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Re: Question about root element background image position.

From: Andrew Fedoniouk <news@terrainformatica.com>
Date: Sat, 17 Jul 2004 10:39:15 -0700
Message-ID: <000201c46c24$fb9428f0$eb01000a@AFedoniouk>
To: "Justin Wood" <jw6057@bacon.qcc.mass.edu>, "W3C Style List" <www-style@w3.org>

Hi, Justin!
>
> html != viewport
>
> html *can* = viewport however.   iirc
>

I do know that "html != viewport" in current implementation of Mozilla

IE behaves as "html/body == viewport" though.
Seems like in IE viewport is *always* covered by border-box
(border+paddings+width/height) of
document root element. And you cannot set margins (which is reasonable).

Personally I cannot see any problems if we would have root (or viewport or
window) declared as:

view /* or @view  */
{
    overflow:auto; // can be changed
    background-* ... // can be changed
    width:viewport-width; // always
    height:viewport-height; // always
    margin:0; //always
    padding:0; //always
}

And allow also background-image, etc. be applied to this
element/quasi-element.
It would be nice also if we would "deprecate" background-attachment:fixed
attribute as it does not needed after that - image applied to the root will
never scroll. In this case it will be possible to use e.g. hardware
acceleration for scrolling. As for now, Mozilla cannot use hardware
acceleration, IE/win32 use it, as it allows  background-attachment:fixed
only in the root element - so it can decide to use ScrollWindow API or not
with zero effort.


Andrew Fedoniouk.
http://terrainformatica.com


Justin Wood:
>
> Andrew Fedoniouk wrote:
>
> >Seems like all active UA's now behave as
> >like following set by default:
> >
> >html
> >{
> >    overflow:auto;
> >    width:viewport-width;
> >    height:viewport-height;
> >    margin:0;
> >    padding:0;
> >}
> >
> >So scrollbars appear when needed.
> >
> >If we change overflow:hidden; then scrollbars will disappear.
> >Which is IMO logical and right behavior: attributes of root element
project
> >to (allows to define) attributes  of  the viewport.
> >
> >So far so good....
> >
> >But if we will try to use background image we have inconsitency...
> >
> >html
> >{
> >    overflow:auto;
> >    background-image: marble.png;
> >    background-repeat: no-repeat;
> >    background-position: 0 0;
> >}
> >
> >All known (to me) UAs scroll background image in this example which is
not
> >what human would expect as:
> >
> >any-other-element
> >{
> >    overflow:auto;
> >    background-image: marble.png;
> >    background-repeat: no-repeat;
> >    background-position: 0 0;
> >}
> >
> >will not scroll the image.
> >Image will always stay in left,top corner of  the 'any-other-element'.
> >
> >Any comments here?
> >What is the desired rendering behavior for the root element?
> >Shall it be reflected in the spec somewhere?
> >
> >
> >Andrew Fedoniouk.
> >http://terrainformatica.com
> >
> >
> >
> >
>
> html != viewport
>
> html *can* = viewport however.   iirc
>
> ~Justin Wood
>
Received on Saturday, 17 July 2004 13:39:50 GMT

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