Current versions of SC and Definitions

• SC for viewing | SC for editing
• SC in draft guidelines

SC Shortname

Concurrent input mechanisms

SC Text

Web content does not restrict use of input modalities available on a platform except where the restriction is essential, required to ensure the security of the content, or respect user settings.

Suggestion for Priority Level (A/AA/AAA)

Level AA

Related Glossary additions or changes

N/A

What Principle and Guideline the SC falls within.

Principle 2, potentially a new guideline concerning general "Input"

Description

There is a wide range of potential input devices that a user may be using to access / interact with a web site or web application. These include keyboard and keyboard-like interfaces, mice, touchscreens, pen/stylus, as well as advanced input mechanisms such as speech and inputs mediated through assistive technologies.

On most devices, it is possible for users to switch between different input mechanisms during the same session/interaction (for instance, on a touchscreen-enabled laptop, users may begin interacting with a site using their trackpad and keyboard, but switch to using the touchscreen for certain interactions).

A site/application should not assume that a user will always start with, and exclusively use, a particular input mechanism, and allow users to operate a site/application with any form of input mechanism available to them.

(Note: there is concern in the MATF about the requirement being too broad / covering "all" possible input types, even when they're unsupported by an OS/UA altogether - this is intended to only cover inputs that are supported by operating systems / are accessibility supported)

Benefits

A site/application that can be used/operated by users with multi-input devices (e.g. a touchscreen enabled laptop, a mobile phone with paired bluetooth keyboard/mouse) and allow users to switch between their different input mechanisms.

Testability

Manual testing - authors should test their site/application using the widest possible range of input devices available, and switching input devices during the same session/interaction.

Techniques

• rely on high-level, input-agnostic events like focus/blur/click; by definition, these events are not input-specific, and generally user agents are designed to trigger these regardless of specific input device; however, note the peculiarities of specific input mechanisms (for instance, how the concepts of focus and blur differ for touchscreen inputs compared to keyboard/mouse)
• register separate event handlers to cover various input devices - e.g. register handlers to cover mouse, keyboard and touch interactions, instead of simply relying on just one set of event handlers specific to a particular input modality