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

On Wed, Sep 24, 2014 at 3:57 AM, Simon Pieters <simonp@opera.com> wrote:
> On Tue, 23 Sep 2014 17:24:35 +0200, Tab Atkins Jr. <jackalmage@gmail.com>
> wrote:
>> On Tue, Sep 23, 2014 at 3:34 AM, Simon Pieters <simonp@opera.com> wrote:
>>>
>>> On Tue, 23 Sep 2014 00:55:59 +0200, Tab Atkins Jr. <jackalmage@gmail.com>
>>> wrote:
>>>>
>>>> It sounds like you're missing the definition of the "canvas" itself.
>>>> The canvas is defined at
>>>> http://www.w3.org/TR/CSS21/intro.html#the-canvas, 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.

~TJ

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