The icon can then be rendered by using it as a gdk.paintable.Paintable,
or you can get information such as the filename and size.
If the available icon_name is not available and fallbacks are
provided, they will be tried in order.
If no matching icon is found, then a paintable that renders the
"missing icon" icon is returned. If you need to do something else
for missing icons you need to use gtk.icon_theme.IconTheme.hasIcon.
Note that you probably want to listen for icon theme changes and
update the icon. This is usually done by overriding the
GtkWidgetClass.css-changed() function.
Looks up a named icon for a desired size and window scale, returning a gtk.icon_paintable.IconPaintable.
The icon can then be rendered by using it as a gdk.paintable.Paintable, or you can get information such as the filename and size.
If the available icon_name is not available and fallbacks are provided, they will be tried in order.
If no matching icon is found, then a paintable that renders the "missing icon" icon is returned. If you need to do something else for missing icons you need to use gtk.icon_theme.IconTheme.hasIcon.
Note that you probably want to listen for icon theme changes and update the icon. This is usually done by overriding the GtkWidgetClass.css-changed() function.