Re: [Texmacs-dev] Two fixes for delayed execution

[Norbert Nemec]

Joris van der Hoeven wrote:
> On Wed, Oct 14, 2009 at 05:27:03PM +0100, Norbert Nemec wrote:
>   
> > Indeed. I guess a proper approach on Qt would be to use processEvents 
> > frequently during drawing. This does not work with the check_event gui 
> > interface, but the necessary change in the interface should be minimal.
> >     
>
> Can this indeed be done? Max told me that somethings are also disallowed
> during the painting phase in Qt. Can we process events during drawing,
> or should we first return to the main loop? Long live old-fashioned GUI API's...
>   
I just found an ancient thread about calling processEvents from paintEvent
   http://lists.trolltech.com/qt-interest/1997-08/thread00023-0.htm

This seems to suggest that it is not impossible in principle, just a bit 
tricky.

Another source on the web warns in principle:
   
http://www.kdab.net/~dfaure/conf/Malaga_AsyncProgramming/html/slide_5.html

but this might simply refer to issues like the one discussed in the 
thread before. As far as I see it, the main danger is that inside the 
TeXmacs code, one must be aware that paintEvent might still be on the 
stack. The whole thing certainly is tricky but I think it should be 
possible.

Greetings,
Norbert