the name of the icon to register
the size in pixels at which to register the icon (different images can be registered for the same icon name at different sizes.)
gdk.Pixbuf that contains the image to use for icon_name
Deprecated: Use IconTheme.addResourcePath to add application-specific icons to the icon theme.
2.4
Registers a built-in icon for icon theme lookups. The idea of built-in icons is to allow an application or library that uses themed icons to function requiring files to be present in the file system. For instance, the default images for all of GTK+’s stock icons are registered as built-icons.
In general, if you use IconTheme.addBuiltinIcon you should also install the icon in the icon theme, so that the icon is generally available.
This function will generally be used with pixbufs loaded via Pixbuf.newFromInline.