001/* ProgressMonitorInputStream.java --
002   Copyright (C) 2002, 2004, 2005, 2006, Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package javax.swing;
040
041import java.awt.Component;
042
043import java.io.FilterInputStream;
044import java.io.InputStream;
045import java.io.InterruptedIOException;
046import java.io.IOException;
047
048/**
049 * An input stream with a {@link ProgressMonitor}.
050 *
051 * @author      Andrew Selkirk
052 * @author  Robert Schuster (robertschuster@fsfe.org)
053 * @status updated to 1.2
054 * @since 1.2
055 */
056public class ProgressMonitorInputStream extends FilterInputStream
057{
058
059  /**
060   * The monitor watching the progress of the input stream.
061   */
062  private ProgressMonitor monitor;
063
064  /**
065   * read
066   */
067  private int read;
068
069  /**
070   * Creates a new <code>ProgressMonitorInputStream</code>.
071   *
072   * @param component  the parent component for the progress monitor dialog.
073   * @param message  the task description.
074   * @param stream  the underlying input stream.
075   */
076  public ProgressMonitorInputStream(Component component, Object message,
077                                    InputStream stream)
078  {
079    super(stream);
080
081    int max = 0;
082
083    try
084      {
085        max = stream.available();
086      }
087    catch ( IOException ioe )
088      {
089        // Behave like the JDK here.
090      }
091
092    monitor = new ProgressMonitor(component, message, null, 0, max);
093  }
094
095  /**
096   * Resets the input stream to the point where {@link #mark(int)} was called.
097   *
098   * @exception IOException TODO
099   */
100  public void reset() throws IOException
101  {
102    super.reset();
103
104    checkMonitorCanceled();
105
106    // TODO: The docs says the monitor should be resetted. But to which
107    // value? (mark is not overridden)
108  }
109
110  /**
111   * Reads an unsigned byte from the input stream and returns it as an
112   * <code>int</code> in the range of 0-255.  Returns -1 if the end of the
113   * stream has been reached.  The progress monitor is updated.
114   *
115   * @return int
116   *
117   * @exception IOException if there is a problem reading the stream.
118   */
119  public int read() throws IOException
120  {
121    int t = super.read();
122
123    monitor.setProgress(++read);
124
125    checkMonitorCanceled();
126
127    return t;
128  }
129
130  /**
131   * Reads bytes from the input stream and stores them in the supplied array,
132   * and updates the progress monitor (or closes it if the end of the stream
133   * is reached).
134   *
135   * @param data  the data array for returning bytes read from the stream.
136   *
137   * @return The number of bytes read, or -1 if there are no more bytes in the
138   *         stream.
139   *
140   * @throws IOException if there is a problem reading bytes from the stream.
141   */
142  public int read(byte[] data) throws IOException
143  {
144    int t = super.read(data);
145
146    if ( t > 0 )
147      {
148        read += t;
149        monitor.setProgress(read);
150
151        checkMonitorCanceled();
152      }
153    else
154      {
155        monitor.close();
156      }
157
158    return t;
159  }
160
161  /**
162   * Reads up to <code>length</code> bytes from the input stream and stores
163   * them in the supplied array at the given index, and updates the progress
164   * monitor (or closes it if the end of the stream is reached).
165   *
166   * @param data  the data array for returning bytes read from the stream.
167   * @param offset  the offset into the array where the bytes should be written.
168   * @param length  the maximum number of bytes to read from the stream.
169   *
170   * @return The number of bytes read, or -1 if there are no more bytes in the
171   *         stream.
172   *
173   * @throws IOException if there is a problem reading bytes from the stream.
174   */
175  public int read(byte[] data, int offset, int length) throws IOException
176  {
177    int t = super.read(data, offset, length);
178
179    if ( t > 0 )
180      {
181        read += t;
182        monitor.setProgress(read);
183
184        checkMonitorCanceled();
185      }
186    else
187      {
188        monitor.close();
189      }
190
191    return t;
192  }
193
194  /**
195   * Skips the specified number of bytes and updates the
196   * {@link ProgressMonitor}.
197   *
198   * @param length the number of bytes to skip.
199   *
200   * @return The actual number of bytes skipped.
201   *
202   * @throws IOException if there is a problem skipping bytes in the stream.
203   */
204  public long skip(long length) throws IOException
205  {
206    long t = super.skip(length);
207
208    // 'read' may overflow here in rare situations.
209    assert ( (long) read + t <= (long) Integer.MAX_VALUE );
210
211    read += (int) t;
212
213    monitor.setProgress(read);
214
215    checkMonitorCanceled();
216
217    return t;
218  }
219
220  /**
221   * Closes the input stream and the associated {@link ProgressMonitor}.
222   *
223   * @throws IOException if there is a problem closing the input stream.
224   */
225  public void close() throws IOException
226  {
227    super.close();
228    monitor.close();
229  }
230
231  /**
232   * Returns the {@link ProgressMonitor} used by this input stream.
233   *
234   * @return The progress monitor.
235   */
236  public ProgressMonitor getProgressMonitor()
237  {
238    return monitor;
239  }
240
241  private void checkMonitorCanceled() throws InterruptedIOException
242  {
243    if (monitor.isCanceled())
244      {
245        throw new InterruptedIOException("ProgressMonitor was canceled");
246      }
247  }
248
249}