allowLineBreak();
      }
  
      /**
       * Loads the given class, and ignores all exceptions which may occur
       * during the loading. If the class was invalid, null is returned instead.
       *
       * @param className the name of the class to be loaded.
       * @return the class or null.
       * 
       * @throws XMLWriterException if there is a writer exception.
       */
      protected XmlWriteHandler loadHandlerClass(final String className)
          throws XMLWriterException {
          if (className == null) {
              throw new XMLWriterException("LoadHanderClass: Class name not defined");
          }
          try {
              final Class c = ObjectUtilities.getClassLoader(getClass()).loadClass(className);
              return (XmlWriteHandler) c.newInstance();
          }
          catch (Exception e) {
              // ignore buggy classes for now ..
              throw new XMLWriterException("LoadHanderClass: Unable to instantiate " + className, e);
          }
      }
      
  }
  