Display-Breite zum App-Start auslesen

public class MainActivity extends Activity {

    private RelativeLayout layout;

    @Override protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        layout =  (RelativeLayout)findViewById(R.id.activity_main);

        bewegen();
    }

    private void bewegen() {
        TextView tv = (TextView) findViewById(R.id.txt_animate);
        int end = 0;
        tv.animate().setDuration(10000);
        int mx = layout.getWidth();

        while(end < 1) {
            tv.animate().x(mx);
            end++;
        }
    }
}

public class MainActivity extends Activity {

    @Override protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        bewegen();
    }

    private void bewegen() {
            // Display Dimensionen holen
        DisplayMetrics dm = getResources().getDisplayMetrics();
            // Laufleiste für Text erstellen und starten
        final TranslateAnimation m_ta = new TranslateAnimation(dm.widthPixels, -1 * (dm.widthPixels), 0f, 0f);
        m_ta.setDuration(10000);        //Zeitdauer für einen Durchlauf
        m_ta.setInterpolator(new LinearInterpolator());     //gleichmässige Bewegung
        m_ta.setRepeatCount(Animation.INFINITE);            //endlos
        TextView m_tv = (TextView)findViewById(R.id.txt_animate);
        m_tv.startAnimation(m_ta);
            // Warten bis "Thread" beendet, dann Animation stopen
        new CountDownTimer(20000, 5000) {
            public void onTick(long millisUntilFinished) { }

            public void onFinish() {
                m_ta.cancel();      //beende Animation
            }
         }.start();
    }
}