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Re: [CSS] Expandable background images, proposal

From: Andrew Fedoniouk <news@terrainformatica.com>
Date: Sun, 25 Nov 2007 00:33:19 -0800
Message-ID: <4749334F.2030000@terrainformatica.com>
To: fantasai <fantasai.lists@inkedblade.net>
CC: www-style <www-style@w3.org>

fantasai wrote:
> Andrew Fedoniouk wrote:
>> fantasai wrote:
>>> Andrew Fedoniouk wrote:
>>>> background-repeat:expand; is defined here:
>>>> http://www.terrainformatica.com/wiki/doku.php?id=h-smile:expandable-backgrounds 
>>> How is this different from the current 'border-image' proposal?
>>> http://www.w3.org/TR/2005/WD-css3-background-20050216/#the-border-image
>> Differences are:
>> First of all: my proposal does not require new attributes like 
>> border-image you have mentioned.
> But it significantly complicates existing properties, so I think that's a
> non-issue.

Beg my pardon but what exactly complicates existing properties?
In any case I believe that complexity is far less than the-border-image.

>> Second: I am using single image for background and borders. As far as 
>> understand the border-image in the way it is defined is mutually 
>> exclusive with background-image. Or probably I do not understand its 
>> idea enough? E.g. what comes first: rendering of such border-image or 
>> rendering of the background-image? As far as I understand either one 
>> of them shall be drawn on top of another. So what is the point to use 
>> them both?
> The border-image image is drawn over the background, not instead of it.
> This allows the possibility of having an image *border* (with a transparent
> center) rather than an expandable image while also having an image
> background that is positioned or tiled as appropriate behind it.

tells us that border is drawn over the place defined by 'border-width' 
attribute. As far as I understand middle section of the source image is 
always stretched to fill padding box. Am I right? If yes then to be 
practically useful this border image will have transparent middle 
section. In most cases.

>> Usually such expandable borders and background is really a single 
>> entity from graphical design perspective so it is better to define 
>> them as a single image.
> Right, and that's how border-image works as well.

Not exactly. In my case middle section can be tiled or stretched.

>> Expandable image is really a background image by its concept.
> It depends on the usage. In the fancy orange button case, yes. But in many
> other cases such as in your first example it is only a border.

These are two basic usages of such background images.
Last two cases at: 

I prefer sole and simple mechanism that allows to cover both cases 
rather than halved solutions.

>> E.g. it is rendered as normal background - in padding box of the 
>> element so can coexist with existing borders. The border-image is 
>> again mutually exclusive with borders: "Specifies an image to use 
>> instead of the border styles given by the 'border-style' properties". 
>> This is too limiting.
> How is it limiting? What use cases do you have that does it not address?

background-repeat:expand does not disable any existing style feature 
available in CSS - it only extends opportunities.

I've seen cases when borders (like: 1px solid red) were used 
additionally to the background image. E.g. different colour schemas that 
use same background with border shadows.

>> The same thing with the 'round' modifier. To be used practically such 
>> roundness shall be implemented as a constraint of dimensions of border 
>> box of the element. In the way it is defined in the border-image it is 
>> not useful at all.
> Why is it not useful at all?

Because it assumes scaling of bitmap image with scale factors close to 
1. The worst case designer can imagine.

Andrew Fedoniouk.

Received on Sunday, 25 November 2007 08:33:25 GMT

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