From: Clifford Heath <no@...>
Date: 2005-08-15T22:11:13+09:00
Subject: Re: Asynchronous events in GTK application?

Ok, I learnt some more, and I think I'm hung up on a GTK "feature".
This is with the Debian Linux version that calls itself 0.9.1.

My asynchronous device events cause a condition variable to get
set. I've written a main loop that checks the variable, like this:

	while true
		processEvent if (@device_event)
		Gtk.main_iteration
	end

(According to the documentation, I should use:
	break if Gtk.main_iteration
but in this version, main_iteration always returns true. I guess
that's a change from the 0.9.1 version.)

In case there are no GUI events, I added a timeout which pumps
the loop. If the timeout is set to 1000ms, 500ms, no problem.
As soon as I drop the timeout much more (like 250ms or, what I'd
like, 100ms) the display never gets refreshed.

It seems that Gtk.main_iteration doesn't seem to ever process
paint (expose) events if an event has occurred recently, including
a timeout event(!).

What I'd like is to inject a NULL event into Gtk's queue when
an asynchronous event occurs, instead of using timeouts. But if
I can just get the timeout down to 100ms, that would work also.

Anyone have a solution to this? I wish the Debian packages weren't
always so far behind :-(.

Clifford Heath.