Adobe® Flex® 4 Language Reference
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mx.collections 
ArrayList 
Packagemx.collections
Classpublic class ArrayList
InheritanceArrayList Inheritance EventDispatcher Inheritance Object
Implements IList, IExternalizable, IPropertyChangeNotifier
Subclasses Conflicts

Language Version: ActionScript 3.0
Product Version: Flex 4
Runtime Versions: Flash Player 10, AIR 1.5

The ArrayList class is a simple implementation of IList that uses a backing Array as the source of the data. Items in the backing Array can be accessed and manipulated using the methods and properties of the IList interface. Operations on an ArrayList instance modify the data source; for example, if you use the removeItemAt() method on an ArrayList, you remove the item from the underlying Array. This base class will not throw ItemPendingErrors but it is possible that a subclass might.
  <mx:ArrayList
  Properties
  source="null"
  />
  

Default MXML Propertysource



Public Properties
 PropertyDefined By
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
  length : int
[read-only] Get the number of items in the list.
ArrayList
 Inheritedprototype : Object
[static] A reference to the prototype object of a class or function object.
Object
  source : Array
The source array for this ArrayList.
ArrayList
  uid : String
Provides access to the unique id for this list.
ArrayList
Public Methods
 MethodDefined By
  
ArrayList(source:Array = null)
Construct a new ArrayList using the specified array as its source.
ArrayList
  
addAll(addList:IList):void
Adds a list of items to the current list, placing them at the end of the list in the order they are passed.
ArrayList
  
addAllAt(addList:IList, index:int):void
Adds a list of items to the current list, placing them at the position index passed in to the function.
ArrayList
 Inherited
addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void
Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event.
EventDispatcher
  
Add the specified item to the end of the list.
ArrayList
  
addItemAt(item:Object, index:int):void
Add the item at the specified index.
ArrayList
 Inherited
Dispatches an event into the event flow.
EventDispatcher
  
getItemAt(index:int, prefetch:int = 0):Object
Get the item at the specified index.
ArrayList
  
Return the index of the item if it is in the list such that getItemAt(index) == item.
ArrayList
 Inherited
Checks whether the EventDispatcher object has any listeners registered for a specific type of event.
EventDispatcher
 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
  
itemUpdated(item:Object, property:Object = null, oldValue:Object = null, newValue:Object = null):void
Notify the view that an item has been updated.
ArrayList
 Inherited
Indicates whether the specified property exists and is enumerable.
Object
  
Remove all items from the list.
ArrayList
 Inherited
removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void
Removes a listener from the EventDispatcher object.
EventDispatcher
  
Removes the specified item from this list, should it exist.
ArrayList
  
Remove the item at the specified index and return it.
ArrayList
  
setItemAt(item:Object, index:int):Object
Place the item at the specified index.
ArrayList
 Inherited
Sets the availability of a dynamic property for loop operations.
Object
  
Return an Array that is populated in the same order as the IList implementation.
ArrayList
 Inherited
Returns the string representation of this object, formatted according to locale-specific conventions.
Object
  
[override] Pretty prints the contents of this ArrayList to a string and returns it.
ArrayList
 Inherited
Returns the primitive value of the specified object.
Object
 Inherited
Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.
EventDispatcher
Protected Methods
 MethodDefined By
  
Called whenever any of the contained items in the list fire an ObjectChange event.
ArrayList
  
If the item is an IEventDispatcher watch it for updates.
ArrayList
  
If the item is an IEventDispatcher stop watching it for updates.
ArrayList
Events
 Event Summary Defined By
 Inherited[broadcast event] Dispatched when the Flash Player or AIR application gains operating system focus and becomes active.EventDispatcher
  Dispatched when the IList has been updated in some way.ArrayList
 Inherited[broadcast event] Dispatched when the Flash Player or AIR application operating loses system focus and is becoming inactive.EventDispatcher
Property Detail

length

property
length:int  [read-only]

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Get the number of items in the list. An ArrayList should always know its length so it shouldn't return -1, though a subclass may override that behavior.



Implementation
    public function get length():int

source

property 
source:Array

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

The source array for this ArrayList. Any changes done through the IList interface will be reflected in the source array. If no source array was supplied the ArrayList will create one internally. Changes made directly to the underlying Array (e.g., calling theList.source.pop() will not cause CollectionEvents to be dispatched.



Implementation
    public function get source():Array
    public function set source(value:Array):void

uid

property 
uid:String

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Provides access to the unique id for this list.



Implementation
    public function get uid():String
    public function set uid(value:String):void
Constructor Detail

ArrayList

()Constructor
public function ArrayList(source:Array = null)

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Construct a new ArrayList using the specified array as its source. If no source is specified an empty array will be used.

Parameters
source:Array (default = null)
Method Detail

addAll

()method
public function addAll(addList:IList):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Adds a list of items to the current list, placing them at the end of the list in the order they are passed.

Parameters

addList:IList — The list of items to add to the current list

addAllAt

()method 
public function addAllAt(addList:IList, index:int):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Adds a list of items to the current list, placing them at the position index passed in to the function. The items are placed at the index location and placed in the order they are recieved.

Parameters

addList:IList — The list of items to add to the current list
 
index:int — The location of the current list to place the new items.

addItem

()method 
public function addItem(item:Object):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Add the specified item to the end of the list. Equivalent to addItemAt(item, length);

Parameters

item:Object — the item to add

addItemAt

()method 
public function addItemAt(item:Object, index:int):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Add the item at the specified index. Any item that was after this index is moved out by one.

Parameters

item:Object — the item to place at the index
 
index:int — the index at which to place the item


Throws
RangeError — if index is less than 0 or greater than the length

getItemAt

()method 
public function getItemAt(index:int, prefetch:int = 0):Object

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Get the item at the specified index.

Parameters

index:int — the index in the list from which to retrieve the item
 
prefetch:int (default = 0) — int indicating both the direction and amount of items to fetch during the request should the item not be local.

Returns
Object — the item at that index, null if there is none

Throws
Error — if the data for that index needs to be loaded from a remote location
 
RangeError — if the index < 0 or index >= length

getItemIndex

()method 
public function getItemIndex(item:Object):int

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Return the index of the item if it is in the list such that getItemAt(index) == item. Note that in this implementation the search is linear and is therefore O(n).

Parameters

item:Object — the item to find

Returns
int — the index of the item, -1 if the item is not in the list.

itemUpdated

()method 
public function itemUpdated(item:Object, property:Object = null, oldValue:Object = null, newValue:Object = null):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Notify the view that an item has been updated. This is useful if the contents of the view do not implement IEventDispatcher. If a property is specified the view may be able to optimize its notification mechanism. Otherwise it may choose to simply refresh the whole view.

Parameters

item:Object — The item within the view that was updated.
 
property:Object (default = null) — A String, QName, or int specifying the property that was updated.
 
oldValue:Object (default = null) — The old value of that property. (If property was null, this can be the old value of the item.)
 
newValue:Object (default = null) — The new value of that property. (If property was null, there's no need to specify this as the item is assumed to be the new value.)

See also

itemUpdateHandler

()method 
protected function itemUpdateHandler(event:PropertyChangeEvent):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Called whenever any of the contained items in the list fire an ObjectChange event. Wraps it in a CollectionEventKind.UPDATE.

Parameters

event:PropertyChangeEvent

removeAll

()method 
public function removeAll():void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Remove all items from the list.

removeItem

()method 
public function removeItem(item:Object):Boolean

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Removes the specified item from this list, should it exist.

Parameters

item:Object — Object reference to the item that should be removed.

Returns
Boolean — Boolean indicating if the item was removed.

removeItemAt

()method 
public function removeItemAt(index:int):Object

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Remove the item at the specified index and return it. Any items that were after this index are now one index earlier.

Parameters

index:int — The index from which to remove the item.

Returns
Object — The item that was removed.

Throws
RangeError — if index < 0 or index >= length.

setItemAt

()method 
public function setItemAt(item:Object, index:int):Object

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Place the item at the specified index. If an item was already at that index the new item will replace it and it will be returned.

Parameters

item:Object — the new value for the index
 
index:int — the index at which to place the item

Returns
Object — the item that was replaced, null if none

Throws
RangeError — if index is less than 0 or greater than or equal to length

startTrackUpdates

()method 
protected function startTrackUpdates(item:Object):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

If the item is an IEventDispatcher watch it for updates. This is called by addItemAt and when the source is initially assigned.

Parameters

item:Object

stopTrackUpdates

()method 
protected function stopTrackUpdates(item:Object):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

If the item is an IEventDispatcher stop watching it for updates. This is called by removeItemAt, removeAll, and before a new source is assigned.

Parameters

item:Object

toArray

()method 
public function toArray():Array

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Return an Array that is populated in the same order as the IList implementation.

Returns
Array

Throws
Error — if the data is not yet completely loaded from a remote location

toString

()method 
override public function toString():String

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Pretty prints the contents of this ArrayList to a string and returns it.

Returns
String
Event Detail

collectionChange

Event
Event Object Type: mx.events.CollectionEvent
property CollectionEvent.type = mx.events.CollectionEvent.COLLECTION_CHANGE

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Dispatched when the IList has been updated in some way.

The CollectionEvent.COLLECTION_CHANGE constant defines the value of the type property of the event object for an event that is dispatched when a collection has changed.

The properties of the event object have the following values. Not all properties are meaningful for all kinds of events. See the detailed property descriptions for more information.

PropertyValue
bubblesfalse
cancelablefalse
currentTargetThe Object that defines the event listener that handles the event. For example, if you use myButton.addEventListener() to register an event listener, myButton is the value of the currentTarget.
itemsAn Array of objects with information about the items affected by the event. The contents of this field depend on the event kind; for details see the items property
kindThe kind of event. The valid values are defined in the CollectionEventKind class as constants.
locationLocation within the target collection of the item(s) specified in the items property.
oldLocationthe previous location in the collection of the item specified in the items property.
targetThe Object that dispatched the event; it is not always the Object listening for the event. Use the currentTarget property to always access the Object listening for the event.
typeCollectionEvent.COLLECTION_CHANGE