When the user wants to exit, he kill the Desktop. Andrea Desktop will send a disconnect request to
Andrea Server. Andrea Server receives that request and performs the following operations:
- Close all existing applications used by the user, including Andrea Desktop
which is closed the last
- Destroy object table and clear all enviroment
- Close Aspect Manager and other servers
- Wait for another connection
4. Why use Andrea?
Users will benefit because:
- they will be able to configure almost every detail from number size of virtual desktop to size,
font style and color of every object
- of possibility to choose prefered aspect by selecting an Aspect Manager
- of possibility to choose prefered servers, if aviables.
- is easy to use (Andrea object handling is the same independent by Aspect Manager)
- can use weak computers connected to network for running powerfull
- of possibility to use predefined settings from Server
- can use Andrea Desktop on platforms different than UNIX (if for that platform was developed
an Andrea Desktop). No emulator needed. For example in a X window it is possible to have an
entire Andrea Desktop.
- of possibility to use the same graphic enviroment from different hosts or
terminals, like telnet or rlogin but in graphic mode.
Programmers will benefit because:
- they will concentrate on what application does, not at how it will look,
because their applications will looks different using different Aspect Managers
(but always all objects will have same properties, including size and position
on the screen).
- the low-level details such as communications between objects and between GUI components
(Client and Server) are hidden into the objects themselves. Anyway we must
not forget to develop applications as much as possible independent of any GUI, separating data
processing by I/O operations and by interacting modes with users. This will make your software
not only portable on different platforms but also on different GUIs (try to think at
- an application will no longer need to be distributed on every workstation on a LAN. It will be maintained
on a single computer. Upgrade will consist only in changing the old version with a new one.
But, unlike Java applets, an application for Andrea will not be downloaded from server to
client. It will work on its host and will receive and send inputs and outputs to and from
- it is possible to develop an application that to display some information on
a machine and some on another. Or to display informations simultanous on several
machines. At this stage of project, cooperative works is not implemented. But it
will be considerated in future.
- can handle a large number of image formats, fonts, icons, and other visual resources.
Network administrators will benefit because:
- there is no need to install and configure an entire graphic enviroment on every workstation.
The only job will be to set up the Server and eventually to multiply on stations a standard personal
- the only machines that must be powerfull (upgraded) will be the server and applications host.
- it's possible to monitorize and record all messages sent by Andrea Server to Andrea Desktop and
to Aspect Manager and to see what a user is (was) doing without his knowledge.
5. Requirements and availability
A host that use a UNIX system
16 MB RAM (estimative)
gcc 2.6.3 or higher
Andrea Window System is distributed under GNU Public License 2.
Official Andrea Web Site is http://www.biosfarm.ro/~dragos/old_projects/Andrea
Maintainer e-mail address is dragos[at]biosfarm[dot]ro
6. About authors
- Radu Filip is graduate of Highschool of Informatics, Iasi, in year 1995.
Actually he is student of "Al. I. Cuza" University Iasi, Computer Science
Department. Visit him online at http://socrate.tuiasi.ro
- Dragos Acostachioaie is system programmer and UNIX administrator. Visit him
online at http://www.biosfarm.ro/~dragos
Note: this text was published in DAS'98
Papers Book, p. 33 - 42.