XWN740

1
XWN740

• X-Windows
• Configuring and Using
• Building a Kiosk
• (Chapter 15)?

2
Agenda

• Building a Kiosk
• Definition / Purpose
• Selecting Kiosk Hardware
• Configuring X for a Kiosk
• Controlling Keyboard / Mouse
• Starting a Fullscreen Application
• Booting a Kiosk

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Building a Kiosk

• Definition / Purpose
• A kiosk is a publicly accessible computer display
  dedicated to a specific task or group of tasks.
  Here are some examples
• An electronic catalog station in a library
• An automated teller machine
• A ticket-vending machine
• A video wall
• A browsing and word-processing systemin an
  Internet café

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Building a Kiosk

• Challenge
• Kiosks differ from normal user-interface
  configurations in the way that they are managed
• Many kiosks do not offer normal windows, and
  instead run a single application that takes up
  the entire display others offer a limited
  selection of applications in a normal window
  environment.
• The user-interface hardware may also be more
  limited than in a desktop configuration. For
  example, there may be no keyboard or it may be
  more rugged. On the other hand, a trackball may
  be used instead of a mouse to control the pointer.

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Building a Kiosk

• Challenge
• If your kiosk will be used only by selected,
  trusted users (e.g., staff) or in a light-duty
  environment (Internet café), you may be able to
  get by with regular PC hardware.
• For any other purpose, you will probably want to
  invest in specialized hardware. Kiosk hardware is
  usually similar to desktop hardware but is
  typically more rugged and is often mounted in a
  custom-built case.
• Obviously, the wide range of kiosk applications
  means that there is also a wide range of possible
  kiosk hardware configurations what is suitable
  for a vending machine is not suitable for an
  Internet café.

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Building a Kiosk

• Monitor
• Although LCDs have long life, low-power
  consumption, and a flat surface, they usually
  have a soft plastic surface that is not
  sufficiently durable for public operation.
  Therefore, many kiosks use an LCD display covered
  by a glass, acrylic, or polycarbonate sheet, or a
  traditional CRT display.
• Since most kiosks are used from a standing
  position, the display may be farther from the
  user than a normal desktop display. Because some
  users may have visual impairment, it is best to
  use a large, bright, highcontrast display.
• The monitor should be positioned to accommodate
  users of many different heights, including people
  in wheelchairs.

7
Building a Kiosk

• Point Devices
• Mice are generally inappropriate for most kiosks,
  because the cord and position sensor are
  susceptible to damage.
• When the kiosk application requires pointer
  positioning (not always the case), a touchscreen,
  touchpad, or trackball are usually used.

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Building a Kiosk

• Keyboards
• Some kiosk applications require a full keyboard.
  Keyboards are susceptible to dirt, abraded
  labels, and liquids to deal with this, some
  kiosk builders use cheap keyboards that can be
  replaced inexpensively, while others choose
  rugged keyboards that resist liquids and can be
  easily cleaned. The keyboard can be mounted
  behind a metal or acrylic panel cut to shape.
• If your application does not require a full
  keyboard, you may be able to use a USB numeric
  keypad instead these are commonly marketed for
  use with laptops.There are a number of companies
  that make custom keycaps for use with keyboards
  or keypads
• Consider using touchscreens if possible...

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Building a Kiosk

• Touch Screens
• Warning Avoid using a touchscreen for password
  or PIN entries, since it's too easy for someone
  else to view (or video-record) the password as it
  being entered.

10
Building a Kiosk

• System Unit / Power Supply / Ventilation
• Most kiosks have an inner and outer case. The
  inner case is usually a standard or rackmount PC
  chassis.
• Because kiosks may run without inspection for
  weeks or months at a time, it is wise to select a
  basic but rugged chassis with a good power supply
  and extra fans for the system unit.
• Ventilation louvers should be positioned to allow
  good airflow while eliminating the possibility of
  liquids or foreign objects reaching internal
  components (an internal baffle can prove
  helpful).
• A good UPS with temperature monitoring is highly
  recommended.

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Building a Kiosk

• Configuring X Windows for a Kiosk
• Configuring X for a kiosk involves removing
  features to limit what the user can do. The three
  main configuration entries for this can be placed
  in the ServerFlags section
• Section "ServerFlags"
• Option "DontZoom"
• Option "DontZap"
• Option "DontVTSwitch"
• EndSection
• This prevents the user from changing the display
  resolution, terminating the X server, or
  switching virtual terminals.

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Building a Kiosk

• Configuring X Windows for a Kiosk
• During the development and testing of the kiosk,
  you may want to store the kiosk X configuration
  in a separate file (such as /etc/X11/xorg.kiosk.co
  nf) so that the default X server retains its
  original configuration.
• To start X with the kiosk configuration, supply
  the -config argument on the command line
• blue X -config /etc/X11/xorg.kiosk.conf

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Building a Kiosk

• Controlling the Keyboard
• Many programs have special functions that can be
  invoked using function keys, Alt-or Ctrl-key
  combinations, or Alt-Ctrl-Shift-modified mouse
  clicks.
• To prevent the users from accessing these
  functions, you can modify the keyboard map using
  the X Keyboard Extension or the xmodmap command.
• In most cases, the xmodmap command provides the
  simplest solution. Refer to X PowerTools text
  page 222 for the procedures to lock-down the
  keyboard...

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Building a Kiosk

• Controlling the Mouse
• If you decide to use a mouse or some type of
  pointing device, you should be aware that the
  middle and left mouse buttons can be used to
  access special features of some programs.
• You can configure which physical mouse buttons
  generate which button event using xmodmap.
  programs have special functions that can be
  invoked using function keys, Alt-or Ctrl-key
  combinations, or Alt-Ctrl-Shift-modified mouse
  clicks.

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Building a Kiosk

• Controlling the Mouse
• Some applications may not use the pointer mapping
  set by xmodmap and may continue to recognize all
  of the mouse buttons. In that case, you can
  disable all but the first mouse button by using
  the Buttons option in the mouse's InputDevice
  section of the X server configuration file
• Section "InputDevice"
• Identifier "Mouse0"
• Driver "mouse"
• Option "Buttons" "1"
• Option "Protocol" "IMPS/
• Option "Device" "/dev/input/
• EndSection

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Building a Kiosk

• Controlling the Mouse
• Refer to X PowerTools text page 223-224 for the
  procedures to lock-down the keyboard...

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Building a Kiosk

• Starting a Full Screen Application
• For a kiosk that runs only one application, it
  makes sense to omit the window manager and just
  start that one application in fullscreen mode.
• For many applications, this can be done with a
  command-line geometry specification on a 1024 x
  768 screen, this opens a full-screen xclock
• xclock -geometry 1024x76800
• You can also employ additional methods like one
  of the previous labs to run a web-browser and
  load up a webpage....

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Building a Kiosk

• Booting a Kiosk
• Most kiosk systems boot directly into the
  configured kiosk application. This can easily be
  configured and tested on a system that supports
  runlevels.
• Traditionally, runlevel 4 is unused, so it is a
  perfect candidate for a kiosk mode. It's easiest
  to start off by copying the scripts for a working
  runlevel. On a Fedora system, you could copy the
  runlevel 5 configuration with this command
• cp -l /etc/rc.d/rc5.d /etc/rc.d/rc4.d(note
  techniques varies by distro...)?

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Building a Kiosk

• Booting a Kiosk
• Next, disable all unnecessary services (this will
  depend on the kiosk application). For example, to
  delete the bluetooth services
• chkconfig bluetooth off
• Warning It is a good idea to leave ssh enabled,
  so that you can log in to the kiosk remotely for
  diagnostic and maintenance work.

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Building a Kiosk

• Booting a Kiosk
• You will then need to modify /etc/inittab to
  disable character-mode logins in runlevel 4
  (refer to page 232 in X Power Tools textbook)
• Append a line to this file to configure init to
  start the kiosk script (and respawn it if it
  dies) only in runlevel 4 (usuing the script name
  kiosh.sh as an example)
• ks4respawn/usr/local/kiosk/kiosk.sh

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Building a Kiosk

• Booting a Kiosk
• Whenever you change /etc/inittab, you must inform
  init of the change
• init q
• You can then test the kiosk mode by switching
  into from your current runlevel
• init 4
• Once you are confident that the kiosk is properly
  configured, you can change the default system
  boot runlevel by changing the initdefault line in
  /etc/inittab