Setting dynamic CSS for a specific widget

I would like to be able to dynamically set font size of a TextView control. I found the modify_font function was deprecated and replaced with override_font which was deprecated as well - and replaced with CSS. However, in case of CSS I need to have predefined styles like CSS classes, etc. which I then apply to widgets. However to allow the user to dynamically select font size, this is not appropriate.

I noticed for some widgets like Entry I can use the use AttrFontDesc to and set an attribute list, but for TextView this does not seem to be possible.

Is there a way to set dynamic, “inline” CSS for a given widget?