Dart SVG animation test

#import('dart:html');

main() {
    State state = new State();
}

class Point {
  num x=-69;
  num y=-666;

  Point(this.x,this.y);
}

class State {
    Point point = new Point(5,5);

    State () {
        display(what: "player", where: point);
        document.on.keyDown.add((event) => _handleKeyDown(event));
        document.on.keyUp.add((event) => _handleKeyUp(event));
    }

    void display({String what, Point where}) {
        var item = window.document.query("#$what");
        item.attributes["cx"] = where.y * 50;
        item.attributes["cy"] = where.x * 50;
    }

    void keyPressed(KeyboardEvent ev) {
        int code = ev.keyCode;
        switch(code) {
            case 37:
                point.y -= 1;
                break;
            case 38:
                point.x -= 1;
                break;
            case 39:
                point.y += 1;
                break;
            case 40:
                point.x += 1;
                break;
            default:
                print("unknown keycode $code");
        }
        display(what: "player", where: point);
    }

    void _handleKeyDown(KeyboardEvent event) {
        //print("Down: ${event.keyCode}");
        keyPressed(event);
    }

    void _handleKeyUp(KeyboardEvent event) {
        print("Up: ${event.keyCode}");
    }
}