MainActivity Seekbar

public class MainActivity extends Activity {

    private int seekR, seekG, seekB;
    SeekBar cervenySeek, zelenySeek, modrySeek;
    LinearLayout mScreen;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        mScreen = (LinearLayout) findViewById(R.id.plocha);
        cervenySeek = (SeekBar) findViewById(R.id.seekBar_R);
        zelenySeek = (SeekBar) findViewById(R.id.seekBar_G);
        modrySeek = (SeekBar) findViewById(R.id.seekBar_B);
        zmenPozadie();

        cervenySeek.setOnSeekBarChangeListener(seekBarChangeListener);
        zelenySeek.setOnSeekBarChangeListener(seekBarChangeListener);
        modrySeek.setOnSeekBarChangeListener(seekBarChangeListener);

    }

    private SeekBar.OnSeekBarChangeListener seekBarChangeListener
    = new SeekBar.OnSeekBarChangeListener()
    {

        @Override
        public void onProgressChanged(SeekBar seekBar, int progress,
                boolean fromUser) {
            // TODO Auto-generated method stub
            zmenPozadie();
        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {
            // TODO Auto-generated method stub

        }


    };

    private void zmenPozadie()
    {
        seekR = cervenySeek.getProgress();
        seekG = zelenySeek.getProgress();
        seekB = modrySeek.getProgress();
        mScreen.setBackgroundColor(
            0xff000000
            + seekR * 0x10000
            + seekG * 0x100
            + seekB
            );
    }
}