Font setting for a specific gtk application -

i want set font used a particular gtk+ 3 application. how can done?

i know can set font used all gtk+ 3 applications in file $xdg_config_home/gtk-3.0/settings.ini, not know how font can set specific application.

edit: not developing application. want run font size different current 1 set desktop.

use gtkcssprovider. don't language you're using gtk in, no code example, here steps:

• create gtkcssprovider
• add css string (such *{font-family:'comic sans';}) gtk_css_provider_load_from_data()
• activate gtk_style_context_add_provider_for_screen(). (you want use default screen, gdk_screen_get_default().)