c_gtk_source_gutter_renderer_activate

Undocumented in source but is binding to C. You might be able to learn more by searching the web for its name.
__gshared extern (C)
void function(GtkSourceGutterRenderer* renderer, GtkTextIter* iter, GdkRectangle* area, GdkEvent* event) c_gtk_source_gutter_renderer_activate;

Meta