//We need these classes for the animation
import fl.transitions.Tween;
import fl.transitions.easing.*;
 
//These are the mask rectangle's width and height
var boxWidth:Number = 40;
var boxHeight:Number = 40;
 
//We want nine rows and 14 columns to make the animation look nice
var rows:Number = 9;
var columns:Number = 14;
 
//We will add the rectangle's into an array (we need this array in the animation)
var rectangles:Array = new Array();
 
//We add the tweens into an array so they don't get carbage collected
var tweens:Array = new Array();
 
//This container will hold all the mask rectangles
var container:Sprite = new Sprite();
 
//Add the container onto the stage
addChild(container);
 
//Set the container to be the image's mask
cityMC.mask = container;
 
//Loop through the rows
for (var i=0; i < rows; i++) {
 
        //Loop through the columns
        for (var j=0; j < columns; j++) {
 
                //Create a new mask rectangle
                var maskRectangle:MaskRectangle = new MaskRectangle();
 
                //Position the mask rectangle
                maskRectangle.x = j * boxWidth;
                maskRectangle.y = i * boxWidth;
 
                //Set the scaleX to be 0, so the rectangle will not be visible
                maskRectangle.scaleX = 0;
 
                //Add the rectangle onto the container
                container.addChild(maskRectangle);
 
                //Add the mask rectangle to the rectangles array
                rectangles.push(maskRectangle);
        }
}
 
//Create and start a timer.
//This timer is called as many times as there are rectangles on the stage.
var timer = new Timer(35,rectangles.length);
timer.addEventListener(TimerEvent.TIMER, animateMask);
timer.start();
 
//This function is called every 0.035 seconds
function animateMask(e:Event):void {
 
        //Save the rectangle to a local variable
        var rectangle = rectangles[timer.currentCount - 1];
 
        //Tween the scaleX of the rectangle
        var scaleTween:Tween = new Tween(rectangle,"scaleX",Regular.easeOut,0,1,1,true);
        tweens.push(scaleTween);
 
}