Android navigation pointer in listview items

I am trying to make a listview with direction pointers in the list items just like gooing latitude: http://www.eurodroid.com/pics/android_google_maps_latitude_update_2.png

I already have working code, but i am worried about the performance. Everytime the orientation sensor(thats a lot) the code rebuilds the entire list with the listview adapter when i only want to rotate the direction pointer image, so it is doing to same as calling for notifyDataSetChanged.

I tried to see what happens if i only call for an setText() whenever the sensor changes, i found out that it does not rebuild the entire list then.

public class SensorWatcher{

private SensorManager mgr = null;
public float azimuth = 0;
private Main main;
SensorWatcher(Main mainContext){
    main = mainContext;
    mgr = (SensorManager)mainContext.getSystemService(Context.SENSOR_SERVICE);
    mgr.registerListener(listener, mgr.getDefaultSensor(Sensor.TYPE_ORIENTATION), SensorManager.SENSOR_DELAY_UI);
}
private SensorEventListener listener = new SensorEventListener() {
        int newAzimuth;
       public void onSensorChanged(Sensor开发者_StackOverflowEvent e) {
         if (e.sensor.getType()==Sensor.TYPE_ORIENTATION) {
             newAzimuth = Math.round(e.values[0]);
             if(newAzimuth != azimuth){
                 azimuth= newAzimuth;
                 updateItems();
                 //main.adapter.notifyDataSetChanged();
             }
         }
       }
    @Override
    public void onAccuracyChanged(Sensor arg0, int arg1) {
        // TODO Auto-generated method stub
    }
};
public void updateItems(){
    ListView list = main.list;

    ImageView img;
    View listItem; 
    if(list != null){
        for(int i =list.getFirstVisiblePosition();i<=list.getLastVisiblePosition();i++ ){
            if(i< list.getChildCount()){
                listItem=(View) list.getChildAt(i); 
                //listItem = list.getAdapter().getView(i, null, null);
                img =(ImageView) listItem.findViewById(R.id.allowtest); 

                Bitmap bmp = BitmapFactory.decodeResource(main.getResources(), R.drawable.arrowup);
                Matrix mtx = new Matrix();
                mtx.postRotate(calculateDirection(list,i));
                Bitmap rotatedBMP = Bitmap.createBitmap(bmp, 0, 0, bmp.getWidth(), bmp.getHeight(), mtx, true);
                BitmapDrawable bmd = new BitmapDrawable(rotatedBMP);
                img.setImageDrawable(bmd);
            }

        }
    }
}

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For making changes in the list u need to call notifyDataSetChanged.. There is no other alternative for that .