Returns the content width or height of the widget.
Which dimension is returned depends on @orientation.
This is equivalent to calling [method@Gtk.Widget.get_width]
for %GTK_ORIENTATION_HORIZONTAL or [method@Gtk.Widget.get_height]
for %GTK_ORIENTATION_VERTICAL, but can be used when
writing orientation-independent code, such as when
implementing [iface@Gtk.Orientable] widgets.
Returns the content width or height of the widget.
Which dimension is returned depends on @orientation.
This is equivalent to calling [method@Gtk.Widget.get_width] for %GTK_ORIENTATION_HORIZONTAL or [method@Gtk.Widget.get_height] for %GTK_ORIENTATION_VERTICAL, but can be used when writing orientation-independent code, such as when implementing [iface@Gtk.Orientable] widgets.