package {
      import flash.display.Sprite;
      import flash.display.StageAlign;
      import flash.events.MouseEvent;
  
      public class @ax-flex-draw extends Sprite {
          
          private var _colorPallet:Array = [0xFFFFFF, 0xFF0000, 0xFF00, 0xFF, 0];
          private var _colorListeners:Array = [onWhite, onRed, onGreen, onBlue, onBlack];
          private var _currentColor:uint = 0;
          private var _paper:Sprite;
          
          public function @ax-flex-draw() {
              stage.align = StageAlign.TOP_LEFT;
              init()
          }
          public function init():void {
              createPaper();
              createPallet();
          }
          private function createPaper():void {
              var _paper:Sprite = new Sprite();
              _paper.graphics.beginFill(0xDDDDDD, 1);
              _paper.graphics.drawRect(0, 0, stage.stageWidth, stage.stageHeight);
              _paper.addEventListener(MouseEvent.MOUSE_DOWN, onBeginDraw);
              _paper.addEventListener(MouseEvent.MOUSE_UP, onEndDraw);
              addChild(_paper);
          }
          private function createPallet():void {
              for(var i:int = 0; i < _colorPallet.length; i++) {
                  var s:Sprite = new Sprite();
                  s.graphics.beginFill(_colorPallet[i], 1);
                  s.graphics.drawCircle(20, 25 * i + 10, 10);
                  s.buttonMode = true;
                  s.useHandCursor = true;
                  s.addEventListener(MouseEvent.CLICK, _colorListeners[i]);
                  addChild(s);
              }
          }
          private function onBeginDraw(e:MouseEvent):void {
              e.target.graphics.endFill();
              e.target.graphics.moveTo(mouseX, mouseY);
              e.target.graphics.lineStyle(5, _currentColor, 1);
              e.target.addEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);
          }
          private function onEndDraw(e:MouseEvent):void {
              e.target.removeEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);
          }
          private function onMouseMove(e:MouseEvent):void {
              e.target.graphics.lineTo(mouseX, mouseY);
          }
          private function onWhite(e:MouseEvent):void {
              _currentColor = 0xFFFFFF;
          }
          private function onRed(e:MouseEvent):void {
              _currentColor = 0xFF0000;
          }
          private function onGreen(e:MouseEvent):void {
              _currentColor = 0xFF00;
          }
          private function onBlue(e:MouseEvent):void {
              _currentColor = 0xFF;
          }
          private function onBlack(e:MouseEvent):void {
              _currentColor = 0;
          }
      }
  }