Java Development

[rwill123]

Hi, I'm a beginning developer and I'm attempting to create an app in which the user selects an audio file on the first screen, which then takes them to a second screen where they will select how long they want the file to play. 

I can't figure out how to make the app remember which audio file the user has selected on the first screen so that a timer can be set for the playback. I found a thread with a similar issue on this board but it didn't really solve my problem. Below, I've tried to call the same player on each screen, which of course did not work. If I leave the player out, it does not recognize the player p for the stop()  I created on the timer screen. 

If someone knows how to fix this, or where I can find the fix, I'd appreciate it. 

Here's my code so far. 

Screen 1:

public class TestSoundFileMainScreen extends MainScreen implements FieldChangeListener {
   
    CustomButtonField sound1Button;
    CustomButtonField sound2Button;
    CustomButtonField sound3Button;
    CustomButtonField sound4Button;
    CustomButtonField sound5Button;
    CustomButtonField sound6Button;
   
   
    int field;
   
    public void updateScreen(int x) {
         field = x;
        }
       
    private void timer() {
        TimerScreen timerScreen = new TimerScreen(this);
        UiApplication.getUiApplication().pushScreen(timerScreen);
    }
   
    public TestSoundFileMainScreen() {
       
        //code here for the appearance of the buttons, left out for brevity
       
        Background headerBackground = BackgroundFactory.createSolidBackground(Color.BLACK);
        HorizontalFieldManager header = new HorizontalFieldManager(Field.FIELD_HCENTER);
        add(new CustomLabelField ("Choose Your Sound", Color.WHITE, 0x000000, 0));
             
         
       
        HorizontalFieldManager buttonManager = new HorizontalFieldManager(Field.FIELD_HCENTER);
        Background blackBackground = BackgroundFactory.createSolidBackground(Color.GRAY);
        buttonManager.setBackground(blackBackground);   
         buttonManager.add(sound1Button);
         sound1Button.setChangeListener(this);
         add(buttonManager);
        
        
         add(new SeparatorField());
        
         
//and so on in this manner for the rest of the buttons...


   
        }
       
        public void fieldChanged(Field field, int context) {
           
            if(field == sound1Button){
                try {
                InputStream inptstrm = getClass().getResourceAsStream("/sound1.wav");   
                final Player p = javax.microedition.media.Manager.createPlayer(inptstrm, "audio/x-wav");
                p.realize();
                VolumeControl volume = (VolumeControl)p.getControl("VolumeControl");
                volume.setLevel(100);
                p.prefetch();
                p.setLoopCount(200);
                p.start();
            }catch(final Exception me){
                   UiApplication.getUiApplication().invokeAndWait(new Runnable() {
                       public void run() {
                           Dialog.inform(me.toString());
                           }
                           });
            }
                                   
                timer();}
            if(field == sound2Button) {timer();}
            if(field == sound3Button){timer();}
            if(field == sound4Button){timer();}
            if(field == sound5Button){timer();}
            if(field == sound6Button){timer();}
            invalidate();           
       
     }  
     
}





Screen 2:

public class TimerScreen extends MainScreen {
   
   
    CustomButtonField fiveMinutes;
    CustomButtonField tenMinutes;
    CustomButtonField fifteenMinutes;
    CustomButtonField twentyMinutes;
    CustomButtonField thirtyMinutes;
    CustomButtonField fortyfiveMinutes;
    CustomButtonField oneHour;
    CustomButtonField twoHours;
   
    TestSoundFileMainScreen _parent;  
   
    public TimerScreen(TestSoundFileMainScreen parent) {
       
        _parent = parent;
       
//again, code creating button fields and their appearance
       
        Background timerscreenBackground = BackgroundFactory.createSolidBackground(Color.BLACK);
        HorizontalFieldManager timerheader = new HorizontalFieldManager(Field.FIELD_HCENTER);
        add(new CustomLabelField ("How Long Should It Play?", Color.WHITE, 0x000000, 0));
       
       
        
         HorizontalFieldManager fiveManager = new HorizontalFieldManager(Field.USE_ALL_WIDTH);
        Background fiveBackground = BackgroundFactory.createSolidBackground(Color.GRAY);
       fiveManager.setBackground(fiveBackground);   
         fiveManager.add(fiveMinutes);
        
         add(fiveManager);
         add(new SeparatorField());
        
         //code here in this same manner for the rest of the time period buttons         
}

 public void fieldChanged(Field fields, int context) {
    
     if (fields == fiveMinutes) {
       try {
                InputStream inptstrm = getClass().getResourceAsStream("/thunder.wav");   
                final Player p = javax.microedition.media.Manager.createPlayer(inptstrm, "audio/x-wav");
                p.realize();
                VolumeControl volume = (VolumeControl)p.getControl("VolumeControl");
                volume.setLevel(100);
                p.prefetch();
                p.setLoopCount(200);
                p.start();
         new Timer().schedule(new TimerTask() {
                    public void run() {
                    try { p.stop();
                    } catch (Exception e) {
                        Dialog.alert(e.toString());
                        }
                        }                     
                }, 300000);
              
                            
            }catch(final Exception me){
                   UiApplication.getUiApplication().invokeAndWait(new Runnable() {
                       public void run() {
                           Dialog.inform(me.toString());
                           }
                           });
            }
        
          
        }
    
    
    }
   
   
           
}

[simon_hain]

if you use a reference to the screen you can execute all public methods.

or you can use a common class, like a dataservice for example, which both screens can access.

[rwill123]

that seems to be working in terms of recognizing the player... thanks for the help. I'll mark solved as soon as I get the timer working. 

[rwill123]

Well this is what I've tried:

I added this reference to the class declaration:

TestSoundFileMainScreen _parent = new TestSoundFileMainScreen();
     

And I removed the second player instance from TimerScreen:

public void fieldChanges(Field fields, int context) {
    _parent.updateScreen(field);
     if (fields == fiveMinutes) {
          
                 
         new Timer().schedule(new TimerTask() {
                    public void run() {
                    try { p.stop();
                    } catch (Exception e) {
                        Dialog.alert(e.toString()); 
                        }
                        }                      
                }, 300000);
               
                             
            
        }
     
     
    }

But I am still getting the following errors:

public class TimerScreen extends MainScreen implements TestSoundFileMainScreen {
                                                       ^
C:\dev\bin\com\apps\testsoundfile\TimerScreen.java:145: cannot find symbol
symbol  : variable field
location: class com.apps.testsoundfile.TimerScreen
     _parent.updateScreen(field);
                          ^
C:\dev\bin\com\apps\testsoundfile\TimerScreen.java:153: cannot find symbol
symbol: variable p
                    try { p.stop();
                          ^
3 errors

 Can someone provide some examples of code that I can try? Thanks.