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Re: canvas origin?

From: Anton Prowse <prowse@moonhenge.net>
Date: Sat, 09 Apr 2011 08:37:57 +0200
Message-ID: <4D9FFEC5.6000707@moonhenge.net>
To: www-style@w3.org
CC: Jack Smiley <zxcv_890@hotmail.com>
On 09/04/2011 02:12, Anton Prowse wrote:
> On 08/04/2011 18:50, Jack Smiley wrote:
>>> On 07/04/2011 22:14, Anton Prowse wrote:
>>
>>>> I suppose the canvas origin is where the top-left corner of the margin
>>>> area box of the root element would be if it had position:static, and
>>>> the
>>>> ICB's top-left corner is incident with that point.
>>>
>>> That was rather careless. How about: ...if it had position:static and
>>> non-auto margin-left, in ltr mode; and in rtl mode it's the top-right
>>> corners and margin-right that we consider.
>
> [And float:none, of course!]

>> (assuming ltr mode) For example, if I do html: {margin-left: -50px},
>> would the canvas origin be 50px to the left of the top left corner of
>> the viewport?
>
> No. It would (as always, by definition) be incident with the top left
> corner of the initial containing block, which is typically the rectangle
> seen in the viewport when the page loads. The leftmost 50px of the root
> element's margin area box would be to the left of the initial containing
> block (and usually impossible to scroll left to in browsers, although
> that's not mandated anywhere AFAIK).

Sorry, I meant to say: "The leftmost 50x of the root element's _border_ 
box would be to the left of the initial containing block".

(The top left margin area corner is incident with both the top left 
corner of the initial containing block and the canvas origin [and 
typically with the top left corner of the viewport when the page first 
loads], as I said above.)

Cheers,
Anton Prowse
http://dev.moonhenge.net
Received on Saturday, 9 April 2011 06:38:27 GMT

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