ButtonBaseAccImpl  - AS3 Flex

Package	spark.accessibility
Class	public class ButtonBaseAccImpl
Inheritance	ButtonBaseAccImpl AccImpl AccessibilityImplementation Object
Subclasses	CheckBoxAccImpl, ToggleButtonAccImpl

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

ButtonBaseAccImpl is the accessibility implementation class for spark.components.supportClasses.ButtonBase.

Although ToggleButton, CheckBox, and RadioButton have their own accessibility implementation subclasses, Button simply uses the one for ButtonBase. Therefore, the rest of this description refers to the commonly-used Button component rather than the ButtonBase base class.

When a Spark Button is created, its accessibilityImplementation property is set to an instance of this class. The Flash Player then uses this class to allow MSAA clients such as screen readers to see and manipulate the Button. See the mx.accessibility.AccImpl and flash.accessibility.AccessibilityImplementation classes for background information about accessibility implementation classes and MSAA.

Children

A Button has no MSAA children.

Role

The MSAA Role of a Button is ROLE_SYSTEM_PUSHBUTTON.

Name

The MSAA Name of a Button is, by default, the label that it displays. When wrapped in a FormItem element, this label will be combined with the FormItem's label. To override this behavior, set the Button's accessibilityName property.

When the Name changes, a Button dispatches the MSAA event EVENT_OBJECT_NAMECHANGE.

Description

The MSAA Description of a Button is, by default, the empty string, but you can set the Button's accessibilityDescription property.

State

The MSAA State of a Button is a combination of:

• STATE_SYSTEM_UNAVAILABLE (when enabled is false)
• STATE_SYSTEM_FOCUSABLE (when enabled is true)
• STATE_SYSTEM_FOCUSED (when enabled is true and the Button has focus)

When the State changes, a Button dispatches the MSAA event EVENT_OBJECT_STATECHANGE.

Value

A Button does not have an MSAA Value.

Location

The MSAA Location of a Button is its bounding rectangle.

Default Action

The MSAA DefaultAction of a Button is "Press".

When an MSAA client tells the Button to perform this action, KEY_DOWN and KEY_UP MouseEvents for the SPACE key are generated, to simulate pressing the ButtonBase via the keyboard, if the Button is enabled.

Focus

A Button accepts focus. When it does so, it dispatches the MSAA event EVENT_OBJECT_FOCUS.

Selection

A Button does not support selection in the MSAA sense.

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