ただ線を描くだけのやつ

ActionScript3.0アニメーション本から

DrawingApp.as

package {
    import flash.display.Sprite;
    import flash.events.MouseEvent;
    public class DrawingApp extends Sprite {
        public function DrawingApp() {
            init();
        }
        private function init():void {
            graphics.lineStyle(1);
            stage.addEventListener(MouseEvent.MOUSE_DOWN, onMouseDown);
            stage.addEventListener(MouseEvent.MOUSE_UP, onMouseUp);
        }
        private function onMouseDown(event:MouseEvent):void {
            graphics.moveTo(mouseX, mouseY)
            stage.addEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);
        }
        private function onMouseUp(event:MouseEvent):void {
            stage.removeEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);
        }
        private function onMouseMove(event:MouseEvent):void {
            graphics.lineTo(mouseX, mouseY);
        }
    }
}