ActionScript 3.0 Language and Components Reference | All Packages | All Classes | Language Elements | Index | Appendixes | Conventions | Frames No Frames |
AccessibilityProperties

Package | flash.accessibility
Class | public class AccessibilityProperties
Inheritance | AccessibilityProperties Object

Language Version : | ActionScript 3.0

Player Version : | 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.

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

flash.accessibility.Accessibility.updateProperties()
flash.display.DisplayObject.accessibilityProperties
flash.display.InteractiveObject.tabIndex
flash.system.Capabilities.hasAccessibility

Public Properties
Hide Inherited Public Properties
Show Inherited Public Properties

| Property | Defined By
--- | --- | ---
|  | constructor : 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
|  | prototype : 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
Hide Inherited Public Methods
Show Inherited Public Methods

| Method | Defined By
--- | --- | ---
|  | AccessibilityProperties() Creates a new AccessibilityProperties object. | AccessibilityProperties
|  | hasOwnProperty(name:String):Boolean Indicates whether an object has a specified property defined. | Object
|  | isPrototypeOf(theClass:Object):Boolean Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter. | Object
|  | propertyIsEnumerable(name:String):Boolean Indicates whether the specified property exists and is enumerable. | Object
|  | setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations. | Object
|  | toString():String Returns the string representation of the specified object. | Object
|  | valueOf():Object Returns the primitive value of the specified object. | Object

Property Detail

description | property

`public var description:String`

Language Version : | ActionScript 3.0

Player Version : | 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.

Corresponds to the Description field in the Accessibility panel.

forceSimple | property |

`public var forceSimple:Boolean`

Language Version : | ActionScript 3.0

Player Version : | 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

Player Version : | 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.

Corresponds to the Name field in the Accessibility panel.

noAutoLabeling | property |

`public var noAutoLabeling:Boolean`

Language Version : | ActionScript 3.0

Player Version : | 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

Player Version : | 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

Player Version : | 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

Player Version : | Flash Player 9

Creates a new AccessibilityProperties object.

Examples How to use examples
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:

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();
        }
    }
    }

Submit Feedback on LiveDocs
© 2004-2008 Adobe Systems Incorporated. All rights reserved.
Tue May 20 2008, 04:02 AM -07:00