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Re: Image maps


From: Guy Hickling
Date: Jan 22, 2020 5:28PM

>> So, with this alternative in mind, what do they do about the map?

You have to look at all the WCAG success criteria and consider how each one
applies to the situation in your website. Specifically there is SC2.1.1
which says "All functionality of the content is operable through a keyboard
interface...." - it's written primarily for keyboard-only users (it usually
helps screen reader users as well, though maybe not so much here).

The functionality of your map allows the user to click anywhere on the map
and get the mobile coverage for that postcode. This should be quite easy to
replicate from the keyboard. Just create a cross-hair pointer that can be
moved using the arrow keys. That provides keyboard users with the much of
the same functionality as mouse users.

But I say "much of" because there is more. Presumably the user, having
clicked on one place (say their home street), can then click on surrounding
streets to easily find coverage for the whole area - or does the map itself
show data for the whole area at that point. Either way, clicking over a
whole area, not just one postcode, is very easy.

If you consider this, that's what people will want. I know this because I
have just bought a mobile phone for my son, and we checked the coverage
maps of the supplier we were considering. We checked our home postcode
(which we knew) and his school - both were good reception. But then looking
at the map at all the streets he traverses on the way to and from school
(obviously we didn't know any of the postcodes for them so that would have
been extremely difficult using postcode retrieval) we found reception was
poor most of the way. Looking further around the map, we discovered
reception was poor across much of our small town. So we went with a
different supplier. The point being that we needed the map for that. We
could not have done that kind of searching by looking up and typing in
dozens and dozens of postcodes.

This illustrates how what might, at first glance, seem to be the
"functionality" of an operation is not necessarily all there is to it! We
have to consider how the users can use it in actual practice. Mouse users,
that is. But we have to ask users who actually use that kind of
functionality in real life to get a true picture!

Then we have to consider how to give the nearest possible thing to
keyboard-only users. That's the arrow keys in this case, so 2.1.1
effectively says you must do that.

Then we have to consider how to give the same ability to screen reader
users, as nearly as possible for blind people. Ok, it's a visual map, so
this is going to be more difficult. But you may be able to come up with
something better than just allowing them to type in one postcode they know.
Perhaps they could type in the name of a town? or a street? - people know
street names much better than postcodes. It bears some thought at least.

(NB: The keyboard arrows above should not need a lot of extra scripting, I
think. When the user presses the Enter key, the scripting gets the
coordinates of the cross, then it would call the same function that is
called on mouse click to retrieve the information. You might need to
convert the cross-hair coordinates to the mouse coordinate system first if
you've used a different measuring system, but that should hopefully be the
only extra scripting needed.)

Guy Hickling
Accessibility Consultant