PySide.QtGui.QShowEvent class provides an event that is sent when a widget is shown.
There are two kinds of show events: show events caused by the window system (spontaneous), and internal show events. Spontaneous ( QEvent.spontaneous() ) show events are sent just after the window system shows the window; they are also sent when a top-level window is redisplayed after being iconified. Internal show events are delivered just before the widget becomes visible.
