Synchronizing Clipboards of Multiple Computers

1
Synchronizing Clipboards of Multiple Computers

• Rob Miller Brad MyersSchool of Computer
  ScienceCarnegie Mellon University

UIST 99 November 7-10, 1999
2
One User, Many Computers

• Desktops
• Laptops
• PDAs
• Cell phones
• Pagers
• Car PCs
• Live Boards
• ...

• Windows
• Unix/X
• Macintosh
• Palm
• Windows CE
• ...

3
Inter-Application Data Transfer

• Same Computer
• Filesystem
• Drag-and-drop
• Clipboard

• Different Computers
• Network filesystem
• Pick-and-drop Rekimoto, UIST 97
• Hyperdragging Rekimoto, CHI 99
• Synchronized clipboards

4
Synchronized Clipboards

• Key idea synchronize the clipboards so that
  their contents are always identical.

• Users clipboard group consists of all computers
  in active personal use (ideally).

5
Advantages

• Cut/copy/paste is a familiar, universal UI
• All popular GUIs have a clipboard
• No extra hardware is required
• Synchronization is invisible
• User doesnt need to explicitly name source or
  target computer in each data transfer (unlike
  other network clipboards)

6
Limitations

• Best for one user only
• Two users cant actively share a synchronized
  clipboard
• Computers must be in close proximity
• Unsuitable for long-range transfers

7
Model 1 Client-Server
Server
X
X
Client
Client

• Network traffic on all client clipboard
  operations
• Client clipboards must be interceptable

8
Model 2 Peer-to-Peer
B
A
Peer
C
A
A
Peer
Peer

• No network traffic for local clipboard operations
• Clipboards must allow delayed data transfer

9
Prototype Uses Both Models

• PalmPilot client-server
• Palm clients connected to server PC by serial
  cable or cradle
• Windows, Unix/X peer-to-peer
• Java/RMI across the network
• Both models interoperate
• Just hook up server as a peer

10
Setting Up Clipboard Group

• PalmPilot plug/unplug Palm in cradle
• Clipboard group connection is automatic
• Windows, Unix add/remove hostnames
• Automatic discovery (e.g. Jini) would help
• My clipboard group should contain all devices Im
  actively using
• But perfect tracking is tricky

11
Security

• Authentication by popup dialog
• SSL, Kerberos, PGP, would help
• But all require some infrastructure trusted
  authorities, key management, etc.

12
Conclusion

• Synchronized clipboards extend the familiar
  clipboard model for seamless data transfer
  between computers
• Prototype (for Palm, Windows, Unix) is available
  at http//www.cs.cmu.edu/rcm/RemoteClip/