Re: New CSS1 draft available

James Miller writes:
 > >   - New, detailed definition of line-height (but see below).
 > After reading through this detailed description of text boxes and spacing,
 > my question is this: Why doesn't CSS simply support leading?  There still
 > seems to be no way to say "I want 3 pixels between the end of each line and
 > the start of the next" in CSS if the line heights vary from line to line.
 > Am I missing something?

We've considered leading, in fact, it has even been in the draft for a
while, but we eventually rejected it for a number of reasons, most
importantly because (1) `leading' is ambiguous (some define it as line
height, others define it as the extra space between lines), and (2) we
don't want to keep the space between lines constant, but rather the
distance between baselines.

In addition, (3) line-height is what is used in the short-hand

    font: 12pt/14pt Helvetica

And (4) most people will know what 'line-height' means when they see
it for the first time, and they will be able to remember it, while
'leading' probably only associates with the verb "to lead" or the
heavy metal.

Reason (2) is easier with line-height than with leading. To put
differently sized fonts on the line while keeping the line height
constant, you can now do

    EM { font-size: 12pt; line-height: 16pt }
    B { font-size: 10pt; line-height: 16pt }
    STRONG { font-size: 14pt; line-height: 16pt }

Otherwise it would have been something like:

 *  EM { font-size: 12pt; leading: 4pt }
 *  B { font-size: 10pt; leading: 6pt }
 *  STRONG { font-size: 14pt; leading: 2pt }

  Bert Bos                                ( W 3 C ) http://www.w3.org/
  http://www.w3.org/pub/WWW/People/Bos/                      INRIA/W3C
  bert@w3.org                             2004 Rt des Lucioles / BP 93
  +33 93 65 77 71                 06902 Sophia Antipolis Cedex, France