// Copyright 2007. Adobe Systems Incorporated. All Rights Reserved.
  package fl.accessibility {
          
          import flash.accessibility.Accessibility;
          import flash.events.Event;
          import fl.controls.listClasses.ICellRenderer;
          import fl.controls.List;
          import fl.core.UIComponent;
  
          

The @ax-student-ar-fl-accessibility-ListAccImpl class, also called the List Accessiblity Implementation class, is used to make a List component accessible. <p>The @ax-student-ar-fl-accessibility-ListAccImpl class supports system roles, object-based events, and states.</p> <p>A List reports the role <code>ROLE_SYSTEM_LIST</code> (0x21) to a screen reader. Items of a List report the role <code>ROLE_SYSTEM_LISTITEM</code> (0x22).</p> <p>A List reports the following states to a screen reader:</p> <ul> <li><code>STATE_SYSTEM_NORMAL</code> (0x00000000)</li> <li><code>STATE_SYSTEM_UNAVAILABLE</code> (0x00000001)</li> <li><code>STATE_SYSTEM_FOCUSED</code> (0x00000004)</li> <li><code>STATE_SYSTEM_FOCUSABLE</code> (0x00100000)</li> </ul> <p>Additionally, items of a List report the following states:</p> <ul> <li><code>STATE_SYSTEM_SELECTED</code> (0x00000002)</li> <li><code>STATE_SYSTEM_FOCUSED</code> (0x00000004)</li> <li><code>STATE_SYSTEM_INVISIBLE</code> (0x00008000)</li> <li><code>STATE_SYSTEM_OFFSCREEN</code> (0x00010000)</li> <li><code>STATE_SYSTEM_SELECTABLE</code> (0x00200000)</li> </ul> <p>A List dispatches the following events to a screen reader:</p> <ul> <li><code>EVENT_OBJECT_FOCUS</code> (0x8005)</li> <li><code>EVENT_OBJECT_SELECTION</code> (0x8006)</li> <li><code>EVENT_OBJECT_STATECHANGE</code> (0x800A)</li> <li><code>EVENT_OBJECT_NAMECHANGE</code> (0x800C)</li> </ul>
see: fl.controls.List List @langversion 3.0 @playerversion Flash 9.0.28.0

  
          public class @ax-student-ar-fl-accessibility-ListAccImpl extends Selectable@ax-student-ar-fl-accessibility-ListAccImpl {
                  

@private Static variable triggering the <code>hookAccessibility()</code> method. This is used for initializing @ax-student-ar-fl-accessibility-ListAccImpl class to hook its <code>createAccessibilityImplementation()</code> method to List class before it gets called from UIComponent. @langversion 3.0 @playerversion Flash 9.0.28.0

  
                  private static var accessibilityHooked:Boolean = hookAccessibility();
  
                  

@private Static method for swapping the <code>createAccessibilityImplementation()</code> method of List with the @ax-student-ar-fl-accessibility-ListAccImpl class. @langversion 3.0 @playerversion Flash 9.0.28.0

   
                  private static function hookAccessibility():Boolean {
                          List.createAccessibilityImplementation = createAccessibilityImplementation;
                          return true;
                  }
  
                  //--------------------------------------------------------------------------
                  //  Class methods
                  //--------------------------------------------------------------------------
  
                  

@private Method for creating the Accessibility class. This method is called from UIComponent.
parameter: component The UIComponent instance that this AccImpl instance is making accessible. @langversion 3.0 @playerversion Flash 9.0.28.0

  
                  public static function createAccessibilityImplementation(component:UIComponent):void {
                          component.accessibilityImplementation = new @ax-student-ar-fl-accessibility-ListAccImpl(component);
                  }
  
                  

Enables accessibility for a List component. This method is required for the compiler to activate the accessibility classes for a component. @langversion 3.0 @playerversion Flash 9.0.28.0

  
                  public static function enableAccessibility():void {
                  }
  
                  //--------------------------------------------------------------------------
                  //  Constructor
                  //--------------------------------------------------------------------------
  
          

@private @internal Nivesh says: I don't think we should document the constructors for the accessibility classes. End-users just have to call the static enableAccessibility method. They don't really create an instance of the classes. Creates a new List Accessibility Implementation.
parameter: master The UIComponent instance that this AccImpl instance is making accessible. @langversion 3.0 @playerversion Flash 9.0.28.0

  
                  public function @ax-student-ar-fl-accessibility-ListAccImpl(master:UIComponent) {
                          super(master);
                  }
  
                  
                  //--------------------------------------------------------------------------
                  //  Overridden methods: AccessibilityImplementation
                  //--------------------------------------------------------------------------
  
                  

@private IAccessible method for returning the value of the ListItem/List which is spoken out by the screen reader The List should return the name of the currently selected item with m of n string as value when focus moves to List.
parameter: childID The child id
returns: Value @langversion 3.0 @playerversion Flash 9.0.28.0

  
                  override public function get_accValue(childID:uint):String {
                          var accValue:String;
                          var list:List = List(master);
                          var index:int = list.selectedIndex;
                          if (childID == 0) {
                                  if (index > -1) {
                                          var ext:String = " " + (index + 1) + " of " + list.dataProvider.length;
                                          var item:Object = list.getItemAt(index);
                                          if (item is String) {
                                                  accValue = item + ext;
                                          } else {
                                                  accValue = list.itemToLabel(item) + ext;
                                          }
                                  }
                          }
                          return accValue;
                  }
  
                  //--------------------------------------------------------------------------
                  //  Overridden methods: AccImpl
                  //--------------------------------------------------------------------------
  
                  

@private method for returning the name of the ListItem/List which is spoken out by the screen reader. The ListItem should return the label as the name with m of n string and List should return the name specified in the Accessibility Panel.
parameter: childID The child id.
returns: Name. @langversion 3.0 @playerversion Flash 9.0.28.0

  
                  override protected function getName(childID:uint):String {
                          if (childID == 0) {
                                  return "";
                          }
                          var list:List = List(master);
                          // Assuming childID is always ItemID + 1
                          // because getChildIDArray is not always invoked.
                          if(list.dataProvider) {
                                  var item:Object = list.getItemAt(childID - 1);
                                  var ext:String = " " + childID + " of " + list.dataProvider.length;
                                  if (item is String) {
                                          return item + ext;
                                  } else {
                                          return list.itemToLabel(item) + ext;
                                  }
                          }
                          return "";
                  }
  
          }
  }
  

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[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

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(C) Æliens 27/08/2009

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