处理 expose 事件

src/include/event-adapter.h

@@ -89,6 +89,8 @@ typedef struct destroy_notify_event_t {
 
 typedef struct expose_event_t {
   event_type_t type;
+  xcb_window_t window;
+  uint32_t count;
 } expose_event_t;
 
 typedef struct motion_notify_event_t {