Re: signal_timeout vs loops (changing label text continuously)

[Bob Caryl <bob fis-cal com>]

The docs page for Glib::Thread is 
http://www.gtkmm.org/docs/glibmm-2.4/docs/reference/html/classGlib_1_1Thread.html

Basically, to use a "thread" you first write a function to do the work 
you wish to have done outside the GUI thread.  Then you create the 
thread using

Glib::Thread *my_thread = 
Glib::Thread::create(sigc::mem_fun(*this,&YourClass::your_thread_function),false);  


Then, your function will be executed by that thread and the thread will 
exit when your function returns. 

In my example the function that is passed to Glib::Thread::create is a 
member of a class, but you do not have to do that if you do not want to; 
you can use sigc::ptr_fun() instead:

Glib::Thread *my_thread = 
Glib::Thread::create(sigc::ptr_fun(&your_thread_function),false);

Hope this helps,

Bob Caryl


Gezim Hoxha wrote:
> On Tue, 2006-27-06 at 08:41 -0500, Bob Caryl wrote:
>   
> > Anytime you create a "loop" in the GUI thread, all GUI operations 
> > (including your call to Gtk::Label::set_text()) are suspended until your 
> > loop finishes and the function in which it runs returns.  You must allow 
> > Gtk::Main to do its job at some point during your loop iteration by 
> > inserting the following statements:
> >
> > while(Gtk::Main::events_pending())
> >     Gtk::Main::iteration();
> >
> > After your call to Gtk::Label::set_text().  This will allow the GUI to 
> > update.  However, you should always avoid doing this sort of processing 
> > in the GUI thread.  A well written application will do such processing 
> > in a separate thread and use a Gtk::Dispatcher to update the GUI if 
> > needed.  See  Gtk::Dispatcher 
> > <http://www.gtkmm.org/docs/glibmm-2.4/docs/reference/html/classGlib_1_1Dispatcher.html>  
> > for more information on how to do this.
> > <http://www.gtkmm.org/docs/glibmm-2.4/docs/reference/html/classGlib_1_1Dispatcher.html> 
> >     
>
> Thanks alot for your answer Bob. Also thanks to Leandro Fanzone.
>
> You keep mentioning threads, but unfortunately I don't know anything
> about them. Which book should I pick up?
>
> Thanks,
> -Gezim
>
>
>   
begin:vcard
fn:Robert Caryl
n:Caryl;Robert
org:Fiscal Systems, Inc.
adr:;;102 Commerce Circle;Madison;AL;35758;USA
email;internet:bob fis-cal com
title:Senior Software Design Engineer
tel;work:356-772-8920 X108
x-mozilla-html:TRUE
url:http://www.fis-cal.com
version:2.1
end:vcard