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From: manheime@nbs-amrf.UUCP (Ken Manheimer)
Newsgroups: net.emacs
Subject: Re: emacs mouse support (an mlisp/gosmacs employment)
Message-ID: <112@nbs-amrf.UUCP>
Date: Fri, 17-Jan-86 14:31:52 EST
Article-I.D.: nbs-amrf.112
Posted: Fri Jan 17 14:31:52 1986
Date-Received: Sun, 19-Jan-86 04:25:58 EST
References: <912@mit-eddie.UUCP> <5@emacs.UUCP>
Organization: National Bureau of Standards
Lines: 74

I've been meaning to post various gadgets and modifications i've
developed for the local installation of emacs, which happens to be
Unipress' (out of gosling's) Emacs V 2.01.  One of the more fun
efforts involved employing the fairly rudimentary handles Unipress
provided to the Sun mouse (to better effect than the trivial
routines provided in ../maclib/D.term/sun.ml with the
distribution).  The most interesting aspect in this effort, for me,
was deciding upon the most suitable functions to implement, given
the handles i had.

The results are mixed.  As with many of the tweaks Unipress provided
to incorporate features of the Sun window system within emacs (e.g.
dynamic resizing of the emacs session's window), the concepts seem
attractive but in practice the gadgets aren't particularly
important.  On the other hand, i am still pleased with the balance
of functionality i wound up with; this may be due to that syndrome
wherein programmers are convinced of the aesthetics of their
programs regardless of their ultimate practical worth...  (And by
aesthetics i don't mean the code (goodness no :-) just the, um,
tidiness of the set of functions/key mappings.)

In any case, i'd like to summarize the functions i provided and, in
case anyone is interested in using them, i'll post the mlisp in a
separate message.


First of all, early on it became clear that i ought to emphasize
browsing (as opposed to mutative) functions for the mouse.  The main
reason for this was in the limitations of the protocols - events
are produced only during the downstroke of single keys and no
shifts are available.  (However, it is possible to do other things,
like determine the position of the cursor just after the event,
which i used to advantage.)

I assigned different functionalities to the three sun
mouse buttons, qualified by the region of the Sun window the mouse
inhabited (relative to the cursor).  Generally, when the mouse is
in the same window as the cursor, the action involves absolute
positioning wrt the mouse position.  Interactions with other
windows happen when the mouse and cursor are in different windows
during an event, and in two instances the echo line is used as a
proportional-positioning (scroll bar) scale when the mouse inhabits
it.

What follows are the particulars (taken, for times sake, pretty much
directly from the mlisp comments):

 - The left mouse button deals with marks.  - The left mouse button
 sets an anonymous mark at the dot (gosmacs term for cursor
 position) if the mouse is not in the minibuffer (gosmacs term for
 the extended-command echo line); otherwise exchanges dot and mark.

 - The middle mouse button provides cursor positioning, within a
 window, between buffers, or throughout a buffer.
 - The middle moves the dot to the mouse if the mouse is within (or
 on the mode line of) a non-minibuffer buffer; the dot is moved
 across buffers if necessary (i.e.  when the mouse and cursor are in
 different buffers).  When the mouse is in the minibuffer the dot is
 moved to a position in the current buffer proportional to the
 position of the mouse on the minibuffer line (first and last
 character positions in the minibuffer line insured to map to the
 beginning and end of the buffer).

 - The right button provides window/buffer scrolling.
 - The right, when clicked in the same buffer as the cursor, moves
 the line containing the cursor to the selected line.  If the mouse
 is in another (non-minibuffer) window then the cursor's buffer is
 swapped into that window and vice-versa (this provides a means for
 juggling the contents of windows on the screen).  If clicked in the
 minibuffer the current buffer window is moved backward/forward a
 portion of a page proportional to the distance of the mouse from
 the minibuffers center, with full left going back and full right
 going forward a full page.  (forward and reverse scrolling up to a
 page at a time).