I\'m using the Qt library to show a slideshow on the second monitor when the user isn\'t using the second monitor. An example is the user playing a game in the first monitor
Widgets don't accept focus by default but presumably you haven't created a plain widget? Which subclass was it? QMainWindow or something else?
It's possible the window subclasses default to accepting focus so try explicitly calling QWidget::setFocusPolicy with Qt::NoFocus before calling QWidget::show().
Also, make sure you're not calling QWidget::activateWindow() on the window or any of its widgets at any point.