[webkit-dev] Implementing the sizes attribute of the link tag from HTML5

[Maciej Stachowiak]

On Apr 19, 2010, at 11:58 PM, Aaron Boodman wrote:

> On Mon, Apr 19, 2010 at 5:53 PM, Peter Kasting <pkasting at google.com>  
> wrote:
>> On Thu, Apr 15, 2010 at 3:41 PM, Aaron Boodman <aa at chromium.org>  
>> wrote:
>>>
>>> I'm not sure what the path is for fetching favicons today. Does
>>> WebCore just implicitly do it, or does it expose the information to
>>> the host, who later may or may not make the request?
>>
>> Answering this is complicated by the fact that Chromium mostly uses a
>> different codepath for all of this stuff than, say, Safari -- e.g. it
>> bypasses the IconDatabase and pretty much all other classes/files  
>> called
>> "IconXXX" entirely.
>
> Yeah, I looked into this over the weekend, and -- shock! -- it turned
> out to be a bigger change than I initially imagined. Since Chromium
> has a different backend, that would mean implementing two sets of
> changes.
>
> Also, I think it would be wasteful to have WebKit download all linked
> icons, even if the hosting browser has no intention of every using
> some of them. So I'd want to add code to allow the browser to tell
> WebKit which sizes it is interested in.
>
> I still want to do this, but I'm going to have to reduce the priority
> a little bit for now. I may come back to it in a month or so.

You'd probably want an API that lets the embedding app request a  
particular icon size, and picks the best fit from the icon links  
available, taking into account size=any as well. Possible niceties -  
return windows-style .ico or mac-style .icns either if explicitly  
specified, or synthesized from available sizes. Not sure if there is a  
conventional multisize icon format on other platforms.

Regards,
Maciej