Yes. You need to extend the view you want to set its font in xml and then make an custom attribute (as enum) to be accessed from xml and call it for example "customFont".
Then in the extended view java code get the "customFont" value and change the font programaticaly.
Then you can use this custom view and set its font through xml ;)
Its possible for some limited font becuase you must define an enum for xml and see in java code wich font was selected and then set it in java code set the selected font.
Though you can set system font in xml without all these. And my explanation was for your custom fonts ;)