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Re: font-style property

From: Nicolas Lesbats <nlesbats@etu.utc.fr>
Date: Thu, 27 May 1999 13:11:33 +0200 (MET DST)
To: www-style@w3.org
Message-ID: <Pine.OSF.4.02.9905271203200.26232-100000@vega.utc.fr>
	Hi,

	I do like L. David Baron's proposal, but it seems a bit complex,
and it doesn't solve all the problems, as Andrew said. Here are some other
ideas on the subject.

 * My goal is not only to simplify the stylesheets. The problem, for
example, of the actual definition of the <em> tag (font-style: italic), is
that it's semantically incorrect. What's you want is not to make <em>
italic; you want it to contrast with its parent by using the visual
difference italic/normal (or oblique/normal).

 * A problem with the simple 'toggle' value is you don't assure forward
compatibility (some people have spoken about some languages which use both
italic to the left and italic to the right). So it would be necessary to
define between which values you want to toggle.

   For instance, the Andrew's proposal 'toggle-italic', or more generally
'toggle(italic, normal)' (or 'toggle(oblique, normal)'), where italic
would be the default value [

     If the parent's value could be determined and if this value is
italic => font-style: normal
     Else => italic

     The 'inherit' value wouldn't be permitted
]

 * We must define if toggle is doing between descendant selectors or
"adjacent sibling" selectors. Here, it's between descendant selectors, but
couldn't there be confusion (it's underlined by JM Leon, I mean) ?

   We can perfectly imagine a toggle between blue and red for instance in
a table with this following rule :

       tr { color: toggle-in-brotherhood(blue, red) }
             The correct name is to be found !! ;-)
            toggle-in-nest.... ???

   In opposition, we could name 'toggle-in-tree' (*or other*) the opposite
value.

 * Then, the value becomes very complex, I think a reasonable solution is
'toggle(#1_value, #2_value)'. But in fact, this value becomes very
specific, so why not to expand it to other properties, why 'font-style'
only ?

   I answered : take the sample style sheet for HTML 4.0 You will see that
it's the only property which have to be relative to his parent and which
is not. The 'font-weight' property is relative thanks to the 'bolder'
value [as a matter of facts, there is too the <sup> and <sub> elements
which won't work correctly in the case <sup><sup></sup></sup> for
instance]. The 'toggle' value would allow to make the default stylesheet
correct and logical, which is not presently.

 * Moreover, the value make the maintenance easier (this is a principle
of CSS, isn't it ?) : if you pass from body: normal to body: italic, you
will have only one line to change.

 * To reply to the "this can already be done" (which isn't a principle of
CSS, right : "there is generally only one way to achieve a certain
effect"), I'm not agree. This can be done, but badly. This
corresponds to what I have just said. The important is, CSS *must* provide
a mechanism to this works better.

 * The problem of 'toggle' is that CSS would begin to become a kind of
scripting language, which is not its goal according to the spec, since the
final value will depend on a condition (if()). There is the same problem
with David's proposal. We have to clearly determine what CSS must become.

 * From this point of view, there is another solution : using a script
function value like

        font-style: javascript("toggle(xxx)")

   where toggle() is a user function. I don't know if javascript can do
what I want to do, but I believe it's possible. I had already proposed
such a value, and it seems Microsoft had already include a similar value
in IE5 for testing, has someone information about it ?).

   The name of the value would be to discuss, script() or function() would
be good, with the scripting language name in settings.

   An opposed argument is to say that script languages can already have
access to style sheets content, but I really think that the contrary is
too necessary, because scripts are *tools* to dynamically change the style
of a page (in part). In my mind, scripting languages are for CSS what CSS
is for HTML.

   Furthermore, allowing calling a script function would solve a lot of
problem of codependance, as determine a color depending on the
background-color and/or its parent's color.

 -> I don't have an advice anymore... I still believe that we could make
an exception with the font-style property because of real need ( I speak
about it with my own experience, the need of formatting a simple journal
text with about 15 elements using the font-style property), but we have to
make attention on what CSS will become...

   What do you think about that, in particular about the function() value?
Don't you believe that a mechanism allowing toggling is absolutely
necessary, and that it's the role of CSS to provide it ?

					Nico

-- 
"Et bien tu vois, Stan, les vaches... c'est le mal. Leur coeur noir
ne pompe pas du sang comme toi et moi mais un liquide visqueux qui circule
dans leurs veines pourries pour irriguer leur cerveau minuscule, ce qui
fait qu'elles adoptent un comportement hallucinatoire (danger : soucoupes) 
et que Dieu les a puni en les envoyant toutes vivre... en Normandie (ou il
pleut trois fois plus qu'a Compi...)." ('xcuse-moi, Milou...)
Received on Thursday, 27 May 1999 07:11:38 GMT

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