- From: Markus Ernst <derernst@gmx.ch>
- Date: Wed, 10 Nov 2010 17:35:38 +0100
- To: "Tab Atkins Jr." <jackalmage@gmail.com>
- Cc: www-style@w3.org, lee.kowalkowski@googlemail.com
-------- Original-Nachricht -------- > Datum: Mon, 8 Nov 2010 13:43:41 -0800 > Von: "Tab Atkins Jr." <jackalmage@gmail.com> > The idea is that, by using an appropriately laid-out spriting image, > you can deliver appropriate backgrounds to elements using less rules. > For example: > > .card { > background-image: url(http://www.example.com/cards.jpg); > /* cards.jpg is an image containing all 52 card images, > laid out in a 4x13 grid */ > width: 100px; > height: 200px; > } > > .card.heart { background-position-x: 0; } > .card.diamond { background-position-x: -100px; } > [snip 2 more rules] > .card.ace { background-position-y: 0; } > .card.two { background-position-y: -200px; } > [snip 11 more rules] > > Thus, a total of 17 rules are needed to position the backgrounds > appropriately on all 52 types of cards. > > Using current CSS, you need 52 different rules, looking like this: > > .card.heart.ace { background-position: 0 0; } > .card.heart.two { background-position: 0 -200px; } > [snip 11 more rules] > .card.diamond.ace { background-position: -100px 0; } > .card.diamond.two { background-position: -100px -200px; } > [snip 37 more rules] > > So, splitting background-position into -x and -y subproperties doesn't > give you any new abilities, it just makes certain patterns of > background-image spriting require somewhat less code in the > stylesheet. Besides the discussion on image spriting being an appropriate use case or not, I think that Lee's actual request is actually not silly. I share his point that it would be consistent to have the possibility to set background position values separately, but I would consider background-position-top, -right, -bottom, and -left properties more appropriate than -x and -y properties, just as for element position, border and whatever. I do not know whether there are explicit use cases for this, but the background-position property as a shorthand is not really intuitive; I myself have to check a manual every time I need this property, because I always forget the order of the values. So, for some authors, separate properties would make a little thing a little bit easier. Thus, in this discussion I would be rather interested in issues like implementation cost, backwards-compatibility and whatever, than in a discussion about the appropriateness of image spriting. -- Neu: GMX De-Mail - Einfach wie E-Mail, sicher wie ein Brief! Jetzt De-Mail-Adresse reservieren: http://portal.gmx.net/de/go/demail
Received on Wednesday, 10 November 2010 16:36:28 UTC