Path: utzoo!attcan!uunet!ogicse!decwrl!bacchus.pa.dec.com!jumbo!msm
From: msm@src.dec.com (Mark S. Manasse)
Newsgroups: comp.windows.x
Subject: Re:  Detecting a double-click
Message-ID: <1990Oct20.100404.21029@src.dec.com>
Date: 20 Oct 90 17:04:04 GMT
References: <9009301901.AA20799@Larry.McRCIM.McGill.EDU>
Organization: DEC Systems Research Center, Palo Alto
Lines: 19


It's not quite true that you can't do this with the existing protocol.  You
could set a time to some appropriate timeout value (which you might need
to precompute by guessing at the round-trip latency to the server).  You
could then cancel that timer if you get a subsequent event from the
server; if you don't, then, upon expiration of the timer, send some query
to the server.  If there are no events in your queue at that point, you
know it's not a double-click.

If the round-trip latency exceeds your double-click timeout, you'll wind
up waiting longer than you ought to to respond, but that's a bad situation
to be in anyhow.  If it's shorter, you can set your timer to some value
that allows you to keep probing the server until the server's idea of time
exceeds the allowed double-click, if you want to get fussy (at least in R4
you can do this).  While it might be simpler to ask the server to run the
timer for you, you can do destructive double-click detection if you really
want.

Mark