UI hangs while updating

[Jason Calhoun <jason thecolossal com>]

Hi,

I'm developing an application using gtkmm-3.0, and running into a bug 
with the UI I haven't been able to track down.  I've never used GTK or 
gtkmm before, and haven't done any real development on linux either.

The application uses a Phidgets RFID reader to read an RFID tag, and 
display some information on a simple UI.  The problem is that the UI 
seems to freeze at some point while handling events.  Once the UI is 
hung, I can close the window, at which point I get the error at the 
console "GLib-CRITICAL **: Source ID XXX was not found when attempting 
to remove it".  This warning or error occurs only in cases when the UI 
has hung.  However, even with the UI apparently hung, the application 
continues to run, it can still read tags and output to the console, for 
instance.  Also, I've noticed this problem only on the target platform, 
which is a Raspberry Pi running the Ubuntu MATE distribution available 
on raspberrypi.org.  I haven't been able to duplicate it on my desktop 
machine, which is running slightly older versions of the glibmm and 
gtkmm libraries.

I use the event handlers defined by the Phidgets library to emit sigc 
signals so I can handle those events in the application's main window.  
In the signal handlers, there are a few simple calls to update the UI, 
such as using the set_text method to update the text in a label, and 
display or clear an image.  I use the built in timeout signal to display 
a clock, and reset the display after a certain period of time.

I'm not sure if the UI freeze is due to some error in my code, or due to 
an error in the gtk/glib libraries somewhere.  I would appreciate any 
help anyone can offer.  I can provide code samples and/or more details 
as needed.

Can anyone help?


Thanks,
Jason