In android for any new view there is a method called setRotation(float) you can use it
textview.setRotation(float);
but please note that this method is Added in API level 11
so if you want to support it you can use this
if (Build.VERSION.SDK_INT < 11) {
RotateAnimation animation = new RotateAnimation(oldAngel, newAngel);
animation.setDuration(100);
animation.setFillAfter(true);
watermarkText.startAnimation(animation);
} else {
watermarkText.setRotation(progress);
}