Writing International Applications for WindowsLast reviewed: January 15, 1998Article ID: Q65124 |
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3.00 3.10
WINDOWS
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SUMMARYThis article is part of a set of seven articles, collectively called the "Windows Developer's Notes." More information about the contents of the other articles can be found in the Microsoft Knowledge Base article:
ARTICLE-ID: Q65260 TITLE : The Windows Developer's NotesDownload INTLAPPS.EXE, a self-extracting file, from the Microsoft Software Library (MSL) on the following services:
MORE INFORMATIONMicrosoft(R) Windows(TM) version provides an environment that allows you to give your applications country and language independence. This document is a collection of information related to international support in Windows. For more information about functions mentioned in this document, see the documentation included with the Windows Software Development Kit (SDK) and Device Development Kit (DDK).
CREATING AN INTERNATIONAL APPLICATION To reach worldwide audiences with your products, you need to create applications that can be marketed in more than one country and that can be modified for new markets. An international application must have the following characteristics:
Ease of localization is the second goal to strive for when writing international applications. Localization can be defined as the process of adapting an application for a market other than the one for which it was originally designed. This adaptation involves translation of the product, addition of new features when required, and modification of the product to meet local needs. Applications should be developed so that localization is a fast and painless task. This document explains how to internationalize your Windows-based application.
ACHIEVING COUNTRY AND LANGUAGE INDEPENDENCE Windows 3.00 provides resources to help your applications achieve country and language independence. These resources consist of international information stored in the WIN.INI file and in language- sensitive Windows functions. By using these resources and following the guidelines described in this section, your application will produce the correct international behavior.
INTERNATIONAL INFORMATION IN WIN.INIThe [Intl] section of the WIN.INI file contains the current Windows country settings. These settings can be modified by the user through the Control Panel, or by the application through the WriteProfileString() function. Applications have access to the current country settings through the GetProfileInt() and GetProfileString() functions. Applications should read the required country settings at start-up, and should monitor the WM_WININICHANGE message to update its country settings accordingly, in case they are changed. The following is a list of the country settings stored in WIN.INI:
Setting Description
------- -----------
iCountry Country code. This value is based on the telephone
country code. The only exception is Canada, for which a
2 is used instead of 1 (1 is used by the United
States). Use this setting if your application has to
control a country-dependent feature not supported by
Windows 3.00.
sCountry String defining the selected country name.
sLanguage The national language selected by the user. Changing
the language using the Control Panel's International
dialog box will change the installed language-dependent
module. The language values are as follows:
Value Language
----- --------
dan Danish
dut Dutch
eng International English
fcf French Canadian
fin Finnish
frn French
ger German
ice Icelandic
itn Italian
nor Norwegian
por Portuguese
spa Spanish
swe Swedish
usa U.S. English
sList List separator. This character is used to separate
elements in a list. The list separator must be
different from the decimal separator to avoid conflicts
with lists of numbers.
iMeasure Measurement system selected by the user, where
0 = metric, 1 = English. Use this setting to control
measurement-dependent features of your application.
iTime Time format. This setting defines the time format: 12
hours or 24 hours, where 0 = 12-hour clock, 1 = 24-hour
clock.
sTime Time separator. This character is displayed between
hours and minutes, and between minutes and seconds.
s1159 In some countries, the time is displayed followed by a
trailing string (AM, for example). This setting
contains the trailing string used for times between
00:00 and 11:59.
s2359 Trailing string (PM, for example) for times between
12:00 and 23:59, when in 12-hour clock format, or
trailing string (GMT, for example) for any time in
24-hour clock format.
iTLZero When displaying time, this value specifies whether or
not the hours should have a leading zero. The
convention is 0 = no leading zero (9:15, for example),
1 = leading zero (09:15, for example).
iDate This is the Windows 2.x style for defining the date
format. It has been kept for compatibility reasons. We
recommend using sShortDate instead. The values for this
setting are:
0 = Month-Day-Year
1 = Day-Month-Year
2 = Year-Month-Day
sDate Date separator. Kept for compatibility with
Windows 2.x. Try using sShortDate instead.
sShortDate This is a new Windows 3.00 format. This string defines
a "date picture" of the short date format. More
information about the short date format can be stored
using this method. sShortDate accepts only the values
M, MM, d, dd, yy and yyyy. See sLongDate for
information about these values and pictures.
sLongDate This setting is like sShortDate, but it also can
contain strings mixed with days of the week, dates,
months, and years. The definition of this date picture
is as follows:
Value Item Format
----- ---- ------
M Month 1-12
MM Month 01-12
MMM Month Jan-Dec
MMMM Month January-December
d Day 1-31
dd Day 01-31
ddd Day Mon-Sun
dddd Day Monday-Sunday
yy Year 00-99
yyyy Year 1900-2040
Examples:
Date Picture Meaning
------------ -------
d MMMM, yyyy 9 January, 1989
dddd, MMMM d, yyyy Friday, February 7, 1989
M/d/yy 3/18/89
dd-MM-yyyy 18-03-1989
d 'of' MMMM, yyyy 9 of January, 1989
sCurrency This string defines the currency symbol of a given
country. Be very careful with this setting. Do not make
global replacements of currency amounts in your
application if the currency symbol is changed through
the Control Panel. Once the user has entered an amount
using certain currency, that currency should stay the
same. Also, be careful with this setting when sharing
files among users or applications.
iCurrency This setting defines the currency format. The
convention is:
0 = Currency symbol prefix, no separation ($1, for
example)
1 = Currency symbol suffix, no separation (1$)
2 = Currency symbol prefix, one character separation
($ 1)
3 = Currency symbol suffix, one character separation
(1 $)
iCurrDigits This value defines the number of digits used for the
fractional part of a currency amount.
iNegCurr This value defines the negative currency format. The
definition follows the convention:
0 = ($1)
1 = -$1
2 = $-1
3 = $1-
4 = (1$)
5 = -1$
6 = 1-$
7 = 1$-
In these examples, the dollar symbol represents any
currency symbol defined by sCurrency.
sThousand This is the symbol used to separate thousands in
numbers with more than three digits.
sDecimal Character used to separate the integer part from the
fractional part of a number.
iDigits Value defining the number of decimal digits that should
be used in a number.
iLzero This setting defines whether a decimal value less than
1.0 (and greater than -1.0) should contain a leading
zero.
0 = No leading zero (for example, .7)
1 = Leading zero (0.7)
LANGUAGE-SENSITIVE WINDOWS FUNCTIONSWindows 3.00 introduces the concept of national language. Language, in conjunction with country, allows Windows to describe more precisely the characteristics of a given geographical location. The following is a list Windows functions that behave differently, depending on the language selected:
AnsiLower() AnsiLowerBuff() AnsiUpper() AnsiUpperBuff() IsCharAlpha() IsCharAlphaNumeric() IsCharLower() IsCharUpper() lstrcmp() lstrcmpi() Comparing and Sorting StringsThe Windows 3.00 functions lstrcmp and lstrcmpi allow applications to compare and/or sort strings based on the natural language selected by the user. These functions take into account different alphabetical orderings, diacritical marks, and special cases that require character compression or expansion. It is very important to notice that these functions do not act the same way as do the C functions strcmp and strcmpi. The comparison done by lstrcmp and lstrcmpi is based on a primary value and a secondary value (see the following table). Each character has a primary and a secondary value. For example, in the following matrix, the letter "d" has a primary value of 4 and a secondary value of 2.
Primary
Values Secondary Values
------ ----------------
1 2 3 4 5 6 7 8 9 10 11 12 13 14
1 A A2 A3 A4 A5 A6 A7 a a2 a3 a4 a5 a6 a7
2 B b
3 C C2 c c2
4 D d
5 E E2 E3 E4 E5 e e2 e3 e4 e5
6 F f
*******************************************************************
NOTE: This table uses these character values because some accented
characters cannot easily be represented for electronic
transmission. The printed application note contains the actual
accented characters and may be easier to read and comprehend.
Capital letters precede the lowercase letters. The following is a
list of the accent codes:
A2 - A with a grave accent
A3 - A with an acute accent
A4 - A with a circumflex
A5 - A with a tilde
A6 - A with an umlaut
A7 - A with a circle
C2 - C with a cedilla
E2 - E with a grave accent
E3 - E with an acute accent
E4 - E with a circumflex
E5 - E with an umlaut
*******************************************************************
Examples of Primary and Secondary Sorting ValuesWhen performing the comparison of two strings, the primary value takes precedence over the secondary value. That is, the secondary value is ignored unless a comparison based on the primary value shows the strings as equivalent. The following examples show the effect of primary and secondary values on string comparisons:
Comparison Reason ---------- ------ A = A Primary values equal A < a Primary values equal, secondary values unequal (A < a) Ab < ab Primary values equal, secondary values unequal (A < a) ab < Ac Primary values unequal (b < c)Note, however, that lstrcmpi ignores the effect of case in determining secondary value. That is, when lstrcmpi is called to compare "AB" and "ab", the two strings will be equivalent. However, lstrcmpi does not ignore diacritical marks, so "Ab" precedes "(a6)b", regardless of whether the comparison is performed by lstrcmp or lstrcmpi. ("a6" is an "a" with an umlaut.) When comparing strings of different lengths, length takes precedence over secondary values. That is, the shorter string will always precede the longer string as long as the primary values in the shorter string equal the primary values of the equivalent characters in the longer string. For example, "ab" precedes "ABC", but "ABC" precedes "AD". Depending on the language module installed, some characters will be treated differently. For example, if the German language module is installed, the beta character expands to "ss". If the Spanish language module is installed, the characters "ch" will be treated as a single character that sorts between "c" and "d".
Case ConversionsThe case conversion functions AnsiLower(), AnsiLowerBuff(), AnsiUpper() and AnsiUpperBuff() depend on the language module installed. Different languages treat case conversions differently. Do not use the C case-conversion functions; they do not take into consideration characters with values more than 128.
Character Classification FunctionsThe functions IsCharAlpha(), IsCharAlphaNumeric(), IsCharLower(), and IsCharUpper() are also language dependent. Use these functions to attain language independence.
Handling Character Sets: ANSI Versus OEMOne of the main problems developers face when writing international Windows-based applications is handling characters sets. It is very important to understand ANSI and OEM. ANSI is the character set used internally by Windows and its applications. Windows does not recognize any character set other than ANSI. OEM is defined by Windows as the character set used by MS-DOS. The term "OEM" does not refer to a specific character set; instead, it refers to any of the different character sets (code pages) that can be installed and used by MS-DOS. Because Windows runs on top of MS-DOS, there must be a layer between Windows and MS-DOS that performs translations between ANSI and OEM. When Windows is first installed, the Windows Setup program looks at the MS-DOS-installed character set, and then installs the correct ANSI-OEM translation tables and Windows OEM fonts. Windows-based applications should use the Windows functions AnsiToOem() and OemToAnsi() when transferring information to and from MS-DOS. Also, applications should use the correct character set when creating filenames. For more information about handling filenames, see the following section. There is no one-to-one mapping between ANSI and OEM. Applying AnsiToOem() and then OemToAnsi() to a given string will not always result in the original string. Keep in mind that both ANSI and OEM are 8-bit character sets. Always use "unsigned char" instead of "signed char". Bugs that result from using "signed char" are very hard to track.
Handling FilenamesOne of the problems dealing with the ANSI and OEM character sets is the handling of filenames. Different applications do file handling differently, depending on factors such as speed, size, and programming style. This section describes the most common methods. The easiest way to deal with filenames in Windows is to use ANSI for all filenames, and use the functions _lcreat(), _lopen(), and OpenFile() to deal with MS-DOS and the OEM character set. Another way to deal with filenames is to use OpenFile() to obtain a fully qualified pathname, the szPathName field, from the OFSTRUCT data structure. Be very careful here. The szPathName field contains characters from the OEM character set. The szPathName field must first be converted to ANSI before it is used as a parameter for OpenFile(), other Windows functions, or in a dialog box. The following example shows this conversion: if (OpenFile("myfile.txt", &of, OF_EXISTS) == -1) {
OemToAnsi(of.szPathName, szAnsiPath);
OpenFile(szAnsiPath, &of, OF_CREATE);
}
Note that the value of of.szPathName must be converted from OEM to
ANSI.
The third, and perhaps most complicated, method of handling files is to directly call MS-DOS [using the DOS3Call() function or an INT 21H instruction]. You must ensure that your application always passes OEM characters to MS-DOS. Another problem occurs when applications try to create filenames in ANSI that have no equivalent characters in OEM. For example, the character E4 (E-circumflex) does not exist in code page 437 (437 is the standard U.S. extended ASCII character set). If the application tries to save the file (E4).TXT, Windows will convert (E4).TXT into E.TXT [by using the AnsiToOem() function], and then it will pass the file to MS-DOS. The end result is a confused user that doesn't understand what happened to his/her file. You can solve this problem by using the ES_OEMCONVERT and CBS_OEMCONVERT control styles. These styles (the first for edit controls and the second for combo boxes) will read the user's input and convert the typed character to a valid character (one that exists in the OEM character set). This way, the user will see on the screen the real filename that will be stored at the MS-DOS level.
Handling the KeyboardThe most important keyboard issue for international applications is the use of the VK_OEM keys as user input. The problem here is that the locations of the VK_OEM keys change, depending on the keyboard layout chosen by the user. The VkKeyScan() function is helpful in these cases. VkKeyScan() is used to translate an ANSI character into a virtual-key code plus a shift state. This function also could be used when one application has to send text to another application by simulating keyboard input. Some other useful functions are the following:
Handling WIN.INI, SYSTEM.INI, SETUP.INF, and Private Initialization FilesThe WIN.INI, SYSTEM.INI, and SETUP.INF files are ANSI files. Normally, applications do not touch SYSTEM.INI or SETUP.INF. For WIN.INI and private initialization files, applications should use the functions GetPrivateProfileInt(), GetPrivateProfileString(), GetProfileInt(), GetProfileString(), WritePrivateProfileString(), and WriteProfileString(). Make sure ANSI is always used with these functions. The section names and setting names in WIN.INI and private initialization files should be independent of the language of the application. Normally, all of these names should be in English. For example, in WIN.INI, the section name [Desktop] and the setting name Wallpaper should always remain in English so that applications in different languages can access the same information.
ACHIEVING EASY LOCALIZATION Creating applications that are easy to localize is not difficult if you follow a few basic rules.
ISOLATION OF LOCALIZABLE INFORMATIONThe most important rule for localization is to never mix functional code with strings, messages, or any other information that has to be modified. In a normal Windows-based application, all the menus, strings, and messages should be placed in the resource script (.RC) file. All the dialog-box information should be placed in the dialog script (.DLG) file. If you do this, there will be no need to recompile the executable file for a new localized version of the product. Just use the resource compiler (RC). Hard-coded strings (strings mixed with functional code) are the worst enemy of localization. Strings that are not meant to be modified (filenames, WIN.INI setting names, etc.) can be placed in the resource script file. In this case, the .RC file should contain comments documenting that the names are permanent. Better yet, mark what has to be translated (explaining limitations, if any) and what should not be modified. The better the documentation, the easier the localization. Place in the .RC files and .DLG files anything that could be a localization item. It is better to have extra information in these files than to have too little. In cases where an .RC or .DLG file cannot be used, place all the information in a file (such as an include file) that is separate from any functional code.
ALLOCATING EXTRA SPACE FOR STRINGSMany languages are more verbose than English; therefore, they require more space to hold strings or to display dialog boxes. There are cases, as with menus, where the space allocation is done dynamically. However, in most cases, the application must provide the space. The following table shows how much additional space should be allocated for strings of various lengths:
Length of
English Text Space Allocation
(In Characters) (In Addition to Text)
-------------- ---------------------
1-10 200 percent
11-20 100 percent
21-30 80 percent
31-50 60 percent
51-70 40 percent
70+ 30 percent
Avoid creating dense menus where most of the available space (a line,
for example) is already used up in the English version. Dialog boxes
should be designed so that items can be moved freely, allowing the
organization of the contents as the translation demands. Do not crowd
status bars with information. Even abbreviations are often longer in
different languages.
HANDLING FOREIGN SYNTAX AND GRAMMARNever make assumptions about syntax or grammar when dealing with foreign languages. The ordering of words can be different, and the number of words required is often greater than in English. All messages should be self contained, not dynamically assembled. For messages that have variables added to them at run time, do not make any assumptions about the position of the variable in the message. The way to handle variables in messages is by using the Windows function wsprintf(). For example, you could place in the .RC file the string containing the variable, as follows:
CannotOpen, "The application could not open the file %s"Use wsprintf() to incorporate the variable into the string, as follows:
LoadString(hInst, CannotOpen, lpFormat, MaxLen); wsprintf(FinalString, lpFormat, FileName);Avoid using a single word in more than one message. Words such as "None" can have different translations (different gender and number) depending on the context. Do not create plurals of words by adding "s". Keep two strings, one for the singular and one for the plural. Avoid parsing text to obtain information. Parsing normally assumes specific syntax. Avoid using slang, abbreviations, and jargon, since they are difficult to translate. When handling graphic objects such as bitmaps, cursors, and icons, try to avoid the use of embedded text. Text is difficult to modify when in graphical form. If you cannot avoid this, be careful about leaving enough space for translation, and try to create tools to simplify the modification. Graphic objects are also language dependent. Always look for graphic objects that represent international concepts.
OTHER RULESDo not hard code the position or size of any element on the screen. Remember that items will change position and size as they get translated. If you must define the size or position of certain object, place this definition in the .RC file. Be careful when using the CreateWindow() function. This function contains two parameters: lpClassName and lpWindowName. The lpClassName parameter should be constant and independent from localization. On the other hand, lpWindowName is the string that will appear in the caption bar and therefore should be localized. The string used for lpWindowName should be taken from the resources.
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