/*
* Copyright (c) 1997, 1999, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package javax.swing;
import java.io.*;
import java.awt.Component;
/**
* Monitors the progress of reading from some InputStream. This ProgressMonitor
* is normally invoked in roughly this form:
* <pre>
* InputStream in = new BufferedInputStream(
* new ProgressMonitorInputStream(
* parentComponent,
* "Reading " + fileName,
* new FileInputStream(fileName)));
* </pre><p>
* This creates a progress monitor to monitor the progress of reading
* the input stream. If it's taking a while, a ProgressDialog will
* be popped up to inform the user. If the user hits the Cancel button
* an InterruptedIOException will be thrown on the next read.
* All the right cleanup is done when the stream is closed.
*
*
* <p>
*
* For further documentation and examples see
* <a href="http://java.sun.com/docs/books/tutorial/uiswing/components/progress.html">How to Monitor Progress</a>,
* a section in <em>The Java Tutorial.</em>
*
* @see ProgressMonitor
* @see JOptionPane
* @author James Gosling
*/
public class ProgressMonitorInputStream extends FilterInputStream
{
private ProgressMonitor monitor;
private int nread = 0;
private int size = 0;
/**
* Constructs an object to monitor the progress of an input stream.
*
* @param message Descriptive text to be placed in the dialog box
* if one is popped up.
* @param parentComponent The component triggering the operation
* being monitored.
* @param in The input stream to be monitored.
*/
public ProgressMonitorInputStream(Component parentComponent,
Object message,
InputStream in) {
super(in);
try {
size = in.available();
}
catch(IOException ioe) {
size = 0;
}
monitor = new ProgressMonitor(parentComponent, message, null, 0, size);
}
/**
* Get the ProgressMonitor object being used by this stream. Normally
* this isn't needed unless you want to do something like change the
* descriptive text partway through reading the file.
* @return the ProgressMonitor object used by this object
*/
public ProgressMonitor getProgressMonitor() {
return monitor;
}
/**
* Overrides <code>FilterInputStream.read</code>
* to update the progress monitor after the read.
*/
public int read() throws IOException {
int c = in.read();
if (c >= 0) monitor.setProgress(++nread);
if (monitor.isCanceled()) {
InterruptedIOException exc =
new InterruptedIOException("progress");
exc.bytesTransferred = nread;
throw exc;
}
return c;
}
/**
* Overrides <code>FilterInputStream.read</code>
* to update the progress monitor after the read.
*/
public int read(byte b[]) throws IOException {
int nr = in.read(b);
if (nr > 0) monitor.setProgress(nread += nr);
if (monitor.isCanceled()) {
InterruptedIOException exc =
new InterruptedIOException("progress");
exc.bytesTransferred = nread;
throw exc;
}
return nr;
}
/**
* Overrides <code>FilterInputStream.read</code>
* to update the progress monitor after the read.
*/
public int read(byte b[],
int off,
int len) throws IOException {
int nr = in.read(b, off, len);
if (nr > 0) monitor.setProgress(nread += nr);
if (monitor.isCanceled()) {
InterruptedIOException exc =
new InterruptedIOException("progress");
exc.bytesTransferred = nread;
throw exc;
}
return nr;
}
/**
* Overrides <code>FilterInputStream.skip</code>
* to update the progress monitor after the skip.
*/
public long skip(long n) throws IOException {
long nr = in.skip(n);
if (nr > 0) monitor.setProgress(nread += nr);
return nr;
}
/**
* Overrides <code>FilterInputStream.close</code>
* to close the progress monitor as well as the stream.
*/
public void close() throws IOException {
in.close();
monitor.close();
}
/**
* Overrides <code>FilterInputStream.reset</code>
* to reset the progress monitor as well as the stream.
*/
public synchronized void reset() throws IOException {
in.reset();
nread = size - in.available();
monitor.setProgress(nread);
}
}