Học Actionscript 3.0 - p 40 pptx

Loading SWFs and Images Chapter 13: Loading Assets 369 load() method. The only other difference between this script and the exam- ple shown in the “Loading SWFs” section is in line 11. Because the example makes no further use of the CustomLoader class, all its listeners are removed. 1 import com.learningactionscript3.loading.CustomLoader; 2 3 var swfLoader:CustomLoader = new CustomLoader("swfToLoad.swf", true); 4 addChild(swfLoader); 5 6 swfLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, 7 onComplete, 8 false, 0, true); 9 function onComplete(evt:Event):void { 10 evt.target.removeEventListener(Event.COMPLETE, onComplete); 11 evt.target.loader.removeListeners(); 12 trace(evt.target); 13 trace(evt.target.content); 14 trace(evt.target.loader); 15 } Loading images The second example, found in the load_jpg_custom.fla, uses CustomLoader much the same way Loader is used. The instantiation process in line 3 passes no values to the constructor, the verbose flag is enabled in line 4, and loading is accomplished via the load() method and a URLRequest instance in line 5. Like the previous JPG loading example, this script also loads the JPG directly to the display list in the last instruction of the onComplete() method. This example also adds the use of the percentLoaded getter to increase the horizontal scale of a progress bar. In line 7 the progress bar is created using the createProgressBar() function found at the end of the script. The func- tion creates a sprite, draws a green rectangle, and returns the sprite to the progressBar variable. The sprite is then added to the display list in line 8. Two listeners are then added to the contentLoaderInfo property of the CustomLoader instance, so the property is stored in a variable for efficiency. In addition to the COMPLETE event listener found in the prior JPG loading example, a PROGRESS event listener is added in lines 13 through 15. It calls the onProgress() function in lines 17 through 19, which updates the scaleX property of the progress bar sprite every time asset data is received during the loading process. 1 import com.learningactionscript3.loading.CustomLoader; 2 3 var jpgLoader:CustomLoader = new CustomLoader(); 4 jpgLoader.verbose = true; 5 jpgLoader.load(new URLRequest("imageToLoad.jpg")); 6 7 var progressBar:Sprite = createProgressBar(); 8 addChild(progressBar); 9 10 var jpgLoaderInfo:LoaderInfo = jpgLoader.contentLoaderInfo; 11 jpgLoaderInfo.addEventListener(Event.COMPLETE, onComplete, 12 false, 0, true); N O T E The event listeners in the example FLA files are not the same as the event lis- teners inside the class. All the internal listeners are at the class level, and are private so nothing outside the class is aware of their existence. The listeners in the example FLA files are applied to class instances. Download from Wow! eBook <www.wowebook.com> Part V: Input/Output 370 Loading Data 13 jpgLoaderInfo.addEventListener(ProgressEvent.PROGRESS, 14 onProgress, 15 false, 0, true); 16 17 function onProgress(evt:Event):void { 18 progressBar.scaleX = evt.target.loader.percentLoaded; 19 } 20 21 function onComplete(evt:Event):void { 22 evt.target.removeEventListener(Event.COMPLETE, onComplete); 23 evt.target.loader.removeListeners(); 24 addChild(evt.target.content); 25 } 26 27 function createProgressBar():Sprite { 28 var sp:Sprite = new Sprite(); 29 var g:Graphics = sp.graphics; 30 g.beginFill(0x00FF00); 31 g.drawRect(0, 0, 100, 10); 32 g.endFill(); 33 sp.x = sp.y = 10; 34 return sp; 35 } Loading Data While the Loader class will load visual assets, data such as text, URL vari- ables, and even binary data, is loaded with the URLLoader class. Using the URLLoader class is similar in many ways to using the Loader class. In fact, we’ll write a custom class for loading data that will closely resemble the program- ming design and syntax of the CustomLoader class we wrote previously. Just like the Loader class can load more than one kind of object (SWF and image), URLLoader can load three kinds of data, selected with the dataFormat property of the URLLoader instance. Plain text (such as text, HTML, CSS and so on) returns a string. URL-encoded variables (such as HTML form data and server responses) returns an instance of the URLVariables class with a collection of variables and corresponding values. Binary data (such as image or sound data) returns a ByteArray. We introduced loading plain text in the “Loading HTML and CSS” section of Chapter 10, but we’ll cover it again here for completeness. We’ll also include examples of loading variables and binary data, including a beyond the basics look at how you can use binary data. Loading Text The default behavior of the URLLoader class is to load text. The following example, found in the load_text.fla source file, is the simplest implementation of the URLLoader class. All you need to do is instantiate the class (line 1), and load the text file using a URLRequest instance. This example uses a COMPLETE event listener to initialize a text field when the loading is finished (lines 4 N O T E If you want your usage of the Loader and CustomLoader classes to be as similar as possible, so you can switch between them with as few edits as possi- ble, you can still enable verbose tracing without loading the asset immediately. You can set up your code like the custom JPG loading example, so the load() method is used separately—just like using the Loader class. However, when instantiating CustomLoader (line 3 in the example), just pass in null and true as the parameter values: new CustomLoader(null, true); This will enable verbose logging, but will not invoke the load() method in the class constructor. N O T E Loading XML is just like loading text. We’ll cover loading XML in detail in Chapter 14 and make use of the CustomURLLoader class you’ll write in this chapter. Download from Wow! eBook <www.wowebook.com> Loading Data Chapter 13: Loading Assets 371 through 15), populate the field with the text data sent with the event (line 13), and add the field to the display list (line 14). 1 var ldrText:URLLoader = new URLLoader(); 2 ldrText.load(new URLRequest("lorem.txt")); 3 4 ldrText.addEventListener(Event.COMPLETE, onComplete, 5 false, 0, true); 6 function onComplete(evt:Event):void { 7 evt.target.removeEventListener(Event.COMPLETE, onComplete); 8 var txtFld:TextField = new TextField(); 9 txtFld.x = txtFld.y = 20; 10 txtFld.width = 500; 11 txtFld.height = 350; 12 txtFld.multiline = txtFld.wordWrap = true; 13 txtFld.text = evt.target.data; 14 addChild(txtFld); 15 } Loading Variables One of the ways to send data between client and server is by using name- value pairs (also called attribute-value pairs). These are assembled in a URL like those sent from an HTML form or returned from some web applications like search tools. An example is firstname=Liz&lastname=Lemon. If your project requires communication using URL variables, you must set the dataFormat property of the URLLoader class to URLLoaderDataFormat. VARIABLES before loading. This automatically changes the data returned from the loading process to a URLVariables object. Names and values are created in the object to match the names and values from the loading result. You can then access those properties to retrieve their values. Web-based applications change frequently, so we’ve demonstrated this syntax using a local file written as URL variables. (Local URLs are no different to URLLoader than remote server URLs.) The file vars.txt contains the following data: name=Joe&age=25 This data will be loaded by the following example, found in load_vars.fla. The example assigns the dataFormat property in line 2, and the property val- ues are traced from the event target’s data property in lines 9 and 10. 1 var ldrVars:URLLoader = new URLLoader(); 2 ldrVars.dataFormat = URLLoaderDataFormat.VARIABLES; 3 ldrVars.load(new URLRequest("vars.txt")); 4 5 ldrVars.addEventListener(Event.COMPLETE, onComplete, 6 false, 0, true); 7 function onComplete(evt:Event):void { 8 evt.target.removeEventListener(Event.COMPLETE, onComplete); 9 trace("name property:", evt.target.data.name); 10 trace("age property:", evt.target.data.age); 11 } Download from Wow! eBook <www.wowebook.com> Part V: Input/Output 372 Loading Data The following is the trace output: //name property: Joe //age property: 25 Loading Binary Data It’s also possible to load binary data from a URL, which is stored in a ByteArray. In this book, we’ve already used the ByteArray to load frequency spectrum data from sounds at runtime. ActionScript 3.0 has also been used to create FTP clients, VNC clients, and image loaders, just to name a few examples. To send or load binary data with the URLLoader class, you must set the data- Format property to URLLoaderDataFormat.BINARY. The following example, found in the load_binary.fla source file, sets the property in line 2, loads an image in line 3, and, upon completing the load, creates a Loader instance to read the bytes of data returned from the URLLoader instance, and adds the instance to the display list (lines 9 through 11). 1 var imgLoader:URLLoader = new URLLoader(); 2 imgLoader.dataFormat = URLLoaderDataFormat.BINARY; 3 imgLoader.load(new URLRequest("imageToLoad.jpg")); 4 5 imgLoader.addEventListener(Event.COMPLETE, onComplete, 6 false, 0, true); 7 function onComplete(evt:Event):void { 8 evt.target.removeEventListener(Event.COMPLETE, onComplete); 9 var ldr:Loader = new Loader(); 10 ldr.loadBytes(evt.target.data); 11 addChild(ldr); 12 } This example was designed to be simple to introduce the syntax for loading binary data. Later in the chapter, a beyond-the-basics example will use this technique to load a Pixel Bender filter to process an image. Writing a Multiuse Data Loading Class Just as our CustomLoader class extended the Loader class, we want to extend the URLLoader class and add similar automatic diagnostic features. We’ll call the new class CustomURLLoader and, as before, we’ll design it to use familiar syntax so you can switch between URLLoader and CustomURLLoader relatively easily. This class is very similar to CustomLoader in design and syntax, so our discussion will focus primarily on what makes it unique. Writing the CustomURLLoader Class Lines 1 through 9 declare the package, and import all the required classes. The classes required are similar to those required by CustomLoader, with the addi- tion of the SecurityErrorEvent class and the substitution of the URLLoader class for Loader. We’ll discuss the SecurityErrorEvent class when we cover N O T E Pixel Bender is an Adobe technology that lets you use a programming lan- guage based on C to write your own image filters. P u s h Y o u r s e l f ! Download from Wow! eBook <www.wowebook.com> Loading Data Chapter 13: Loading Assets 373 the listeners. Line 11 declares the class and extends URLLoader. Again, this makes available the accessible properties and methods of the URLLoader class. Lines 13 through 15 contain private properties also used in CustomLoader to contain the asset path, the logging Boolean, and a number that reports what percentage of the asset has loaded. 1 package com.learningactionscript3.loading { 2 3 import flash.events.Event; 4 import flash.events.HTTPStatusEvent; 5 import flash.events.IOErrorEvent; 6 import flash.events.ProgressEvent; 7 import flash.events.SecurityErrorEvent; 8 import flash.net.URLLoader; 9 import flash.net.URLRequest; 10 11 public class CustomURLLoader extends URLLoader { 12 13 private var _path:String; 14 private var _verbose:Boolean; 15 private var _loadedPercent:Number = 0; The constructor is nearly identical to that of the CustomLoader class. Starting with their similarities, this class accepts the asset path string and Boolean for verbose logging as arguments during instantiation (lines 17 and 18), populates the related properties (lines 20 and 21), adds the needed listeners (line 24), and tries to load the asset if a path was provided (lines 26 through 31). The big dif- ference between the two classes is that this class also accepts the format string argument, with a default value of “text” (line 19), and assigns that value to the dataFormat property of the class, inherited from URLLoader, (line 22). 16 //constructor 17 function CustomURLLoader(path:String=null, 18 verbose:Boolean=false, 19 format:String="text") { 20 _path = path; 21 _verbose = verbose; 22 this.dataFormat = format; 23 24 addListeners(); 25 26 if (path != null) { 27 try { 28 this.load(new URLRequest(path)); 29 } catch (err:Error) { 30 trace("URL load error:", err.message); 31 } 32 } 33 } The remainder of the class is also nearly identical to that of CustomLoader. Starting with the event listeners, the addListeners() and removeListeners() methods also add and remove listeners, respectively (lines 35 through 63). The INIT and UNLOAD listeners are absent, as they do not apply to URLLoader, and the SecurityErrorEvent.SECURITY_ERROR has been added (lines 47 through 49, and 61 through 62). The latter is dispatched when you attempt Download from Wow! eBook <www.wowebook.com> Part V: Input/Output 374 Loading Data to load data from a URL outside the security sandbox used by the SWF, and calls the method in lines 85 through 87. Flash Player security is a big topic, which is discussed in greater detail on the companion website. Put simply, however, not every asset can be loaded with- out permission. Notably, a SWF can’t readily access the user’s local file system and remote URLs at the same time unless permission is granted, nor can you load content from different domains without permission—typically granted with a cross-domain policy file, which is an XML file on the remote server, listing any IP addresses that are allowed access. As your experience grows, and you start to work on projects where either of these needs arise, you’ll want to leave ample time to study security issues. See the post “Security Overview” on the companion website for more information. Finally, the getter and setter (lines 93 through 99) are identical to those found in the CustomLoader class, returning the percentage of bytes loaded, and enabling or disabling the verbose logging feature, respectively. 34 //listeners 35 private function addListeners():void { 36 this.addEventListener(Event.OPEN, 37 onOpen, false, 0, true); 38 this.addEventListener(ProgressEvent.PROGRESS, 39 onProgress, false, 0, true); 40 this.addEventListener(HTTPStatusEvent.HTTP_STATUS, 41 onStatusEvent, 42 false, 0, true); 43 this.addEventListener(Event.COMPLETE, 44 onComplete, false, 0, true); 45 this.addEventListener(IOErrorEvent.IO_ERROR, 46 onIOError, false, 0, true); 47 this.addEventListener(SecurityErrorEvent.SECURITY_ERROR, 48 onSecError, 49 false, 0, true); 50 } 51 52 public function removeListeners():void { 53 this.removeEventListener(Event.OPEN, onOpen); 54 this.removeEventListener(ProgressEvent.PROGRESS, 55 onProgress); 56 this.removeEventListener(HTTPStatusEvent.HTTP_STATUS, 57 onStatusEvent); 58 this.removeEventListener(Event.COMPLETE, onComplete); 59 this.removeEventListener(IOErrorEvent.IO_ERROR, 60 onIOError); 61 this.removeEventListener(SecurityErrorEvent.SECURITY_ERROR, 62 onSecError); 63 } 64 65 private function onOpen(evt:Event):void { 66 if (_verbose) { trace("Loading begun:", _path); } 67 } 68 69 private function onProgress(evt:ProgressEvent):void { 70 _loadedPercent = evt.bytesLoaded / evt.bytesTotal; 71 if (_verbose) { 72 trace("Loading", _path, N O T E When doing anything that might cause a possible security concern, includ- ing loading assets, test your work in a browser as often as is practical. Flash Professional is considered a trusted zone that is not susceptible to most Flash Player security issues. As a result you may think your file is working without security problems throughout development, only to find out at the last minute that restrictions do apply in the browser. The default settings of Flash Professional allow you to test in a browser easily using the Ctrl+F12 (Windows) or Cmd+F12 (Mac) key- board shortcut. Download from Wow! eBook <www.wowebook.com> Loading Data Chapter 13: Loading Assets 375 73 " progress (0-1):", _loadedPercent); 74 } 75 } 76 77 private function onStatusEvent(evt:HTTPStatusEvent):void { 78 if (_verbose) { trace("HTTP status:", evt.status); } 79 } 80 81 private function onComplete(evt:Event):void { 82 if (_verbose) { trace("Loading complete:", _path); } 83 } 84 85 private function onSecError(evt:SecurityErrorEvent):void { 86 trace("Security error:", evt.text); 87 } 88 89 private function onIOError(evt:IOErrorEvent):void { 90 trace("Loading error:", evt.text); 91 } 92 93 public function get percentLoaded():Number { 94 return _loadedPercent 95 } 96 97 public function set verbose(bool:Boolean):void { 98 _verbose = bool; 99 } 100 } 101 } Using the CustomURLLoader Class As you might imagine from their complementary design, using the CustomURLLoader class is very similar to using the CustomLoader class. We’ll show examples for loading text, variables, and binary data. Loading text The following example, found in the load_text_custom.fla source file, is a simple use of the class. It passes the path of the text file into the class con- structor to let the class handle the loading (lines 3 and 4), and it uses verbose logging so you can see what’s going on. Other than using our custom class and removing its internal listeners (line 10), it’s the same in every other respect as the basic text-loading example explained earlier in the chapter. 1 import com.learningactionscript3.loading.CustomURLLoader; 2 3 var ldrText:CustomURLLoader = new CustomURLLoader("lorem.txt", 4 true); 5 6 ldrText.addEventListener(Event.COMPLETE, onComplete, 7 false, 0, true); 8 function onComplete(evt:Event):void { 9 evt.target.removeEventListener(Event.COMPLETE, onComplete); 10 evt.target.removeListeners(); 11 var txtFld:TextField = new TextField(); 12 txtFld.x = txtFld.y = 20; N O T E As with the CustomLoader class, the companion website includes an alter- nate version of CustomURLLoader that overrides the load() method. This simplifies the use of both classes because their internal listeners—those responsible for the verbose logging— are added and removed automatically. See the post, “Overriding the load() Method in Custom Loader Classes,” at the companion website, http://www. LearningActionScript3.com. Download from Wow! eBook <www.wowebook.com> Part V: Input/Output 376 Loading Data 13 txtFld.width = 500; 14 txtFld.height = 350; 15 txtFld.multiline = txtFld.wordWrap = true; 16 txtFld.text = evt.target.data; 17 addChild(txtFld); 18 } Loading variables The next example, found in the load_vars_custom.fla source file, employs syntax similar to what you used with the URLLoader class. The class is instan- tiated with no arguments (line 3), the dataFormat property is set separately (line 4), and the load() method is called using a URLRequest instance (line 5). Two things that are different than the previous variable loading example are the removal of the self-contained class listeners (line 11) and the fact that the event listener method demonstrates using a for in loop (lines 12 through 14) to iterate through all variables, rather than retrieving their values by name. 1 import com.learningactionscript3.loading.CustomURLLoader; 2 3 var ldrVars:CustomURLLoader= new CustomURLLoader(); 4 ldrVars.dataFormat = URLLoaderDataFormat.VARIABLES; 5 ldrVars.load(new URLRequest("vars.txt")); 6 7 ldrVars.addEventListener(Event.COMPLETE, onComplete, 8 false, 0, true); 9 function onComplete(evt:Event):void { 10 evt.target.removeEventListener(Event.COMPLETE, onComplete); 11 evt.target.removeListeners(); 12 for (var prop in evt.target.data) { 13 trace(prop + ": " + evt.target.data[prop]); 14 } 15 } Loading binary data The final use of our CustomURLLoader class will again demonstrate loading binary data. This time, however, we’ll load a Pixel Bender filter. Adobe devel- oped Pixel Bender to allow users to program image processing filters using a C-based language. Filters are typically written using the Pixel Bender Toolkit (an integrated development environment created expressly for this purpose) and then used by other Adobe applications like Photoshop, AfterEffects, and Flash Player. You don’t have to be able to write the filters to use them, however. Many filters exist under a variety of licenses, including open source, freeware, shareware, and commercial. One place to find Pixel Bender filters is the Adobe Pixel Bender Exchange. Visit http://www.adobe.com/cfusion/exchange/, select the Pixel Bender exchange, and then browse or search for filters that can be used with Flash. P u s h Y o u r s e l f ! N O T E You can learn more about Pixel Bender from the Pixel Bender Developer Center: http://www.adobe.com/devnet/ pixelbender/. Download from Wow! eBook <www.wowebook.com> Loading Data Chapter 13: Loading Assets 377 In this example, we’ll use the SquarePattern filter created by the talented Flash Platform evangelist, teacher, and developer Lee Brimelow. You can read about it at Lee’s blog, The Flash Blog, at http://blog.theflashblog.com/?p=432. In ActionScript, this process begins by creating a shader using the Shader class. A shader defines a function that executes on all the pixels of an image, one pixel at a time. Shaders can be used for filters, fills, blend modes, and even numeric calculations. The benefit of these efforts is that Pixel Bender shaders can improve performance of these processor-intensive tasks. In this example, we’ll create a filter using the ShaderFilter class. The following class, CustomLoadBinaryExample.as, is a document class used by the accompanying CustomLoadBinaryExample.fla source file. It will use the CustomLoader class to import an image and add it to the display list, then load the SquarePattern filter using the CustomURLLoader class, and finally animate the filter using an enter frame event listener. Lines 1 through 11 declare the package and import all the required classes. Line 13 declares the class, which extends MovieClip so it can be used as a document class, if desired. Lines 15 through 20 declare a set of private proper- ties that will hold the CustomLoader’s LoaderInfo instance (line 15), the loaded image (line 16), a CustomURLLoader instance (line 17), the Pixel Bender Shader and ShaderFilter (lines 18 and 19), and a property to hold the changing filter values during animation (line 20). The constructor (lines 22 through 29) then uses the CustomLoader class to load an image (lines 23 and 24) and create an event listener to respond to the COMPLETE event (lines 25 through 28). 1 package { 2 3 import flash.display.Bitmap; 4 import flash.display.LoaderInfo; 5 import flash.display.MovieClip; 6 import flash.display.Shader; 7 import flash.filters.ShaderFilter; 8 import flash.events.Event; 9 import flash.net.URLLoaderDataFormat; 10 import com.learningactionscript3.loading.CustomLoader; 11 import com.learningactionscript3.loading.CustomURLLoader; 12 13 public class CustomLoadBinaryExample extends MovieClip { 14 15 private var _ldrInfo:LoaderInfo; 16 private var _penguins:Bitmap; 17 private var _ldrBinary:CustomURLLoader; 18 private var _shader:Shader; 19 private var _shaderFilter:ShaderFilter; 20 private var _val:Number = 0; 21 22 public function CustomLoadBinaryExample() { 23 var jpgLoader:CustomLoader = 24 new CustomLoader("penguins.jpg"); N O T E Lee Brimelow also created the Pixel Bender Viewer, a tool that allows you to load Pixel Bender filters, experiment with their settings, and export them in a format compatible with Flash Player. For more information, see http://blog. theflashblog.com/?p=385. Download from Wow! eBook <www.wowebook.com> Part V: Input/Output 378 Loading Data 25 _ldrInfo = jpgLoader.contentLoaderInfo; 26 _ldrInfo.addEventListener(Event.COMPLETE, 27 onImgLoaded, 28 false, 0, true); 29 } Once the image has loaded, the onImgLoaded() method (lines 31 through 44) is called. The COMPLETE event listener is removed from the CustomLoader’s LoaderInfo instance (lines 32 and 33), the class’s internal listeners are removed (line 34), and the loaded bitmap is then added to the display list (lines 35 and 36). Next, the CustomURLLoader class is used to load the Pixel Bender filter file as binary data (lines 38 through 40), and another COMPLETE listener is created (lines 41 through 43)—this time calling its method when the filter is completely loaded. 30 //load filter 31 private function onImgLoaded(evt:Event):void { 32 evt.target.removeEventListener(Event.COMPLETE, 33 onImgLoaded); 34 evt.target.loader.removeListeners(); 35 _penguins = Bitmap(evt.target.content); 36 addChild(penguins); 37 38 _ldrBinary = 39 new CustomURLLoader("squarepattern.pbj", true, 40 URLLoaderDataFormat.BINARY); 41 _ldrBinary.addEventListener(Event.COMPLETE, 42 onFilterLoaded, 43 false, 0, true); 44 } When the filter file is loaded, the onFilterLoaded() method (lines 46 through 55) is called. The COMPLETE event listener is removed from the CustomURLLoader (lines 47 and 48), and the class’s internal listeners are removed on line 49. Next a Shader instance is created from the loaded Pixel Bender data, and a ShaderFilter instance is derived from the Shader instance. The last task of the method sets up the filter animation by creating an enter frame event listener (lines 53 through 54). 45 //create Shader and ShaderFilter 46 private function onFilterLoaded(evt:Event):void { 47 _ldrBinary.removeEventListener(Event.COMPLETE, 48 onFilterLoaded); 49 evt.target.removeListeners(); 50 _shader = new Shader(evt.target.data); 51 _shaderFilter = new ShaderFilter(shader); 52 53 this.addEventListener(Event.ENTER_FRAME, onEnter, 54 false, 0, true); 55 } Finally, the enter frame event listener method onEnter() (lines 57 through 66) animates the filter. First, the filter is assigned to the Bitmap instance’s filters property, as discussed in Chapter 9. Next the _val property is incremented (line 60). Then the _val property is used to update the SquarePattern’s amount property value. The property takes an array of three numbers: minimum, Download from Wow! eBook <www.wowebook.com> . = new Sprite(); 29 var g:Graphics = sp.graphics; 30 g.beginFill(0x00FF 00) ; 31 g.drawRect (0, 0, 100 , 10) ; 32 g.endFill(); 33 sp.x = sp.y = 10; 34 return sp; 35 } Loading Data While the Loader class. respond to the COMPLETE event (lines 25 through 28). 1 package { 2 3 import flash.display.Bitmap; 4 import flash.display.LoaderInfo; 5 import flash.display.MovieClip; 6 import flash.display.Shader; 7. this.addEventListener(Event.OPEN, 37 onOpen, false, 0, true); 38 this.addEventListener(ProgressEvent.PROGRESS, 39 onProgress, false, 0, true); 40 this.addEventListener(HTTPStatusEvent.HTTP_STATUS, 41 onStatusEvent, 42