Packageqnx.utils
Classpublic class ImageCache
InheritanceImageCache Inheritance flash.events.EventDispatcher

The ImageCache class provides image caching functionality for your application. The class can be used in conjuction with the Image component class.

See also

cache()


Public Properties
 PropertyDefined By
  cacheSize : int
Gets or sets the cache size for your image cache given an integer representing the number of images to cache.
ImageCache
Public Methods
 MethodDefined By
  
Creates a new ImageCache instance.
ImageCache
  
addImageData(url:String, data:BitmapData):void
Updates the bitmap image data for an element in the cache given a URL to the image and new bitmap data.
ImageCache
  
clear(force:Boolean = false):void
Clear the image cache and disposes the BitmapData.
ImageCache
  
getImage(url:String, load:Boolean):BitmapData
Returns an image from the cache, given the URL of the image and a Boolean that determines whether or not to load the image from the URL provided.
ImageCache
  
reloadImage(url:String):void
Reloads an image from the cache given the URL to the image.
ImageCache
  
unlock(url:String):void
Unlocks an image in the cache, given a URL to the image.
ImageCache
Events
 Event Summary Defined By
   Dispatched when an image has loaded.ImageCache
   Dispatched when an image has failed to load.ImageCache
Property Detail
cacheSizeproperty
cacheSize:int

Gets or sets the cache size for your image cache given an integer representing the number of images to cache.

The default value is Number.POSITIVE_INFINITY.


Implementation
    public function get cacheSize():int
    public function set cacheSize(value:int):void
Constructor Detail
ImageCache()Constructor
public function ImageCache()

Creates a new ImageCache instance.

Method Detail
addImageData()method
public function addImageData(url:String, data:BitmapData):void

Updates the bitmap image data for an element in the cache given a URL to the image and new bitmap data.

This method will dispatch an ImageCacheEvent.IMAGE_LOADED event, so listeners can update automatically.

Parameters

url:String — The URL to the image.
 
data:BitmapData — The new bitmap data for the image.

clear()method 
public function clear(force:Boolean = false):void

Clear the image cache and disposes the BitmapData.

Parameters

force:Boolean (default = false) — If true ALL images will be disposed, including one whch may be on the stage, if false only unlocked images will be disposed

getImage()method 
public function getImage(url:String, load:Boolean):BitmapData

Returns an image from the cache, given the URL of the image and a Boolean that determines whether or not to load the image from the URL provided.

If the image is in the cache it is locked before it is returned. It must be unlocked when no longer in use.

Parameters

url:String — The URL to the image.
 
load:Boolean — A Boolean indicating whether or not to load the image.

Returns
BitmapData — The Image as BitmapData.
reloadImage()method 
public function reloadImage(url:String):void

Reloads an image from the cache given the URL to the image.

If the image is not in the cache nothing is done.

Parameters

url:String — The URL to the image.

unlock()method 
public function unlock(url:String):void

Unlocks an image in the cache, given a URL to the image.

An unlocked image can be flushed from cache if space is required.

Parameters

url:String — The URL to the image.

Event Detail
imageLoaded Event
Event Object Type: qnx.events.ImageCacheEvent
ImageCacheEvent.type property = qnx.events.ImageCacheEvent.IMAGE_LOADED

Dispatched when an image has loaded.

See also

imageLoadError Event  
Event Object Type: qnx.events.ImageCacheEvent
ImageCacheEvent.type property = qnx.events.ImageCacheEvent.IMAGE_LOAD_ERROR

Dispatched when an image has failed to load.

See also