Re: Comments on SVG Accessibility Mappings -- Default and Allowed Semantics

Hi Amelia,

I think that it depends on the application but the default should be that
the user agent renders a tooltip from the title attribute. If no aria label
is applied and there is a title attribute then it falls back to <title>.
The problem is that because user agents don't specify how to definitively
process it then authors don't know how to reliably use it. That, to me, is
a problem with SVG.

Now that we have aria-label I think it would be much safer to make it a
normative requirement that <title> show a tooltip. Note: Google originally
asked for this as there were times where they did not want to render text
visibly that acted as a label and they did not want to go through the
difficulty of dealing with aria-labelledby and hiding the text. What I
don't know is the backward compatibility impact.

So, if you were creating say a menu bar then you would not want to add a
title attribute and you would need to either render the text directly. Some
applications may use the title as a visible "hint" vs. label text. That is
why it is left as a last resort.

aria-describedby is use to reference a much longer description embedded in
the page that may or may not be visible depending on the authors intent. It
may be there just for assistive technologies but it may also be used to
reference a long description such as a detailed description for a large
drawing on the page.



Rich Schwerdtfeger

From:	Amelia Bellamy-Royds <>
To:	Richard Schwerdtfeger/Austin/IBM@IBMUS
Date:	01/23/2015 12:27 PM
Subject:	Re: Comments on SVG Accessibility Mappings -- Default and
            Allowed Semantics

Then perhaps the "tooltip" ARIA role isn't correct, but that content should
still be available to the user somehow.  Maybe just as plain text content
for the parent shape.

If it isn't, then we need to be very clear in guidance to authors that if
you use `aria-label` you need to duplicate the tooltip information or
explicitly point to the title using `aria-describedby`.

The SVG 1.1 language may say that it is optional to display <title> as
tooltips, but every interactive implementation does it, and there are notes
in the SVG2 draft about possibly making it a normative requirement.


On 23 January 2015 at 10:54, Richard Schwerdtfeger <>
  I do not agree.

  We do not do that for title in HTML for the title attribute. Also,
  tooltips need to be shown when you mouse over them. This is not stated
  anywhere in the SVG specification. In fact, I consider this a problem
  with SVG.

  From my perspective this is underspecified. Also if it the tooltip were
  rendered on a hover it would mean that there would be no need to have a
  special role of tooltip for it. In the case of tooltip the real value add
  is that a sighted user with a cognitive impairment can move their mouse
  over an element and have the tooltip text rendered to the user.

  The reason for tooltip text in the aria spec. is to addressed the
  situation where an author creates a custom tooltip that is rendered using
  CSS or javaScript.


  Rich Schwerdtfeger

  Inactive hide details for Amelia Bellamy-Royds ---01/23/2015 10:41:45
  AM---Another follow-up. If <title> is NOT used as (partAmelia
  Bellamy-Royds ---01/23/2015 10:41:45 AM---Another follow-up. If `<title>`
  is NOT used as (part of) the ARIA name for its parent because

  From: Amelia Bellamy-Royds <>
  Date: 01/23/2015 10:41 AM
  Subject: Re: Comments on SVG Accessibility Mappings -- Default and
  Allowed Semantics

  Another follow-up.

  If `<title>` is NOT used as (part of) the ARIA name for its parent
  because of ARIA labelling attributes, it SHOULD be included in the
  accessibility tree with the role of "tooltip", to match its function on a
  visible display.

  This would correspond with advice to authors: Use <title> to label an
  element, except when the <title> value is used for a tooltip that does
  not make an effective name, in which case add an `aria-label` or
  `aria-labelledby` attribute.  However, in this case we still want the
  tooltip information to be available to AT users!

  An example would be the following very simple bar chart.  The `<title>`
  elements on the bars are used as tooltips to give the exact numerical
  value of each bar.  The natural label for each bar, however, is the label
  from the x-axis:
        <svg viewBox="0 0 100 120">
          <rect id="bar1" aria-labelledby="label1"
                x="10" y="50" height="50" width="30" fill="red">
          <rect id="bar2" aria-labelledby="label2"
                x="60" y="30" height="70"  width="30" fill="blue">
          <line x1="0" x2="100" y1="100" y2="100" stroke="black" />
          <g  text-anchor="middle" font-size="10">
          <text id="label1" x="25"
                y="100" dy="1em">Team A</text>
          <text id="label2" x="75"
                y="100" dy="1em">Team B</text>
  Live Example:
  Or view it full page if you want to test it with current ATs, without all
  the code being read back to you:

  I don't know what, if anything, should be done with <desc> elements if
  the author has included both a <desc> and something else linked with
  aria-describedby.  The content of <desc> is not available through normal
  use of the SVG, so I guess the most consistent behavior is also to ignore
  it for accessibility APIs.

  --Amelia BR

Received on Friday, 23 January 2015 19:47:30 UTC