[webkit-dev] Proposal: Add support for focus rings in Canvas 2d
cabanier at gmail.com
Mon Oct 14 14:50:35 PDT 2013
On Mon, Oct 14, 2013 at 2:38 PM, Ryosuke Niwa <rniwa at webkit.org> wrote:
> Sorry, the original email had lots of typos. I've fixed them below:
> On Mon, Oct 14, 2013 at 2:35 PM, Ryosuke Niwa <rniwa at webkit.org> wrote:
>> On Mon, Oct 14, 2013 at 2:28 PM, Rik Cabanier <cabanier at gmail.com> wrote:
>>> On Mon, Oct 14, 2013 at 1:31 PM, Timothy Hatcher <timothy at apple.com>wrote:
>>>> On Oct 14, 2013, at 12:43 PM, Rik Cabanier <cabanier at gmail.com> wrote:
>>>> Also, how would your suggestion tell the UA about what areas are
>>>> associated with the elements? What happens if an element is no longer
>>>> focused? The ring is drawn into the canvas bitmap so those pixels have to
>>>> be regenerated.
>>>> Focus rings are usually larger than the control they surround. How is
>>>> the developer suppose to know the pixel padding needed for each platform's
>>>> focus ring? Guess and hope for the best?
>>> Why would he need to know this? Is it for the path that describes the
>> Isn't focus ring drawn on the canvas? If so, it's important that the
>> focus ring fits within the canvas. e.g. consider focusing an element of
>> 100px by 100px inside a canvas of the same size. If the focus ring were to
>> be drawn around the element that currently has focus, then the entire focus
>> ring would be drawn outside of the visible region.
True. That sounds like bad design though.
Wouldn't you have the same problem with focusable content in an
"overflow:hidden" element that just fits its child?
>> Would drawing the system focus ring taint the canvas pixels? (Drawing
>>>> form controls into canvas via SVG images and <foreignObject> has been
>>>> considered taint worthy because it could leak the user's UI theme.)
>>> I'm unsure if it should taint the canvas. How much information would be
>>> leaked that isn't already available through other means?
>> It may, for example, leak information as to whether user's machine is in
>> high contrast mode, which is another dimension for finger-printing user.
Yes, maybe this should taint. Dominic, what do you think?
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the webkit-dev