Michiel wrote: > Guido van Rossum wrote: > > >On 11/9/05, Michiel Jan Laurens de Hoon > <[EMAIL PROTECTED]> wrote: > > > > > >>My application doesn't need a toolkit at all. My problem is that because > >>of Tkinter being the standard Python toolkit, we cannot have a decent > >>event loop in Python. So this is the disadvantage I see in Tkinter. > >> > >> > > > >That's a non-sequitur if I ever saw one. Who gave you that idea? > There is no connection. > > > I have come to this conclusion after several years of maintaining > a scientific plotting package and trying to set up an event loop > for it. Whereas there are some solutions that more or less work, > none of them work very well, and the solutions that we found tend > to break. Other visualization packages are struggling with the > same problem. I'm trying the best I can to explain in my other > posts why I feel that Tkinter is the underlying reason, and why > it would be difficult to solve.
I believe this problem all boils down to this paragraph from the first mail on this topic: : Currently, event loops are available in Python via PyOS_InputHook, a : pointer to a user-defined function that is called when Python is idle : (waiting for user input). However, an event loop using PyOS_InputHook : has some inherent limitations, so I am thinking about how to improve : event loop support in Python. Either we have an unusual definition of "event loop" (as many many other toolkits have implemented event loops without PyOS_InputHook), or the requirement is for an event loop that plays nicely with the "interactive loop" in Python.exe. Assuming the latter, I would suggest simply not trying to do that! Look at the "code" module for a way you can create your own interactive loop that plays nicely with your event loop (rather than trying to do it the other way around). Otherwise, I suggest you get very specific about what this event loop should do. From a previous mail in this thread (an exchange between you and Martin): > >> Which is why Tkinter needs to be in charge of the event loop. For > >> other GUI toolkits, I don't see a reason why they'd need their own > >> event loop. > > > > They need to fetch events from the operating system level, and dispatch > > them to the widgets. > This is a perfect task for an event loop located in Python, instead of > in an extension module. I believe the point Martin was trying to make is that we have 2 "unknown" quantities here - the "operating system" and the "widgets". Each OS delivers raw GUI events differently, and each GUI framework consumes and generates events differently. I can't see what a single event loop would look like. Even on Windows there is no single, standard "event loop" construct - MFC and VB apps both have custom message loops. Mozilla XUL applications (which are very close to being able to be written in Python <wink>) have an event loop that could not possibly be expressed in Python - but they do expose a way to *call* their standard event loop (which is quite a different thing - you are asking to *implement* it.) > I could write a prototype event loop for Python > to demonstrate how this would work. I think that would be the best way forward - this may all simply be one big misunderstanding <wink>. The next step after that would be to find even one person who currently uses an event-loop based app, and for whom your event loop would work. Mark. _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
