Use Case Inventory

Draw Sketch

Precondition
Peers are added in the peer lists

Post condition
Sketch message is constructed and sent to peer

1. Capture sketch activites until pen up.
2. Increase the logical time for new event
3. Construct sketch message
4. For each peer in the list, send the message


Add Peer

Precondition
Peers IP address are known

Post condition
Peers are added in peer list

1. User input peer's ip address
2. User input peer's port number
3. User specify protocol
4. Add the peer into list

Search Peer

Precondition
Peers are in local area network
User use the correct port
Peers JSketchPad service has been started

Post condition
Found peers and add to peer list

1. User set up poinvoke a search for peers
2. System sends out queries to each IP in LAN
3. If any peer has JSketchPad service on the same port, add to the list

Add Message

Precondition
JSketchPad service is started in the correct port

Post condition
Sketch messages are processed/drawn on the screen

1. Remote JSketchPad sends out the sketch messages
2. System get and parse the message
3. If logical time is bigger, forward the logical clock
4. Execute the message

Setup My Info

Precondition
none

Post condition
My info is set up
If port number is different, new service is started

1. User input the port number and user name
2. If port number is different, restart service in new port.

Save Sketch

Precondition
There is persistable storage space

Post condition
Sketch message is saved

1. User request save
2. System save the sketch message in xml form

Open Sketch

Precondition
Saved file is available

Post condition
Sketch is re-constructed and sent to peer

Assign new logical timestamp for the reconstructed message
1. User request open
2. Load saved sketch data
3. Construct sketch message
4. For each peer in the list, send the message

Print Sketch

Precondition
Printing service is available (for PC)

Post condition
Sketch is printed

1. User request print
2. System print the sketch