(Flex Data Visualization components only)
Packagemx.charts.chartClasses
Classpublic class InstanceCache
InheritanceInstanceCache Inheritance Object

InstanceCache is a utility that governs the task of creating and managing a set of n object instances, where n changes frequently.


Public Properties
 PropertyDefined By
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
  count : int
The number of items currently required in the cache.
InstanceCache
  creationCallback : Function
A callback invoked when new instances are created.
InstanceCache
  discard : Boolean = false
Determines if unneeded instances are discarded.
InstanceCache
  factory : IFactory
A factory that generates the type of object to cache.
InstanceCache
  format : TextFormat
A TextFormat to apply to any instances created.
InstanceCache
  hide : Boolean = true
Determines if unneeded instances should be hidden.
InstanceCache
  insertPosition : int
[write-only] The position of the instance in the parent's child list.
InstanceCache
  instances : Array
[read-only] The Array of cached instances.
InstanceCache
  properties : Object
A hashmap of properties to assign to new instances.
InstanceCache
 Inheritedprototype : Object
[static] A reference to the prototype object of a class or function object.
Object
  remove : Boolean = false
Determines if unneeded instances should be removed from their parent.
InstanceCache
Public Methods
 MethodDefined By
  
InstanceCache(type:Object, parent:Object = null, insertPosition:int = -1)
Constructor.
InstanceCache
 Inherited
hasOwnProperty(name:String):Boolean
Indicates whether an object has a specified property defined.
Object
 Inherited
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
 Inherited
propertyIsEnumerable(name:String):Boolean
Indicates whether the specified property exists and is enumerable.
Object
 Inherited
setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void
Sets the availability of a dynamic property for loop operations.
Object
 Inherited
toString():String
Returns the string representation of the specified object.
Object
 Inherited
valueOf():Object
Returns the primitive value of the specified object.
Object
Property Detail
countproperty
count:int  [read-write]

The number of items currently required in the cache.


Implementation
    public function get count():int
    public function set count(value:int):void
creationCallbackproperty 
public var creationCallback:Function

A callback invoked when new instances are created. This callback has the following signature: 

      function creationCallback(newInstance:Object, cache:InstanceCache):void;

discardproperty 
public var discard:Boolean = false

Determines if unneeded instances are discarded. If set to true, extra elements are discarded when the cache count is reduced. Otherwise, extra elements are kept in a separate cache and reused when the count is increased.

factoryproperty 
factory:IFactory  [read-write]

A factory that generates the type of object to cache. Assigning to this discards all current instances and recreate new instances of the correct type.


Implementation
    public function get factory():IFactory
    public function set factory(value:IFactory):void
formatproperty 
format:TextFormat  [read-write]

A TextFormat to apply to any instances created. If set, this format is applied as the current and default format for the contents of any instances created. This property is only relevant if the factory generates TextField instances.


Implementation
    public function get format():TextFormat
    public function set format(value:TextFormat):void
hideproperty 
public var hide:Boolean = true

Determines if unneeded instances should be hidden. If true, the visible property is set to false on each extra element when the cache count is reduced, and set to true when the count is increased.

This property is only relevant when the factory generates DisplayObjects. Setting this property to true for other factory types generates a run-time error.

insertPositionproperty 
insertPosition:int  [write-only]

The position of the instance in the parent's child list.


Implementation
    public function set insertPosition(value:int):void
instancesproperty 
instances:Array  [read-only]

The Array of cached instances. There may be more instances in this Array than currently requested. You should rely on the count property of the instance cache rather than the length of this Array.


Implementation
    public function get instances():Array
propertiesproperty 
properties:Object  [read-write]

A hashmap of properties to assign to new instances. Each key/value pair in this hashmap is assigned to each new instance created. The property hashmap is assigned to any existing instances when set.

The values in the hashmap are not cloned; object values are shared by all instances.


Implementation
    public function get properties():Object
    public function set properties(value:Object):void
removeproperty 
public var remove:Boolean = false

Determines if unneeded instances should be removed from their parent. If true, the removeChild() method is called on the parent for each extra element when the cache count is reduced.

This property is only relevant when the factory generates DisplayObjects. Setting this property to true for other factory types generates a run-time error.

Constructor Detail
InstanceCache()Constructor
public function InstanceCache(type:Object, parent:Object = null, insertPosition:int = -1)

Constructor.

Parameters
type:Object — The type of object to construct. This can be either a Class or an IFactory.
 
parent:Object (default = null) — An optional DisplayObject to add new instances to.
 
insertPosition:int (default = -1) — Where in the parent's child list to insert instances. Set to -1 to add the children to the end of the child list.



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Fri Feb 15 2008, 2:47 AM GMT-08:00