void evas_object_ref(Evas_Object *obj)

This increments the reference count of the object obj, which, if greater than 0, will defer deletion by evas_object_del() until all references are released back (counter back to 0). References cannot go below 0 and unreferencing past that will result in the reference count being limited to 0. References are limited to (2^32) -1 for an object. Referencing it more than this will result in it being limited to this value.

This is a very simple reference counting mechanism! For instance, Evas is not ready to check for pending references on a canvas deletion, or things like that. This is useful in scenarios where, inside a code block, callbacks exist which would possibly delete an object we are operating on afterwards. Then, one would evas_object_ref() it at the beginning of the block and evas_object_unref() it at the end. It would then be deleted at this point, if it should be.

Example

  evas_object_ref(obj);
  // action here...
  evas_object_smart_callback_call(obj, SIG_SELECTED, NULL);
  // more action here...
  evas_object_unref(obj);

See Also

evas_object_del()
evas_object_unref()

Evas_Object