getSize method

@override Future<Size?> getSize()

Implementation

@override
Future<Size?> getSize() async {
  /// clientWidth and clientHeight are in pixels,
  /// so we have to test for a larger size to minimize rounding errors.
  const multiplicator = 50;
  final fResolution = getResolution();
  var element = window.document.getElementById("millimetersPluginProbe");

  if (element == null) {
    element = DivElement()
      ..id = "millimetersPluginProbe"
      ..style.position = "absolute"
      ..style.top = "0"
      ..style.left = "0"
      ..style.width = "${multiplicator}mm"
      ..style.height = "${multiplicator}mm"
      ..style.visibility = "hidden";
    window.document.getElementsByTagName("body").first.append(element);
  }

  final ratio = Size(element.clientWidth / multiplicator,
      element.clientHeight / multiplicator);
  final resolution = (await fResolution)!;

  return Size(
      resolution.width / ratio.width, resolution.height / ratio.height);
}