#331 globla stylesheet bug

[Anonymous]

Hello there:
My environment QT5.12+VisualStudio2019+Qwt6.1.6
When trying your sample "refreshtest", I found a very serious bug.
I set the global stylesheet in QApplication: "qApp->setStyleSheet("style.qss");
everything is OK when opengl is turned off, when opengl is turned on , The waveform is abnormal.
after I call the replot function: the historical data is not cleared! The new plot is superimposed on the old plot.
If I comment out the style.qss about QWidget, it will be ok again

style.qss before modify
QWidget {
background-color: #252526;
border: 0px solid #2D2D30;
padding: 0px;
color: #E0E1E3;
selection-background-color: #346792;
selection-color: #E0E1E3;
}

style.qss after modify

.QWidget {
background-color: #252526;
border: 0px solid #2D2D30;
padding: 0px;
color: #E0E1E3;
selection-background-color: #346792;
selection-color: #E0E1E3;
}