001    /* SimpleDoc.java -- 
002       Copyright (C) 2006 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package javax.print;
040    
041    import java.io.ByteArrayInputStream;
042    import java.io.CharArrayReader;
043    import java.io.IOException;
044    import java.io.InputStream;
045    import java.io.Reader;
046    import java.io.StringReader;
047    
048    import javax.print.attribute.AttributeSetUtilities;
049    import javax.print.attribute.DocAttributeSet;
050    
051    /**
052     * Simple implementation of the <code>Doc</code> interface capable of handling 
053     * the predefined document flavors of <code>DocFlavor</code>.
054     * <p>
055     * This implementation can construct a reader or stream for the service from 
056     * the print data and ensures that always the same object is returned on each
057     * method call. It does simple checks that the supplied data matches the 
058     * specified flavor of the doc object and supports thread safe access.
059     * </p> 
060     * 
061     * @author Wolfgang Baer (WBaer@gmx.de)
062     */
063    public final class SimpleDoc implements Doc
064    {  
065      private final Object printData;
066      private final DocFlavor flavor;
067      private final DocAttributeSet attributes;
068      
069      private InputStream stream;
070      private Reader reader;
071    
072      /**
073       * Constructs a SimpleDoc with the specified print data, doc flavor and doc attribute set.
074       * @param printData the object with the data to print.
075       * @param flavor the document flavor of the print data.
076       * @param attributes the attributes of the doc (may be <code>null</code>).
077       * 
078       * @throws IllegalArgumentException if either <code>printData</code> or
079       *   <code>flavor</code> are <code>null</code>, or the print data is not
080       *   supplied in the document format specified by the given flavor object.
081       */
082      public SimpleDoc(Object printData, DocFlavor flavor, 
083          DocAttributeSet attributes)
084      {
085        if (printData == null || flavor == null)
086          throw new IllegalArgumentException("printData/flavor may not be null");
087        
088        if (! (printData.getClass().getName().equals(
089               flavor.getRepresentationClassName())
090            || flavor.getRepresentationClassName().equals("java.io.Reader")
091               && printData instanceof Reader
092            || flavor.getRepresentationClassName().equals("java.io.InputStream")
093               && printData instanceof InputStream))
094          {
095            throw new IllegalArgumentException("data is not of declared flavor type");
096          }          
097        
098        this.printData = printData;
099        this.flavor = flavor;
100        
101        if (attributes != null)
102          this.attributes = AttributeSetUtilities.unmodifiableView(attributes);
103        else
104          this.attributes = null;
105        
106        stream = null;
107        reader = null;
108      }
109    
110      /**
111       * Returns the unmodifiable view of the attributes of this doc object.
112       * <p>
113       * The attributes of this doc's attributes set overrides attributes of 
114       * the same category in the print job's attribute set. If an attribute 
115       * is not available in this doc's attributes set or <code>null</code>
116       * is returned the attributes of the same category of the print job are
117       * used. 
118       * </p>
119       * 
120       * @return The unmodifiable attributes set, or <code>null</code>.
121       */
122      public DocAttributeSet getAttributes()
123      {
124        return attributes;
125      }
126    
127      /**
128       * Returns the flavor of this doc objects print data.
129       * 
130       * @return The document flavor.
131       */
132      public DocFlavor getDocFlavor()
133      {
134        return flavor;
135      }
136    
137      /**
138       * Returns the print data of this doc object.
139       * <p>
140       * The returned object is an instance as described by the associated
141       * document flavor ({@link DocFlavor#getRepresentationClassName()})
142       * and can be cast to this representation class.
143       * </p>
144       * 
145       * @return The print data in the representation class.
146       * @throws IOException if representation class is a stream and I/O
147       * exception occures.
148       */
149      public Object getPrintData() throws IOException
150      {
151        return printData;
152      }
153    
154      /**
155       * Returns a <code>Reader</code> object for extracting character print data
156       * from this document.
157       * <p>
158       * This method is supported if the document flavor is of type:
159       * <ul>
160       * <li><code>char[]</code></li>
161       * <li><code>java.lang.String</code></li>
162       * <li><code>java.io.Reader</code></li>
163       * </ul>
164       * otherwise this method returns <code>null</code>.
165       * </p> 
166       * 
167       * @return The <code>Reader</code> object, or <code>null</code>.
168       * 
169       * @throws IOException if an error occurs.
170       */
171      public Reader getReaderForText() throws IOException
172      {
173        synchronized (this)
174          {
175            // construct the reader if applicable on request
176            if (reader == null)
177              {
178                if (flavor instanceof DocFlavor.CHAR_ARRAY)
179                  reader = new CharArrayReader((char[]) printData);
180                else if (flavor instanceof DocFlavor.STRING)
181                  reader = new StringReader((String) printData);
182                else if (flavor instanceof DocFlavor.READER)
183                  reader = (Reader) printData;
184              }
185            
186            return reader;
187          }   
188      }
189    
190      /**
191       * Returns an <code>InputStream</code> object for extracting byte print data
192       * from this document.
193       * <p>
194       * This method is supported if the document flavor is of type:
195       * <ul>
196       * <li><code>byte[]</code></li>
197       * <li><code>java.io.InputStream</code></li>
198       * </ul>
199       * otherwise this method returns <code>null</code>.
200       * </p> 
201       * 
202       * @return The <code>InputStream</code> object, or <code>null</code>.
203       * 
204       * @throws IOException if an error occurs.
205       */
206      public InputStream getStreamForBytes() throws IOException
207      {
208        synchronized (this)
209          {
210            // construct the stream if applicable on request
211            if (stream == null)
212              {
213                if (flavor instanceof DocFlavor.BYTE_ARRAY)
214                  stream = new ByteArrayInputStream((byte[]) printData);
215                else if (flavor instanceof DocFlavor.INPUT_STREAM)
216                  stream = (InputStream) printData;
217              }
218            
219            return stream;
220          }    
221      }
222    
223    }