Editor with DecWindows

[trost at reed.edu]

In article <1991May6.132302.11959 at pronto.mh.nl>, jv at mh.nl (Johan Vromans) writes:
    ... except that you cannot cut&paste between DECwindows
    applications (like DECterm) and standard X11 applications (like
    GNU Emacs/Epoch) since DECwindows uses a different cut/paste
    mechanism.

Careful what you say there -- emacs is probably the one at fault
there, since you can't cut and paste between emacs and, say, xterm or
xedit.  To be precise:

There are two methods for exchanging information between X clients,
cutbuffers and selections.  Emacs only uses cut buffers; specifically,
it writes its string out to the CUT_BUFFER0 property on "the" root
window.

With the other method, a client (like xterm) takes ownership
of the selection (in this case, the PRIMARY selection); when someone
wants the contents of the selection, xterm receives a SelectionRequest
(I think) event and then is expected to put the information in a
property on a window specified in the event.

Then, when a standard X client like xterm is trying to "paste", the
first thing it does is ask for the PRIMARY selection.  If no one owns
it, or if it doesn't get a reply in a "reasonable" amount of time (2
seconds or so), it gives up and uses the CUT_BUFFER0 instead.

Emacs will use both when version 19 comes out (how many times have we
heard *that* one?  :-)  ).