W3 and CSS measurements of "em"

W3 and CSS measurements of "em"

[T. V. Raman]

This is possibly due to changes in Emacs 22 in the last few
months --- I'm not the best to debug this since it took me a few
months to even notice:-)

W3 implements CSS (Cascading Style Sheets ) and CSS can specify
things like margins in "em" units i.e. width of an 'm'.

The default CSS style file that comes with w3 sets left-margin
for bullets to 5em ---
I'm assuming that that did the right thing at some point.
However under emacs 22 CVS, this ends up having bulleted items
indented way far to the right --- approx 50 spaces.

I suspect that there is a bug in the W3 code that computes how
many spaces an 'm' should take -- could well do with this being
older code that incorrectly uses ints instead of chars perhaps.

Anyway, I'm sending this so it makes it into the archives and
hopefully serves to save the next person who hits the problem
some time. In my own environment I've since set left-margin for
bullets to 0.1 (absolute units instead of char width).

-- 
Best Regards,
--raman

      
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Re: W3 and CSS measurements of "em"

[Magnus Henoch]

"T. V. Raman" <raman@users.sf.net> writes:

> This is possibly due to changes in Emacs 22 in the last few
> months --- I'm not the best to debug this since it took me a few
> months to even notice:-)

A change in W3 on 15th of December last year, actually.  I've posted
about this to the w3-dev list, to find out whether that change should
be reverted.

You could use revision 1.8 of w3/lisp/css.el, and either restart Emacs
or evaluate (w3-find-default-stylesheets).

Magnus

Re: W3 and CSS measurements of "em"

[Klaus Straubinger]

Magnus Henoch wrote:

> "T. V. Raman" <address@hidden> writes:
>
>> This is possibly due to changes in Emacs 22 in the last few
>> months --- I'm not the best to debug this since it took me a few
>> months to even notice:-)
>
> A change in W3 on 15th of December last year, actually.

The change had been proposed by me, to correct way too large font sizes.

> I've posted about this to the w3-dev list, to find out whether that
> change should be reverted.

I tried to answer there, but my mail never appeared on the list of
archived messages, so I try here.

I still think my proposed change is a step in the right direction.
It has to be extended, though.

1.) The function css-expand-length should return always a number in the
    same unit of measurement. The percentage cases still calculate
    pixels, not points as the other cases.

2.) The callers of this function expect different units of measurement:
    css-split-font-shorthand expects point values, css-expand-value
    expects characters(?). These usages should be aligned, for example
    by using an extra parameter in css-expand-length to indicate in
    which unit of measurement the return value has to be calculated.

-- 
Klaus Straubinger