Re: [cssom-view] Origin of a canvas & scrollable element

On Wed, Sep 24, 2014 at 3:57 AM, Simon Pieters <> wrote:
> On Tue, 23 Sep 2014 17:24:35 +0200, Tab Atkins Jr. <>
> wrote:
>> On Tue, Sep 23, 2014 at 3:34 AM, Simon Pieters <> wrote:
>>> On Tue, 23 Sep 2014 00:55:59 +0200, Tab Atkins Jr. <>
>>> wrote:
>>>> It sounds like you're missing the definition of the "canvas" itself.
>>>> The canvas is defined at
>>>>, but it doesn't seem
>>>> to quite go into enough detail to nail down that the "origin" of it
>>>> would be the rectangle it ordinarily limits rendering to.
>>> That's not a correct definition, I think. See the test case above. The
>>> origin needs to be the point on the canvas where the top left corner of
>>> the
>>> viewport is when the viewport is in the default scroll position, or some
>>> such, where the default scroll position depends on writing
>>> mode/direction.
>> Yes, that's the "finite region of the canvas" that "rendering
>> generally occurs witihin".  It's not defined anywhere near
>> specifically enough for your purposes, but that's definitely the
>> concept you need; we just need to put down a better definition of the
>> canvas and its "finite region" somewhere so you can point to it.
> OK. Thanks. Let me know when there is something I can reference. :-)
> How do you explain the element case?

Same deal, isn't it?  The containing block generated by an element is
based on the element's geometry, not its scrollable area.


Received on Thursday, 2 October 2014 20:43:31 UTC