Objects should have device-independent interface |
WAI / WCAG 1.0 Priority 2 checkpoint 9.2
Issue Description The page contains event handlers and/or objects (using OBJECT, EMBED, APPLET tags) that should provide a user interface that is device independent. Make sure if the event handlers and/or objects offer a user interface, that the interface can be operated with any possible input device.
How to check Potentially critical objects are Java applets, VB scripts, objects used via plug-ins like Flash, Shockwave, RealAudio, and RealVideo. Examine these objects and determine whether the user interface they offer (buttons, images, text, etc.) can be operated by devices other than the mouse. As a quick test, try to use all the features of the page with the keyboard only (don't touch the mouse). Is it possible to get to all the controls (links, buttons, etc.) and operate all of them? If this quick test fails, then the page is not accessible. If it succeeds, do a more thorough test with assistive technology.
Issue Explanation Programmatic objects can have their own user interface that is not directly implemented in HTML. If this user interface cannot be operated (and perceived) with all the input and output devices that can be used by disabled users, then the page is not accessible. As defined by W3C/WAI (see Web Content Accessibility Guidelines 1.0 [http://www.w3.org/TR/WCAG10/wai-pageauth.html#gl-interim-accessibility#device-independent] ), "device independence" means that visitors must be able to interact with a website using the supported input and output devices of their choice and according to their needs. Input devices may include pointing devices, keyboards, Braille devices, head wands, microphones, and others. Output devices may include monitors, speech synthesizers, and Braille devices. Note that "device-independent support" does not mean that the browser must support every input or output device. It should offer redundant input and output mechanisms for those devices that are supported. For example, if a browser supports keyboard and mouse input, users should be able to interact with all features using either the keyboard or the mouse. Device-independent access means that the visitor may interact with the browser or document with a preferred input (or output) device. For example, if a form control can only be activated with a mouse or other pointing device, someone using the page without sight, with voice input, or with a keyboard will not be able to use the form. The form is an example of device dependence, because its use would be possible only through a mouse. Generally, pages that allow keyboard interaction are also accessible through speech input or a command-line interface.