UA controlling display of tooltip

On the last call (Aug 2, 2007)[1], we discussed tooltips as they relate to
user agent. Just wanted to capture some thought in text rather than minutes
of calls.

Definition from Wikipedia:
The tooltip is a common graphical user interface element. It is used in
conjunction with a cursor, usually a mouse pointer. The user hovers the
cursor over an item, without clicking it, and a small box appears with
supplementary information regarding the item being hovered over...Another
system, on the Macintosh computer, that aims to solve the same problem, but
in a slightly different way, is balloon help. Another term for tooltip, used
in Microsoft end-user documentation, is “ScreenTip”.[2]

Note: this discussion does not apply to the debate of the appropriateness of
a tooltip being displayed for @alt on images.

Currently, tooltips are displayed when the mouse pointer hovers over an
element with a @title (title attribute). The tooltip displays the value of
the @title of the element.

As far as I know, at least on Windows (need information from other
platforms), 'tooltip' configuration happens at the operating system level.
The UA has no control.

A review of CSS ( shows no CSS control for any
aspects related to tooltips. There are attribute selectors, such as @alt and
@title, that could be used by authors to change the appearance of tooltips.
I could not find instances of using these attributes to modify tooltip
rendering on the web. Any instances are appreciated.

There are work-arounds for changing UA behavior for tooltips, for example, however,
this example (as well as others) uses "a:hover" and  "span" but not @title.

1. the UAAG definition of 'rendered content' states "Rendered content is the
part of content that the user agent makes available to the user's senses of
sight and hearing (and only those senses for the purposes of this document).
Any content that causes an effect that may be perceived through these senses
constitutes rendered content. This includes text characters, images, style
sheets, scripts, and anything else in content that, once processed, may be
perceived through sight and hearing."

To me value of a 'title' attribute is visually rendered content according to
the definition and Checkpoint 4.1 Configure text scale (P1), 4.2 Configure
font family (P1), and 4.3 Configure text colors (P1) should apply. That is,
when the user configures font size, family, and color the configuration
should apply to the 'tooltip'.

However, there is a problem, in that 'tooltips' are generally rendered
differently (background is different and it has a border), to make it more
visible. May need a new checkpoint or a new provision to existing


2. 'tooltip' behavior, that is the tooltip appears when a user hovers the
mouse pointer over content that the UA chooses to render visually. This
fails Checkpoint 1.1 Full keyboard access (P1),


Jim Allan, Webmaster & Statewide Technical Support Specialist
Texas School for the Blind and Visually Impaired
1100 W. 45th St., Austin, Texas 78756
voice 512.206.9315    fax: 512.206.9264
"We shape our tools and thereafter our tools shape us." McLuhan, 1964

Received on Wednesday, 8 August 2007 19:14:12 UTC