revised topic overviews (letters g,h)

[wxWidgets.git] / docs / doxygen / overviews / unicode.h

diff --git a/docs/doxygen/overviews/unicode.h b/docs/doxygen/overviews/unicode.h
index 810d17d55cdfd8a4968d26ba0774e646b8c29383..fb944794d85be4b33d3866b59d0c958bd76677b5 100644 (file)
--- a/docs/doxygen/overviews/unicode.h
+++ b/docs/doxygen/overviews/unicode.h
@@ -7,9 +7,9 @@
 /////////////////////////////////////////////////////////////////////////////
 
 /*!
 /////////////////////////////////////////////////////////////////////////////
 
 /*!

- 
- @page unicode_overview Unicode support in wxWidgets
- 
+
+ @page overview_unicode Unicode support in wxWidgets
+

  This section briefly describes the state of the Unicode support in wxWidgets.
  Read it if you want to know more about how to write programs able to work with
  characters from languages other than English.
  This section briefly describes the state of the Unicode support in wxWidgets.
  Read it if you want to know more about how to write programs able to work with
  characters from languages other than English.


@@ -19,10 +19,10 @@
  @ref unicodeoutsidewxw_overview
  @ref unicodesettings_overview
  @ref topic8_overview
  @ref unicodeoutsidewxw_overview
  @ref unicodesettings_overview
  @ref topic8_overview

- 
- 
+
+

  @section whatisunicode What is Unicode?
  @section whatisunicode What is Unicode?

- 
+

  wxWidgets has support for compiling in Unicode mode
  on the platforms which support it. Unicode is a standard for character
  encoding which addresses the shortcomings of the previous, 8 bit standards, by
  wxWidgets has support for compiling in Unicode mode
  on the platforms which support it. Unicode is a standard for character
  encoding which addresses the shortcomings of the previous, 8 bit standards, by


@@ -41,24 +41,24 @@
  from using Unicode because they will work more efficiently - there will be no
  need for the system to convert all strings the program uses to/from Unicode
  each time a system call is made.
  from using Unicode because they will work more efficiently - there will be no
  need for the system to convert all strings the program uses to/from Unicode
  each time a system call is made.

- 
+

  @section unicodeandansi Unicode and ANSI modes
  @section unicodeandansi Unicode and ANSI modes

- 
+

  As not all platforms supported by wxWidgets support Unicode (fully) yet, in
  many cases it is unwise to write a program which can only work in Unicode
  environment. A better solution is to write programs in such way that they may
  be compiled either in ANSI (traditional) mode or in the Unicode one.
  This can be achieved quite simply by using the means provided by wxWidgets.
  Basically, there are only a few things to watch out for:
  As not all platforms supported by wxWidgets support Unicode (fully) yet, in
  many cases it is unwise to write a program which can only work in Unicode
  environment. A better solution is to write programs in such way that they may
  be compiled either in ANSI (traditional) mode or in the Unicode one.
  This can be achieved quite simply by using the means provided by wxWidgets.
  Basically, there are only a few things to watch out for:

- 
- 
+
+

   Character type (@c char or @c wchar_t)
   Literal strings (i.e. @c "Hello, world!" or @c '*')
   String functions (@c strlen(), @c strcpy(), ...)
   Character type (@c char or @c wchar_t)
   Literal strings (i.e. @c "Hello, world!" or @c '*')
   String functions (@c strlen(), @c strcpy(), ...)

-  Special preprocessor tokens (@c __FILE__, @c __DATE__ 
+  Special preprocessor tokens (@c __FILE__, @c __DATE__

  and @c __TIME__)
  and @c __TIME__)

- 
- 
+
+

  Let's look at them in order. First of all, each character in an Unicode
  program takes 2 bytes instead of usual one, so another type should be used to
  store the characters (@c char only holds 1 byte usually). This type is
  Let's look at them in order. First of all, each character in an Unicode
  program takes 2 bytes instead of usual one, so another type should be used to
  store the characters (@c char only holds 1 byte usually). This type is


@@ -73,69 +73,69 @@
  Of course, the usual standard C functions don't work with @c wchar_t
  strings, so another set of functions exists which do the same thing but accept
  @c wchar_t * instead of @c char *. For example, a function to get the
  Of course, the usual standard C functions don't work with @c wchar_t
  strings, so another set of functions exists which do the same thing but accept
  @c wchar_t * instead of @c char *. For example, a function to get the

- length of a wide-character string is called @c wcslen() (compare with 
+ length of a wide-character string is called @c wcslen() (compare with

  @c strlen() - you see that the only difference is that the "str" prefix
  standing for "string" has been replaced with "wcs" standing for "wide-character
  string").
  And finally, the standard preprocessor tokens enumerated above expand to ANSI
  strings but it is more likely that Unicode strings are wanted in the Unicode
  @c strlen() - you see that the only difference is that the "str" prefix
  standing for "string" has been replaced with "wcs" standing for "wide-character
  string").
  And finally, the standard preprocessor tokens enumerated above expand to ANSI
  strings but it is more likely that Unicode strings are wanted in the Unicode

- build. wxWidgets provides the macros @c __TFILE__, @c __TDATE__ 
+ build. wxWidgets provides the macros @c __TFILE__, @c __TDATE__

  and @c __TTIME__ which behave exactly as the standard ones except that
  they produce ANSI strings in ANSI build and Unicode ones in the Unicode build.
  To summarize, here is a brief example of how a program which can be compiled
  in both ANSI and Unicode modes could look like:
  and @c __TTIME__ which behave exactly as the standard ones except that
  they produce ANSI strings in ANSI build and Unicode ones in the Unicode build.
  To summarize, here is a brief example of how a program which can be compiled
  in both ANSI and Unicode modes could look like:

- 
+

  @code
  #ifdef __UNICODE__
      wchar_t wch = L'*';
      const wchar_t *ws = L"Hello, world!";
      int len = wcslen(ws);
  @code
  #ifdef __UNICODE__
      wchar_t wch = L'*';
      const wchar_t *ws = L"Hello, world!";
      int len = wcslen(ws);

- 
+

      wprintf(L"Compiled at %s\n", __TDATE__);
  #else // ANSI
      char ch = '*';
      const char *s = "Hello, world!";
      int len = strlen(s);
      wprintf(L"Compiled at %s\n", __TDATE__);
  #else // ANSI
      char ch = '*';
      const char *s = "Hello, world!";
      int len = strlen(s);

- 
+

      printf("Compiled at %s\n", __DATE__);
  #endif // Unicode/ANSI
  @endcode
      printf("Compiled at %s\n", __DATE__);
  #endif // Unicode/ANSI
  @endcode

- 
+

  Of course, it would be nearly impossibly to write such programs if it had to
  be done this way (try to imagine the number of @c #ifdef UNICODE an average
  program would have had!). Luckily, there is another way - see the next
  section.
  Of course, it would be nearly impossibly to write such programs if it had to
  be done this way (try to imagine the number of @c #ifdef UNICODE an average
  program would have had!). Luckily, there is another way - see the next
  section.

- 
+

  @section unicodeinsidewxw Unicode support in wxWidgets
  @section unicodeinsidewxw Unicode support in wxWidgets

- 
+

  In wxWidgets, the code fragment from above should be written instead:
  In wxWidgets, the code fragment from above should be written instead:

- 
+

  @code
  wxChar ch = wxT('*');
      wxString s = wxT("Hello, world!");
      int len = s.Len();
  @endcode
  @code
  wxChar ch = wxT('*');
      wxString s = wxT("Hello, world!");
      int len = s.Len();
  @endcode

- 
+

  What happens here? First of all, you see that there are no more @c #ifdefs
  at all. Instead, we define some types and macros which behave differently in
  the Unicode and ANSI builds and allow us to avoid using conditional
  compilation in the program itself.
  What happens here? First of all, you see that there are no more @c #ifdefs
  at all. Instead, we define some types and macros which behave differently in
  the Unicode and ANSI builds and allow us to avoid using conditional
  compilation in the program itself.

- We have a @c wxChar type which maps either on @c char or @c wchar_t 
+ We have a @c wxChar type which maps either on @c char or @c wchar_t

  depending on the mode in which program is being compiled. There is no need for
  depending on the mode in which program is being compiled. There is no need for

- a separate type for strings though, because the standard 
+ a separate type for strings though, because the standard

  #wxString supports Unicode, i.e. it stores either ANSI or
  Unicode strings depending on the compile mode.
  Finally, there is a special #wxT() macro which should enclose all
  literal strings in the program. As it is easy to see comparing the last
  fragment with the one above, this macro expands to nothing in the (usual) ANSI
  mode and prefixes @c 'L' to its argument in the Unicode mode.
  #wxString supports Unicode, i.e. it stores either ANSI or
  Unicode strings depending on the compile mode.
  Finally, there is a special #wxT() macro which should enclose all
  literal strings in the program. As it is easy to see comparing the last
  fragment with the one above, this macro expands to nothing in the (usual) ANSI
  mode and prefixes @c 'L' to its argument in the Unicode mode.

- The important conclusion is that if you use @c wxChar instead of 
+ The important conclusion is that if you use @c wxChar instead of

  @c char, avoid using C style strings and use @c wxString instead and
  don't forget to enclose all string literals inside #wxT() macro, your
  program automatically becomes (almost) Unicode compliant!
  Just let us state once again the rules:
  @c char, avoid using C style strings and use @c wxString instead and
  don't forget to enclose all string literals inside #wxT() macro, your
  program automatically becomes (almost) Unicode compliant!
  Just let us state once again the rules:

- 
- 
+
+

   Always use @c wxChar instead of @c char
   Always enclose literal string constants in #wxT() macro
  unless they're already converted to the right representation (another standard
   Always use @c wxChar instead of @c char
   Always enclose literal string constants in #wxT() macro
  unless they're already converted to the right representation (another standard


@@ -143,11 +143,11 @@
  need for @c wxT() in this case) or you intend to pass the constant directly
  to an external function which doesn't accept wide-character strings.
   Use @c wxString instead of C style strings.
  need for @c wxT() in this case) or you intend to pass the constant directly
  to an external function which doesn't accept wide-character strings.
   Use @c wxString instead of C style strings.

- 
- 
- 
+
+
+

  @section unicodeoutsidewxw Unicode and the outside world
  @section unicodeoutsidewxw Unicode and the outside world

- 
+

  We have seen that it was easy to write Unicode programs using wxWidgets types
  and macros, but it has been also mentioned that it isn't quite enough.
  Although everything works fine inside the program, things can get nasty when
  We have seen that it was easy to write Unicode programs using wxWidgets types
  and macros, but it has been also mentioned that it isn't quite enough.
  Although everything works fine inside the program, things can get nasty when


@@ -155,46 +155,46 @@
  ANSI strings (a notable exception is the entire Win32 API which accepts either
  Unicode or ANSI strings and which thus makes it unnecessary to ever perform
  any conversions in the program). GTK 2.0 only accepts UTF-8 strings.
  ANSI strings (a notable exception is the entire Win32 API which accepts either
  Unicode or ANSI strings and which thus makes it unnecessary to ever perform
  any conversions in the program). GTK 2.0 only accepts UTF-8 strings.

- To get an ANSI string from a wxString, you may use the 
+ To get an ANSI string from a wxString, you may use the

  mb_str() function which always returns an ANSI
  mb_str() function which always returns an ANSI

- string (independently of the mode - while the usual 
+ string (independently of the mode - while the usual

  #c_str() returns a pointer to the internal
  representation which is either ASCII or Unicode). More rarely used, but still
  useful, is wc_str() function which always returns
  the Unicode string.
  #c_str() returns a pointer to the internal
  representation which is either ASCII or Unicode). More rarely used, but still
  useful, is wc_str() function which always returns
  the Unicode string.

- Sometimes it is also necessary to go from ANSI strings to wxStrings.  
+ Sometimes it is also necessary to go from ANSI strings to wxStrings.

  In this case, you can use the converter-constructor, as follows:
  In this case, you can use the converter-constructor, as follows:

-  
- 
+
+

  @code
  const char* ascii_str = "Some text";
     wxString str(ascii_str, wxConvUTF8);
  @endcode
  @code
  const char* ascii_str = "Some text";
     wxString str(ascii_str, wxConvUTF8);
  @endcode

- 
+

  This code also compiles fine under a non-Unicode build of wxWidgets,
  but in that case the converter is ignored.
  For more information about converters and Unicode see
  the @ref mbconvclasses_overview.
  This code also compiles fine under a non-Unicode build of wxWidgets,
  but in that case the converter is ignored.
  For more information about converters and Unicode see
  the @ref mbconvclasses_overview.

- 
+

  @section unicodesettings Unicode-related compilation settings
  @section unicodesettings Unicode-related compilation settings

- 
+

  You should define @c wxUSE_UNICODE to 1 to compile your program in
  Unicode mode. This currently works for wxMSW, wxGTK, wxMac and wxX11. If you
  You should define @c wxUSE_UNICODE to 1 to compile your program in
  Unicode mode. This currently works for wxMSW, wxGTK, wxMac and wxX11. If you

- compile your program in ANSI mode you can still define @c wxUSE_WCHAR_T 
+ compile your program in ANSI mode you can still define @c wxUSE_WCHAR_T

  to get some limited support for @c wchar_t type.
  This will allow your program to perform conversions between Unicode strings and
  to get some limited support for @c wchar_t type.
  This will allow your program to perform conversions between Unicode strings and

- ANSI ones (using @ref mbconvclasses_overview) 
+ ANSI ones (using @ref mbconvclasses_overview)

  and construct wxString objects from Unicode strings (presumably read
  from some external file or elsewhere).
  and construct wxString objects from Unicode strings (presumably read
  from some external file or elsewhere).

- 
+

  @section topic8 Traps for the unwary
  @section topic8 Traps for the unwary

- 
- 
- 
+
+
+

       Casting c_str() to void* is now char*, not wxChar*
       Passing c_str(), mb_str() or wc_str() to variadic functions
  doesn't work
       Casting c_str() to void* is now char*, not wxChar*
       Passing c_str(), mb_str() or wc_str() to variadic functions
  doesn't work

- 
+

  */
  */

- 
- 
+
+