BlackBerry stream audio/STOP Stream - blackberry

Question

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I'm newbie in programming and have problem.
My code:
choiceFieldANTYFM = new ObjectChoiceField("Wybierz stację(6)", new String[]{"Warszawa [96kb]"});
choiceFieldANTYFM.setChangeListener(this);
btnSelectantyfm = new ButtonField("Słuchaj!", FIELD_HCENTER | ButtonField.CONSUME_CLICK);
btnSelectantyfm.setChangeListener(this);
stopplaying = new ButtonField("STOP", FIELD_HCENTER | ButtonField.CONSUME_CLICK);
stopplaying.setChangeListener(this);
add(choiceFieldANTYFM);
add(btnSelectantyfm);
add(stopplaying);
and other:
public void fieldChanged(Field field, int context) {
if (field == btnSelectantyfm)
{
System.out.println("Selected item: " + Integer.toString(choiceField.getSelectedIndex()));
}if (field == btnSelect)
{
switch (choiceField.getSelectedIndex())
{
case 0:
try {
String url = "http://94.23.220.75:6000;deviceside=false;ConnectionUID=GPMDSEU01";
Player player;
player = javax.microedition.media.Manager.createPlayer(url);
player.start();
}
catch (Exception e) {
Dialog.alert(e.toString());
}
break;
Ok,When I push play it goes music in the application.
When push it again looped back. This is the second problem :)
I want to stop the stream when push stop button and even if it was possible to change the volume keys + and - :)
JDE 5.0 :)
Regards.

Answer 1

Rather than do btnSelectantyfm.setChangeListener(this); which would imply that your Screen is implementing FieldChangeListener declare separate FieldChangeListener objects for each button as follows:
btnSelectantyfm.setChangeListener(new FieldChangeListener(){
public void fieldChanged(Field field, int context){
//start playing code here
player.start();
}
});
stopplaying.setChangeListener(new FieldChangeListener(){
public void fieldChanged(Field field, int context){
//stop playing code here
player.stop();
}
});
Now you need to declare the Player object as a member variable so that the play and pause FieldChangeListeners can access it. To stop the Player playing just do player.stop().
For changing the volume when the volume keys are pressed you will need to:
Implement a KeyListener to perform actions when the side volume keys are pressed
Get the VolumeControl from the Player by doing player.getControl("VolumeControl");
Update the VolumeControl with the new desired volume