Android keep screen on

AndroidManifest.xml

<uses-permission android:name="android.permission.WAKE_LOCK" />

MyActivity.java

public class MyActivity extends Activity {

    protected PowerManager.WakeLock mWakeLock;

    @Override
    public void onCreate(final Bundle bundle) {
        setContentView(R.layout.main);

        /* This code together with the one in onDestroy() 
         * will make the screen be always on until this Activity gets destroyed. */
        final PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
        this.mWakeLock = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "My Tag");
        this.mWakeLock.acquire();
    }

    @Override
    public void onDestroy() {
        this.mWakeLock.release();
        super.onDestroy();
    }
}