Re: Jonathan's concern: Zoom in responsive drops content

Thanks David,



I’ve added that here:

https://www.w3.org/WAI/GL/wiki/Possible_wording_from_Jason/David_for_LVTF_re:_zoom_without_horizontal_scroll#Types_of_zoom



The more I think about it, the more I see a dividing line between desktop & mobile devices.



I know there is a continuum of devices, but the way layout & sizing works is very different depending on the meta-vieewport setting.



When you create a site and set: <meta name="viewport" content="width=device-width">



Browsers divide into two groups: those that use the setting (generally mobile/tablet) and those that don’t (generally desktop).



1.       If a device uses the setting, any level of zoom causes horizontal scrolling. That is by definition as the browser starts by setting the layout to the width of the device. As it does not re-flow, any zoom causes scrolling.



2.       If a device does not use the setting and the screen is over 1000px wide, then 300% without scrolling is easy with media queries.



Therefore I think we will need a note or two on user-agents. Starter for 10:



SC X.X.X If text is resized up to 300%* without assistive technology, the layout of the Web page ensures that it can be viewed in its entirety without bi-directional**scrolling, and without loss of content or functionality except for elements of the page where the spatial layout of the content is essential to its use.

Note: If a user-agent fits the layout to the viewport and does not provide a means of reflowing content, the author can ignore the requirement to prevent horizontal scrolling.



* Picking 300% an easily achievable level.

** Using the LVTF’s term “bi-directional scrolling” as some languages might work the other way around.



-Alastair