I have a little game I'm making in qt 4.1. Right now I'm doing this part while on a windows XP machine. I have a mainwindow which basicall gets created like this

Qt Code: 
  1. GUI::GUI() {
  2. 	// setting the max/min size
  3. 	setMinimumSize(350, 450);
  4. 	setMaximumSize(350, 450);
  5.  
  6. 	// filling the background with white
  7. 	//setAutoFillBackground(true);
  8. 	QPalette palette;
  9. 	palette.setColor(QPalette::Background, Qt::white);
  10. 	setPalette(palette);
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Now when i start a new game I want to overlay like a black widget that has like a 50% transparency so you can still see the little gameboard and such. I am having no such luck getting another widget to be transparent over my mainwindow

Here is my latest attempt at trying to get it to work

Qt Code: 
  1. QWidget *blackBG = new QWidget(this);
  2.     blackBG->setGeometry(0,0,350,450);
  3.     blackBG->setAutoFillBackground(true);
  4.     blackBG->setPalette(QPalette(QPalette::Background, Qt::black));
  5.     blackBG->setWindowOpacity(.5);
  6.     blackBG->show();
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any help? thanks!