Re: hit testing and retained graphics

On Fri, Jul 1, 2011 at 7:41 AM, Charles McCathieNevile <chaals@opera.com> wrote:
> On Fri, 01 Jul 2011 09:02:29 +0200, Henri Sivonen <hsivonen@iki.fi> wrote:
>
>> On Wed, 2011-06-29 at 14:23 +0000, Blessing, Kimberly wrote:
>>>
>>> Consumer electronics manufacturers are buying in to HTML5 and my
>>> understanding is that canvas could be used to render not just the
>>> on-screen guides
>>
>> <canvas> seems like a terrible tool for that job compared to HTML text
>> styled using CSS.
>
> I agree.
>
>> Why would CE manufacturers want to render on-screen guides using <canvas>?
>
> Reasons I can think of straight away (from listening to the reasons that
> such people have given for such decisions in the past) include:
>
> Better control of look and feel
> Better performance
> Better integration with existing work patterns
> The developer just wants to do it that way
> More easily adaptable
>
> Personally I find only one of these convincing. But I'm not the decision
> maker, and I see others being convinced to do things that seem to me
> completely and utterly wrong, like choose a heavyweight and complicated
> technology, every day. My personal candidate for most common example is
> getting a simple piece of text as a word document or PDF attached to an
> email, which among other things highlights that different people have
> different work styles and environments, which lead to different priorities
> and therefore different technical decisions.
>
> Why would you believe for a moment that nobody would make such a decision?

Because it's *really* hard.  *Much* harder than just using HTML.  It
is seductive, though - many of our own engineers have tried to walk
down that path, and been burned for it.  Rendering engines are tough,
but for some reason they sound easy to a subset of us hackers.

Honestly, attempting to reimplement HTML in <canvas> sounds like a
great way to give your competitors a free head-start against you.

(Imo, we should continue to make it difficult to do full-featured text
and UI in canvas, so that it stays painful.  Then we can make it less
painful to do things the right way, and natural incentives will help
people make the right choice.)

~TJ

Received on Friday, 1 July 2011 19:16:21 UTC