as3: reloading an image - apache-flex

Question

I have an image that I am attempting to load, and then reload. Here is my code for the loading of the image:
public function loadImage(url:String, _w:int, _h:int):void
{
this._stwidth = _w;
this._stheight = _h;
this._imageURL = url;
if(!_imageURL)
{
return;
}
this.alpha = 1.0; //need this because we might have just faded the image out
_ldr.alpha = 0.0;
_prog.alpha = 1.0;
_sqr.alpha = 0.0;
_sqr.graphics.clear();
if(_hasLoaded)
{
try
{
_ldr.close();
_ldr.unload();
}
catch(e:Error)
{
//trace("bmdisplay has loaded once, but there was an error: " + e.message);
}
}
_ldr.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, onProgress);
_ldr.contentLoaderInfo.addEventListener(Event.COMPLETE, onComplete);
_ldr.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, onError);
_ldr.contentLoaderInfo.addEventListener(SecurityErrorEvent.SECURITY_ERROR, onError);
_ldr.contentLoaderInfo.addEventListener(Event.INIT, onOpen);
_ldr.load(new URLRequest(_imageURL));
}
For some reason, this code will not load the image without issuing an Error upon the 2nd load.
Can someone please help me figure this out?
I am totally lost on why my variable _asLoaded would do me wrong.
I have an onComplete() handler, which sets that var to true, and I never set it to false after that.
I don't know what else I should be trying...
Thanks

Answer 1

Sometimes back I wrote a helper class to achieve something similar. The helper class extends Loader and provides automatic scaling of image. Here is the code for that class:package {
import flash.display.Loader;
import flash.geom.Rectangle;
import flash.net.URLRequest;
import flash.events.Event;
import flash.events.IOErrorEvent;
import flash.events.SecurityErrorEvent;
public class ImageLoader extends Loader {
private var _imageURL:String; // URL of image
private var _imageBoundary:Rectangle; // boundary rectangle for the image
private var _loaded:Boolean; // flag which tells whether image is loaded or not.
private var _isLoading:Boolean; // flag which say if any loading is in progress
//Constructor function, which calls Loader's constructor
// and loads and resize the image
public function ImageLoader(url:String = null, rect:Rectangle = null):void {
super();
_imageURL = url;
_imageBoundary = rect;
_loaded = false;
_isLoading = false;
loadImage();
}
// sets the image for the loader and loads it
public function set imageURL(url:String):void {
_imageURL = url;
loadImage();
}
// sets the boundary of the image and resizes it
public function set boundary(rect:Rectangle):void {
_imageBoundary = rect;
resizeImage();
}
private function removeListeners():void {
this.contentLoaderInfo.removeEventListener(Event.COMPLETE, onComplete);
this.contentLoaderInfo.removeEventListener(IOErrorEvent.IO_ERROR, onError);
this.contentLoaderInfo.removeEventListener(SecurityErrorEvent.SECURITY_ERROR, onError);
}
private function onComplete(e:Event):void {
_loaded = true;
_isLoading = false;
removeListeners();
resizeImage();
}
//In case of error, we are not propogating the event
private function onError(e:Event):void {
e.stopImmediatePropagation();
removeListeners();
}
// real loading goes here
// it first closes and unloads the loader and
// then loads the image
private function loadImage():void {
if (_isLoading) {
trace("Some loading is in progess");
return;
}
try {
this.close();
this.unload();
}
catch(e:Error) {
//discarded
}
if (!_imageURL)
return;
_loaded = false;
_isLoading = true;
this.contentLoaderInfo.addEventListener(Event.COMPLETE, onComplete);
this.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, onError);
this.contentLoaderInfo.addEventListener(SecurityErrorEvent.SECURITY_ERROR, onError);
this.load(new URLRequest(_imageURL));
}
// standard resizing function for image so that it's
// aspect ratio is maintained.
private function resizeImage():void {
if (!_imageBoundary || !_loaded)
return;
var aspect:Number = width / height;
var cAspect:Number = _imageBoundary.width / _imageBoundary.height;
if (aspect <= cAspect) {
this.height = _imageBoundary.height;
this.width = aspect * this.height;
}
else {
this.width = _imageBoundary.width;
this.height = this.width / aspect;
}
this.x = (_imageBoundary.width-this.width)/2 + _imageBoundary.x;
this.y = (_imageBoundary.height-this.height)/2 + _imageBoundary.y;
}
}
} And you can use it like this:var _imageLoader:ImageLoader = new ImageLoader();
_imageLoader.imageURL = "http://some-image-url";
_imageLoader.boundary = new Rectangle(0, 0, stage.stageWidth, stage.stageHeight); // or whatever suits you
ImageLoader extends Loader class so you can listen to all the Events dispatches by Loader class. Hope it helps.

Answer 2

i would declare _ldr inside the function so its dead every time you start this function. and i also would not use this unload() and close() methods. its much simpler if make some thing like this (you need to have a empty movieclip called "ldrHelper"):
public function loadImage(url:String, _w:int, _h:int):void
{
// do your job and die bravely, no need to be global
var _ldr:Loader = new Loader();
this._stwidth = _w;
this._stheight = _h;
this._imageURL = url;
if(!_imageURL)
{
return;
}
this.alpha = 1.0; //need this because we might have just faded the image out
// now you will need to make alpha = 1 on ldrHolder since _ldr is dead after this function
ldrHolder.alpha = 0.0;
_prog.alpha = 1.0;
_sqr.alpha = 0.0;
_sqr.graphics.clear();
// remove the old image, doesn't matter whether its empty or not
while(ldrHolder.numChildren > 0){
ldrHolder.removeChildAt(0);
}
//add image
ldrHolder.addChild(_ldr);
_ldr.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, onProgress);
_ldr.contentLoaderInfo.addEventListener(Event.COMPLETE, onComplete);
_ldr.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, onError);
_ldr.contentLoaderInfo.addEventListener(SecurityErrorEvent.SECURITY_ERROR, onError);
_ldr.contentLoaderInfo.addEventListener(Event.INIT, onOpen);
_ldr.load(new URLRequest(_imageURL));
}

Answer 3

Try instantiating new Loader, probably trying to recycle it is giving you the problem