AS3 animate dynamically created movie clips with ENTER_FRAME

Question

I have some code which loads a movie clip from the library, reproduces it and spreads it around the stage in different sizes, positions and rotations. What I can't figure out is how to then animate each one with an ENTER_FRAME event listener - So maybe I can also animate the scale, position and rotations? Any help greatly appreciated. Thanks.

for (var i = 0; i < 20; i++ )
{

    //Generate Item from library
    var MovieClip_mc:mcMovieClip = new mcMovieClip();
    addChild(MovieClip_mc);

    //Size
    var RandomSize = (Math.random() * 0.5) + 0.5;
    MovieClip_mc.scaleX = RandomSize;
    MovieClip_mc.scaleY = RandomSize;

    //Rotation
    var RandomRotation:Number = Math.floor(Math.random()*360);
    MovieClip_mc.rotation = RandomRotation;

    //Position
    MovieClip_mc.x = Math.floor(Math.random() * CanvasWidth);
    MovieClip_mc.y = Math.floor(Math.random() * CanvasHeight);

}

Answer 1

You don't actually need to do that from the outside. You can animate it with its own script in the first frame, so each instance will be animated:

addEventListener(Event.ENTER_FRAME, onFrame);

function onFrame(e:Event):void
{
    // Math.random() - 0.5 will produce a random value from -0.5 to 0.5

    x += Math.random() - 0.5;
    y += Math.random() - 0.5;

    scaleX += (Math.random() - 0.5) / 10;
    scaleY = scaleX;

    rotation += (Math.random() - 0.5) * 5;
}

Answer 2

For performance benefits, it is better to do it using one ENTER_FRAME handler. The handler can be located in your main class and update each mcMovieClip's properties by calling certain methods declared in the mcMovieClip class. Below is a simple example.

Main class

var mcs:Array = [];
for(var i:int = 0; i < 1; i++)
{
    mcs.push(new mcMovieClip());
    addChild(mcs[i]);
}
addEventListener(Event.ENTER_FRAME, updateTime);

function updateTime(e:Event):void
{
    for(var j:int = 0; j < mcs.length; j++)
    {
        mcs[j].updatePosition(Math.random() * stage.stageWidth, 
                              Math.random() * stage.stageHeight);
        mcs[j].updateRotation(Math.random() * 360);
        mcs[j].updateSize(Math.random());
    }
}

mcMovieClip class

function updateSize(size:Number):void
{
    this.scaleX = this.scaleY = size;
}
function updateRotation(rot:Number):void
{
    this.rotation = rot;
}
function updatePosition(newX:Number, newY:Number):void
{
    this.x = newX;
    this.y = newY;
}