W3C home > Mailing lists > Public > www-style@w3.org > June 2008

Re: Publishing the flexible box model

From: Andrew Fedoniouk <news@terrainformatica.com>
Date: Mon, 09 Jun 2008 21:24:42 -0700
Message-ID: <484E020A.6040700@terrainformatica.com>
To: robert@ocallahan.org
CC: fantasai <fantasai.lists@inkedblade.net>, Anne van Kesteren <annevk@opera.com>, dbaron@dbaron.org, www-style@w3.org

Robert O'Callahan wrote:
> On Tue, Jun 10, 2008 at 2:23 PM, Andrew Fedoniouk 
> <news@terrainformatica.com <mailto:news@terrainformatica.com>> wrote:
> 
>     Robert O'Callahan wrote:
> 
>            In this terms flex lengths and dimensions of position:absolute
>            and position:fixed elements can be computed against their layout
>            containers too.
> 
>            Thus:
>            div
>            {
>             position:absolute;
>             width:25%;
>             height:25%;
>             left:1*; top:1*; right:1*; bottom:1*;
>            }
> 
>            will position such an element in the middle of abs. pos.
>            container.
> 
> 
>         OK but how is this going to interact with the rules here, for
>         example:
>         http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width
> 
> 
>     I see no problems there either.
>     In most cases 'shrink-to-fit' is 1* exactly.
>     Practically in all cases 'auto' value can be replaced
>     by 1* value.
>     1* is a mathematically correct way of saying 'auto' :)
> 
> 
> That doesn't answer my question. You need to extend the rules in that 
> section to describe what happens when flexunits (not just "1*") appear 
> for margins, padding or content.

For
   flow:vertical;
   box-sizing:content-box; ( default value )

vertical margins, paddings, content and borders in flex units
share the same free space. So for style:

div.inner { padding:1* 0; }

This markup
<div style="height:YYpx; flow:vertical">
   <div class=inner>First</div>
   <div class=inner>Second</div>
</div>

will be rendered as

|------------
|
|First
|
|
|Second
|
|------------

Rule is simple: free space is distributed among all lengths
in the direction in the block that establishes box with free space.

>  
> 
> 
>            position:relative elements do not have concept of layout
>            container for computation of left,top,right and bottom
>            so flex values for these attributes are treated as undefined.
> 
> 
>         What does 'undefined' mean? 'auto'?
> 
> 
>     Here (for position:relative) it means 'auto' or just '0' (for
>     left,top,right and bottom)
> 
> 
> OK. This is all stuff that needs to be added to your spec.
> 
>     Consider this:
> 
>     <div style="overflow:hidden; width:xx; height:yy">
>      <img align=left id=first />
>      <p flex=1>...</p>
>      <img align=left id=second />
>     </div>
> 
>     You will have *exactly* the same kind of problems.
> 
> 
> No. The flex on the <p> is ignored because the container is not a 
> flexbox. If the container was a flexbox, then the <img> elements would 
> not float.

Exactly the same thing as with flex units. Just replace 'flexbox' by
'flow'.

> 
>     About flex paddings, consider task of vertical alignment of content
>     of some div. With flex units that is simple and naturally as:
> 
>     div
>     {
>      box-sizing: border-box;
>      height:1*;
>      border:1px solid;
>      padding:1* 10px;
>     }
> 
> 
> I agree that flexunits are very powerful.
> 
> 
> 
>         You do have to account for how flexboxes behave in non-flexbox
>         containers, and how non-flexboxes behave in flexbox containers,
>         but this is considerably easier than reevaluating everything
>         that already exists.
> 
> 
>     I do not see any problems here too.
> 
> 
> I was talking about flexboxes, not flexunits. The flexbox spec needs to 
> define, for example, what happens when you have a horizontal flexbox 
> containing a number of block children with flex --- how the horizontal 
> space allocated to each child is computed. (Your flexunits spec needs to 
> define that too.)
> 
> Rob


-- 
Andrew Fedoniouk.

http://terrainformatica.com
Received on Tuesday, 10 June 2008 04:25:18 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 27 April 2009 13:55:07 GMT