getSize
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.
Return
The size of @widget in @orientation.
Parameters
orientation
the orientation to query