I need to know when a window is restored or maximized. When this state-change happens, I need to take an action. I need to be careful however that this action only occurs once per state-change. I have the following code:

Qt Code: 
  1. void TextArea::changeEvent(QEvent* event)
  2. {
  3.     if (event->type() == QEvent::WindowStateChange)
  4.     {
  5.         if (static_cast<QWindowStateChangeEvent*>(event)->oldState() == windowState())
  6.         {
  7.             return;
  8.         }
  9.         if (isMaximized())
  10.         {
  11.  
  12.         }
  13.         else
  14.         {
  15.  
  16.         }
  17.     }
  18.     QWidget::changeEvent(event);
  19. }
To copy to clipboard, switch view to plain text mode 

Even with the preceding code, the action is firing twice with the old-state being 0 and new state being 2. Is there any way to ensure that this fires only once?