X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/2b5f62a0b2db198609b45dec622a018dae37008e..39434ba375389eab72ad84184d6d54a92c2b3551:/docs/latex/wx/tunicode.tex diff --git a/docs/latex/wx/tunicode.tex b/docs/latex/wx/tunicode.tex index bbbc90c9ee..606859f61f 100644 --- a/docs/latex/wx/tunicode.tex +++ b/docs/latex/wx/tunicode.tex @@ -1,6 +1,6 @@ %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% Name: tunicode.tex -%% Purpose: Overview of the Unicode support in wxWindows +%% Purpose: Overview of the Unicode support in wxWidgets %% Author: Vadim Zeitlin %% Modified by: %% Created: 22.09.99 @@ -9,15 +9,15 @@ %% Licence: wxWindows license %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\section{Unicode support in wxWindows}\label{unicode} +\section{Unicode support in wxWidgets}\label{unicode} -This section briefly describes the state of the Unicode support in wxWindows. +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. -\subsection{What is Unicode?} +\subsection{What is Unicode?}\label{whatisunicode} -Starting with release 2.1 wxWindows has support for compiling in Unicode mode +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 using at least 16 (and possibly 32) bits for encoding each character. This @@ -40,14 +40,14 @@ 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. -\subsection{Unicode and ANSI modes} +\subsection{Unicode and ANSI modes}\label{unicodeandansi} -As not all platforms supported by wxWindows support Unicode (fully) yet, in +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 wxWindows. +This can be achieved quite simply by using the means provided by wxWidgets. Basically, there are only a few things to watch out for: \begin{itemize} @@ -81,7 +81,7 @@ 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. wxWindows provides the macros {\tt \_\_TFILE\_\_}, {\tt \_\_TDATE\_\_} +build. wxWidgets provides the macros {\tt \_\_TFILE\_\_}, {\tt \_\_TDATE\_\_} and {\tt \_\_TTIME\_\_} which behave exactly as the standard ones except that they produce ANSI strings in ANSI build and Unicode ones in the Unicode build. @@ -109,9 +109,9 @@ be done this way (try to imagine the number of {\tt \#ifdef UNICODE} an average program would have had!). Luckily, there is another way - see the next section. -\subsection{Unicode support in wxWindows} +\subsection{Unicode support in wxWidgets}\label{unicodeinsidewxw} -In wxWindows, the code fragment from above should be written instead: +In wxWidgets, the code fragment from above should be written instead: \begin{verbatim} wxChar ch = wxT('*'); @@ -121,7 +121,7 @@ In wxWindows, the code fragment from above should be written instead: What happens here? First of all, you see that there are no more {\tt \#ifdef}s at all. Instead, we define some types and macros which behave differently in -the Unicode and ANSI builds and allows us to avoid using conditional +the Unicode and ANSI builds and allow us to avoid using conditional compilation in the program itself. We have a {\tt wxChar} type which maps either on {\tt char} or {\tt wchar\_t} @@ -130,31 +130,31 @@ a separate type for strings though, because the standard \helpref{wxString}{wxstring} supports Unicode, i.e. it stores either ANSI or Unicode strings depending on the compile mode. -Finally, there is a special {\tt 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 {\tt 'L'} to its argument in the Unicode mode. +Finally, there is a special \helpref{wxT()}{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 {\tt 'L'} to its argument in the Unicode mode. The important conclusion is that if you use {\tt wxChar} instead of {\tt char}, avoid using C style strings and use {\tt wxString} instead and -don't forget to enclose all string literals inside {\tt wxT()} macro, your +don't forget to enclose all string literals inside \helpref{wxT()}{wxt} macro, your program automatically becomes (almost) Unicode compliant! Just let us state once again the rules: \begin{itemize} \item Always use {\tt wxChar} instead of {\tt char} -\item Always enclose literal string constants in {\tt wxT()} macro unless -they're already converted to the right representation (another standard -wxWindows macro {\tt \_()} does it, so there is no need for {\tt wxT()} in this -case) or you intend to pass the constant directly to an external function -which doesn't accept wide-character strings. +\item Always enclose literal string constants in \helpref{wxT()}{wxt} macro +unless they're already converted to the right representation (another standard +wxWidgets macro \helpref{\_()}{underscore} does it, for example, so there is no +need for {\tt wxT()} in this case) or you intend to pass the constant directly +to an external function which doesn't accept wide-character strings. \item Use {\tt wxString} instead of C style strings. \end{itemize} -\subsection{Unicode and the outside world} +\subsection{Unicode and the outside world}\label{unicodeoutsidewxw} -We have seen that it was easy to write Unicode programs using wxWindows types +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 it tries to communicate with the outside world which, sadly, often expects @@ -162,7 +162,7 @@ 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 a 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 string (independently of the mode - while the usual \helpref{c\_str()}{wxstringcstr} returns a pointer to the internal @@ -170,19 +170,31 @@ 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. +In this case, you can use the converter-constructor, as follows: + +\begin{verbatim} + const char* ascii_str = "Some text"; + wxString str(ascii_str, wxConvUTF8); +\end{verbatim} + +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 \helpref{wxMBConv classes overview}{mbconvclasses}. + % TODO describe fn_str(), wx_str(), wxCharBuf classes, ... -\subsection{Unicode-related compilation settings} +\subsection{Unicode-related compilation settings}\label{unicodesettings} You should define {\tt wxUSE\_UNICODE} to $1$ to compile your program in -Unicode mode. Note that it currently only works in Win32 and GTK 2.0 and -that some parts of -wxWindows are not Unicode-compliant yet (ODBC classes, for example). If you +Unicode mode. This currently works for wxMSW, wxGTK, wxMac and wxX11. If you compile your program in ANSI mode you can still define {\tt wxUSE\_WCHAR\_T} to get some limited support for {\tt wchar\_t} type. This will allow your program to perform conversions between Unicode strings and -ANSI ones (\helpref{wxEncodingConverter}{wxencodingconverter} depends on this -partially) and construct wxString objects from Unicode strings (presumably read +ANSI ones (using \helpref{wxMBConv classes}{mbconvclasses}) +and construct wxString objects from Unicode strings (presumably read from some external file or elsewhere).