#include <QApplication>
#include <QGuiApplication>

#include <QWidget>
#include <QFrame>

#include <QGridLayout>


int main(int argc, char *argv[])
{ // non-integer device-pixel ratio causes problems
  QGuiApplication::setHighDpiScaleFactorRoundingPolicy(Qt::HighDpiScaleFactorRoundingPolicy::PassThrough);

  // application
  QApplication app(argc,argv);

  // tested on 4K screen under Windows 10 with a device pixel ratio 1.5
  QFrame *frame = new QFrame();
  frame->setLineWidth(1);
  frame->setFrameShape(QFrame::Box);

  QGridLayout *layout = new QGridLayout();
  layout->addWidget(frame,0,0);

  // resize this widget to see the inconsistent line widths of the frame when
  // shown on screen with non-integer device pixel ratio
  QWidget widget;
  widget.setLayout(layout);
  widget.setMinimumSize(200,201);
  widget.show();

  return QApplication::exec();
}