Re: What is "update queue"?

[Steffen Macke <dia diagramr biz>]

Hi Bao,

On 05.07.2013 07:06, Bao Niu wrote:
>  From the python API documentation I read this term "update queue" in
> several places.
> - add_update_all()
> - flush()
> - add_update()
> - update_extents()
>
> But I can't find a definition for this term. Could someone please give me a
> little explanation on this term and also a brief explanation on the
> circumstances that one should use one of the above four different methods?
When you change diagrams programatically, the diagram displays are not
always up to date. Your changes are first written to the "update queue".

Calling update_extents() will recalculate every object to update the 
diagram extents
and flush() will cause the diagram/display to be redrawn according to 
the update queue.
add_update() can be used to mark specific regions for redrawal and
add_update_all() marks the entire visible area for update.

Regards,

Steffen