RE: [gtk-list] Re: GtkProgressBar && RE: updating a progress bar

[Tony Gale <gale daedalus dera gov uk>]

On 06-Mar-98 Sergei Naumov wrote:
> mysql_query() is not written by me. It is a part of the library
> that
> supports MySQL engine. As far as I understand, I can not get any
> information
> on how the query is progressing. The way it works is that you give
> it an SQL
> query, it connects to a mysql daemon running either on a local
> machine or
> on a remote host. The daemon processes this query and gives the
> result (data
> stream) back. That's why I asked the question because it seemed I
> could not
> use progress bar to show the query.

Ok, so you can't use a GTK idle/timer callback, as they only operate
whilst inside gtk_main, and won't get called while your
waiting for mysql_query to return.

If you don't want to go multi-threaded, then you will have to set a
timer which calls a signal handler which updates the progress bar, as
feed back to the user. See the setitimer and alarm functions.

General comment to the world in general:
On an HCI design front, it is always good to give the user feedback
during a long process, otherwise they tend to think things have gone
wrong and start taking it out on the reset button. 

Hope this helps.

Tony
--
E-Mail: Tony Gale <gale@daedalus.dera.gov.uk>
HUGH BEAUMONT died in 1982!!

The views expressed above are entirely those of the writer
and do not represent the views, policy or understanding of
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