i want a font chooser in preferences of my app so that selecting a specific font can change font of my textViews how to do that in android studio java code example

Example: How to chage font progrmatically

TextView tv = (TextView) findViewById(R.id.appname);
Typeface face = Typeface.createFromAsset(getAssets(),
            "fonts/epimodem.ttf");
tv.setTypeface(face);