Call method from non-Activity class in Android

Question

I have a Popup window (non-Activity class) that have some buttons. one of them (btn_audio), play or pause sound and it works like a charm.
Now I want to call two method, play() and pause() in my HomeActivity and inside of onStop() method in all of my Activities. it doesn't work, call play() and pause() in other Activity's occur NullPointException.

public class Popup_Menu extends Activity implements OnClickListener {
  Button btn_audio;
  public static MediaPlayer player;     String play_or_pause;
  int num_ply, tim_pos; int [] resID;// Audio
  SharedPreferences sp;
void showPopup(final Activity context) {

  this.context=context;
  LinearLayout viewGroup = (LinearLayout) context.findViewById(R.id.popup);
       LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
       layout = layoutInflater.inflate(R.layout.popup_layout_menu, viewGroup);
  sp = context.getSharedPreferences("text", MODE_PRIVATE);
       btn_audio = (Button) layout.findViewById(R.id.btn_audio);    // audio
        layout.findViewById(R.id.btn_audio).setOnClickListener(this);


        @Override
        public void onClick(View whichButtonIsClicked) {
  switch (whichButtonIsClicked.getId())  {
  case R.id.btn_audio:                      
    if (play_or_pause.equals("play")) { 
      pause();
  } else {
      play(context);
  }
  sp.edit().putString("play_or_pause", play_or_pause).commit();   // save current stat
}   ////// close of showPopup()

          //define play and pause methods   
public void pause() {
  player.pause();
  btn_audio.setBackgroundResource(R.drawable.icon_audio_pause);
  play_or_pause="pause"; // current state is 'pause'
            }

public void play(final Context context) {
  if(num_ply==9){num_ply=0; }
  resID = new int []{ R.raw.tarane,R.raw.toofan,R.raw.shane,R.raw.kharazmi,R.raw.golhaye_khofte,R.raw.rang,R.raw.naghmeh,R.raw.dar_rahe_to,R.raw.emperor};
  player=MediaPlayer.create(context,resID[num_ply]);
  player.seekTo(tim_pos);           
  player.start();
  btn_audio.setBackgroundResource(R.drawable.icon_audio_play);
  play_or_pause="play";      // current state is 'play'
  player.setOnCompletionListener(new OnCompletionListener() {
  public void onCompletion(MediaPlayer player) {
  tim_pos=0;            num_ply++;      play(context);
          }
      });
  } 
 }

and my HomeActivity :

public class HomeActivity extends Activity implements OnClickListener {
 Popup_Menu ppp;
 @Override
protected void onCreate..............
 ppp = new Popup_Menu();
 SharedPreferences sp = getSharedPreferences("text", MODE_PRIVATE);

 if(sp.getString("play_or_pause", "play").equals("pause")){
   ppp.play(getApplicationContext());                 // ERROR
    }    // audio

}  /// close of onCreate

@Override
public void onStop() {
  super.onStop();                               
  if(play_or_pause.equals("play")){
  ppp.tim_pos= ppp.player.getCurrentP

Ok, I decided to use service to resolve this problem and it works well for play(). but when playing, still i can't call pause() method from SoundService because player object is null. I think by creating an object, from SoundService class, (ss in Popup_Menu class) , default constructor put player value to null (when playing and player object wasn't null). and calling player.pause occur error. How PLEASE can i pause this one_week_friend!!!

public class SoundService extends Service {

    MediaPlayer player;     int num_ply, tim_pos;   int [] resID;


public int onStartCommand(Intent intent, int flags, int startId) {

    resID = new int []{ R.raw.tarane,R.raw.toofan,R.raw.shane,R.raw.kharazmi,
            R.raw.golhaye_khofte,R.raw.rang,R.raw.naghmeh,R.raw.dar_rahe_to,R.raw.emperor     };
        player=MediaPlayer.create(this,resID[num_ply]);

        play();
        return Service.START_FLAG_REDELIVERY;
 }

public void play() {
    if(num_ply==9){num_ply=0; }
    player.seekTo(tim_pos);         
    player.start();
    player.setOnCompletionListener(new OnCompletionListener() {         
    public void onCompletion(MediaPlayer player) {
        tim_pos=0;          num_ply++;      play();
    }
    });
}

    public void resume(){
    player.seekTo(tim_pos);         
    player.start();
}

public void pause() {
    tim_pos= player.getCurrentPosition();          ////// ERROR
    player.pause();          ////// ERROR
    num_ply++;
}


public IBinder onBind(Intent arg0) {
    // TODO Auto-generated method stub
    return null;
  }
}

And my Popup_Menu class:

@Override
public void onClick(View whichButtonIsClicked) {
    switch (whichButtonIsClicked.getId())  {

    case R.id.btn_audio:
    if (play_or_pause.equals("play")) {
        btn_audio.setBackgroundResource(R.drawable.icon_audio_pause);
        play_or_pause="pause";       // current state is 'pause'
        SoundService ss = new SoundService();
        ss.pause();          ////// ERROR
    } else {
        btn_audio.setBackgroundResource(R.drawable.icon_audio_play);
        play_or_pause="play";        // current state is 'play'
        Intent sound_Intent = new Intent(context , SoundService.class);     // start service
        context.startService(sound_Intent);
    }
        sp.edit().putString("play_or_pause", play_or_pause).commit();   // save current state
    break;

LogCat:

08-05 01:03:31.440: E/AndroidRuntime(25356): FATAL EXCEPTION: main
08-05 01:03:31.440: E/AndroidRuntime(25356): java.lang.NullPointerException
08-05 01:03:31.440: E/AndroidRuntime(25356):    at com.codegostarNiloo.negar.SoundService.pause(SoundService.java:47)
08-05 01:03:31.440: E/AndroidRuntime(25356):    at com.codegostarNiloo.negar.Popup_Menu.onClick(Popup_Menu.java:234)
08-05 01:03:31.440: E/AndroidRuntime(25356):    at android.view.View.performClick(View.java:4209)
08-05 01:03:31.440: E/AndroidRuntime(25356):    at android.view.View$PerformClick.run(View.java:17457)
08-05 01:03:31.440: E/AndroidRuntime(25356):    at android.os.Handler.handleCallback(Handler.java:725)
08-05 01:03:31.440: E/AndroidRuntime(25356):    at android.os.Handler.dispatchMessage(Handler.java:92)
08-05 01:03:31.440: E/AndroidRuntime(25356):    at android.os.Looper.loop(Looper.java:153)
08-05 01:03:31.440: E/AndroidRuntime(25356):    at android.app.ActivityThread.main(ActivityThread.java:5341)
08-05 01:03:31.440: E/AndroidRuntime(25356):    at java.lang.reflect.Method.invokeNative(Native Method)
08-05 01:03:31.440: E/AndroidRuntime(25356):    at java.lang.reflect.Method.invoke(Method.java:511)
08-05 01:03:31.440: E/AndroidRuntime(25356):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:929)
08-05 01:03:31.440: E/AndroidRuntime(25356):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:696)
08-05 01:03:31.440: E/AndroidRuntime(25356):    at dalvik.system.NativeStart.main(Native Method)
08-05 01:03:32.066: D/dalvikvm(25356): threadid=11: interp stack at 0x5f1c9000

Answer 1

Yeah...!!! Done. It now working.it doesn't need to create new object. I must change modifire of (object)player and pause() methode and everything in it, to STATIC. So righte now i can access all objects and variables. Thanks cricket_007...

Answer 2

First, off, don't extend an Activity if it's a non Activity, as you claim, then passing a Context is preferred over an Activity

Secondly, there is a class called DialogFragment that is intended to be used as a popup dialog

I think you are looking for something like the following, though

public class Popup_Menu implements OnClickListener {
    Button btn_audio;
    public MediaPlayer player;     
    String play_or_pause;
    int num_ply, tim_pos; 
    int [] resID;// Audio
    SharedPreferences sp;
    Context context ;

    public Popup_Menu(final Context context) {

        this.context= context;
        sp = this.context.getSharedPreferences("text", Context.MODE_PRIVATE);

       // LinearLayout viewGroup = (LinearLayout)  view.findViewById(R.id.popup);

        LayoutInflater layoutInflater = LayoutInflater.from(this.context);
        layout = layoutInflater.inflate(R.layout.popup_layout_menu, viewGroup);
        btn_audio = (Button) layout.findViewById(R.id.btn_audio);    // audio
        btn_audio.setOnClickListener(this);
} 

You can now create a new Popup_Menu(HomeActivity.this)