Question

I’ve 3 different MovieClips that I need to move at the same time across the screen. (From bottom to top)
What is the best way of doing this without using a tweening class like Caurina?

Thank you for tips.

Answer 1

You could add an event listener to the parent container of the display objects which listens for the Event.ENTER_FRAME event. On each Event.ENTER_FRAME event you simply decrement the y property of the display objects like in the following example.

package 
{
    import flash.display.Sprite;
    import flash.events.Event;

    [SWF(width="600", height="500")]
    public class Main extends Sprite 
    {
        private var _squares:Vector.<Square>;

        public function Main():void 
        {
            if (stage) init();
            else addEventListener(Event.ADDED_TO_STAGE, init);

        }// end function

        private function init(e:Event = null):void 
        {
            removeEventListener(Event.ADDED_TO_STAGE, init);

            _squares = new Vector.<Square>();

            var redSquare:Square = new Square(0xFF0000, 100);
            redSquare.x = 0; 
            redSquare.y = 400;
            addChild(redSquare);

            var greenSquare:Square = new Square(0x00FF00, 100);
            greenSquare.x = 300; 
            greenSquare.y = 300;
            addChild(greenSquare);

            var blueSquare:Square = new Square(0x0000FF, 100);
            blueSquare.x = 500; 
            blueSquare.y = 100;
            addChild(blueSquare);

            _squares.push(redSquare, greenSquare, blueSquare);

            addEventListener(Event.ENTER_FRAME, onEnterFrame);

        }// end function

        private function onEnterFrame(e:Event):void
        {
            for each(var square:Square in _squares)
            {
                if (square.y > 0) square.y -= 5;

            }// end for

        }// end function

    }// end class

}// end package

import flash.display.Sprite;

internal class Square extends Sprite
{
    public function Square(color:uint, size:Number)
    {
        graphics.beginFill(color);
        graphics.drawRect(0, 0, size, size);
        graphics.endFill();

    }// end function

}// end function

I think you’d be making life easier for yourself though if you simply used Greensock’s Tweening platform instead.