Re: data acqusition, display and control

[Tristan Van Berkom <tvb gnome org>]

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