MainActivity.java

public void updateSeekBar(final long currentPosition, long duration){
  //seekbar
  binding.musicSeekBar.setMax((int) (duration / 1000));

  if(mHwAudioPlayerManager != null){
      int mCurrentPosition = (int) (currentPosition / 1000);
      binding.musicSeekBar.setProgress(mCurrentPosition);

      setProgressText(mCurrentPosition);
  }

  binding.musicSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
      @Override
      public void onStopTrackingTouch(SeekBar seekBar) {
          //Log.i("ONSTOPTRACK", "STOP TRACK TRIGGERED.");
      }

      @Override
      public void onStartTrackingTouch(SeekBar seekBar) {
          //Log.i("ONSTARTTRACK", "START TRACK TRIGGERED.");
      }

      @Override
      public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
          if(mHwAudioPlayerManager != null && fromUser){
              mHwAudioPlayerManager.seekTo(progress*1000);
          }
          if(!isReallyPlaying){
              setProgressText(progress); //when the song is not playing and user updates the seekbar, seekbar still should be updated
          }
      }
  });
}

public void setProgressText(int progress){
  String progressText = String.format(Locale.US, "%02d:%02d",
          TimeUnit.MILLISECONDS.toMinutes(progress*1000),
          TimeUnit.MILLISECONDS.toSeconds(progress*1000) -
                  TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(progress*1000))
  );
  binding.progressTextView.setText(progressText);
}

public void setSongDetails(HwAudioPlayItem currentItem){
  if(currentItem != null){
      getBitmapOfCover(currentItem);

      if(!currentItem.getAudioTitle().equals(""))
          binding.songNameTextView.setText(currentItem.getAudioTitle());
      else{
          binding.songNameTextView.setText("Try choosing a song");
      }
      if(!currentItem.getSinger().equals(""))
          binding.artistNameTextView.setText(currentItem.getSinger());
      else
          binding.artistNameTextView.setText("From the playlist");
      binding.albumNameTextView.setText("Album Unknown"); //there is no field assinged to this in HwAudioPlayItem
      binding.progressTextView.setText("00:00"); //initial progress of every song

      long durationTotal = currentItem.getDuration();
      String totalDurationText = String.format(Locale.US, "%02d:%02d",
              TimeUnit.MILLISECONDS.toMinutes(durationTotal),
              TimeUnit.MILLISECONDS.toSeconds(durationTotal) -
                      TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(durationTotal))
      );
      binding.totalDurationTextView.setText(totalDurationText);
  }
  else{
  //Here is measure to prevent the bad first opening of the app. After user
  //selects a song from the playlist, here should never be executed again.
      binding.songNameTextView.setText("Try choosing a song");
      binding.artistNameTextView.setText("From the playlist");
      binding.albumNameTextView.setText("It is at right-top of the screen");
  }
}