W3C home > Mailing lists > Public > www-style@w3.org > March 2005

Re: Stand-in color before images load

From: Emrah BASKAYA <emrahbaskaya@hesido.com>
Date: Tue, 29 Mar 2005 12:37:55 +0300
To: www-style@w3.org
Message-ID: <opsod7phwu8nstxa@lomarnona>

>
>> div {
>> background-color: #fff;          /* white bg in div */
>> }
>>
>> h2 {
>> color: $fff;                     /* white text in header */
>> background-image: url(cool.png); /* a dark yet transparent image */
>> background-standin-colour: #000 ; /*the bg will be black till image
>
> This doesn't degrade gracefully.  If you set a foreground colour, you
> must set a background colour that contrasts, and you must do using the
> same generation of CSS attributes as used to set the foreground colour.
>
>

I hope my mail reaches the list.

Yes it doesn't seem to degrade gracefully but that is the current  
situation anyway, and this way the new generation will benefit while the  
older will be served the same and will have to wait for the image to kick  
in.

But this does degrade:

background-color: #000;
background-image: url(cool.png);
background-switchback: true; /* tells the user agent to switch bg
                             color to transparent once bg image
                             is loaded. */

But this time, the multibit alpha shows through in the older generation.  
So it is a bad degradation because it ruins it for ALL the older agents  
that load images.

So here we are so many people with above average IQ could propose a  
totally graceful degrading solution, because we have this problem at hand:
*PNG alpha is a reality and it really helps designers use assets that can  
be placed -anywhere- in the document without showing edge artefacts.

*We will have custom image borders and PNGalpha's will play a really  
important rule (I propose the same standin approach for the borders, tho  
this is not as vital)

*If the designer wants to use a light text-color on a light-colored  
document bg and use a PNG to define the BG of the foreground object, the  
image somehow has to be loaded for the text to be read properly, and  
because that may not be possible, the designer is withold from using it at  
all.

*We have a damning limitation in the current CSS specs, that will be  
effective long enough.

*We must fix this behaviour at some point in the CSS evolution, other wise  
it will be too late.



I'm eager to hear possible solutions to the 'degrade' problem from you.  
Here's one from me:

{background-image-replacebgcolor: url(cool.png);}
The image will replace the bg color (will be set to transparent)
and will be only loaded by the new generation browsers.

We could still have "background-standin-color" property along with this so  
this gives authors to choose between two solutions:
1-) Use "background-standin-color" approach and be sure new generations  
show an accessible page even without images but page will be shown true to  
its intent on all browsers when images are loaded even on older browsers.  
Benefit is more than the risk, I believe.
2-) Use "background-image-replacebgcolor" approach and let the older  
browsers just use the bg color and not the alpha image. This will be  
recommended for people who wants guaranteed access.



Yours,
Emrah BASKAYA
www.hesido.com














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Received on Wednesday, 30 March 2005 05:34:21 GMT

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