ui->graphicsView->setScene(m_scene);
    QLinearGradient grad(QPointF(0, 22), QPointF(0, 62));
    grad.setColorAt(0.0001, Qt::yellow);
    grad.setColorAt(0.5, Qt::red);
    grad.setColorAt(0.8, Qt::darkBlue);
    grad.setColorAt(1.0, Qt::darkMagenta);
    m_scene->setBackgroundBrush(grad);
    m_scene->update();