001 /* ProgressMonitorInputStream.java --
002 Copyright (C) 2002, 2004, 2005, 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.swing;
040
041 import java.awt.Component;
042
043 import java.io.FilterInputStream;
044 import java.io.InputStream;
045 import java.io.InterruptedIOException;
046 import 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 */
056 public 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 }