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Re: Fw: RE: [css-flexbox] Summary of planned changes to Flexbox Module

From: Andrew Fedoniouk <news@terrainformatica.com>
Date: Thu, 13 May 2010 22:31:56 -0700
Message-ID: <BF1AA31DA6904406AC327DC8264D9EF8@terra3>
To: "Alex Mogilevsky" <alexmog@microsoft.com>, "Tab Atkins Jr." <jackalmage@gmail.com>, <robert@ocallahan.org>
Cc: "Adam Del Vecchio" <adam.delvecchio@go-techo.com>, <www-style@w3.org>

From: "Alex Mogilevsky" <alexmog@microsoft.com>
Sent: Thursday, May 13, 2010 8:32 PM
To: "Tab Atkins Jr." <jackalmage@gmail.com>; <robert@ocallahan.org>
Cc: "Adam Del Vecchio" <adam.delvecchio@go-techo.com>; <www-style@w3.org>
Subject: RE: Fw: RE: [css-flexbox] Summary of planned changes to Flexbox 

> What is the purpose of (1a)? If author wanted "1fl" instead of "auto" they 
> would have said so. Why make it a special case?

width:auto is getting resolved to different values in different layout 
systems. E.g. for the same
element in normal flow and when it floats its width:auto will lead to 
different values.
Flex layout system is not an exception regarding auto's.

Consider 3 blocks in horizontal flow.  Each block has width:auto (default 
What would be you expectation about block widths? All of them should have 
the same
width. And that is exactly what happens as if they would have width:1*; 
(a.k.a. 1fl)
> (3) is different from current spec in how it treats negative extra space. 
> Is there evidence that current behavior is undesirable?

It is not clear what value to use as a "base value" in Additive Flexes.
See: http://lists.w3.org/Archives/Public/www-style/2010May/0209.html

It appears as nobody has clear understanding
of how this "base value" (or "preferred value") is computed.

As an example, what would be that base value for the case:
div { min-width:20px; width:10px; }

There is no evidence that Additive Flexes are required either.
If you have and idea where exactly Additive Flexes are useful then could
you share it?

> (4) should be unnecessary. If flex is allowed in padding (not that I agree 
> it is a good idea), it should be clearly stated which set of flexes it 
> belongs to. It should be either internal to Flexbox or external, not 
> conditional.

Flex values are all about computing dimensions inside some box.
Flexes in children are computed against content box of their container.

Therefore child element here:

   padding-top: 1*;
   height: 100px;
   flow: vertical; /* or whatever we will come up with */

   padding-top: 1*;

will be bottom aligned inside 100px content box of the container.

container's padding-top: 1*; is not participating in flex computation
of its children.

BTW: border-width in flexes also make sense in shed of light of
border-image and probably border-radius.

> It is not quite clear from the algorithm if it is moving from "additive" 
> flex to "absolute". It looks like it is absolute. Is it?

I hope it is about "absolute" flexes.
 "additive" flexes create  more problems than solutions.
Anyway no one have real proof of additive flex necessity so far...

Andrew Fedoniouk


> -----Original Message-----
> From: Tab Atkins Jr. [mailto:jackalmage@gmail.com]
> Sent: Thursday, May 13, 2010 5:56 PM
> To: robert@ocallahan.org
> Cc: Alex Mogilevsky; Adam Del Vecchio; www-style@w3.org
> Subject: Re: Fw: RE: [css-flexbox] Summary of planned changes to Flexbox 
> Module
> Well, turns out the algorithm for calculating flexes is remarkably easy.

Received on Friday, 14 May 2010 10:59:09 UTC

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