Collaborative computer based system

摘要

The invention provides for protecting floating blocks of text or other portions of a shared data object in collaborative computer based system from simultaneous manipulation originating with two or more users. The collaborative computer based system includes a network connecting a plurality of terminals for communication. Each terminal includes an output display device and a user input device. A shared data object (116) is simultaneously accessible by a plurality of users of the system. Responsive to a user obtaining access to the shared data object, the user is assigned a cursor (130, 138, 140) available for display on the visual display devices of all current users. Responsive to movement by a user of his or her cursor, an attempt is made to establish a lock region (142, 134, 123) in the shared data object by determining position coordinates. If the position coordinates do not include any portion of any previously established lock region, a lock region associated with the user's cursor may be established. Movement of a cursor operates to release any prior lock region associated with the cursor if a new lock is established or if the cursor leaves the old lock.