Re: [Discuss-gnuradio] error using SetLabel

[Matteo Campanella]

Thank you so much Johnatan for the hint - that was the problem indeed!!!
I followed the approach used in scopesink.py, encapsulating a gr message
in a wx DATA EVENT, letting the panel manage the data extraction and
presentation. It works fine now!

thank you very much
Matteo iz2eeq

On Sun, 2007-01-14 at 08:30 -0800, Johnathan Corgan wrote:
> On Sun, 2007-01-14 at 08:50 +0100, Matteo Campanella wrote:
> 
> > Pango-ERROR **: file pango-layout.c: line 3230
> > (pango_layout_check_lines): assertion failed: (!layout->log_attrs)
> > aborting...
> 
> I have had a very similar problem in the past.
> 
> I'd give it a high probability you are running into a threading issue.
> wxWidgets is *not* reentrant, and updating controls from a thread
> different from the one that is running the wxWidgets event loop will
> create all sorts of problems eventually.
> 
> The solution is to create a custom wxWidgets event, then use wxPostEvent
> in your GR call back function.  You then use a normal wxWidgets callback
> function to handle that event to update the control.
> 
> This link has some slightly outdated notes on doing this from C++;
> you'll have to translate them mentally to the wxPython domain:
> 
> http://www.wxwidgets.org/wiki/index.php/Custom_Events
> 
> It's a major pain, especially if you have to do it for several different
> event types.  But the key difference is that wxWidgets main thread is
> the one that is running and calling your wxWidgets event handler, so
> there are no reentrancy issues.
> 
> I beat my head against the wall for a couple days on this once :-(
>