Re: data acqusition, display and control

[Premsagar C <premsagar c gmail com>]

On 10/17/05, Tristan Van Berkom <tvb gnome org> wrote:
> Premsagar C wrote:
> > I am using gtk to develop a control interface. Am a bit new to this.
> > BAsically I am acquiring data using some library functions and
> > dispalying them in 6 text boxes . When i click on the bacq function
> > this acquistion starts.
> gtk_signal_connect(GTK_OBJECT(bacq),"clicked",GTK_SIGNAL_FUNC(button_funcacq),NULL);
>
> > My problem is that when this happend the dispaly window goes blank and
> > am unable to control it. I need to be able to access another button
> > when this acqusition is occuring and it id part of the same window.
> > How do I do that ? Is there some other signal event I can use.
>
> If I'm reading you right; your button_funcacq() function is doing a
> lengthly calculation or some lengthly data acquisition operations and
> while this function is running; your UI is unresponsive... dont panic,
> this is normal :)
>
> What you need to do is one of the following:
> o Split your data acquisition operation into small itterations
> (example: limit your sql queries to 100 rows per result set)
> and run these itterations in an idle or timeout handler.
>
> o If you are stuck with some proprietary API that allows
> you only to call one funtion for an entire operation
> thats going to take a half an hour to execute, you'll
> have to use a "worker thread" to aquire the data silently
> in the background and notify the primary thread after
> the lengthly offending culprit function finally returns
> (probably using an idle handler for notification, or these
> days you can probably use a GChildWatchSource).
>
> I recommend you read the juicy parts of this page:
> http://developer.gnome.org/doc/API/2.0/glib/glib-The-Main-Event-Loop.html
>
> Cheers,

 -Tristan
>

  Tristian,
A timeouthandler did the job howvever I still have a few bugs. My data
acuqisition is working and getstting displayed on my text widget as I have
included my timeout in the main . On clicking a button i require to stop the
data acqusition and do a few other operations(they all work). however on
removing the timeout I am not able to use the main menu button anymore. The
system crashes saying there is a segmentation error