title: Application got/lost focus event
body: <p>I have a application that opens some child windows with the parameterless Show()-Methode. So the child-windows have no owner, which enabled them to be behind or in front of the main window.</p>
  
  <p>Now I would like to know if the whole application gets or losts focus. Is there a single event to do this?</p>
  
  <p>I tried OnActivate/OnDeactivate and OnGotFocus/OnLostFocus which only reports events for a single form. This means the OnLostFocus-event is fired when the application lost focus, but also if another form is focused.</p>