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

Jason wrote:

> The specification which is intended to address the handling of layout on devices with different

> viewport sizes and orientations is CSS Device Adaptation Level 1:

https://www.w3.org/TR/css-device-adapt-1/




> There is a note in the draft which requests implementation on both “mobile” and “desktop”

> versions of user agents. It is also made clear that this draft replaces <meta name=”viewport”>,

> which has apparently never been subject to standardization.



AC: I don’t think it will replace the meta element any time soon, support for @viewport is minimal so far. I also note that the spec references a PPK article similar to the one I linked to before for the explanation of layout approaches.



The last two sections (11.1 & 11.2) imply that large-screen UAs should take a similar approach to small screen ones, which would be a bad thing for accessibility IMHO. However, I’m not sure I’m understanding that properly. The document overall doesn’t really make clear the approach browsers should take to viewports which might be good feedback for them?!





> What happens if some user agents respect the author’s request and others don’t



AC: I’m not sure I understand what you mean? The small screen browsers take one approach, the large screen browsers take a different approach. It is one or the other. (Although the correlation between approach and screen size will not be 100%, they all take one approach or the other.)





> Perhaps the right way to handle this would be to include <meta name=”viewport”>, or CSS

> Device Adaptation, in the set of technologies relied upon for purposes of conformance when

> the author makes a conformance claim.



AC: It could be dealt with as a sufficient technology thing, but I think it would need a note by the SC for such an important exception.

Otherwise there is a whole class of devices (the majority now?) that appear to undermine websites trying to apply this SC.



David and I have been updating the page, worth another read, we’re up to 4 versions now!

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




Cheers,



-Alastair