Re: [Bulk] User Agents Do Not Implement Absolute Length Units, Places Responsive Design in Jeopardy

On Internet Explorer 9 on my Windows Phone, absolute units are right. 

I can however understand why other browsers are reluctant to do this since some websites makers are failling to understand not all screen sports 96dpi and you (sometime) ends up by having a website messed up by this design choice (big font next to very small font because one is specified in px and the other one in pt). It’s however the fault of the website, not of the browser.

However, you must know that not all screen really have the dpi number they report. They may say they are 96dpi-screens and have 94 or 98 as physical dpi. The web browser can never know if its computation is perfect. It does what he think to be the best output with the data he have. Accuracy is up to the hardware maker.

From: Brian Blakely 
Sent: Wednesday, October 05, 2011 4:17 PM
To: www-style@w3.org 
Subject: [Bulk] User Agents Do Not Implement Absolute Length Units, Places Responsive Design in Jeopardy
See spec for a refresh: http://www.w3.org/TR/css3-values/#absolute-lengths 

As far as I know, UAs have never actually implemented this, but always pretended to anyway.  If you size something as "1in", you're more than likely going to get 90px, regardless of the accuracy of this output.

This is important because physical screen dimensions are going to become very crucial in the near-term for content and layout delivery, especially in regards to Media Queries.

The problem which was years away is now an impending reality: the day when 720p+ mobile devices become the norm.  Unless these devices are all pixel-doubling and -quadrupling without exception, using Media Queries for the most common responsive design practice — horizontal resolution detection in pixels — won't work anymore.  They will simply cease to be a solution, leaving no replacement.

We need a new way to do generic device detection, or we need absolute length units to work.

Anyone from representative groups (Mozilla, Chrome Team, Apple) want to comment?  Does the spec need to be changed?

Best,
-Brian