Window state change event data (event.window.*)
Defined in SDL_events.h
typedef struct SDL_WindowEvent
{
    Uint32 type;        /**< SDL_WINDOWEVENT */
    Uint32 timestamp;   /**< In milliseconds, populated using SDL_GetTicks() */
    Uint32 windowID;    /**< The associated window */
    Uint8 event;        /**< SDL_WindowEventID */
    Uint8 padding1;
    Uint8 padding2;
    Uint8 padding3;
    Sint32 data1;       /**< event dependent data */
    Sint32 data2;       /**< event dependent data */
} SDL_WindowEvent;