Collaborative Editing Application Sharing Tool

Computer Supported Cooperative Work (CSCW) emerges as promising research field and has being paid more attention. It is a new emerging research field based on multiprinciple disciplines and has attracted much attention over the last few years. With the combination of computer technology and communication technology, CSCW pushes the traditional isolated work mode to group cooperative work mode ,and revolutionizes the way by which people work. It is sure that there will be a very broad application prospective with CSCW in the coming future.Collaboration transparency (application sharing) technology is able to convert legacy single-user application into cooperative application without modifying the source code, users are not motivated to abandon their favorite single user applications , a more plausible way is thus to add groupware features to single user applications . but almost all the existing application sharing system cannot provide the groupware features, e.g. concurrent control, group awareness。In this paper, I analyses the characters of traditional CSCW applications, the characters and the process of group work, the defects of traditional application sharing system, and the related technologies. According to above studies, a replicated application sharing structure based on Windows operating system is designed. This structure can better support group work style and fit the need of change from traditional editing to cooperative editing compared with traditional structures.In the communication service, the architecture of group communications is presented. Then we introduce IP multicast address and some multicast protocols. A multicast routing algorithm is presented on the analysis of the characteristic of real-time multicast. It can both minimize network cost and shorten network delay , and it can meet therequirement of application sharing.In cooperative editing, people can aware co-authors' any change explicit. In order to reduce network traffic and latency problem, I adopt the method of event capture and event replay, the local operation can execute immediately. According to the study of Windows message and API, a control program to intercept and replay events is designed.In application sharing, consistency control is the basic requirement to the system, and it is also very difficult. Concurrency control is the key technology of consistency control in CSCW, people have done lots of studies and got much achievement. But most research works can hardly satisfy the requirements of CSCW very well. The operation transformation concurrency control approaches are rather popular in real-time CSCW systems with fully replicated architecture, especially in text-based group editors, and two transformation algorithms are presented.In order to support multi-user edit synchronously in the relaxed WYSIWIS view, I present methods of consistency maintenance of telepointers and telepointers mapping, overloaded semantics of dynamic telepointers are designed, a total monitor is given in order to improve the flexibility and usability of awareness. In the process of awareness, the flexible filtering of awareness information improves the efficiency of cooperative awareness.At last, a system of Real Time Collaboration Editor -CoNotepad is presented through the research of the related technologies.