Package | spark.accessibility |
Class | public class DropDownListBaseAccImpl |
Inheritance | DropDownListBaseAccImpl ListBaseAccImpl AccImpl AccessibilityImplementation Object |
Subclasses | ComboBoxAccImpl |
Language Version: | ActionScript 3.0 |
Product Version: | Flex 4 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
Although ComboBox has its own accessibility implementation subclass, DropDownList simply uses the one for DropDownListBase. Therefore, the rest of this description refers to the commonly-used DropDownList component rather than the DropDownListBase base class.
When a Spark DropDownList 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 DropDownList.
See the mx.accessibility.AccImpl and
flash.accessibility.AccessibilityImplementation classes
for background information about accessibility implementation
classes and MSAA.
Children
The MSAA children of a DropDownList are its list items.
The number of children is the number of items
in the dataProvider
not just the number of visible renderers.
As described below, the accessibility of the list items
is managed by the DropDownList;
the accessibilityImplementation
and accessibilityProperties
of the item renderers
are ignored by the Flash Player.
Role
The MSAA Role of a DropDownList is ROLE_SYSTEM_COMBOBOX.
The Role of each list item is ROLE_SYSTEM_LISTITEM.
Name
The MSAA Name of a DropDownList is, by default, an empty string.
When wrapped in a FormItem element, the Name is the FormItem's label.
To override this behavior,
set the DropDownList's accessibilityName
property.
The Name of each list item is determined by the DropDownList's
itemToLabel()
method.
When the Name of the DropDownList or one of its items changes, a DropDownList dispatches the MSAA event EVENT_OBJECT_NAMECHANGE with the proper childID for a list item or 0 for itself.
Description
The MSAA Description of a DropDownList is, by default,
an empty string, but you can set the DropDownList's
accessibilityDescription
property.
The Description of each list item is the empty string.
State
The MSAA State of a DropDownList 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 DropDownList has focus)
- STATE_SYSTEM_EXPANDED (when it is open)
- STATE_SYSTEM_COLLAPSED (when it is closed)
The State of a list item is a combination of:
- STATE_SYSTEM_FOCUSABLE
- STATE_SYSTEM_FOCUSED (when it has focus)
- STATE_SYSTEM_SELECTABLE
- STATE_SYSTEM_SELECTED (when it is selected)
When the State of the DropDownList or one of its list items changes, a DropDownList dispatches the MSAA event EVENT_OBJECT_STATECHANGE with the proper childID for the list item or 0 for itself.
Value
The MSAA Value of a DropDownList is the MSAA Name of the currently selected list item.
The Value of each list item is the empty string.
When the Value of the DropDownList changes, it dispatches the MSAA event EVENT_OBJECT_VALUECHANGE.
Location
The MSAA Location of a DropDownList or a list item is its bounding rectangle.
Default Action
A DropDownList does not have an MSAA DefaultAction
The DefaultAction of a list item is "Double click".
Focus
The DropDownList itself can receive focus, as well as its list items (either while the DropDownList is collapsed or expanded). The EVENT_OBJECT_FOCUS is fired when this happens.
Selection
The DropDownList allows a single item to be selected, in which case an EVENT_OBJECT_SELECTION event is fired.
Method | Defined By | ||
---|---|---|---|
DropDownListBaseAccImpl(master:UIComponent)
Constructor. | DropDownListBaseAccImpl | ||
An IAccessible method that performs the default action associated with the component
that this AccessibilityImplementation represents or of one of its child elements. | AccessibilityImplementation | ||
MSAA method for returning a DisplayObject or Rectangle
specifying the bounding box of a child element in the AccessibilityImplementation. | AccessibilityImplementation | ||
IAccessible method for altering the selection in the component
that this AccessibilityImplementation represents. | AccessibilityImplementation | ||
[static]
Enables accessibility in the DropDownListBase class. | DropDownListBaseAccImpl | ||
MSAA method for returning the default action of the component
that this AccessibilityImplementation represents or of one of its child elements. | AccessibilityImplementation | ||
MSAA method for returning the unsigned integer ID of the child element, if any,
that has child focus within the component. | AccessibilityImplementation | ||
MSAA method for returning the name for the component
that this AccessibilityImplementation represents or for one of its child elements. | AccessibilityImplementation | ||
MSAA method for returning the system role for the component
that this AccessibilityImplementation represents or for one of its child elements. | AccessibilityImplementation | ||
MSAA method for returning an array containing the IDs of all child elements that are selected. | AccessibilityImplementation | ||
IAccessible method for returning the current runtime state of the component that this
AccessibilityImplementation represents or of one of its child elements. | AccessibilityImplementation | ||
MSAA method for returning the runtime value of the component that this
AccessibilityImplementation represents or of one of its child elements. | AccessibilityImplementation | ||
Returns an array containing the unsigned integer IDs of all child elements
in the AccessibilityImplementation. | AccessibilityImplementation | ||
[static]
Method for supporting Form Accessibility. | AccImpl | ||
Indicates whether an object has a specified property defined. | Object | ||
[static]
Method for supporting state Accessibility. | AccImpl | ||
Indicates whether an instance of the Object class is in the prototype chain of the object specified
as the parameter. | Object | ||
Indicates whether the specified property exists and is enumerable. | Object | ||
Sets the availability of a dynamic property for loop operations. | Object | ||
Returns the string representation of this object, formatted according to locale-specific conventions. | Object | ||
Returns the string representation of the specified object. | Object | ||
Returns the primitive value of the specified object. | Object |
DropDownListBaseAccImpl | () | Constructor |
public function DropDownListBaseAccImpl(master:UIComponent)
Language Version: | ActionScript 3.0 |
Product Version: | Flex 4 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
Constructor.
Parametersmaster:UIComponent — The UIComponent instance that this AccImpl instance
is making accessible.
|
enableAccessibility | () | method |
public static function enableAccessibility():void
Language Version: | ActionScript 3.0 |
Product Version: | Flex 4 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
Enables accessibility in the DropDownListBase class.
This method is called by application startup code
that is autogenerated by the MXML compiler.
Afterwards, when instances of DropDownListBase are initialized,
their accessibilityImplementation
property
will be set to an instance of this class.
Fri Mar 19 2010, 02:45 AM -07:00