Wisebisoft - Adobe Flash, Flex and AIR.

package
{
    import com.wisebisoft.CustomCircle;
 
    import flash.display.Sprite;
    import flash.display.StageAlign;
    import flash.display.StageScaleMode;
    import flash.events.MouseEvent;
 
    public class MainClass extends Sprite
    {
        // ----------------------------------------
        //  CONSTRUCTOR
        // ----------------------------------------
 
        public function MainClass()
        {
            // Default stage settings
            stage.scaleMode = StageScaleMode.NO_SCALE;
            stage.showDefaultContextMenu = false;
            stage.align = StageAlign.LEFT;
 
            init();
        }
 
        // ----------------------------------------
        //  Private Methods
        // ----------------------------------------
 
        /**
        * Handles the application initialization; it creates a
        * CustomCircle instance passing in two values ( radius, color ) and
        * adds a MOUSE_DOWN and MOUSE_UP event listener to our newly
        * created circle; the two event listeners will handle the dragging.
        */
        private function init():void
        {
            var circle:CustomCircle = new CustomCircle(100, 0x000000);
            circle.buttonMode = true;
            circle.x = 280; circle.y = 200;
            circle.addEventListener(MouseEvent.MOUSE_DOWN, startDragHandler);
            circle.addEventListener(MouseEvent.MOUSE_UP, stopDragHandler);
            this.addChild(circle);
        }
 
        /**
        * Starts dragging the targeted object.
        */
        private function startDragHandler(event:MouseEvent):void
        {
            event.target.startDrag();
        }
 
        /**
        * Stops dragging the targeted object.
        */
        private function stopDragHandler(event:MouseEvent):void
        {
            event.target.stopDrag();
        }
    }
}

package com.wisebisoft
{
    import flash.display.Sprite;
 
    public class CustomCircle extends Sprite
    {
        // ----------------------------------------
        //  CONSTRUCTOR
        // ----------------------------------------
 
        public function CustomCircle(radius:Number, color:uint)
        {
            drawCircle(radius, color);
        }
 
        // ----------------------------------------
        //  Private Methods
        // ----------------------------------------
 
        /**
        * Draws a circle with the help of the arguments
        * that are passed to it.
        */
        private function drawCircle(radius:Number, color:uint):void
        {
            this.graphics.beginFill(color, 1);
            this.graphics.drawCircle(0, 0, radius);
            this.graphics.endFill();
        }
    }
}