W3C home > Mailing lists > Public > public-sysapps@w3.org > February 2013

Re: question about screen_size in Runtime and Security Model

From: Marcos Caceres <w3c@marcosc.com>
Date: Fri, 22 Feb 2013 15:47:01 +0000
To: Lars Knudsen <larsgk@gmail.com>
Cc: public-sysapps@w3.org
Message-ID: <AD6A35AA3D7C40A890B4D2DC1755F7A6@marcosc.com>


On Thursday, 21 February 2013 at 07:23, Jonas Sicking wrote:

> On Wed, Feb 20, 2013 at 9:59 PM, Lars Knudsen <larsgk@gmail.com (mailto:larsgk@gmail.com)> wrote:
> > On Thu, Feb 21, 2013 at 2:24 AM, Jonas Sicking <jonas@sicking.cc (mailto:jonas@sicking.cc)> wrote:
> > >  
> > > On Wed, Feb 20, 2013 at 1:31 PM, Lars Knudsen <larsgk@gmail.com (mailto:larsgk@gmail.com)> wrote:
> > > > Hi,
> > > >  
> > > > ( related proposal:
> > > >  
> > > > http://mounirlamouri.github.com/sysapps/proposals/RunTime-Security/Overview.html
> > > > )
> > > >  
> > > > I think it's good that you are working on a spec to encapsulate what is
> > > > needed to make it somewhat easy to do generic app descriptors for web
> > > > apps -
> > > > as opposed to fiddling with all kinds of Apple (or other) specific tags
> > > > and
> > > > tricks to make webapps behave the same across platforms. However, I am
> > > > not
> > > > too fond of the spec proposal I found on github, where the screen_size
> > > > options seem limited to minimum width/height.
> > > >  
> > > > What I need as an app developer, is the viewport meta tag "done right",
> > > > where I can say, e.g. "give me a screen of 1920 x 1080 (virtual) pixels"
> > > > and
> > > > the platform would figure out how to best match it within the device
> > > > currently displaying it. Of course, the actual pixel count could be
> > > > made
> > > > available to the application, but to make it very simple for 99% cases,
> > > > where you just need a virtual fixed size game/app area - and be sure
> > > > it's
> > > > fixed - why not just provide an easy way of doing so? Currently, it
> > > > seems
> > > > that - apart from preventing auto orientation change, iOS is the only
> > > > platform providing this (through viewport tricks, event stealing, etc.)
> > > > and
> > > > IE is getting there.
> > >  
> > >  
> > >  
> > > Wouldn't this result in black top/bottom or left/right edges on most
> > > screens? Isn't this fairly undesirable in most cases?
> >  
> >  
> >  
> >  
> > Please see my postscript that seemed to have been deleted from the reply:
> > "PS Yes, I know there will be differences in aspect ratio - but this
> > *could* be fixed either by just enforcing one of the sizes (width or height)
> > or by simply having empty black space around."
>  
>  
>  
> Sure, but I think my question still stands. Is there really a time
> when the black frame behavior is desirable?
>  
> I don't really understand how the "enforce one of the sizes" would
> work. Can you explain?
>  
> > > Also, I wonder if this wouldn't be better solved using CSS somehow.
> > > I.e. to be able to say that you want a window to be scaled to a
> > > certain aspect ratio. In particular, this seems like something that
> > > web page authors would want access to, which means that sticking this
> > > feature in an application manifest isn't a good solution.
> >  
> >  
> >  
> > Well - that is true. However, none of the browser vendors seem to have made
> > their browsers ready
> > for simple apps and games with this little thing just yet.
>  
>  
>  
> I don't think that browsers are more willing to implement a features
> such as this just because it's proposed as part of the manifest as
> opposed to as part of CSS. My experience is that browser developers
> are more willing to implement well designed features, even if they are
> a bit more work to implement.
>  
> > Of course, there might be a larger push for it
> > as the whole industry now seems to converge on HTML(5) for RealApps(TM).
>  

Maybe the @viewport CSS rule could help…   
http://dev.w3.org/csswg/css-device-adapt/#the-atviewport-rule

Random thought (and possibly a crappy hack…but): I'm wondering if one could use something like the full screen API to achieve what you are describing?
https://developer.mozilla.org/en-US/docs/DOM/Using_fullscreen_mode

You could fullscreen an HTML element based on a virtual viewport size, then adjust an element inside that to fit. Didn't try it, but you never know; might work.   

--  
Marcos Caceres

http://datadriven.com.au  
Received on Friday, 22 February 2013 15:47:33 UTC

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