| Methods Summary |
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| public void | actionPerformed(java.awt.event.ActionEvent e) updateDisplay();
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| public void | destroy() if (image != null) image.flush();
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| public java.lang.String | getAppletInfo()
return "Countdown applet Copyright (c) 2003 by David Flanagan";
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| public java.lang.String[][] | getParameterInfo() return parameterInfo;
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| public void | init()
// Figure out how long to count for by reading the "minutes" parameter
// defined in a <param> tag inside the <applet> tag. Convert to ms.
String minutes = getParameter("minutes");
if (minutes != null) remaining = Integer.parseInt(minutes) * 60000;
else remaining = 600000; // 10 minutes by default
// Create a JLabel to display remaining time, and set some properties.
label = new JLabel();
label.setHorizontalAlignment(SwingConstants.CENTER);
label.setOpaque(true); // So label draws the background color
// Read some parameters for this JLabel object
String font = getParameter("font");
String foreground = getParameter("foreground");
String background = getParameter("background");
String imageURL = getParameter("image");
// Set label properties based on those parameters
if (font != null) label.setFont(Font.decode(font));
if (foreground != null) label.setForeground(Color.decode(foreground));
if (background != null) label.setBackground(Color.decode(background));
if (imageURL != null) {
// Load the image, and save it so we can release it later
image = getImage(getDocumentBase(), imageURL);
// Now display the image in the JLabel.
label.setIcon(new ImageIcon(image));
}
// Now add the label to the applet. Like JFrame and JDialog, JApplet
// has a content pane that you add children to
getContentPane().add(label, BorderLayout.CENTER);
// Get an optional AudioClip to play when the count expires
String soundURL = getParameter("sound");
if (soundURL != null) sound=getAudioClip(getDocumentBase(), soundURL);
// Obtain a NumberFormat object to convert number of minutes and
// seconds to strings. Set it up to produce a leading 0 if necessary
format = NumberFormat.getNumberInstance();
format.setMinimumIntegerDigits(2); // pad with 0 if necessary
// Specify a MouseListener to handle mouse events in the applet.
// Note that the applet implements this interface itself
addMouseListener(this);
// Create a timer to call the actionPerformed() method immediately,
// and then every 1000 milliseconds. Note we don't start the timer yet.
timer = new Timer(1000, this);
timer.setInitialDelay(0); // First timer is immediate.
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| public void | mouseClicked(java.awt.event.MouseEvent e)
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| public void | mouseEntered(java.awt.event.MouseEvent e)
pause(); // pause countdown
showStatus("Paused"); // display statusline message
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| public void | mouseExited(java.awt.event.MouseEvent e)
resume(); // resume countdown
showStatus(""); // clear statusline
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| public void | mousePressed(java.awt.event.MouseEvent e)
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| public void | mouseReleased(java.awt.event.MouseEvent e)
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| void | pause()
// Subtract elapsed time from the remaining time and stop timing
long now = System.currentTimeMillis();
remaining -= (now - lastUpdate);
timer.stop(); // Stop the timer
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| void | resume()
// Start or resume the countdown
// Restore the time we're counting down from and restart the timer.
lastUpdate = System.currentTimeMillis();
timer.start(); // Start the timer
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| public void | start() resume();
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| public void | stop() pause();
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| void | updateDisplay()
long now = System.currentTimeMillis(); // current time in ms
long elapsed = now - lastUpdate; // ms elapsed since last update
remaining -= elapsed; // adjust remaining time
lastUpdate = now; // remember this update time
// Convert remaining milliseconds to mm:ss format and display
if (remaining < 0) remaining = 0;
int minutes = (int)(remaining/60000);
int seconds = (int)((remaining%60000)/1000);
label.setText(format.format(minutes) + ":" + format.format(seconds));
// If we've completed the countdown beep and display new page
if (remaining == 0) {
// Stop updating now.
timer.stop();
// If we have an alarm sound clip, play it now.
if (sound != null) sound.play();
// If there is a newpage URL specified, make the browser
// load that page now.
String newpage = getParameter("newpage");
if (newpage != null) {
try {
URL url = new URL(getDocumentBase(), newpage);
getAppletContext().showDocument(url);
}
catch(MalformedURLException ex) { showStatus(ex.toString()); }
}
}
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