Sets a custom font map to use for this font chooser widget.
A custom font map can be used to present application-specific fonts instead of or in addition to the normal system fonts.
```c FcConfig *config; PangoFontMap *fontmap;
config = FcInitLoadConfigAndFonts (); FcConfigAppFontAddFile (config, my_app_font_file);
fontmap = pango_cairo_font_map_new_for_font_type (CAIRO_FONT_TYPE_FT); pango_fc_font_map_set_config (PANGO_FC_FONT_MAP (fontmap), config) ;
gtk_font_chooser_set_font_map (font_chooser, fontmap); ```
Note that other GTK widgets will only be able to use the application-specific font if it is present in the font map they use:
```c context = gtk_widget_get_pango_context (label); pango_context_set_font_map (context, fontmap); ```
this |
a `GtkFontChooser` |
fontmap |
a `PangoFontMap` |