function RotaryEncoder() {
    this._name = function () {
        return "Encoder";
    };
    this._bounds = function () {
        return { x: -15, y: -15, width: 30, height: 30 };
    };
    this._print = function(g, options) {
        g.drawCircle( 10, 0, 1);
        g.drawCircle( -10, 0, 1);
        g.drawRectangle(- 8, - 6, 15, 12);
//        if (options.front) {
//            g.drawRectangle(-10, -10, 20, 20);//調整中
//        } else {
//        }
        if (!options.print) {
          g.drawRectangle(- 10, - 10, 20, 20);
          g.drawCircle(+ 10, 0, 2);
          g.drawCircle(- 10, 0, 2);
          g.drawText(this._name(), - 10, + 10);
        }
    };
}