# 10 Drawing Board

### Michael Mehl, Ralf Scheidhauer, Christian Schulte and Gert Smolka

[ Start Applet | How to enable Applets ]

The drawing board allows multiple, distributed users to create and manipulate graphics. All users have the same, consistent view of the drawing.

## Drawing

Tools

  The selected tool determines the kind of graphical object that is created when clicking the drawing area.

Create

  Clicking over the drawing area, a graphical object as determined by the selected is created at the mousposition.

Modify

  Object can be modified by clicking them with the middle mouse button. While they are modified other users can not alter the particulat object.

Delete

  Clicking an object with the right mouse button deletes it.

## Mailing Applets

Pressing Mail Applet, generates a new board applet on the fly and sends it by mail. The recipient can execute the applet and can by this join into the existing drawing board.

Note that mailing applets is currently not possible on windows platforms at all. In addition, mailing applets relies on the program `metasend`, which is part of the `metamail` package. A discussion of the software package you can find in [Pee95]. The package is available at

North America | `ftp://thumper.bellcore.com/pub/nsb/mm2.7.tar.Z`
Europe | `ftp://ftp.funet.fi/pub/unix/mail/metamail/mm2.7.tar`

Most Linux distributions I am aware of also include the package.

The currently participating users are listed by their mail address in the `Users` area.

## Saving Applets

Pressing Save Applet, generates a new board applet on the fly and saves it to a pickle. Executing the pickled applet joins into the drawing board from which the applet was saved.

## Implementation