ACTION-1642: New aria-kbdshortcuts property (for Issue 711)

Please review this proposal based on a proposal from Dominic Mazzoni for
the Thursday ARIA call. We may come up for another name for this ... like
aria-shortcuts, aria-key, or aria-keygboardshortcuts:

aria-kbdshortcuts (property)

Indicates keyboard shortcuts that can be pressed to activate widgets, such
as a button, link or menuitem. Any widget that has a default activation
behavior when clicked can have a keyboard shortcut.

The value of the aria-kbdhortcuts attribute is a space-delimited list of
keyboard shortcuts that can be pressed to activate the command widget. Each
keyboard shortcut consists of one or more tokens delimited by the plus sign
("+") representing zero or more modifier keys and exactly one non-modifier
key that must be pressed simultaneously to activate the given shortcut.

Modifier keys must be specified exactly according to the DOM Level 3
KeyboardEvent key Values spec: http://www.w3.org/TR/DOM-Level-3-Events-key/
- for example, "Alt", "Control", "Shift", "Meta", or "AltGraph". Note that
Meta corresponds to the Command key on Apple computers.

The valid names for non-modifier keys are any printable character such as
"A", "B", "1", "2", "$", "Plus" for a plus sign, "Space" for the spacebar,
or the names of any other non-modifier key specified in the DOM Level 3
KeyboardEvent key Values spec: http://www.w3.org/TR/DOM-Level-3-Events-key/
- for example, "Enter", "Tab", "ArrowRight", "PageDown", "Escape", or "F1".

When modifier keys are part of a shortcut, they must come first. The
non-modifier key is required and must come last. The order of the modifier
keys is not otherwise significant, so "Alt+Shift+T" and "Shift+Alt+T" are
equivalent, but "T+Shift+Alt" is not valid because all of the modifier keys
don't come first, and "Alt" is not valid because it doesn't include at
least one non-modifier key.

When specifying an alphabetic key, both the uppercase and lowercase
variants are considered equivalent: "a" and "A" are the same, as are "ü"
and "Ü".

When specifying a key on the keyboard that changes when you hold down a
modifier key other than an alphabetic key, you must specify the unmodified
key name. For example, on most U.S. English keyboards, the percent sign "%"
can be printed by pressing Shift+5. The correct way to specify this
shortcut is "Shift+5". It is incorrect to specify "%" or "Shift+%".
However, note that on some international keyboards the percent sign may be
an unmodified key, in which case "%" and "Shift+"%" would be correct on
those keyboards.

If the key that needs to be specified is illegal in the host language or
would cause a string to be terminated, use the string escaping sequence of
the host language to specify it. For example, the double-quote character
can be encoded as " in HTML.

Examples of valid keyboard shortcuts include:

"A"
"Shift+Space"
"Control+Alt+."
"Ctrl+%quot;"

Examples of valid values for the aria-key attribute, which can include more
than one space-delimited shortcut, include:

aria-kbdshortcuts="Alt+Shift+P"
aria-kbdshortcuts="/ Ctrl+F"
aria-kbdshortcuts="Meta+C Meta+Shift+C"

Adding the aria-keyshortcuts attribute to an element does not change the
behavior of the user agent by mapping the specified keyboard shortcuts to
the triggering of the element's activation function. It is still up to the
application to implement support for the keyboard shortcuts. The
aria-keyshortcuts attribute exposes the fact that these shortcuts exist so
that assistive technologies can communicate this information to users.

Keyboard shortcuts are assumed to be global. If a button is present in a
document and it is visible and enabled, and it exposes a keyboard shortcut,
it is assumed that as long as the document has focus, pressing that
keyboard shortcut will activate that button. If the button or other element
is not currently available to be activated normally, for example because
it's currently invisible or hidden, or explicitly marked as disabled, that
implies that the keyboard shortcut is unavailable too.

Characteristics:
Related Concepts:
<a ref="http://en.wikipedia.org/wiki/Keyboard_shortcut">Keyboard
shortcut</a>

Used in Roles:
command
checkbox
option
gridcell

Inherits into roles:
button
columnheader
link
radio
rowheader
menuitem
menuitemcheckbox
menuitemradio
treeitem

Value:
string



Rich Schwerdtfeger