Path: utzoo!attcan!uunet!mcvax!kth!draken!ttds!jonasn
From: jonasn@ttds.UUCP (Jonas Nygren)
Newsgroups: comp.windows.x
Subject: XNextEvent and Unix-signals
Message-ID: <1205@ttds.UUCP>
Date: 26 May 89 11:26:43 GMT
Reply-To: jonasn@ttds.UUCP (Jonas Nygren)
Organization: The Royal Inst. of Techn., Stockholm
Lines: 27


Two problems I have encountered while implementing my own scrollbars.
The first is connected with use of the intervall timer and the second
with expected behaviour of the LeaveNotify-event.

I have implemented scrollbars using one window for each of the 5 scrollbar
parts. For the parts that should act repetitively, eg up-button, I have
used the intervaltimer 'setitimer(0,...)' to generate the scroll, while
the client loops for events ButtonRelease, LeaveNotify and EnterNotify.
This scheme works well most of the time but sometimes the X-server reports
'out of sequence' and the client eventually hangs, the 'out of sequence'
perhaps indicates that the signal-interrupt corrupts the event-queue(s).
Can anybody help me with an explanation to what is happening and a work
around if possible?

The page-up and page-down parts are implemented as two windows which
change size as part of the scrolling, during page-down scroll the 
page-up windows grows as much as the page-down window  diminishes. If
the pointer is not moved it will, as a result of the scroll, leave the
page-down window and enter the thumb- or page-up window. My problem is that
I never get a LeaveNotify event which I should get, shouldn't I?

(what equipment? DEC3100,Ultrix,dxwm,Xlib)

Thanx in advance

Jonas