charlescfenwick.com

This one can be pretty nifty. In my certain case I had a bunch of on screen items that I continually updating their alpha property but when there was a mouse over I didn’t want to update that property anymore and peg it right at 1 so it stood out. In this case it was a text field so here is a class with the not important parts taken out.

package{
	import flash.text.TextField;
	import flash.events.MouseEvent;
	public class Tag extends TextField{
		private var alpha_locked:Boolean;
		public function Tag():void{
			this.alpha_locked = false;
			this.addEventListener(MouseEvent.MOUSE_OVER, mouse_over);
			this.addEventListener(MouseEvent.MOUSE_OUT, mouse_out);
		}
		private function mouse_over(e:MouseEvent):void{
			this.alpha = 1;
			this.alpha_locked = true;
		}
		private function mouse_out(e:MouseEvent):void{
			this.alpha_locked = false;
		}
		override public function set alpha(a:Number):void{
			if(!alpha_locked) super.alpha = a;
		}
	}
}

The magic happens with the super.alpha, super which refers to the parent class that Tag inherits from. It checks the alpha_locked variable and if things are ok it sets it, otherwise it’s ignored. Then the alpha locked variable is controlled by the MouseOver and MouseOut events.

I’ve run into this problem a few times I want to rotate and object by an arbitrary point. First off actionscript doesn’t let you change you point from which you rotate when you change the rotation attribute of an object. By default when you rotate using the rotation attribute flash rotates the objects at it’s index point (0, 0). Simple solution move the object so it’s center point is at the index point of it’s container move clip then rotate it, then move it back it’s original position. To make things easier you can of course wrap this up in a function inside of an object or use this snippet.

	function rotate(item:DisplayObject, angle:Number, point:Point) {
		var matrix:Matrix = item.transform.matrix.clone();
		matrix.translate(-point.x, -point.y);
		matrix.rotate (angle*(Math.PI/180));
		matrix.translate(point.x, point.y);
		item.transform.matrix = matrix;
	}

Simple enough to use just pass the function the moveclip you want to rotate the angle just like you would with the rotation attribute and the point from the index point that you want to rotate your clip.

	rotate(thing, 90, new Point(50, 50));

Ahhh a sandbox violation if you are stating to pull content from other sites or even pull external content period to your SWF get used to them. They really do suck and at first it is overwhelming when you get them all the time, take it from me though after some time getting your hands dirty with Actionscript these things become a thing of the past.

First up, why do I get these errors?
Easy it’s to protect everyone on out there in the tubes.
These cross domain scripting errors happen because code from one domain is not allowed to modify content from another domain. This is so that say you are browsing your bank’s site doing your normal bank things but at the same time you are also browsing Matt Evilphen’s site. He has some code on there that detects that you are your banking site and transfer all your money to his account, oh no, you’re broke. Well fortunately you cannot do this, oh course there are million other ways to have you bank account drained, this is not one of them.

It’s very strict too. www.charlescfenwick and blog.charlescfenwick.com are not the same and neither is www.charlescfenwick.com:8080

So how does one get around this?
well first off you need a crossdomain.xml file on the server which the remote is being accessed from.

 
<?xml version="1.0"?>
<!DOCTYPE cross-domain-policy SYSTEM "http://www.macromedia.com/xml/dtds/cross-domain-policy.dtd">
<cross-domain-policy>
   <allow-access-from domain="*" />
</cross-domain-policy>

This is an example of course you’ll probably want to change the * to what ever domain the swf is coming from.

then as usual load your content, but take special note of the LoaderContext class

  // don't forget these
  import flash.system.LoaderContext;
  import flash.net.URLLoader;
  import flash.net.URLRequest;
 
  // create your request to the resource
  var request:URLRequest=new URLRequest("http://www.somesite.com/someresource");
  // create the loader to do the actual load
  var loader:URLLoader=new URLLoader();
  // this is the loader context
  var context:LoaderContext = new LoaderContext();
  // set the check policy flag in the loader context
  context.checkPolicyFlag=true;
 
  // add the handler for when the event completes
  loader.addEventListener(Event.COMPLETE, completeHandler);
 
  // retrieve the resource
  loader.load(request, context);

One of the things I find annoying when I’m looking for a quick solution to some programing problem is that people don’t post everything you need to get going such as the import lines, to you know, actually get their snippets of code to work.

So first off you need to import some stuff

import flash.net.URLLoader;
import flash.net.URLRequest;
import flash.net.URLRequestHeader;
import flash.net.URLRequestMethod;
import flash.net.URLVariables;

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