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/**********************************************************************
* GUIMediaStatistics - a GUI allowing the user to select a media
* file from tjelocal file system and gain statistics on that media
* (audio or video) concerning its tracks and their format/composition.
*
* The class is built atop the MediaStatistics class and arguably
* provides a more user friendly mechanism for determining the
*format of media.
*
* @author Spike Barlow
***********************************************************************/
import java.awt.*;
import java.awt.event.*;
import javax.media.*;
import java.util.*;
public class GUIMediaStatistics extends Frame implements ActionListener {
/** Object to determine the format ofthe media. Performs all the real work. */
protected MediaStatistics stats;
/** User wants to search for a file. */
protected Button browseButton;
/** User wants to know the format of the current file. */
protected Button getStatsButton;
/** Current state of processing. */
protected int state;
/** Where the format informationis displayed. */
protected TextArea results;
/** Area i which the user can type the name of a file. */
protected TextField mediaField;
/** Pause in milliseconds between checks to see if format is known. */
public static final int PAUSE = 50;
/** Maximum wait before giving up on determining theformat. */
public static final int MAX_WAIT_PERIOD = 10000;
/** Directory that the user last searched for files. */
protected String lastDirectory;
/**********************************************************************
* Construct the GUIMediaStatistics object, constructing the various
* components and laying them out on the screen.
**********************************************************************/
public GUIMediaStatistics() {
super("GUIMediaStatistics");
setLayout(new BorderLayout());
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0); } });
Panel filePanel = new Panel();
filePanel.add(new Label("File:"));
mediaField = new TextField(40);
filePanel.add(mediaField);
browseButton =new Button("browse...");
filePanel.add(browseButton);
browseButton.addActionListener(this);
getStatsButton = new Button("get stats...");
filePanel.add(getStatsButton);
getStatsButton.addActionListener(this);
add(filePanel,"North");
results = new TextArea(80,10);
results.setEditable(false);
add(results,"Center");
}
/************************************************************************
* Respond to user button presses - either browsing for a file or
* gathering format info on the current file.
************************************************************************/
public void actionPerformed(ActionEvent e) {
/////////////////////////////////
// Browse - use FileDialog class.
/////////////////////////////////
if (e.getSource() == browseButton) {
FileDialog choice = new FileDialog(this, "Media File Choice",
FileDialog.LOAD);
if (lastDirectory != null)
choice.setDirectory(lastDirectory);
choice.show();
String selection = choice.getFile();
if (selection != null) {
lastDirectory = choice.getDirectory();
mediaField.setText("file://" + choice.getDirectory()
+ selection);
}
}
////////////////////////////////////////////////////////
// Get statistics - create a MediaStatistics object and
// monitor its progress.
///////////////////////////////////////////////////////
else {
stats = new MediaStatistics(mediaField.getText());
monitorAndReport();
}
}
/************************************************************************
* Monitor the progress of the MediaStatistics object as it attempts to
* determineformatinformation for the current file. It periodically
* polls the object, obtaining a report from it and printing it to the
* screen. The polling stops as soon as the format is known, it is
* found that it isimpossible to determine a format, or a certain time
* period is exceeded.
**************************************************************************/
private void monitorAndReport() {
int elapsed = 0;
state = stats.getState();
while (elapsed < MAX_WAIT_PERIOD
&& (state != MediaStatistics.FAILED && state != MediaStatistics.KNOWN)) {
results.setText(stats.getReport());
try {
Thread.sleep(PAUSE);
} catch (Exception e) {
}
elapsed += PAUSE;
state = stats.getState();
}
if (state == MediaStatistics.FAILED || state == MediaStatistics.KNOWN)
results.setText(stats.getReport());
else
results.setText("Timing out after maximum period of "
+ MAX_WAIT_PERIOD + "ms");
}
/***************************************************************************
* Main method - construct a GUIMediaStatistics frame and show it on the
* screen.
**************************************************************************/
public static void main(String[] args) {
GUIMediaStatistics gui = new GUIMediaStatistics();
gui.pack();
gui.setSize(600, 400);
gui.show();
}
}
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