Re: [manifest] Manifest "sizes" fallback logic

Having guidelines in the specification is something we can do but we
can't have any requirements in there because browser UI will ultimately
be up to the browser vendor. Web developers should be encouraged to have
various sized icons so a browser will be able to pick the best one
depending on its own requirements. For example, if Chrome needs a 48px
icon for the homescreen, it will not use a 40px icon instead. However,
if it needs a 256px icon, it might pick a 192px icon. These are purely
case by case UI decisions that the spec couldn't define rigorously.

-- Mounir

On Tue, 13 Oct 2015, at 10:07, Binyamin wrote:
> בע"ה
> 
> 
> Maybe lets define standard spec for it
> https://github.com/w3c/manifest/issues/409, so that every browser
> vendor/engine would know what is correct to do. For example lets help to
> decide to pick 32x32.png or 48x48.png while requiring missing 40x40
> size image.
> 
> 
> Binyamin
> 
> 
> On Tue, Oct 13, 2015 at 11:51 AM, Mounir Lamouri <mounir@lamouri.fr>
> wrote:
> 
> > Hi Binyamin,
> >
> > Thank you for your question.
> >
> > I think this behaviour should be left to the implementation there is a
> > lot of UI decisions here that can't be spec'd. For example, Chrome would
> > likely pick a 32x32 image when it needs a 16x16 one but might not do the
> > other way around. Some UA might avoid taking a 32x32 image instead of a
> > 16x16 image because one is twice as big as the other and might not be
> > optimized to be seen as small. Obviously, all browsers should do a best
> > effort in picking an image.
> >
> > -- Mounir
> >
> > On Mon, 12 Oct 2015, at 21:01, Binyamin wrote:
> > > בע"ה
> > >
> > >
> > > Hi,
> > >
> > >
> > > Does "sizes" (https://w3c.github.io/manifest/#sizes-member) has any
> > > fallback for device required different icon sizes?
> > >
> > >     {
> > >         "icons": [
> > >             {
> > >                 "src": "32x32.png",
> > >                 "sizes": "32x32"
> > >             }, {
> > >                 "src": "48x48.png",
> > >                 "sizes": "48x48"
> > >             }, {
> > >                 "src": "128x128.png",
> > >                 "sizes": "128x128"
> > >             }
> > >         ]
> > >     }
> > >
> > > 1. For example, would device request for 16x16 return scaled down image
> > > 32x32.png?
> > > 2. What about request 40x40 - would it scale up 32x32.png or scale down
> > > 48x48.png (40x40 is in middle of both those sizes (+8 = 48, -8 = 32))?
> > > 3. Would request 96x96 use 128x128.png?
> > > 4. Would request 192x192 and 512x512 use 128x128.png?
> > >
> > >
> > >
> > > Binyamin
> >

Received on Tuesday, 13 October 2015 10:08:02 UTC