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Re: [css-round-display] Summary of a discussion about polar positioning in every positioning schemes

From: Florian Rivoal <florian@rivoal.net>
Date: Thu, 21 Jan 2016 01:48:32 +0900
Cc: Brad Kemper <brad.kemper@gmail.com>, fantasai <fantasai.lists@inkedblade.net>, www-style list <www-style@w3.org>
Message-Id: <D3B85D9A-1273-4B43-927F-572DFAF34E0A@rivoal.net>
To: Jihye Hong <jh.hong@lge.com>

> On Jan 20, 2016, at 16:39, Jihye Hong <jh.hong@lge.com> wrote:
> 
> We have discussed about using polar positioning as a part of absolute
> positioning on several emails[1][2] and telecons [3].
> It would be needed to summarize about the discussion for resolving the issue
> and helping the other WG members catch up with it.
> 
> = Agreed =
> * Polar positioning is possible in all positioning schemes not only when
> position is 'polar'.

You mean polar positioning is activated if:
* the position property is something other than static
and
* polar-distance is something else than auto
right?

I'm ok with that.

> * If one of the properties such as left/top/right/bottom is non auto,
> polar-* properties are ignored

I'm ok with that.

> * polar-origin and polar-anchor can be used independently from the polar
> positioning.

I am not necessarily opposed, but I am not fully convinced. Did the rest of the WG agree to that,
or were you describing consensus between Brad, you (and maybe me)?

> * polar-origin and polar-anchor need to get rid of a prefix, 'polar-'

Assuming we actually agree on the previous point, then I agree on this one.

> * auto values for polar-origin and polar-anchor to resolve differently when
> polar-distance is auto or non-auto
>    - when polar-distance is auto, 
>      - polar-origin: auto becomes polar-anchor: 0 0
>      - polar-anchor: auto becomes polar-anchor: 0 0
>    - when polar-distance is non auto, 
>      - polar-origin: auto becomes polar-anchor: center center
>      - polar-anchor: auto becomes polar-anchor: 0 0

Assuming we agree polar-origin does anything when polar-distance is auto, then I agree with what you said about polar-origin, but I don't see why polar-anchor needs an auto value. Shouldn't its initial value just be center center (not 0 0)?

> = Need to be discussed =
> * Naming of the property which decides the origin point of polar coordinates
>    - original: polar-origin
>    - My suggestion: origin-position
>    - Florian's suggestion: box-align
>    - Brad's suggestion: center
> 
> * Changing the name of polar-anchor
>    - My suggestion: anchor-position
>    - Florian's suggestion: box-anchor

I am not a huge fan of any of these names, including the ones I suggested. But I am not sure I have a better alternative.

> 
> * Whether or not margin-left/margin-top can be used instead of polar-anchor
>    - Using margin-left and margin-top would be the same result of using
> polar-anchor
>      - If the containing block has height: 100px, width: 100px, item1 and
> item2 have same results.
>         item1 {
>           position: absolute;
>           width: 20px;
>           height: 20px;
>           polar-distance: 0%;
>           polar-anchor: 25% 25%;
>         }
> 
>         item2 {
>           position: absolute;
>           width: 20px;
>           height: 20px;
>           polar-distance: 0%;
>           margin-top: 5px;
>           margin-left: 5px;
>         }
> 
>    - Difference between polar-anchor and margin-left/margin-top
>      - In case of margin-left/margin-top, percentages resolve to the width
> of the element itself
>      - In case of polar-anchor, percentage resolves to the width and height
> of the containing block

I don't think polar-anchor is as important as the rest of the polar positioning proposal, but I do think it serves these use cases better than margins.

> Please tell me if there is something that I miss.

* If we allow polar positioning to apply to relative positioning, we need to define what percentages in "polar-distance: ???%" refer to, and how contain works in "polar-distance: ???% contain" in relative positioning.

 - Florian
Received on Wednesday, 20 January 2016 16:48:59 UTC

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