I have written one style for TextView and I set that one for my TextView
as style=\"@style/popup_window_text_style\"
working fine, no issues.
This should work for you:
textView.setTextAppearance(getApplicationContext(), R.style.popup_window_text_style);
But note that some properties may not be affected and may have to be set manually as specified in the Android developer docs.
Unfortunately the current SDK appears to lack any form of a setStyle() method.