W3C home > Mailing lists > Public > www-svg@w3.org > November 2012

RE: marker-pattern syntax

From: David Dailey <ddailey@zoominternet.net>
Date: Tue, 27 Nov 2012 21:36:44 -0500
To: "'Cameron McCormack'" <cam@mcc.id.au>, "'Dirk Schulze'" <dschulze@adobe.com>
Cc: "'Tab Atkins Jr.'" <jackalmage@gmail.com>, "'SVG public list'" <www-svg@w3.org>
Message-ID: <000d01cdcd11$34e62ad0$9eb28070$@net>
You know... <replicate> already does most of this.

Just saying


-----Original Message-----
From: Cameron McCormack [mailto:cam@mcc.id.au] 
Sent: Tuesday, November 27, 2012 6:02 PM
To: Dirk Schulze
Cc: Tab Atkins Jr.; SVG public list
Subject: Re: marker-pattern syntax

Tab Atkins Jr.:
>> The required "segment" or "path" keyword at the start of 
>> 'marker-pattern' would disambiguate.  (Without it, a single "url()" 
>> is a valid 'marker-pattern' value, and thus is ambiguous in the
>> shorthand.)

Oh, that's a nice feature of having the keyword in there.  Can/should we make it optional in marker-pattern?

Dirk Schulze:
> If we would decide to make marker a shorthand. Not sure if it is worth it.

I think we should, if only because it currently is a shorthand (for
marker-{start,mid,end}) and I find it strange if it isn't a shorthand for all of these marker-* properties.

>> We could potentially do some fanciness to simplify the common case 
>> that marker-segment is trying to address, too, and make it so that an 
>> omitted offset defaults to "50%" in "segment" mode, rather than the 
>> "0" of "path" mode.  Dunno if that's worthwhile, but it does mean 
>> that we're simply replacing "marker-segment: url()" with "marker-pattern:
>> segment url()", rather than "marker-pattern: segment 50% url()".  (In 
>> addition to being more verbose, it's not immediately clear what the 
>> difference is between that last one and "marker-pattern: segment 
>> url() 50%;", which actually draws *three* markers, at the beginning, 
>> middle, and end of each segment.  Shortening the default case might 
>> make this easier to get right.)  However, defaults changing based on 
>> other parts of the declaration can also be confusing on their own, so I dunno.

I'm also unsure about this.  But I'm in favour of making the
marker-segment:url() case simple to write.

I think I am still not quite convinced about having the offset as the length value before the first url().  Since all the values after that optional length are url()s and lengths, in any order, I feel like the initial length looks like it is part of that repeating list.  Can we distinguish it somehow?

   marker-pattern: 20px path url() 40px, ...
   marker-pattern: path(20px, url() 40px), ...
   marker-pattern: path 20px repeat(url() 40px), ...

(I don't really like any of those.)

In terms of whether I'm OK with the overall approach, yes, if we can ensure the marker-segment case can be written easily.
Received on Wednesday, 28 November 2012 02:37:19 UTC

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