Re: Variable pitch text filling

[Lars Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

>> That'd probably be more efficient, but some cursory testing seems to
>> indicate that putting a min-width on every char in a pretty big buffer
>> works fine.
>
> I don't like such an implementation.  It's a kludge at best, IMO.
> Please let's not go that way.

Yes, I was pondering other solutions for several different, but somewhat
related, use cases.

1) We want to display the "-" wider in the variable-pitch mode line
2) In the justification case, we want to add some blank pixels more free-form
3) A much-requested feature is to be able to "snap" characters to an
integer multiple of the standard font (in a fixed-width buffer).
(Mostly relevant for people that mix fonts, like CJK and roman.)

All three of these are essentially the same: Add some pixels to the
glyphs in a region.

So we could do just that.  I.e., not a complex display spec, but a
simpler char-based one, for instance `char-spacing', that could have
values:

1) 1.0, to be at least 1 normal character wide
2) 3, to add three blank pixels to the end
3) `grid', to add enough blank pixels to have a width that's an
   integer multiple of the normal character width

So standard-mode-line-format would have

             (list
              :propertize
              (list ""
                    'mode-line-mule-info
                    'mode-line-client
                    'mode-line-modified
                    'mode-line-remote)
              'display '(min-width (5.0))
              'char-spacing 1.0)

while inter-character justification would use 'char-spacing 1 to add an
extra pixel after all the chars on the line, for instance. 

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no