static void check_changed_cb(void *data, Evas_Object *obj, void *event_info) {
	//here we use check's state pointer passed in data
	if (*(Eina_Bool *) data) {
		dlog_print(DLOG_DEBUG, LOG_TAG, "checked");
	} else {
		dlog_print(DLOG_DEBUG, LOG_TAG, "unchecked");
	}
}

static void check_test(Evas_Object *parent) {
	//create a check
	Evas_Object *check = elm_check_add(parent);
	evas_object_move(check, 0, 50);
	evas_object_resize(check, 200, 30);
	elm_object_style_set(check, "popup");
	elm_object_text_set(check, "Label");

	//create an Eina_Bool variable for storing check's state
	Eina_Bool value;

	//connect this variable with the actual check's state
	elm_check_state_pointer_set(check, &value);

	//now you can use it in check's change callback
	evas_object_smart_callback_add(check, "changed", check_changed_cb, &value);

	//Check's state pointer can only be used for read operations. To change the state you have to use this function:
	elm_check_state_set(check, EINA_TRUE);

	evas_object_show(check);
}