Adobe® Flex® 4 Language Reference
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flash.accessibility 
AccessibilityProperties 
Packageflash.accessibility
Classpublic class AccessibilityProperties
InheritanceAccessibilityProperties Inheritance Object
Subclasses UIComponentAccProps

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0 Flash Player 9

The AccessibilityProperties class lets you control the presentation of Flash objects to accessibility aids, such as screen readers.

You can attach an AccessibilityProperties object to any display object, but Flash Player will read your AccessibilityProperties object only for certain kinds of objects: entire SWF files (as represented by DisplayObject.root), container objects (DisplayObjectContainer and subclasses), buttons (SimpleButton and subclasses), and text (TextField and subclasses).

The name property of these objects is the most important property to specify because accessibility aids provide the names of objects to users as a basic means of navigation. Do not confuse AccessibilityProperties.name with DisplayObject.name; these are separate and unrelated. The AccessibilityProperties.name property is a name that is read aloud by the accessibility aids, whereas DisplayObject.name is essentially a variable name visible only to ActionScript code.

In Flash Professional, the properties of AccessibilityProperties objects override the corresponding settings available in the Accessibility panel during authoring.

To determine whether Flash Player is running in an environment that supports accessibility aids, use the Capabilities.hasAccessibility property. If you modify AccessibilityProperties objects, you need to call the Accessibility.updateProperties() method for the changes to take effect.

View the examples

See also



Public Properties
 PropertyDefined By
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
  description : String
Provides a description for this display object in the accessible presentation.
AccessibilityProperties
  forceSimple : Boolean
If true, causes Flash Player to exclude child objects within this display object from the accessible presentation.
AccessibilityProperties
  name : String
Provides a name for this display object in the accessible presentation.
AccessibilityProperties
  noAutoLabeling : Boolean
If true, disables the Flash Player default auto-labeling system.
AccessibilityProperties
 Inheritedprototype : Object
[static] A reference to the prototype object of a class or function object.
Object
  shortcut : String
Indicates a keyboard shortcut associated with this display object.
AccessibilityProperties
  silent : Boolean
If true, excludes this display object from accessible presentation.
AccessibilityProperties
Public Methods
 MethodDefined By
  
Creates a new AccessibilityProperties object.
AccessibilityProperties
 Inherited
Indicates whether an object has a specified property defined.
Object
 Inherited
Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.
Object
 Inherited
Indicates whether the specified property exists and is enumerable.
Object
 Inherited
Sets the availability of a dynamic property for loop operations.
Object
 Inherited
Returns the string representation of this object, formatted according to locale-specific conventions.
Object
 Inherited
Returns the string representation of the specified object.
Object
 Inherited
Returns the primitive value of the specified object.
Object
Property Detail

description

property
public var description:String

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0 Flash Player 9

Provides a description for this display object in the accessible presentation. If you have a lot of information to present about the object, it is best to choose a concise name and put most of your content in the description property. Applies to whole SWF files, containers, buttons, and text. The default value is an empty string.

In Flash Professional, this property corresponds to the Description field in the Accessibility panel.

forceSimple

property 
public var forceSimple:Boolean

Runtime Versions: AIR 1.0 Flash Player 9

If true, causes Flash Player to exclude child objects within this display object from the accessible presentation. The default is false. Applies to whole SWF files and containers.

name

property 
public var name:String

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0 Flash Player 9

Provides a name for this display object in the accessible presentation. Applies to whole SWF files, containers, buttons, and text. Do not confuse with DisplayObject.name, which is unrelated. The default value is an empty string.

In Flash Professional, this property corresponds to the Name field in the Accessibility panel.

noAutoLabeling

property 
public var noAutoLabeling:Boolean

Runtime Versions: AIR 1.0 Flash Player 9

If true, disables the Flash Player default auto-labeling system. Auto-labeling causes text objects inside buttons to be treated as button names, and text objects near text fields to be treated as text field names. The default is false. Applies only to whole SWF files.

The noAutoLabeling property value is ignored unless you specify it before the first time an accessibility aid examines your SWF file. If you plan to set noAutoLabeling to true, you should do so as early as possible in your code.

shortcut

property 
public var shortcut:String

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0 Flash Player 9

Indicates a keyboard shortcut associated with this display object. Supply this string only for UI controls that you have associated with a shortcut key. Applies to containers, buttons, and text. The default value is an empty string.

Note: Assigning this property does not automatically assign the specified key combination to this object; you must do that yourself, for example, by listening for a KeyboardEvent.

The syntax for this string uses long names for modifier keys, and the plus(+) character to indicate key combination. Examples of valid strings are "Ctrl+F", "Ctrl+Shift+Z", and so on.

silent

property 
public var silent:Boolean

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0 Flash Player 9

If true, excludes this display object from accessible presentation. The default is false. Applies to whole SWF files, containers, buttons, and text.

Constructor Detail

AccessibilityProperties

()Constructor
public function AccessibilityProperties()

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0 Flash Player 9

Creates a new AccessibilityProperties object.

AccessibilityPropertiesExample.as

The following example uses the AccessibilityExample, CustomAccessibleButton, CustomSimpleButton, and ButtonDisplayState classes to create an accessibility-compliant menu that works with common screen readers. The main functionality of the AccessibilityProperties class is as follows:
  1. Call configureAssets, which creates a custom button and sets its label and description. These are the values that the screen reader conveys to the end user.
  2. Call setTimeOut() to ensure that Flash Player has enough time to detect the screen reader before updating the properties.

Note: Call setTimeout() before checking Accessibility.active. to give Flash Player the 2 seconds it needs to connect to a screen reader, if one is available. If you do not provide a sufficient delay time, the setTimeout call might return false, even if a screen reader is available.

The following example processes the Accessibility.updateProperties() method only if the call to Accessibility.active returns true, which occurs only if Flash Player is currently connected to an active screen reader. If updateProperties is called without an active screen reader, it throws an IllegalOperationError exception.

package {
    import flash.display.Sprite;
    import flash.accessibility.Accessibility;
    import flash.utils.setTimeout;
    
    public class AccessibilityPropertiesExample extends Sprite {
        public static const BUTTON_WIDTH:uint = 90;
        public static const BUTTON_HEIGHT:uint = 20;
        
        private var gutter:uint = 5;
        private var menuLabels:Array = new Array("PROJECTS", "PORTFOLIO", "CONTACT");
        private var menuDescriptions:Array = new Array("Learn more about our projects"
                                                     , "See our portfolio"
                                                     , "Get in touch with our team");
        
        public function AccessibilityPropertiesExample() {
            configureAssets();
            setTimeout(updateAccessibility, 2000); 
        }
        
        private function updateAccessibility():void {
            trace("Accessibility.active: " + Accessibility.active);
            if(Accessibility.active) {
                Accessibility.updateProperties();
            }
        }
        
        private function configureAssets():void {
            var child:CustomAccessibleButton;
            for(var i:uint; i < menuLabels.length; i++) {
                child = new CustomAccessibleButton();
                child.y = (numChildren * (BUTTON_HEIGHT + gutter));
                child.setLabel(menuLabels[i]);
                child.setDescription(menuDescriptions[i]);
                addChild(child);
            }
        }
    }


import flash.accessibility.AccessibilityProperties;
import flash.display.Shape;
import flash.display.SimpleButton;
import flash.display.Sprite;
import flash.events.Event;
import flash.text.TextFormat;
import flash.text.TextField;
    
class CustomAccessibleButton extends Sprite {
    private var button:SimpleButton;
    private var label1:TextField;
    private var description:String;
    private var _name:String;
        
    public function CustomAccessibleButton(_width:uint = 0, _height:uint = 0) {
        _width = (_width == 0) ? AccessibilityPropertiesExample.BUTTON_WIDTH : _width;
        _height = (_height == 0) ? AccessibilityPropertiesExample.BUTTON_HEIGHT : _height;
            
        button = buildButton(_width, _height);
        label1 = buildLabel(_width, _height);
            
        addEventListener(Event.ADDED, addedHandler);
    }
        
    private function addedHandler(event:Event):void {
        trace("addedHandler: " + name);
        var accessProps:AccessibilityProperties = new AccessibilityProperties();
        accessProps.name = this._name;
        accessProps.description = description;
        accessibilityProperties = accessProps;
        removeEventListener(Event.ADDED, addedHandler);
    }
        
    private function buildButton(_width:uint, _height:uint):SimpleButton {
        var child:SimpleButton = new CustomSimpleButton(_width, _height);
        addChild(child);
        return child;
    }

    private function buildLabel(_width:uint, _height:uint):TextField {
        var format:TextFormat = new TextFormat();
        format.font = "Verdana";
        format.size = 11;
        format.color = 0xFFFFFF;
        format.align = TextFormatAlign.CENTER;
        format.bold = true;
            
        var child:TextField = new TextField();
        child.y = 1;
        child.width = _width;
        child.height = _height;
        child.selectable = false;
        child.defaultTextFormat = format;
        child.mouseEnabled = false;
            
        addChild(child);
        return child;
    }
        
    public function setLabel(text:String):void {
        label1.text = text;
        this._name = text;
    }
        
    public function setDescription(text:String):void {
        description = text;
    }
}
    
class CustomSimpleButton extends SimpleButton {
    private var upColor:uint = 0xFFCC00;
    private var overColor:uint = 0xCCFF00;
    private var downColor:uint = 0x00CCFF;

    public function CustomSimpleButton(_width:uint, _height:uint) {
        downState = new ButtonDisplayState(downColor, _width, _height);
        overState = new ButtonDisplayState(overColor, _width, _height);
        upState = new ButtonDisplayState(upColor, _width, _height);
        hitTestState = new ButtonDisplayState(upColor, _width, _height);
        useHandCursor = true;
    }        
}

class ButtonDisplayState extends Shape {
    private var bgColor:uint;
    private var _width:uint;
    private var _height:uint;

    public function ButtonDisplayState(bgColor:uint, _width:uint, _height:uint) {
        this.bgColor = bgColor;
        this._width = _width;
        this._height = _height;
        draw();
    }

    private function draw():void {
        graphics.beginFill(bgColor);
        graphics.drawRect(0, 0, _width, _height);
        graphics.endFill();
    }
}
}