SDL_ActiveEvent - Application visibility event structure

SDL_ActiveEvent is a member of the SDL_Event union and is used when an event of type  SDL_ACTIVEEVENT  is
       reported.

       When  the mouse leaves or enters the window area a SDL_APPMOUSEFOCUS type activation event occurs, if the
       mouse entered the window then gain will be  1,  otherwise  gain  will  be  0.  A  SDL_APPINPUTFOCUS  type
       activation  event  occurs  when  the  application loses or gains keyboard focus. This usually occurs when
       another application is made active. Finally, a SDL_APPACTIVE type event occurs when  the  application  is
       either minimised/iconified (gain=0) or restored.

              Note:

              This event does not occur when an application window is first created.

       SDL_ActiveEvent - Application visibility event structure

SDL_Event, SDL_GetAppState

SDL                                          Tue 11 Sep 2001, 22:59                           SDL_ActiveEvent(3)

typeSDL_ACTIVEEVENT.gain                0 if the event is a loss or 1 if it is a gain.

       stateSDL_APPMOUSEFOCUS if mouse focus was gained or lost, SDL_APPINPUTFOCUS if input focus
                           was  gained  or  lost,  or SDL_APPACTIVE if the application was iconified (gain=0) or
                           restored(gain=1).

       typedef struct{
         Uint8 type;
         Uint8 gain;
         Uint8 state;
       } SDL_ActiveEvent;