+typedef int (*page_callback_t) (void *user_data);
+
+struct page_callbacks_s
+{
+ page_callback_t top_left;
+ page_callback_t top_center;
+ page_callback_t top_right;
+ page_callback_t middle_left;
+ page_callback_t middle_center;
+ page_callback_t middle_right;
+ page_callback_t bottom_left;
+ page_callback_t bottom_center;
+ page_callback_t bottom_right;
+};
+typedef struct page_callbacks_s page_callbacks_t;
+
+#define PAGE_CALLBACKS_INIT \
+{ NULL, NULL, NULL, \
+ NULL, NULL, NULL, \
+ NULL, NULL, NULL }
+