SWF It Good

So a couple of weeks ago a friend and I were talking about the now hardship of as3 and retrieving class properties when building app.

Ok, lets say in Class A I load an image.

Class B – I am calling two copies of Class A to make two loaded images. make Objects in Class B. If I try to space them equally with classAobj2.x = classAobj1.width + 5,

I get “5″. That is a problem.
(“But Josh, you shouldn’t have a ton of loader objects.” I know I should make a iterator or something but I’m not there yet)

devonair on gotoandlearn.com forums told me about how to pass that var buy creating a custom event. It works but it’s a waste of time to do that for every time you need it. The same friend I was talking to gave me the great “catch all” for passing var through certain events.

See here:

[as]package events
{
import flash.events.Event;

public class GenericEvent extends Event {
public var _data:*;

function GenericEvent (evt:String) {
super(evt);
}

}
}[/as]

So I tested it and it’s nice I can pass a crap load of stuff because it’s an Object i.e.: generic._data = ({width: load.width, height: load.height});

So let’s do that example:

We are going to make three classes, build it like this:

• /root
• -customEventExample.as

• /events
  • -GenericEvent.as

• /display
  • Loading.as

Let’s start w/ Loading.as because we already have the GenericEvent.

[as]

package display
{
import flash.display.Sprite;
import flash.display.Loader;
import flash.net.URLRequest;
import flash.events.Event;
import flash.events.ProgressEvent;
import events.GenericEvent;

public class Loading extends Sprite
{

private var load:Loader;

public function Loading()
{
load = new Loader();
load.load(new URLRequest(“http://www.kornitaly.com/Discografia/Korn.jpg”));
addChild(load);
load.contentLoaderInfo.addEventListener(Event.COMPLETE, loadHandler);

}
private function loadHandler(event:Event):void
{
var generic:GenericEvent = new GenericEvent(Event.COMPLETE);
generic._data = ({width: load.width, height: load.height});
dispatchEvent(generic);
}
}
}[/as]

Now the main class file customEventExample:

[as]

package {
import flash.display.Sprite;
import flash.display.SimpleButton;
import flash.display.Shape;
import flash.events.MouseEvent;
import events.GenericEvent;
import display.Loading

import flash.events.Event;
import flash.display.StageAlign;
import flash.display.StageScaleMode;
[SWF(width="450", height="450")]
public class customEventExample extends Sprite
{
private var _width:int;
private var image:Loading;
private var image2:Loading;

public function customEventExample()
{
image = new Loading();
image2 = new Loading();
addChild(image);
addChild(image2);

stage.align = StageAlign.TOP_LEFT;
stage.scaleMode = StageScaleMode.EXACT_FIT;

image.addEventListener(Event.COMPLETE, clickHandler);
image.addEventListener(Event.COMPLETE, clickHandler);
}

public function clickHandler(event:GenericEvent):void
{

_width = event._data.width

trace(_width);
if(image2)
{
image2.x = _width + 5;
}

}
}
}
[/as]

dowload zip

I think this is called a proxy of some sort. I’m still learning Design Patterns. Also I’ve learned you can achieve this w/ the DataEvent.

This entry was posted on Monday, June 11th, 2007 at 11:43 pm and is filed under as3. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.