Fix bug 9798.

[lyx.git] / src / support / docstream.h

diff --git a/src/support/docstream.h b/src/support/docstream.h
index c1f4f1ad8b056bbfcdd8930b36f77519021fd9d6..409c7557a85cbdd8a854f80f127a2f6c58dd0bee 100644 (file)
--- a/src/support/docstream.h
+++ b/src/support/docstream.h
@@ -19,6 +19,12 @@
 
 namespace lyx {
 
+class iconv_codecvt_facet_exception : public std::exception {
+public:
+       virtual ~iconv_codecvt_facet_exception() throw() {}
+       virtual const char * what() const throw();
+};
+
 /// Base class for UCS4 input streams
 typedef std::basic_istream<char_type> idocstream;
 
@@ -28,47 +34,86 @@ typedef std::basic_istream<char_type> idocstream;
     \endcode, not \code
     os << c;
     \endcode . The latter will not output the character, but the code point
-    as number. This is because we can't overload operator<< (our character
-    type is not a real type but a typedef). Narrow characters of type char
-    can be output as usual.
+    as number if USE_WCHAR_T is not defined. This is because we can't overload
+    operator<< (our character type is not always a real type but sometimes a
+    typedef). Narrow characters of type char can be output as usual.
  */
 typedef std::basic_ostream<char_type> odocstream;
 
+struct SetEnc;
+
 /// File stream for reading UTF8-encoded files with automatic conversion to
 /// UCS4.
-class idocfstream : public std::basic_ifstream<char_type> {
+/// Buffering must be switched off if the encoding is changed after
+/// construction by calling rdbuf()->pubsetbuf(0, 0).
+class ifdocstream : public std::basic_ifstream<char_type> {
        typedef std::basic_ifstream<char_type> base;
 public:
-       idocfstream();
-       explicit idocfstream(const char* s,
-               std::ios_base::openmode mode = std::ios_base::in);
-       ~idocfstream() {}
+       ifdocstream();
+       /// Create a stream with a specific encoding \p enc.
+       /// We must not pass \p enc as string, to avoid confusing it with a file name.
+       explicit ifdocstream(SetEnc const & enc);
+       explicit ifdocstream(const char* s,
+               std::ios_base::openmode mode = std::ios_base::in,
+               std::string const & encoding = "UTF-8");
+       ~ifdocstream() {}
 };
 
-/// File stream for writing UTF8-encoded files with automatic conversion from
-/// UCS4.
-class odocfstream : public std::basic_ofstream<char_type> {
+/// File stream for writing files in 8bit encoding \p encoding with automatic
+/// conversion from UCS4.
+
+class ofdocstream : public std::basic_ofstream<char_type> {
        typedef std::basic_ofstream<char_type> base;
 public:
-       odocfstream();
-       explicit odocfstream(const char* s,
-               std::ios_base::openmode mode = std::ios_base::out|std::ios_base::trunc);
-       ~odocfstream() {}
+       ofdocstream();
+       /// Create a stream with a specific encoding \p enc.
+       /// We must not pass \p enc as string, to avoid confusing it with a file name.
+       explicit ofdocstream(SetEnc const & enc);
+       explicit ofdocstream(const char* s,
+               std::ios_base::openmode mode = std::ios_base::out|std::ios_base::trunc,
+               std::string const & encoding = "UTF-8");
+       ~ofdocstream() {}
+       ///
+       void reset(std::string const & encoding);
 };
 
+
+
 /// UCS4 input stringstream
 typedef std::basic_istringstream<char_type> idocstringstream;
 
-/// UCS4 output stringstream
-typedef std::basic_ostringstream<char_type> odocstringstream;
+/// UCS4 output manipulator
+typedef odocstream & (*odocstream_manip)(odocstream &);
 
-inline
-odocstream & operator<<(odocstream & os, char c)
-{
-    os.put(c);
-    return os;
-}
 
-}
+/// Helper struct for changing stream encoding
+struct SetEnc {
+       /**
+        * It is important that this constructor is explicit.
+        * Otherwise the attempt to output a std::string to an odocstream
+        * would compile, but cause a (probably failing) encoding change
+        * instead of string output (we do not define
+        * operator<<(odocstream &, std::string) since we want to avoid
+        * outputting strings with unspecified encoding)
+        */
+       explicit SetEnc(std::string const & e) : encoding(e) {}
+       std::string encoding;
+};
+
+/// Helper function for changing stream encoding
+SetEnc setEncoding(std::string const & encoding);
+
+/** Change the encoding of \p os to \p e.encoding.
+    \p e.encoding must be a valid iconv name of an 8bit encoding.
+    This does nothing if the stream is not a file stream, since only
+    file streams do have an associated 8bit encoding.
+    Usage: \code
+    os << setEncoding("ISO-8859-1");
+    \endcode
+ */
+odocstream & operator<<(odocstream & os, SetEnc e);
+idocstream & operator<<(idocstream & os, SetEnc e);
+
+} // namespace lyx
 
 #endif