Obtains the full path to @widget. The path is simply the name of a widget and all its parents in the container hierarchy, separated by periods. The name of a widget comes from gtk_widget_get_name(). Paths are used to apply styles to a widget in gtkrc configuration files. Widget names are the type of the widget by default (e.g. "GtkButton") or can be set to an application-specific value with gtk_widget_set_name(). By setting the name of a widget, you allow users or theme authors to apply styles to that specific widget in their gtkrc file. @path_reversed_p fills in the path in reverse order, i.e. starting with @widget's name instead of starting with the name of @widget's outermost ancestor.