Accessibility in Flex

Accessibility in Flex History, Methods, Concerns, Advice Michelle M Bagur Senior Developer, EffectiveUI [email_address] fugaciousness Slideshare.net/fugaciousness

Introduction: What to Expect

Accessibility as a whole

Definitions, history, necessity, complexity

The components that comprise accessibility: the web, assistive devices

Examples (both good and bad)

Accessibility in Flex

My participation in this effort

How it’s supposed to work

Implementation examples (tips and tricks)

The outlook for Flex 4

Definitions and Considerations

Basic definition

Allowing people with disabilities or impairment to use the web or software applications

Not just one group should be targeted.

People who are blind, have motor impairment, the elderly, the hard of hearing

A Little History

Rehabilitation Act - 1973

Prohibits discrimination on basis of disability

Section 508 - 1998

Required Federal agencies to make their electronic and information technology accessible to people with disabilities

Includes not only internally used applications, but any information that is provided to the general public

http://www.section508.gov/ has technical standards, training information, FAQs, forums, etc

Acronyms to Know: WAI, W3C, WCAG

WWW Consortium (W3C)

International consortium of member organizations, full time staff, and the public

Develops interoperable technologies

Forum for communication and ‘collective understanding’

Web accessibility initiative (WAI)

Part of the W3C

Develops accessibility guidelines, reports, and resources to help make the Web available to people with disabilities: WCAG

WCAG (Web content accessibility guidelines)

Created by the WAI

Series of documents, part of a bigger series of accessibility guidelines

Initially published in 1999, Version 2 out in 2008

The Spirit of Things

Principles of accessibility (developed by the WCAG)

Perceivable

Operable

Understandable

Robust

Compliance

How do you know if you comply?

Test against guidelines

Find an impaired user

Combination of automated tools and best judgment

Is the ‘spirit’ of compliance good enough?

Alternative approaches, are they different but equal?

Why Does it Matter?

Target Lawsuit

Why were they sued?

By whom?

What were the results?

Read any blog, there are debates amongst people

Common phrase: Go elsewhere, use another site, businesses will suffer

Not actually the way it works; what if there are no alternatives?

Why Target, if they are not a government agency?

Assistive Technologies

Keyboard Navigation

No extra requirements

Tabbing, hotkeys

Screen Readers

JAWS by Freedom Scientific

Window Eyes by GW Micro

VoiceOver by Apple

How do Screen Readers Work?

MSAA (Microsoft Active Accessibility)

API introduced in 1997

IAccessible COM interface

Four pieces exposed by API: Name, Type, Value, State

UI Automation

Properties

Client asks server

“ give me this info”

get_accRole()

get_accName()

get_accDescription()

get_accState()

get_accValue()

get_accParent()

get_accChildCount()

Events Server notifies client “ this just happened” OBJECT_CREATE OBJECT_DESTROY OBJECT_NAMECHANGE OBJECT_FOCUS OBJECT_SELECTION

Examples: You Decide

Good?

www.Amazon.com

www.dignubia.org (only in IE)

Bad?

www.Target.com

www.Google.com -> www.recipes.com

http://www.w3.org/WAI/wcag-curric/sam26-0.htm

http://examples.adobe.com/flex2/inproduct/sdk/flexstore/flexstore.html

Flex 3 and MSAA

Three main classes:

Flash.accessibility.AccessibilityImplementation

Flash.accessibility.AccessibilityProperties

Flash.accessibility.Accessibility

Compile with –accessible = true:

package mx.controls {

[AccessibilityClass(implementation="mx.accessibility.ButtonAccImpl")] public class Button { … }

}

Initialized with: button.accessibilityImplementation = new

ButtonAccImpl(button)

Example: AccImpl A Button’s MSAA name is the label that it displays, so JAWS speaks the label class ButtonAccImpl extends AccessibilityImplementation { override public function get_accName():String { return label; } }

AccessibilityProperties

Code example

AccPropertiesEx.mxml

Accessibility.active

Accessibility.updateProperties()

How’s it Supposed to Work?

Flex 3:

JAWS 8, 9,or 10

Internet Explorer

JAWS scripts

The chain of command:

Flex SDK

Flash player

JAWS scripts

JAWS

The Official Documentation

28 Accessible components:

Accordion

Advanced Data Grid

Alert Button

Checkbox

ColorPicker

Combobox

DataGrid

DateChooser

DateFeld

Form

Image

Label

LinkButton

List

Menu

MenuBar

Panel

RadioButton

RadioButtonGroup

Slider

TabNavigator

Text

TextInput

TitleWindow

TooltipManager

Tree

Tips and Tricks: Prepare Thyself

Make sure scripts are installed:

Insert + q

Start tabIndex at 1, rather than 0

tabIndex = 1;

Don’t be afraid of the focusThickness property

focusThickness = 3;

Get focus into Flash application (semi successfully)

ExternalInterface.call( "s = function() {document.getElementById('“ + this.id + "').focus(); }" );

Possible method to force the tab to stay within the app

keyFocusChange="event.preventDefault();

focusManager.getNextFocusManagerComponent(event.shiftKey).setFocus()“

Form Validation

Validation message gets added to end of accessibilityName, should

get read when field is focused.

Tips and Tricks: Tooltips

If control has:

Tooltip, no name, no description

Tooltip used for name value and visual tooltip

Tooltip, has name, no description:

Tooltip used for description value and visual tooltip

Tooltip, no name, has description:

Tooltip used for name value and visual tooltip

Tooltip, has name, has description:

Tooltip used only for visual tooltip

Tooltip bugs:

Sometimes they’re just not read: NAB

Can’t read tooltip on textArea if it’s not editable IS a bug

Tips and Tricks: JAWS

Press Enter to move into and out of forms mode. This is no longer on by default , in the newest scripts.

Press Insert + Z to toggle virtual cursor mode. Not possible on a MAC laptop, must be reassigned via JAWS.

Use JAWS Keyboard manager to reassign keys, make changes to voice, change verbosity.

JAWS can take over keystrokes, as there is a long list of preassigned key combinations. Be aware if you’re developing when JAWS is running, you will have issues.

The Outlook for Flex 4

“ We will continue to invest in accessibility in each version of Flex, but sometimes that support will be staggered across releases. In Flex 4 we have fixed a number of bugs, and we hope to continue to do so, including backporting those fixes to Flex 3. We are not implementing accessibility for Spark controls in 4.0, but there will be a follow-up release not too long after that will add support in.

“ We are also investigating the next generation of accessibility support as part of a future version of the Flash Player. Adobe has membership in the relevant committees (like WCAG 2) and we are working with industry leaders to make sure that we're supporting the right things. It will take a release or two for that substantial upgrade to occur, but is definitely on our roadmap.”

Helpful Links and References