1. Unicode and Keyboards on Windows
25 March 2003
Unicode and Keyboards on Windows
Michael Kaplan Cathy Wissink
Globalization Infrastructure and Font Technology
Windows International
Microsoft
23rd Internationalization and Unicode Conference

2. Who is this talk geared towards?
This is a high-level introduction to keyboards on Windows, assuming no prior knowledge.
Audience:
Developers new to concept
People who need to understand keyboards enough to understand how applications can work with them
Not completely intended to be a “nuts and bolts” talk
25 March 2003
Prague, Czech Republic (IUC23)

3. Keyboards are simple, right?
Fonts
Rendering engines
135 different locales on Windows
Custom keyboard layouts
Turns out they are not so simple!
25 March 2003
Prague, Czech Republic (IUC23)

4. Keyboard Layout, defined
A collection of data for each keystroke and shift state combination with a particular keyboard driver (DLL)
In other words, it is not the keyboard hardware but the software that connects the hardware to the system
25 March 2003
Prague, Czech Republic (IUC23)

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Anatomy of a keystroke
User presses a key
Key contains a scan code
Keyboard layout DLL maps the scan code to a virtual key (VK)
OS sends the VK to the application
If asked, the DLL maps the VK/shift state to characters (if they are assigned)
25 March 2003
Prague, Czech Republic (IUC23)

6. Prague, Czech Republic (IUC23)
25 March 2003
Prague, Czech Republic (IUC23)

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Language features
single character keystrokes
ligatures
dead keys
shift states
SGCap
Caps lock key
25 March 2003
Prague, Czech Republic (IUC23)

8. Prague, Czech Republic (IUC23)
Ligatures
For keyboard layouts, not the same as the typographic/linguistic term
A combination of 2 to 4 UTF-16 code points inserted by a single keystroke
25 March 2003
Prague, Czech Republic (IUC23)

9. Examples of ligatures on keyboard
Tamil keyboard in the shifted state, showing linguistic characters Sri, Ksa, and others as ligatures
25 March 2003
Prague, Czech Republic (IUC23)

10. Prague, Czech Republic (IUC23)
Dead keys
A combination of two keystrokes to insert a single character
Used often in European languages for diacritics
Called “dead” since the first keystroke does not appear to do anything
Not intuitive to people who are not used to them
25 March 2003
Prague, Czech Republic (IUC23)

11. Dead key example: Diaeresis on the Finnish keyboard
Input keys
Type ¨ (deadkey)
Type ¨ + a
Type ¨ + A
Type ¨ + o
Type ¨ + O
...
Type ¨ + <space>
Result
Nothing ä Ä ö Ö
...
¨ (spacing diaeresis)
25 March 2003
Prague, Czech Republic (IUC23)

12. Prague, Czech Republic (IUC23)
Shift states
Only physical keys to work with on the keyboard
Shift states expand that number by many times
For languages with casing, usually they are cased variants of each other
More shift states available (AltGr, Ctrl)
25 March 2003
Prague, Czech Republic (IUC23)

13. The Greek Keyboard, shifted and unshifted
25 March 2003
Prague, Czech Republic (IUC23)

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Caps lock
Usually intended to be a persistent Shift keypress (in other words, it acts like a typewriter caps lock)
Generally used to get at shift state without having to press two keys concurrently
Often used with cased languages
May do nothing in languages without case, or be used for other purposes
25 March 2003
Prague, Czech Republic (IUC23)

15. Prague, Czech Republic (IUC23)
SGCap
Advanced usage of the Caps Lock key
Used by Swiss German, Czech, and Hebrew keyboards
Adds two additional shift states
Only intuitive to people who understand the mechanism
25 March 2003
Prague, Czech Republic (IUC23)

16. Prague, Czech Republic (IUC23)
APIs
keybd_event
MapVirtualKey[Ex]
OemKeyScan
SendInput
ToAscii[Ex]
ToUnicode[Ex]
VkKeyScan[Ex]
The APIs allow developers to do the same mappings the OS does when moving between scan codes, VKs, and characters.
25 March 2003
Prague, Czech Republic (IUC23)

17. Factors in keyboard layout creation
National/regional standard?
What languages need to be supported?
Is the set of characters needed for the language complete?
Focus on code points and not glyphs?
Do all required characters exist in Unicode?
Consistent use of features such as dead keys, ligatures, etc.?
25 March 2003
Prague, Czech Republic (IUC23)

18. Prague, Czech Republic (IUC23)
Where do IMEs fit in?
For most languages, they don’t!
For CJK languages, even 47 keys X 8 shift states is not enough
Different mechanisms and APIs are used for IME interaction
More information can be found in the Platform SDK (
25 March 2003
Prague, Czech Republic (IUC23)

19. Prague, Czech Republic (IUC23)
FAQs about keyboards
Does Microsoft make these layouts up?
How do I add every glyph for my language?
Don’t I need an IME?
How do I replace the layout for my language if I do not like the one provided?
How do I add my own keyboard layout?
25 March 2003
Prague, Czech Republic (IUC23)

20. MSKLC Microsoft Keyboard Layout Creator
Create new keyboard layouts:
Brand new layouts
Modified from existing keyboards
Deploy the created keyboard layout to NT4, Win2000, WinXP, or Win Server 2003 machines
Save the definition of the keyboard for later development
25 March 2003
Prague, Czech Republic (IUC23)

21. Prague, Czech Republic (IUC23)
MSKLC demos
25 March 2003
Prague, Czech Republic (IUC23)

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Other References
This tutorial's corresponding paper
Windows Keyboard Layouts
Nadine Kano, Developing International Software (out of print, but still available on the web)
New! Developing International Software , 2nd edition
Internationalization with Visual Basic
Get on the MSKLC Beta!
25 March 2003
Prague, Czech Republic (IUC23)

23. Prague, Czech Republic (IUC23)
Questions?
25 March 2003
Prague, Czech Republic (IUC23)

24. Don't forget to fill out your evaluations!
Unicode and Keyboards on Windows
25 March 2003
Prague, Czech Republic (IUC23)