SimplePlayerAppletpublic class SimplePlayerApplet extends Applet implements ControllerListener| This is a Java Applet that demonstrates how to create a simple
media player with a media event listener. It will play the
media clip right away and continuously loop.
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| Fields Summary |
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| Player | player | | Component | visualComponent | | Component | controlComponent | | Component | progressBar | | boolean | firstTime | | long | CachingSize | | Panel | panel | | int | controlPanelHeight | | int | videoWidth | | int | videoHeight |
| Methods Summary |
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| void | Fatal(java.lang.String s)
// Applications will make various choices about what
// to do here. We print a message
System.err.println("FATAL ERROR: " + s);
throw new Error(s); // Invoke the uncaught exception
// handler System.exit() is another
// choice.
| | public synchronized void | controllerUpdate(javax.media.ControllerEvent event)This controllerUpdate function must be defined in order to
implement a ControllerListener interface. This
function will be called whenever there is a media event
// If we're getting messages from a dead player,
// just leave
if (player == null)
return;
// When the player is Realized, get the visual
// and control components and add them to the Applet
if (event instanceof RealizeCompleteEvent) {
if (progressBar != null) {
panel.remove(progressBar);
progressBar = null;
}
int width = 320;
int height = 0;
if (controlComponent == null)
if (( controlComponent =
player.getControlPanelComponent()) != null) {
controlPanelHeight = controlComponent.getPreferredSize().height;
panel.add(controlComponent);
height += controlPanelHeight;
}
if (visualComponent == null)
if (( visualComponent =
player.getVisualComponent())!= null) {
panel.add(visualComponent);
Dimension videoSize = visualComponent.getPreferredSize();
videoWidth = videoSize.width;
videoHeight = videoSize.height;
width = videoWidth;
height += videoHeight;
visualComponent.setBounds(0, 0, videoWidth, videoHeight);
}
panel.setBounds(0, 0, width, height);
if (controlComponent != null) {
controlComponent.setBounds(0, videoHeight,
width, controlPanelHeight);
controlComponent.invalidate();
}
} else if (event instanceof CachingControlEvent) {
if (player.getState() > Controller.Realizing)
return;
// Put a progress bar up when downloading starts,
// take it down when downloading ends.
CachingControlEvent e = (CachingControlEvent) event;
CachingControl cc = e.getCachingControl();
// Add the bar if not already there ...
if (progressBar == null) {
if ((progressBar = cc.getControlComponent()) != null) {
panel.add(progressBar);
panel.setSize(progressBar.getPreferredSize());
validate();
}
}
} else if (event instanceof EndOfMediaEvent) {
// We've reached the end of the media; rewind and
// start over
player.setMediaTime(new Time(0));
player.start();
} else if (event instanceof ControllerErrorEvent) {
// Tell TypicalPlayerApplet.start() to call it a day
player = null;
Fatal(((ControllerErrorEvent)event).getMessage());
} else if (event instanceof ControllerClosedEvent) {
panel.removeAll();
}
| | public void | destroy()
//$ System.out.println("Applet.destroy() is called");
player.close();
| | public void | init()Read the applet file parameter and create the media
player.
setLayout(null);
panel = new Panel();
panel.setLayout( null );
add(panel);
panel.setBounds(0, 0, 320, 240);
// input file name from html param
String mediaFile = null;
// URL for our media file
MediaLocator mrl = null;
URL url = null;
// Get the media filename info.
// The applet tag should contain the path to the
// source media file, relative to the html page.
if ((mediaFile = getParameter("FILE")) == null)
Fatal("Invalid media file parameter");
try {
url = new URL(getDocumentBase(), mediaFile);
mediaFile = url.toExternalForm();
} catch (MalformedURLException mue) {
}
try {
// Create a media locator from the file name
if ((mrl = new MediaLocator(mediaFile)) == null)
Fatal("Can't build URL for " + mediaFile);
// Create an instance of a player for this media
try {
player = Manager.createPlayer(mrl);
} catch (NoPlayerException e) {
System.out.println(e);
Fatal("Could not create player for " + mrl);
}
// Add ourselves as a listener for a player's events
player.addControllerListener(this);
} catch (MalformedURLException e) {
Fatal("Invalid media file URL!");
} catch (IOException e) {
Fatal("IO exception creating player for " + mrl);
}
// This applet assumes that its start() calls
// player.start(). This causes the player to become
// realized. Once realized, the applet will get
// the visual and control panel components and add
// them to the Applet. These components are not added
// during init() because they are long operations that
// would make us appear unresposive to the user.
| | public void | start()Start media file playback. This function is called the
first time that the Applet runs and every
time the user re-enters the page.
//$ System.out.println("Applet.start() is called");
// Call start() to prefetch and start the player.
if (player != null)
player.start();
| | public void | stop()Stop media file playback and release resource before
leaving the page.
//$ System.out.println("Applet.stop() is called");
if (player != null) {
player.stop();
player.deallocate();
}
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