Re: [css-device-adapt] Remove support for device-width, device-height

On Wed, 29 May 2013 13:02:41 +0200, John Mellor <>  

> +1. When authors use width=device-width what they usually intend is  
> "this website has a flexible width layout, and its width >should fit the  
> window size, rather than being zoomed".
> So in extending viewports from mobile into contexts where windows aren't  
> always full width, it no longer makes sense to >specify viewports in  
> terms of the full width/height of the device.
> So I support removing device-width/height from @viewport, but I would go  
> further, and when translating meta viewport, I >would map  
> width=device-width onto a width:auto @viewport (assuming width:auto  
> means window width - i.e. I'd want >"width=device-width" on its own to  
> behave the same as "zoom:1").

I'm assuming that "height=device-height" or "width=device-height" have not  
been significantly used in the wild, so that should be fine, not causing  
interoperability issues. Yes, width:auto means window width (unless  
there's a non-auto height which yields a width based on height and aspect  
ratio). So yes, I'm fine with that change too.

> On Wed, May 29, 2013 at 9:22 AM, Rune Lillesveen <> wrote:
>> There have been experimentation with enabling viewport meta for all  
>> products in Blink and I was brought into the >>discussion.
>> Device-width and device-height works when the browser window uses the  
>> whole screen and isn't resizable. When you start to >>support @viewport  
>> (or viewport meta) in browsers where the window is smaller than the  
>> screen, you'll get undesireable >>results. The question is if there is  
>> really a need for device-width/device-height at all since the author  
>> would normally >>mean "@viewport { width: auto; height: auto; }"  
>> instead.
>> The viewport meta background is that Safari and Presto, at least, have  
>> been truly using device-width and device-height as >>what they are:  
>> width and height of the device in CSS px. It's detectable for  
>> device-height as content="initial-scale=1" >>will give you an ICB  
>> height that subtracts the height of the UI chrome from the  
>> device-height, while >>content="height=device-height" will give you the  
>> height of the screen in CSS px regardless of the presence of UI chrome.  
>> >>Now, the current implementation in Blink will actually translate  
>> device-width/height to the width/height of the ICB >>established by the  
>> browser window showing no difference between content="initial-scale=1"  
>> and content="height".
>> An important argument in favor of removing the support for the device-*  
>> values in @viewport is that authors would likely >>continue to use  
>> those values as they match what they're used to from viewport meta,  
>> which would be bad.
>> PROPOSAL: Remove device-width and device-height from <viewport-length>  
>> and keep them in the viewport meta part.
>> --Rune Lillesveen

Rune Lillesveen

Received on Wednesday, 29 May 2013 11:34:26 UTC