Re: new line in labels (post enh)

[Ethan M. <merritt@u.washington.edu>]

On Friday 02 April 2004 01:30 am, Giuseppe G. N. Angilella wrote:
> Mmm. That does not work with keys, at least, e.g. with
>
> set term post enh
> set out 't.ps'
> plot x t "first line\nsecond line"
>
> (It does work with set label, on the contrary, as is indeed explained in
> help syntax.)
>
> Is that a bug?

Let's call it a "design decision" rather than a bug.

The key box layout is calculated, and space is reserved
for it, before any of the plots are actually generated.
The routine that does this size calculation doesn't know
exactly what is going to be printed for each plot title,
so it only reserves one line per plot.  Consistent with
this, when it is time to actually print out the plot key title
gnuplot calls term->put_text directly rather than calling
write_multiline().  Because of this, newline characters are
not  expanded into actual line breaks.

If you were to call write_multiline() instead, the first
title would indeed span multiple lines. But then the 
next title printed would be placed right on top of the
second line of your first title, which is no good.

If we were to allow multi-line plot key entries, we would
have to totally re-write the key generation code.
That would be a very large task, although if someone
wants a gnuplot development project to work on that
is a good candidate.  The key generation code has
built up into a horrible tangle, and starting over could
potentially make it much cleaner and extensible.  


-- 
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195