Swing and jmf

Question

can u please have a look to the attached file
i know that this involves the jmf API but I have the feeling that has to do more with swing, thats whay I post my question here
this simple application is based on the MDI.java example of the jmf web
pages
I also added a slider and want to set the playback rate for the player from
there if possible
that is I want everytime that I move the slider and the value is biggerthan
50 the rate to be reduced according to a simple calculation that converts
the slider value to a value between 0 an1 for the rate...
so all i want to do is pass the slider value to the player everytime that
the slider changes value and this is bigger than 50
the attached file can do that only when the player starts playing the
file,,,,
after the player has started and the rate is set I cant change it even if
the slider moves
when I tried to do that from within the stateChanged method of the slider I
was getting a Nullpointer exception because of the EventDispatching thread,
so I thought to take this piece of code out of there (create the setnewrate
method in the jmframe instead),,,,but then of course doesnt work like I
would want,,,,,
do I have to register the class that implements the frame for the player as
a ChangeListener on the slider to achieve that, is something like that
possible....
I know that swing is not supposed to be thread safe, so maybe this is what
the problem is after all...any suggestions to that direction?
Can u please have a look??
I am a beginner so any help would really be very much appreciated
thanx :)
maria
.....and the attached file
I think the problem is with the stateChanged method for the Jslider...
I am getting a null pointerexception because of the eventdispatching thread
pls ignore any silly mistakes I am a completely newbie in java
myAppfr2.java
import javax.media.*;
import com.sun.media.ui.*;
import javax.media.protocol.*;
import javax.media.protocol.DataSource;
import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.io.*;
import java.util.Vector;
import javax.swing.border.Border.*;
import java.util.Hashtable;
public class myAppfr2 extends Frame {
* VARIABLES
JMFrame jmframe = null;
JDesktopPane desktop;
FileDialog fd = null;
CheckboxMenuItem cbAutoLoop = null;
Player player ;
//Player newPlayer = null;
String filename;
boolean stopped;
public my_slider test_slider;//put it here so I can use it by name by all code
float rate;
* MAIN PROGRAM / STATIC METHODS
public static void main(String args[]) {
//if (args.length > 0)
     //rate=Float.parseFloat(args[0]);
myAppfr2 mdi = new myAppfr2();
static void Fatal(String s) {
MessageBox mb = new MessageBox("JMF Error", s);
* METHODS
public myAppfr2() {
super("VHE Demo");
// Add the desktop pane
setLayout( new BorderLayout() );
desktop = new JDesktopPane();
desktop.setDoubleBuffered(true);
     desktop.setDragMode(JDesktopPane.OUTLINE_DRAG_MODE);//makes dragging faster
add("Center", desktop);
setMenuBar(createMenuBar());
setSize(640, 480);
setVisible(true);
     test_slider = new my_slider("networkutil");
     createnetworkutil();
     try {
     UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel") ;
} catch (Exception e) {
System.err.println("Could not initialize personal look and feel");
addWindowListener( new WindowAdapter() {
public void windowClosing(WindowEvent we) {
System.exit(0);
Manager.setHint(Manager.LIGHTWEIGHT_RENDERER, new Boolean(true));
private MenuBar createMenuBar() {
ActionListener al = new ActionListener() {
public void actionPerformed(ActionEvent ae) {
String command = ae.getActionCommand();
if (command.equals("Open")) {
if (fd == null) {
fd = new FileDialog(myAppfr2.this, "Open File",
FileDialog.LOAD);
fd.setDirectory("~/movies");
fd.show();
if (fd.getFile() != null) {
String filename = fd.getDirectory() + fd.getFile();
openFile("file:" + filename);
} else if (command.equals("Exit")) {
dispose();
System.exit(0);
MenuItem item;
MenuBar mb = new MenuBar();
// File Menu
Menu mnFile = new Menu("File");
mnFile.add(item = new MenuItem("Open"));
item.addActionListener(al);
mnFile.add(item = new MenuItem("Exit"));
item.addActionListener(al);
// Options Menu
Menu mnOptions = new Menu("Options");
cbAutoLoop = new CheckboxMenuItem("Auto replay");
cbAutoLoop.setState(true);
mnOptions.add(cbAutoLoop);
mb.add(mnFile);
mb.add(mnOptions);
return mb;
//create slider and add it to desktop
public void createnetworkutil(){
test_slider.pack();
desktop.add(test_slider);
test_slider.setVisible(true);
* Open a media file.
private void openFile(String filename) {
String mediaFile = filename;
Player player = null;
// URL for our media file
URL url = null;
try {
// Create an url from the file name and the url to the
// document containing this applet.
if ((url = new URL(mediaFile)) == null) {
Fatal("Can't build URL for " + mediaFile);
return;
// Create an instance of a player for this media
try {
player = Manager.createPlayer(url);
} catch (NoPlayerException e) {
Fatal("Error: " + e);
} catch (MalformedURLException e) {
Fatal("Error:" + e);
} catch (IOException e) {
Fatal("Error:" + e);
if (player != null) {
this.filename = filename;
JMFrame jmframe = new JMFrame(player, filename);
desktop.add(jmframe);
class JMFrame extends JInternalFrame implements ControllerListener {
public Player mplayer;
Component visual = null;
Component control = null;
int videoWidth = 0;
int videoHeight = 0;
int controlHeight = 30;
int insetWidth = 10;
int insetHeight = 30;
// boolean firstTime = true;
public JMFrame(Player player, String title) {
super(title, true, true, true, true);
getContentPane().setLayout( new BorderLayout() );
//setSize(320, 10);
setLocation(200, 25);
setVisible(true);
mplayer = player;
mplayer.addControllerListener((ControllerListener) this);
mplayer.realize();
addInternalFrameListener( new InternalFrameAdapter() {
public void internalFrameClosing(InternalFrameEvent ife) {
mplayer.close();
public void controllerUpdate(ControllerEvent ce) {
// System.out.println("controllerUpdate");
//SwingUtilities.isEventDispatchThread();
if (ce instanceof RealizeCompleteEvent) {
mplayer.prefetch();
} else if (ce instanceof PrefetchCompleteEvent) {
if (visual != null)
return;
     //setnewrate();
     //rate=mplayer.getRate();
     System.out.println( mplayer.getRate());
if ((visual = mplayer.getVisualComponent()) != null) {
Dimension size = visual.getPreferredSize();
videoWidth = size.width;
videoHeight = size.height;
getContentPane().add("Center", visual);
} else
videoWidth = 320;
/*if ((control = mplayer.getControlPanelComponent()) != null) {
controlHeight = control.getPreferredSize().height;
getContentPane().add("South", control);
setSize(videoWidth + insetWidth,
videoHeight + controlHeight + insetHeight);
validate();
mplayer.start();
} else if (ce instanceof StartEvent){
     if (test_slider.netutil==0) {
     mplayer.stop();
     } else if (ce instanceof EndOfMediaEvent && cbAutoLoop.getState()) {
mplayer.setMediaTime(new Time(0));
          boolean stopped=true;
          mplayer.prefetch();
          mplayer.start();
          stopped=false;
class my_slider extends JInternalFrame implements ChangeListener{
//Set up parameters.
int netini=50;
public int netutil=netini;
public my_slider(String windowTitle) {
super(windowTitle, false, false, false, false);
getContentPane().setLayout(new BorderLayout());
setLocation(25,25);// for the internal frame that contains the slider
setVisible(true); //..same
//Create the slider(the component included in "my_slider" internal frame
     JSlider mslider = new JSlider(JSlider.VERTICAL,
0, 100, netini);
mslider.addChangeListener((ChangeListener) this);
mslider.setMajorTickSpacing(10);
mslider.setPaintTicks(true);
//Create the label table.
Hashtable labelTable = new Hashtable();
labelTable.put(new Integer( 0 ),
new JLabel("0%") );
labelTable.put(new Integer( 25 ),
new JLabel("25%") );
labelTable.put(new Integer( 50 ),
new JLabel("50%") );
labelTable.put(new Integer(75),
new JLabel("75%") );
     labelTable.put(new Integer( 100),
new JLabel("100%") );     
mslider.setLabelTable(labelTable);
mslider.setPaintLabels(true);
mslider.setBorder(
BorderFactory.createEmptyBorder(0,0,0,10));
     //Put everything in the content pane.
getContentPane().add(mslider, BorderLayout.CENTER);
public void stateChanged(ChangeEvent e) { //System.out.println("stateChanged");
// SwingUtilities.isEventDispatchThread();
if (e instanceof ChangeEvent){
JSlider source = (JSlider)e.getSource();
if (!source.getValueIsAdjusting()) {
netutil= (int)source.getValue();
     System.out.println(netutil);
          if (jmframe.mplayer!=null) {
     jmframe.mplayer.setRate((float)(netutil/(netutil+(0.3*netutil))));
          if (jmframe.mplayer.getTargetState() <Player.Started)
     jmframe.mplayer.prefetch();
i am stuck so any help would be really very much appreciated

Answer 1

did you ever resolve this.
I may be having similar problems
I have an JMF application running under webstart. It runs ok in Java 1.3
Now I am trying to get ti to run under Java 1.4. The attached error is rather useless,
but by guess at what is happening is that the JMF control has some .awt. stuff included
but that Java 1.4 emulates .awt. in swing. But something was not set and the default does not
work.
This error messages does not appear in the 1.3 run
Any suggestions would be greatly appriatated.
1.4 result:
mg version 2.1.1a
player created com.sun.media.content.unknown.Handler@3a1834
ctr com.sun.media.PlaybackEngine$BitRateA@4a9a7d
ctr com.sun.media.BasicJMD[panel0,0,0,512x200,invalid,layout=java.awt.BorderLayout]
duration? javax.media.Time@6b5666 sec = 9.223372036854776E9
time unknown javax.media.Time@754699
will realize the player
realize
javax.media.TransitionEvent[source=com.sun.media.content.unknown.
Handler@3a1834,previous=Unrealized,current=Realizing,
target=Realized]
start smxBADS
bass start
Exception occurred during event dispatching:
java.lang.NullPointerException
at javax.swing.plaf.metal.MetalLookAndFeel.getControlInfo(Unknown Source)
at javax.swing.plaf.metal.MetalScrollButton.paint(Unknown Source)
at javax.swing.JComponent.paintChildren(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JComponent.paintWithBuffer(Unknown Source)
at javax.swing.JComponent._paintImmediately(Unknown Source)
at javax.swing.JComponent.paintImmediately(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Exception occurred during event dispatching:
java.lang.NullPointerException
at javax.swing.plaf.metal.MetalLookAndFeel.getControlInfo(Unknown Source)
at javax.swing.plaf.metal.MetalScrollButton.paint(Unknown Source)
at javax.swing.JComponent.paintChildren(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JComponent.paintWithBuffer(Unknown Source)
at javax.swing.JComponent._paintImmediately(Unknown Source)
at javax.swing.JComponent.paintImmediately(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
realize done
panel found java.awt.Panel[panel1,0,0,0x0,invalid] java.awt.Panel[panel2,4,216,292x30,layout=java.awt.FlowLayout]
press a button
Exception occurred during event dispatching:
java.lang.NullPointerException
at javax.swing.plaf.metal.MetalLookAndFeel.getControlInfo(Unknown Source)
at javax.swing.plaf.metal.MetalScrollButton.paint(Unknown Source)
at javax.swing.JComponent.paintChildren(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JComponent.paintWithBuffer(Unknown Source)
at javax.swing.JComponent._paintImmediately(Unknown Source)
at javax.swing.JComponent.paintImmediately(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Exception occurred during event dispatching:
java.lang.NullPointerException
1.3 result
mg version 2.1.1a
player created com.sun.media.content.unknown.Handler@354749
ctr com.sun.media.PlaybackEngine$BitRateA@5b484d
ctr com.sun.media.BasicJMD[panel3,0,0,512x200,invalid,layout=java.awt.BorderLayout]
duration? javax.media.Time@46d228 sec = 9.223372036854776E9
time unknown javax.media.Time@f7386
will realize the player
realize
javax.media.TransitionEvent[source=com.sun.media.content.unknown.
Handler@354749,previous=Unrealized,current=Realizing,
target=Realized]
start smxBADS
bass start
javax.media.DurationUpdateEvent[source=com.sun.media.content.unknown.Handler@354749,duration=javax.media.Time@55c0f9
javax.media.Time@55c0f9
javax.media.RealizeCompleteEvent[source=com.sun.media.content.unknown.Handler@354749,previous=Realizing,current=Realized,target=Realized]
realized complete
prefetch
realize done
controlComp com.sun.media.ui.DefaultControlPanel[,0,0,74x21,invalid,layout=java.awt.BorderLayout]
add controlComp 21 java.awt.Panel[panel4,10,-12,258x47,invalid]
javax.media.TransitionEvent[source=com.sun.media.content.unknown.Handler@354749,previous=Realized,current=Prefetching,target=Prefetched]
start smxBADS
bass start
running ok from here on