Implementation

KDE Kiosk Mode HOWTO
Prev |  |

# 3. Implementation

## 3.1. Source Code Patches

Some files in kdebase-2.1.1 have to be patched:

- appletop_mnu.cpp.patch: Applets on the panel can be moved and removed, but the Preferences dialog is disabled.

- k_mnu.cpp.patch: Run Command... and Configure Panel entries are removed from the standard K Menu

- khc_man.cc.patch: Online Help is completely disabled. This would open konqueror.

- konq_popupmenu.cc.patch: right-mouse menu on icons on the desktop are reduced to Cut, Copy, Paste, Delete, ... but no Open With ..., no Edit File Type... and no Poperties... dialogs.

- pagerapplet.cpp.patch: on minipager selection of type (Preview, Number, Name) is disabled. this caused trouble in multihead environment.

- panel.cpp.patch: right mouse menu on Panel is disabled.

## 3.2. Global modifications

Instead of a dcop call, a program screensaver is executed, which must be found in the `PATH`. Just create a script called screensaver with the following contents:

    #!/bin/bash

    dcop kdesktop KScreensaverIface lock

make it executable and put it in `$KDEDIR/bin`.

Instead of the normal procedure, a program klogout is called, which must be found in the `PATH`. Create a script called klogout with the following contents:

    #!/bin/bash

    dcop kdesktop KDesktopIface logout

make it executable and put it in `$KDEDIR/bin`, where `$KDEDIR` is the install directory of KDE and `$KDEDIR/bin` is found in your `PATH`.

- krootwm.cc.patch: klogout is executed instead of a dcop call

- systemtrayapplet.cpp.patch: again call of klogout and screensaver instead of dcop calls.

- workspace.cpp.patch: call of klogout instead of dcop call.

Everything else can be done with normal configuration, that is: (Configuration files can be found in `$KDEDIR/share/config`) Remove Trash, Templates and Autostart Icons from the desktop and disable Alt+F2 by modifying `kdeglobals`. Make sure the following entries exist:

    [Paths]

    Trash=$HOME/.kde2/Trash/

    Autostart=$HOME/.kde2/Autostart/

    Templates=$HOME/.kde2/Templates/

    Desktop=$HOME/.kde2/Desktop/

    [Global Keys]

    Execute command=

(it may be `.kde` instead of `.kde2`)

disable Desktop menu and tips on start. Make sure the following entry exists in `kdesktoprc`:

    [Mouse Buttons]

    Right=

    [General]

    TipsOnStart=false

You could also login as the special user, and configure it only for him, then the config files are found in `$KDEHOME/share/config` where `$KDEHOME` is normally `$HOME/.kde`.

## 3.3. How to set the variable KDE_MODE

To answer this, you must understand what happens after you successfully authorized yourself to the system: Depending on your distribution, some scripts are executed, from which one should be modified to set `KDE_MODE`. There is a script called Xsession under `/etc/X11/xdm` or `/usr/X11R6/lib/xdm`, which you could modify, or startkde, that is located under `$KDEDIR/bin`. Note however, that the variable must be set prior to calling the kde processes.

Since we had the need to make a setup for a big environment (now reaching 300 users) we wrote an application that enables us to administer. It also creates the KDE Menus. It writes a file called `.env.sh` in a user's home directory, that will be sourced in Xsession. That is what you could do. So you could put in `.env.sh` of that specific user's home directory:

    #!/bin/sh

    KDE_MODE="restricted"

    export KDE_MODE

and add to Xsession, somewhere prior to calling startkde:

    if [ -f $HOME/.env.sh ]; then

        . $HOME/.env.sh

    fi

We also have two kdedirs that looks like to separate installations of KDE, this was neccessary so "normal" users could still have a full-featured KDE. So we have an original kdedir, and a restricted kdedir, in which we removed entries under `share/applnk` and set the variable `KDEDIR` (under KDE 2 the variable `KDEDIRS` was introduced but `KDEDIR` is still used). The files under `share/applnk` make up the menu. Caution, you cannot just remove all files there, because some are needed to initialize KDE.

You also set the Variable `KDEDIR` in Xsession, after sourcing `.env.sh` like this:

    case "$KDE_MODE" in

        restricted)

            KDEDIR=/usr/local/kde/restricted_kdedir

            ;;

        *)

            KDEDIR=/usr/local/kde

    esac

    export KDEDIR

Replace `/usr/local/kde` with the install directory of your KDE. The contents of `/usr/local/kde/restricted_kdedir` looks like:

    bin -> ../bin

    cgi-bin -> ../cgi-bin

    etc -> ../etc

    lib -> ../lib

    share

only share is a real directory, every other directory is a symbolic link pointing to original kdedir. `/usr/local/kde/restricted_kdedir/share` has the following contents:

    aclocal -> ../../share/aclocal

    applnk

    apps -> ../../share/apps

    autostart -> ../../share/autostart

    config -> ../../share/config

    doc -> ../../share/doc

    fonts -> ../../share/fonts

    icons -> ../../share/icons

    locale -> ../../share/locale

    mimelnk -> ../../share/mimelnk

    services -> ../../share/services

    servicetypes -> ../../share/servicetypes

    sounds -> ../../share/sounds

    templates -> ../../share/templates

    wallpapers -> ../../share/wallpapers

only applnk is a real directory. As a minimal requirement remove everything except:

    Settings/Peripherals/mouse.desktop

    Settings/LookNFeel/background.desktop

                      /colors.desktop

                      /kwinoptions.desktop

                      /style.desktop

                      /virtualdesktops.desktop

under `/usr/local/kde/restricted_kdedir/share/applnk`

Prev | Home |
Motivation |  |