@Override public void onStopTrackingTouch(SeekBar seekBar){
  final int pos=mItemList.indexOf(mSelectedTracker);
  final int delta=840 / mItemList.size();
  cp_mover.setProgress(pos * delta + delta / 2);
}

@ Override public void onStopTrackingTouch ( SeekBar seekBar ) { final int pos = mItemList . indexOf ( mSelectedTracker ) ; final int delta = 840 / mItemList . size ( ) ; cp_mover . setProgress ( pos * delta + delta / 2 ) ; }
set the seek bar position relative to the selected button .
