Returns the current serial number of @layout. The serial number is
initialized to an small number larger than zero when a new layout
is created and is increased whenever the layout is changed using any
of the setter functions, or the #PangoContext it uses has changed.
The serial may wrap, but will never have the value 0. Since it
can wrap, never compare it with "less than", always use "not equals".
This can be used to automatically detect changes to a #PangoLayout, and
is useful for example to decide whether a layout needs redrawing.
To force the serial to be increased, use pango_layout_context_changed().
Returns the current serial number of @layout. The serial number is initialized to an small number larger than zero when a new layout is created and is increased whenever the layout is changed using any of the setter functions, or the #PangoContext it uses has changed. The serial may wrap, but will never have the value 0. Since it can wrap, never compare it with "less than", always use "not equals".
This can be used to automatically detect changes to a #PangoLayout, and is useful for example to decide whether a layout needs redrawing. To force the serial to be increased, use pango_layout_context_changed().