flash.geom.ColorTransform

[Flep]

Since the ColorTransform class is very enjoyable (and useful)"why don"t we play with it a little.
Browsing the web and in particular Flash sites, you"ll have come across some applications using a kind of fade-in/fade-out of the background from one colour to another.
I find it very intelligent as it allows to distinguish the sections of the site by their background colour.
I"ve written a class that shows how to execute this fading, here it is:

package 
{
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.MouseEvent;
	import flash.geom.ColorTransform;
	import flash.display.Stage;
		
	public class CambiaSfondo extends Sprite 
	{
		private var _sprite:Sprite;
		
		private var rosso1:Number=1;
		private var verde1:Number=0;
		private var blu1:Number=0;
		
		private var rosso2:Number=0;
		private var verde2:Number=.5;
		private var blu2:Number=1;
		
		private var speed:Number=0.1;
		
		private var colors_array:Array;
		
		public function CambiaSfondo() 
		{
			initArray();
			drawSprite();
			addListeners();
		}
		
		public function initArray():void
		{
			colors_array=new Array('light-blue','purple','red','green',
								   'brown','blue','orange','yellow');
		}
		
		public function drawSprite():void
		{
			_sprite=new Sprite();
			_sprite.graphics.beginFill(0xffffff,100);
			_sprite.graphics.drawRect(0,0,stage.stageWidth,stage.stageHeight);
			_sprite.graphics.endFill();
			_sprite.buttonMode=true;
			_sprite.useHandCursor=true;
			addChild(_sprite);
		}
		
		public function addListeners():void
		{
			_sprite.addEventListener(Event.ENTER_FRAME, onEnterFrame);
			_sprite.addEventListener(MouseEvent.CLICK,onClick);
		}
		
		public function reCall():void
		{
			_sprite.addEventListener(Event.ENTER_FRAME, onEnterFrame);
		}
		
		public function onEnterFrame(event:Event):void
		{
			var arrR:Number=rosso2;
			var dr:Number=rosso2-rosso1;
			var ar:Number=dr*speed;
			rosso1+=ar;
			verde1+=(verde2-verde1)*speed;
			blu1+=(blu2-blu1)*speed;
			_sprite.transform.colorTransform=
			new ColorTransform(rosso1,verde1,blu1);
			if(Math.abs(dr)<=.01)
			{
				_sprite.removeEventListener(Event.ENTER_FRAME,onEnterFrame);
			}
		}
		
		public function onClick(event:MouseEvent):void 
		{
			var n:Number=Math.floor(Math.random()*colors_array.length);
			setColor(colors_array[n]);
		}
		
		public function setColor(s:String):void
		{
			switch(s)
			{
				case 'randomize':
				rosso2=Math.random();
				verde2=Math.random();
				blu2=Math.random();
				break;
				
				case 'light-blue':
				rosso2=0;
				verde2=.5;
				blu2=1;
				break;
				
				case 'purple':
				rosso2=.8;
				verde2=.3;
				blu2=.85;
				break;
				
				case 'red':
				rosso2=.88;
				verde2=.19;
				blu2=.31;
				break;
				
				case 'green':
				rosso2=.18;
				verde2=.47;
				blu2=.26;
				break;
				
				case 'brown':
				rosso2=.54;
				verde2=.38;
				blu2=.25;
				break;
				
				case 'blue':
				rosso2=.14;
				verde2=.10;
				blu2=.34;
				break;
				
				case 'orange':
				rosso2=.98;
				verde2=.53;
				blu2=.20;
				break;
				
				case 'yellow':
				rosso2=.92;
				verde2=.94;
				blu2=.24;
				break;
			}
			reCall();
		}
	}
}

I"ve also included a case for "randomize", so that we can use random colours.

Stay tuned!