W3C home > Mailing lists > Public > www-style@w3.org > June 2007

border-image clarifications needed

From: Andrew Smith <asmith15@learn.senecac.on.ca>
Date: Tue, 12 Jun 2007 11:18:30 -0400
To: www-style@w3.org
Message-id: <466EB946.6000600@learn.senecac.on.ca>

Hello

I am implementing border-image in Mozilla. There are parts of the spec 
which I don't understand. That may be because I'm clueless about style 
sheets but it may also be because that the specification can use some 
updating. I hope this is the right list to post on.

Regarding http://www.w3.org/TR/css3-background/#the-border-image

1) Of the three keywords (stretch, repeat, and round) only two are 
explaned. If 'repeat' is explained somewhere else, a reference is needed.

2) The sample source image in Example 1 does not break cleanly into 3x3. 
This is entirely unexpected. The coordinates should be 0-26 for the 
first diamond, 27-53 for the second, 54-80 for the third. The image the 
way it is now is hard to use for testing, because of 1 or 2-pixel 
artifacts. I can make a replacement if you like.

3) "If the first keyword is 'round', the top, middle and bottom images 
are reduced in width" - I assume that means they get squashed 
horisontally, but on the example it looks like they haven't lost their 
proportions, which is very unlikely unless the container is sized to 
accomodate the border image. Should clarify this.

4) "If the first keyword is 'round', the top, middle and bottom images 
are reduced in width, so that exactly a whole number of them fit in the 
width of the padding box" - if the width of the padding box is a prime 
number the only way to fit a whole number of images in it is to have 
them sized to 1 or to the width of the padding area. Should clarify this.

5) "X' = W / ceil(W / X)" - this doesn't give me a whole number, is it 
supposed to? If not, what am I to do with this formula? If it does make 
sense, a reference to where this is explained would help a lot.

6) If the width of two consecutive sides isn't the same, what's done to 
the corner? There are at least three different ways to deal with it. 
Should clarify this.

7) There is no mention of what is to happen if the source image is 
animated. While animated borders could be used for some cool things, i 
don't know how many rendering engines can handle them easily. Also an 
animated border-image would be very hard to create, and there can't be 
any guarantee of synchronisation between the border sides and corners. I 
think it would be good to recommend that animation in the source image 
be ignored.

I hope this made sense.

Andrew
Received on Tuesday, 12 June 2007 17:53:36 GMT

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