Object-Associated Telepointer for Real-time Collaborative Document Editing Systems

Abstract

Telepointers are a real-time groupware interface feature to indicate where other users are pointing. None of existing telepointer techniques, however, is capable of tracking the reference object and preserving the relative position in the face of dynamic content and view changes in real-time collaborative document editing systems. In this paper, we report a novel Object-Associated Telepointer (OAT) technique with the following features in the face of dynamic content and view changes: (1) relocating telepointers to track the reference object, (2) preserving the position relative to the reference object, and (3) providing feedback of the telepointer relocation to the local user with a virtual local cursor. The key technique for supporting OAT is to extend the operational transformation technique with a generic Refer operation to support adjusting the reference object position. The OAT technique has been implemented in the CoWord system based on the transparent adaptation approach so that it can provide the OAT support to a range of realtime collaborative applications.