Re: Another neat Eclipse'ism

[Stefan Monnier <monnier@iro.umontreal.ca>]

>>> While I try to do most of my editing from Emacs, occasionally I will
>>> find myself using the Eclipse Java editor.  One of the more convenient
>>> niceties, in the absence of auto-fill-mode, is having the print-margin
>>> displayed.  This is a useful feature in its own right, i.e. show a 1
>>> pixel background line in Emacs where the right margin is set.
>>> Needless to say, I have not a clue how to implement it.
>> Not 100% the same but there is column-marker-mode available (search the
>> emacswiki).  It will highlight a given column iff the line is at least
>> that long.
> FWIW, column-marker.el is pretty cool but it pales by comparison to the
> approach used in Eclipse.   The Eclipse solution is barely noticeable
> whereas the Emacs highlighting solution is very much in your face. If truth
> be told I like the merged notion of having multiple such column indicators
> that can be tailored by width and face.  I have a strong hunch they will
> need to be implemented at the C level.  I wonder how to do that ... and if
> this is an itch I want to scratch right about now ...

All the Elisp-level approaches are just hacks.  You might be able to get
reasonably far at the Elisp level, depending on your tolerance to pain.

But one question remains: for what is this meant?  If it's for
`fill-column', then there's a problem with variable-width fonts since
in that case fill-column has a variable pixel position.

Personally, I use a much simpler solution: I use my right window border
as "vertical column".  It has worked for as long as I remember (even
under xterm) and it saves screen real estate.


        Stefan