MAINTAINING DOCUMENT STATE HISTORY

摘要

Methods and apparatus embodying techniques useful in systems for creating and modifying documents. A state history of a document for storing document states is maintained; and, whenever an interesting operation has occurred, the state of the document is automatically captured as it exists after the operation. The captured state is added to the state history. In another aspect, the techniques identify for a user on a display device a set of states that the document has been in by operation of the system; and enable the user to designate any arbitrary one of the identified states for further operations. The techniques may provide both linear and non-linear history.