Does it work using setOpacity for you? I have tried to use it but as an effect the entire window (including all the children) gets transparent, and not only the background.
for eg: using Qt 4.x
it was easy, by using setAttribute(Qt::WA_TranslucentBackground); and viewer.setStyleSheet("background:transparent;");
Q_DECL_EXPORT int main(int argc, char *argv)
QScopedPointer<QApplication> app(createApplication(argc, argv));
But I have no clue how to port the previous code to Qt5, and keeping the transparent background?
any working solution here?