Warning
gtk_icon_factory_add has been deprecated since version 3.10 and should not be used in newly-written code. Use GtkIconTheme instead.
Adds the given icon_set to the icon factory, under the name
stock_id. stock_id should be namespaced for your application,
e.g. "myapp-whatever-icon". Normally applications create a
GtkIconFactory, then add it to the list of default factories with
gtk_icon_factory_add_default(). Then they pass the stock_id to
widgets such as GtkImage to display the icon. Themes can provide
an icon with the same name (such as "myapp-whatever-icon") to
override your application's default icons. If an icon already
existed in factory for stock_id, it is unreferenced and replaced
with the new icon_set.
Warning gtk_icon_factory_add has been deprecated since version 3.10 and should not be used in newly-written code. Use GtkIconTheme instead. Adds the given icon_set to the icon factory, under the name stock_id. stock_id should be namespaced for your application, e.g. "myapp-whatever-icon". Normally applications create a GtkIconFactory, then add it to the list of default factories with gtk_icon_factory_add_default(). Then they pass the stock_id to widgets such as GtkImage to display the icon. Themes can provide an icon with the same name (such as "myapp-whatever-icon") to override your application's default icons. If an icon already existed in factory for stock_id, it is unreferenced and replaced with the new icon_set.