CasaLoader

/*
    CASA Framework for ActionScript 3.0
    Copyright (c) 2011, Contributors of CASA Framework
    All rights reserved.
    
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are met:
    
    - Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
    
    - Redistributions in binary form must reproduce the above copyright notice,
      this list of conditions and the following disclaimer in the documentation
      and/or other materials provided with the distribution.
    
    - Neither the name of the CASA Framework nor the names of its contributors
      may be used to endorse or promote products derived from this software
      without specific prior written permission.
    
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.
*/
package org.casalib.load {
    import flash.display.DisplayObject;
    import flash.display.Loader;
    import flash.display.LoaderInfo;
    import flash.events.Event;
    import flash.events.HTTPStatusEvent;
    import flash.events.IEventDispatcher;
    import flash.events.SecurityErrorEvent;
    import flash.system.LoaderContext;
    import org.casalib.load.LoadItem;
    
    [Event(name="init", type="flash.events.Event")]
    [Event(name="unload", type="flash.events.Event")]
    [Event(name="httpStatus", type="flash.events.HTTPStatusEvent")]
    [Event(name="securityError", type="flash.events.SecurityErrorEvent")]
    
    /**
        Wraps Loader and extends from {@link LoadItem} and {@link Process}.
        
        In almost all cases you will want to use {@link ImageLoad} or {@link SwfLoad} instead of this class.
        
        @author Aaron Clinger
        @version 02/13/10
        @example
            
                package {
                    import org.casalib.display.CasaMovieClip;
                    import org.casalib.events.LoadEvent;
                    import org.casalib.load.CasaLoader;
                    
                    
                    public class MyExample extends CasaMovieClip {
                        protected var _casaLoader:CasaLoader;
                        
                        
                        public function MyExample() {
                            super();
                            
                            this._casaLoader = new CasaLoader("test.jpg");
                            this._casaLoader.addEventListener(LoadEvent.COMPLETE, this._onComplete);
                            this._casaLoader.start();
                        }
                        
                        protected function _onComplete(e:LoadEvent):void {
                            this.addChild(this._casaLoader.loader);
                        }
                    }
                }
            
    */
    public class CasaLoader extends LoadItem {
        public static const FLASH_CONTENT_TYPE:String = 'application/x-shockwave-flash';
        public static const JPEG_CONTENT_TYPE:String  = 'image/jpeg';
        public static const GIF_CONTENT_TYPE:String   = 'image/gif';
        public static const PNG_CONTENT_TYPE:String   = 'image/png';
        protected var _context:LoaderContext;
        
        
        /**
            Creates and defines a CasaLoader.
            
            @param request: A String or an URLRequest reference to the file you wish to load.
            @param context: An optional LoaderContext object.
            @throws ArguementTypeError if you pass a type other than a String or an URLRequest to parameter request.
            @throws Error if you try to load an empty String or URLRequest.
        */
        public function CasaLoader(request:*, context:LoaderContext = null) {
            super(new Loader(), request);
            
            this._context = context;
            
            this._initListeners(this.loaderInfo);
        }
        
        /**
            The Loader being used to load the image or SWF.
        */
        public function get loader():Loader {
            return this._loadItem as Loader;
        }
        
        /**
            The content received from the CasaLoader. Available after load is complete.
            
            @throws Error if method is called before the SWF has loaded.
        */
        public function get content():DisplayObject {
            if (!this.loaded)
                throw new Error('Cannot access an external asset until the SWF has loaded.');
            
            return this.loader.content;
        }
        
        /**
            The LoaderInfo corresponding to the object being loaded.
        */
        public function get loaderInfo():LoaderInfo {
            return this._loadItem.contentLoaderInfo;
        }
        
        /**
            @exclude
        */
        override public function get bytesTotal():Number {
            return (this._loadItem.contentLoaderInfo.bytesTotal == 0 && this.bytesLoaded != 0) ? Number.POSITIVE_INFINITY : this._loadItem.contentLoaderInfo.bytesTotal;
        }
        
        /**
            @exclude
        */
        override public function get bytesLoaded():uint {
            return this._loadItem.contentLoaderInfo.bytesLoaded;
        }
        
        override public function destroy():void {
            this._dispatcher.removeEventListener(Event.INIT, this.dispatchEvent);
            this._dispatcher.removeEventListener(Event.UNLOAD, this.dispatchEvent);
            this._dispatcher.removeEventListener(HTTPStatusEvent.HTTP_STATUS, this._onHttpStatus);
            this._dispatcher.removeEventListener(SecurityErrorEvent.SECURITY_ERROR, this.dispatchEvent);
            
            super.destroy();
        }
        
        override protected function _load():void {
            this._loadItem.load(this._request, this._context);
        }
        
        /**
            @sends Event#INIT - Dispatched when the properties and methods of a loaded SWF file are accessible.
            @sends Event#UNLOAD - Dispatched when unload is called.
            @sends HTTPStatusEvent#HTTP_STATUS - Dispatched if class is able to detect and return the status code for the request.
            @sends SecurityErrorEvent#SECURITY_ERROR - Dispatched if load is outside the security sandbox.
        */
        override protected function _initListeners(dispatcher:IEventDispatcher):void {
            super._initListeners(dispatcher);
            
            this._dispatcher.addEventListener(Event.INIT, this.dispatchEvent, false, 0, true);
            this._dispatcher.addEventListener(Event.UNLOAD, this.dispatchEvent, false, 0, true);
            this._dispatcher.addEventListener(HTTPStatusEvent.HTTP_STATUS, this._onHttpStatus, false, 0, true);
            this._dispatcher.addEventListener(SecurityErrorEvent.SECURITY_ERROR, this.dispatchEvent, false, 0, true);
        }
    }
}