W3C home > Mailing lists > Public > www-svg@w3.org > November 2013

Re: 'stroke' shorthand

From: Jeremie Patonnier <jeremie.patonnier@gmail.com>
Date: Wed, 13 Nov 2013 12:05:55 +0100
Message-ID: <CAEi838mr0jG2BRKLT+iP45hjwZLvpYmKZ94T_O4Lt4oX5HoepA@mail.gmail.com>
To: Dirk Schulze <dschulze@adobe.com>
Cc: "Tab Atkins Jr." <jackalmage@gmail.com>, www-svg <www-svg@w3.org>
Hi :)

As an author I have mixed feelings about this.

On the one hand I'd love to have stroke behaving like a regular short hand.
For author that come from the HTML world it will make things highly
predictable and therefor easier to understand.

On the other hand, as I know SVG, having the behavior of stroke changing
and breaking my existing content will piss me off (as well as all existing
authors that already use SVG).

That said I suggest the following to resolve that issue:

Make stroke a short hand that allows to get several stroke-* value and
introduce a new stroke-color property/attribute. But to not breaking
existing content make stroke NOT overriding long hand property is they are
already set and if they are not explicitly set in the short hand.

Some example to clarify:

1. the following produce a path with a blue 10px wide stroke

path {
  stroke-width: 10px;
  stroke-color: blue;
}

2. the following produce a path with a red 5px wide stroke (normal
overriding)

path {
  stroke-width: 10px;
  stroke-color: blue;

  stroke: red 5px;
}

3. the following produce a path with a red 10px wide stroke (explicit
overriding for color, no implicit overriding for width)

path {
  stroke-width: 10px;
  stroke-color: blue;

  stroke: red;
}

4. the following produce a path with a blue 10px wide stroke and a linejoin
and linecape round (no implicit overriding at all)

path {
  stroke-width: 10px;
  stroke-color: blue;

  stroke: round round;
}

5. The following will actually produce a 1px black stroke:

path {
  stroke-width: 10px;
  stroke-color: blue;

  stroke: all;
  stroke: black;
}

6. it would also be interesting to allow the following syntax to let
authors perform a true reset in a single line

path {
  stroke-width: 10px;
  stroke-color: blue;

  stroke: all, black;
}

7. Even more fun (and useful for author) would be to add the ability to set
up several stroke definition (with blending and stroke positioning —
remember there is a proposal to add that new property to stroke — painted
in the same order as the background property). The following will produce 3
strokes that blend on top of each other:

path {
  stroke: 1px black, 3px red outside, 3px green inside;
}

The result of this could be this (I zoomed and materialized the pixel grid
to figure it out)

[image: Images intégrées 1],

or as a true pixel rendering (still with the pixel grid):

[image: Images intégrées 2]

All of this is exactly the kind of behavior I would love to have if stroke
become a CSS short hand :)

My 2cts,
-- 
Jeremie
.............................
Web : http://jeremie.patonnier.net
Twitter : @JeremiePat <http://twitter.com/JeremiePat>



2013/11/13 Dirk Schulze <dschulze@adobe.com>

>
> On Nov 13, 2013, at 10:04 AM, Tab Atkins Jr. <jackalmage@gmail.com> wrote:
>
> > On Tue, Nov 12, 2013 at 6:00 PM, Dirk Schulze <dschulze@adobe.com>
> wrote:
> >> 2) Furthermore, a shorthand can not have its “own” syntax. It can only
> inherit the syntax of one of the longhand. Following the rules of CSS, we
> would need to introduce a new longhand property taking the values of the
> current ’stroke’ property.
> >
> > Slight clarification: it can have its own syntax, but it must
> > decompose into longhand properties.  That is, a shorthand is *defined*
> > solely by the values of the longhand properties it decomposes into.
> >
> > But yes, your conclusion is right - the current value of 'stroke'
> > would have to move into a longhand, probably 'stroke-color' or
> > something.
>
> I hoped it would be clear from my last mail that I am less worried about
> point 2) but more about the first point. Let me paste it again:
>
> 1) The CSS WG uses the shorter initial part of a term as a so called
> "shorthand property". A shorthand property sets all “longhand properties”
> by reseting them to the initial value or reseting them again. The “longhand
> properties” are all related properties which also share the same initial
> part of a term. Meaning, ‘stroke' would be the shorthand property for all
> other listed properties above.
>
> That also means that in the following example, the shorthand property
> resets all previously set properties according to the regulations of the
> CSS WG:
>
> stroke-width: 2px;
> stroke-linecap: round;
> stroke-linejoin: round;
> stroke-dasharray: 4px 3px;
> stroke: green;
>
> stroke-width would be reset to 1px, stroke-linecap to butt stoke-linejoin
> to miter and stroke-dasharray to none, because stroke (the shorthand) is
> set after these properties.
>
> This makes property handling significantly different in SVG and
> potentially break existing content.
>
> Greetings,
> Dirk
>
>
> >
> > ~TJ
>

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Received on Wednesday, 13 November 2013 11:07:07 UTC

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