In Document Server hardware we have two own devices:
In order to free Document Server software from hardware communication, we have two daemons to communicate in abstract way with those devices.
This daemon handles the LCD display with seven buttons and three multi-color leds. This daemon works as a browser, it can display xml pages. At start, daemon shows an index page with all processes listed. User can select a process and go to the process index page.
<page> <head> <title>Example</title> </head> <body> <text>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumyeirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diamvoluptua. At vero eos et accusam et justo duo dolores et</text> <button id="close">Ok</button> <img>/path/to/file.jpg</img> <text>Check Status</text> <button id="check">Check</button> </body> </page>
The process send its own index page at start. The daemon send the id of the button, if selected, and wait for the next page.
This daemon manage the login by a smart card. All process can listen the login and logout events by D-BUS. The process send a signal when an user is logged.