J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-1999 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | |
| 27 | |
| 28 | package javax.swing; |
| 29 | |
| 30 | |
| 31 | |
| 32 | import java.io.*; |
| 33 | import java.awt.Component; |
| 34 | |
| 35 | |
| 36 | |
| 37 | /** |
| 38 | * Monitors the progress of reading from some InputStream. This ProgressMonitor |
| 39 | * is normally invoked in roughly this form: |
| 40 | * <pre> |
| 41 | * InputStream in = new BufferedInputStream( |
| 42 | * new ProgressMonitorInputStream( |
| 43 | * parentComponent, |
| 44 | * "Reading " + fileName, |
| 45 | * new FileInputStream(fileName))); |
| 46 | * </pre><p> |
| 47 | * This creates a progress monitor to monitor the progress of reading |
| 48 | * the input stream. If it's taking a while, a ProgressDialog will |
| 49 | * be popped up to inform the user. If the user hits the Cancel button |
| 50 | * an InterruptedIOException will be thrown on the next read. |
| 51 | * All the right cleanup is done when the stream is closed. |
| 52 | * |
| 53 | * |
| 54 | * <p> |
| 55 | * |
| 56 | * For further documentation and examples see |
| 57 | * <a href="http://java.sun.com/docs/books/tutorial/uiswing/components/progress.html">How to Monitor Progress</a>, |
| 58 | * a section in <em>The Java Tutorial.</em> |
| 59 | * |
| 60 | * @see ProgressMonitor |
| 61 | * @see JOptionPane |
| 62 | * @author James Gosling |
| 63 | */ |
| 64 | public class ProgressMonitorInputStream extends FilterInputStream |
| 65 | { |
| 66 | private ProgressMonitor monitor; |
| 67 | private int nread = 0; |
| 68 | private int size = 0; |
| 69 | |
| 70 | |
| 71 | /** |
| 72 | * Constructs an object to monitor the progress of an input stream. |
| 73 | * |
| 74 | * @param message Descriptive text to be placed in the dialog box |
| 75 | * if one is popped up. |
| 76 | * @param parentComponent The component triggering the operation |
| 77 | * being monitored. |
| 78 | * @param in The input stream to be monitored. |
| 79 | */ |
| 80 | public ProgressMonitorInputStream(Component parentComponent, |
| 81 | Object message, |
| 82 | InputStream in) { |
| 83 | super(in); |
| 84 | try { |
| 85 | size = in.available(); |
| 86 | } |
| 87 | catch(IOException ioe) { |
| 88 | size = 0; |
| 89 | } |
| 90 | monitor = new ProgressMonitor(parentComponent, message, null, 0, size); |
| 91 | } |
| 92 | |
| 93 | |
| 94 | /** |
| 95 | * Get the ProgressMonitor object being used by this stream. Normally |
| 96 | * this isn't needed unless you want to do something like change the |
| 97 | * descriptive text partway through reading the file. |
| 98 | * @return the ProgressMonitor object used by this object |
| 99 | */ |
| 100 | public ProgressMonitor getProgressMonitor() { |
| 101 | return monitor; |
| 102 | } |
| 103 | |
| 104 | |
| 105 | /** |
| 106 | * Overrides <code>FilterInputStream.read</code> |
| 107 | * to update the progress monitor after the read. |
| 108 | */ |
| 109 | public int read() throws IOException { |
| 110 | int c = in.read(); |
| 111 | if (c >= 0) monitor.setProgress(++nread); |
| 112 | if (monitor.isCanceled()) { |
| 113 | InterruptedIOException exc = |
| 114 | new InterruptedIOException("progress"); |
| 115 | exc.bytesTransferred = nread; |
| 116 | throw exc; |
| 117 | } |
| 118 | return c; |
| 119 | } |
| 120 | |
| 121 | |
| 122 | /** |
| 123 | * Overrides <code>FilterInputStream.read</code> |
| 124 | * to update the progress monitor after the read. |
| 125 | */ |
| 126 | public int read(byte b[]) throws IOException { |
| 127 | int nr = in.read(b); |
| 128 | if (nr > 0) monitor.setProgress(nread += nr); |
| 129 | if (monitor.isCanceled()) { |
| 130 | InterruptedIOException exc = |
| 131 | new InterruptedIOException("progress"); |
| 132 | exc.bytesTransferred = nread; |
| 133 | throw exc; |
| 134 | } |
| 135 | return nr; |
| 136 | } |
| 137 | |
| 138 | |
| 139 | /** |
| 140 | * Overrides <code>FilterInputStream.read</code> |
| 141 | * to update the progress monitor after the read. |
| 142 | */ |
| 143 | public int read(byte b[], |
| 144 | int off, |
| 145 | int len) throws IOException { |
| 146 | int nr = in.read(b, off, len); |
| 147 | if (nr > 0) monitor.setProgress(nread += nr); |
| 148 | if (monitor.isCanceled()) { |
| 149 | InterruptedIOException exc = |
| 150 | new InterruptedIOException("progress"); |
| 151 | exc.bytesTransferred = nread; |
| 152 | throw exc; |
| 153 | } |
| 154 | return nr; |
| 155 | } |
| 156 | |
| 157 | |
| 158 | /** |
| 159 | * Overrides <code>FilterInputStream.skip</code> |
| 160 | * to update the progress monitor after the skip. |
| 161 | */ |
| 162 | public long skip(long n) throws IOException { |
| 163 | long nr = in.skip(n); |
| 164 | if (nr > 0) monitor.setProgress(nread += nr); |
| 165 | return nr; |
| 166 | } |
| 167 | |
| 168 | |
| 169 | /** |
| 170 | * Overrides <code>FilterInputStream.close</code> |
| 171 | * to close the progress monitor as well as the stream. |
| 172 | */ |
| 173 | public void close() throws IOException { |
| 174 | in.close(); |
| 175 | monitor.close(); |
| 176 | } |
| 177 | |
| 178 | |
| 179 | /** |
| 180 | * Overrides <code>FilterInputStream.reset</code> |
| 181 | * to reset the progress monitor as well as the stream. |
| 182 | */ |
| 183 | public synchronized void reset() throws IOException { |
| 184 | in.reset(); |
| 185 | nread = size - in.available(); |
| 186 | monitor.setProgress(nread); |
| 187 | } |
| 188 | } |