[pygtk] Blocking main loop during execution of external program

[Vláďa]

Hi,

I'd like to ask you for help with solving my problem. First I'll try to 
describe what I'm doing:

I have a PyGTK application which needs to run an external command. I use 
subprocess.Popen to do it. Then I run a gtk.Dialog (saying "Please 
wait") and wait until the process is finished. After the external 
process finishes I close the dialog and the program continues. So far 
everything works fine. But now I want to change it a little. After the 
process is finished, I want to return to the main loop but keep the 
dialog opened. Then process results of the external program and run the 
external program again. Repeat this a couple times and then finally 
close the "Please wait" dialog.

I found out that I can return back while leaving the dialog opened by 
calling dialog.return(0). But when I run the dialog again with 
dialog.run(), Python (the interpreter) crashes. What is the problem? Is 
it impossible to run the same dialog twice? What else could I do?

I need to block the main program loop because it can't continue before 
the external program finishes. At the same time I want to have a pop up 
window with a "Cancel" button (the window must be responsive). I'm 
afraid I'm not experienced enough to use threading, which would be 
probably best suited for this task. What would be the most simple way to 
solve my problem?

I hope it is clear what I'm trying to do. Unfortunately my English is 
far away from being perfect. If a code sample would help, I can post it.

Best regards,
Vlada