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From: mic@ut-ngp.UUCP (Mic (just take out the c's and sound it out) Kaczmarczik)
Newsgroups: comp.os.vms
Subject: Re: Questions on VMS Workstation Software: In UIS, how do you...?
Message-ID: <6394@ut-ngp.UUCP>
Date: Tue, 29-Sep-87 10:44:11 EDT
Article-I.D.: ut-ngp.6394
Posted: Tue Sep 29 10:44:11 1987
Date-Received: Wed, 30-Sep-87 07:08:26 EDT
References: <870928060020.040@Lbl.Arpa>
Reply-To: mic@ngp.UUCP (Mic Kaczmarczik)
Distribution: world
Organization: UT Austin Computation Center, User Services Digital Support Group
Lines: 57
Keywords: UIS terminal emulator mouse click
Summary: UIS 3.2 is rumored to use escape sequences to report mouse input

In article <870928060020.040@Lbl.Arpa> nagy%warner.hepnet@LBL.ARPA (Frank J. Nagy/VAX Guru) writes:
>
>    On the VAXStation, we want to allow the user to use the mouse to
>    do the field selection, 
>    [...discussion removed for brevity's sake...]
>    We believe one way to do this with our extra UIS code could be done
>    if we had the window id of the VT220 emulator window.

At the Spring DECUS in Nashville, I asked a DEC UIS developer about
this very question.  He said that 1) there isn't, nor will there ever
be a documented mechanism to get the ``wdid'' (window id) for a UIS
terminal emulator.  I can understand this, because publishing the
window identifier would force future implementations of the UIS
terminal emulator to do the same thing, which might have a negative
impact on some other aspect of the emulator. Using the wdid is also
somewhat of a kludge, albeit a nice one from some perspectives.

He also mentioned that 2) an undocumented feature of UIS 3.2 (I think
it's 3.2, but he might have been speaking of a pre-pre-release 3.3) is
that mouse clicks in a terminal emulator window can be reported via
escape sequences.  If you wanted to ``see'' mouse clicks in the
keyboard input stream, you would define the system-wide logical name
UIS$VT_ENABLE_LOCATOR to TRUE.  After that, whenever you clicked the
mouse in a VT window, the emulator would insert an escape sequence
into the keyboard input stream, indicating where you clicked, what
button you used, whether the shift key was down, and so on.  I have no
idea of the format of the escape sequences, or even if they're really
implemented under UIS 3.2; we're still running 3.1. 

This technique of reporting mouse activity is not restricted to UIS
terminal emulators; he hinted that future DEC terminals might have a
mouse attached to them, and would report mouse clicks in the same way.
In fact, I'm planning on modifying my Amiga's VT100 emulator to send
those escape sequences (once I figure them out), and teaching GNU
Emacs and TPU how to parse them. 

Disclaimer: It's been a few months since I went to DECUS, so I may not
remember everything perfectly clearly.  The developer may have been
overly tired.  Stuff happens.  Buy low, sell high. :-)

>= Frank J. Nagy   "VAX Guru"
>= Fermilab Research Division EED/Controls
>= HEPNET: WARNER::NAGY (43198::NAGY) or FNAL::NAGY (43009::NAGY)
>= BitNet: NAGY@FNAL
>= USnail: Fermilab POB 500 MS/220 Batavia, IL 60510

Mic Kaczmarczik			don't push me 'cause I'm standing in line.
UT Austin Computation Center	here -- calm down -- have a sip of wine.
mic@ngp.utexas.edu		it's like a party sometimes it makes me wonder
ccep001@utadnx.bitnet		how I keep myself so slender


-- 
Mic Kaczmarczik			don't push me 'cause I'm standing in line.
UT Austin Computation Center	here -- calm down -- have a sip of wine.
mic@ngp.utexas.edu		it's like a party sometimes it makes me wonder
ccep001@utadnx.bitnet		how I keep myself30 (give255