procedure UpdateAnnotationObject(AnnotIndex: Integer; PageObj: Pointer);
| AnnotIndex | Integer. Zero-based index of the annotation on the current page. |
| PageObj | Pointer. Handle of an object already owned by that annotation, typically the Handle field of AnnotationObjectInfo. nil is ignored. |
Editing an object handle changes the object but leaves the annotation unaware, so its appearance is not rebuilt. This call marks the object as changed and refreshes the page, which is what makes the edit visible when the page renders or is saved
It applies to objects the annotation already owns; adding new artwork goes through AddPathToAnnotation
On a PDFium build without annotation object editing the call returns without changing anything