include/wx/unichar.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/unichar.h
   3 // Purpose:     wxUniChar and wxUniCharRef classes
   4 // Author:      Vaclav Slavik
   5 // Created:     2007-03-19
   6 // RCS-ID:      $Id$
   7 // Copyright:   (c) 2007 REA Elektronik GmbH
   8 // Licence:     wxWindows licence
   9 ///////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef _WX_UNICHAR_H_
  12 #define _WX_UNICHAR_H_
  13
  14 #include "wx/defs.h"
  15 #include "wx/chartype.h"
  16 #include "wx/stringimpl.h"
  17
  18 class WXDLLIMPEXP_FWD_BASE wxUniCharRef;
  19 class WXDLLIMPEXP_FWD_BASE wxString;
  20
  21 // This class represents single Unicode character. It can be converted to
  22 // and from char or wchar_t and implements commonly used character operations.
  23 class WXDLLIMPEXP_BASE wxUniChar
  24 {
  25 public:
  26     // NB: this is not wchar_t on purpose, it needs to represent the entire
  27     //     Unicode code points range and wchar_t may be too small for that
  28     //     (e.g. on Win32 where wchar_t* is encoded in UTF-16)
  29     typedef wxUint32 value_type;
  30
  31     wxUniChar() : m_value(0) {}
  32
  33     // Create the character from 8bit character value encoded in the current
  34     // locale's charset.
  35     wxUniChar(char c) { m_value = From8bit(c); }
  36     wxUniChar(unsigned char c) { m_value = From8bit((char)c); }
  37
  38     // Create the character from a wchar_t character value.
  39 #if wxWCHAR_T_IS_REAL_TYPE
  40     wxUniChar(wchar_t c) { m_value = c; }
  41 #endif
  42
  43     wxUniChar(int c) { m_value = c; }
  44     wxUniChar(unsigned int c) { m_value = c; }
  45     wxUniChar(long int c) { m_value = c; }
  46     wxUniChar(unsigned long int c) { m_value = c; }
  47     wxUniChar(short int c) { m_value = c; }
  48     wxUniChar(unsigned short int c) { m_value = c; }
  49
  50     wxUniChar(const wxUniCharRef& c);
  51
  52     // Returns Unicode code point value of the character
  53     value_type GetValue() const { return m_value; }
  54
  55 #if wxUSE_UNICODE_UTF8
  56     // buffer for single UTF-8 character
  57     struct Utf8CharBuffer
  58     {
  59         char data[5];
  60         operator const char*() const { return data; }
  61     };
  62
  63     // returns the character encoded as UTF-8
  64     // (NB: implemented in stringops.cpp)
  65     Utf8CharBuffer AsUTF8() const;
  66 #endif // wxUSE_UNICODE_UTF8
  67
  68     // Returns true if the character is an ASCII character:
  69     bool IsAscii() const { return m_value < 0x80; }
  70
  71     // Returns true if the character is representable as a single byte in the
  72     // current locale encoding and return this byte in output argument c (which
  73     // must be non-NULL)
  74     bool GetAsChar(char *c) const
  75     {
  76 #if wxUSE_UNICODE
  77         if ( !IsAscii() )
  78         {
  79 #if !wxUSE_UTF8_LOCALE_ONLY
  80             if ( GetAsHi8bit(m_value, c) )
  81                 return true;
  82 #endif // !wxUSE_UTF8_LOCALE_ONLY
  83
  84             return false;
  85         }
  86 #endif // wxUSE_UNICODE
  87
  88         *c = wx_truncate_cast(char, m_value);
  89         return true;
  90     }
  91
  92     // Conversions to char and wchar_t types: all of those are needed to be
  93     // able to pass wxUniChars to verious standard narrow and wide character
  94     // functions
  95     operator char() const { return To8bit(m_value); }
  96     operator unsigned char() const { return (unsigned char)To8bit(m_value); }
  97 #if wxWCHAR_T_IS_REAL_TYPE
  98     operator wchar_t() const { return (wchar_t)m_value; }
  99 #endif
 100     operator int() const { return (int)m_value; }
 101     operator unsigned int() const { return (unsigned int)m_value; }
 102     operator long int() const { return (long int)m_value; }
 103     operator unsigned long int() const { return (unsigned long)m_value; }
 104     operator short int() const { return (short int)m_value; }
 105     operator unsigned short int() const { return (unsigned short int)m_value; }
 106
 107     // We need this operator for the "*p" part of expressions like "for (
 108     // const_iterator p = begin() + nStart; *p; ++p )". In this case,
 109     // compilation would fail without it because the conversion to bool would
 110     // be ambiguous (there are all these int types conversions...). (And adding
 111     // operator unspecified_bool_type() would only makes the ambiguity worse.)
 112     operator bool() const { return m_value != 0; }
 113     bool operator!() const { return !((bool)*this); }
 114
 115     // And this one is needed by some (not all, but not using ifdefs makes the
 116     // code easier) compilers to parse "str[0] && *p" successfully
 117     bool operator&&(bool v) const { return (bool)*this && v; }
 118
 119     // Assignment operators:
 120     wxUniChar& operator=(const wxUniChar& c) { if (&c != this) m_value = c.m_value; return *this; }
 121     wxUniChar& operator=(const wxUniCharRef& c);
 122     wxUniChar& operator=(char c) { m_value = From8bit(c); return *this; }
 123     wxUniChar& operator=(unsigned char c) { m_value = From8bit((char)c); return *this; }
 124 #if wxWCHAR_T_IS_REAL_TYPE
 125     wxUniChar& operator=(wchar_t c) { m_value = c; return *this; }
 126 #endif
 127     wxUniChar& operator=(int c) { m_value = c; return *this; }
 128     wxUniChar& operator=(unsigned int c) { m_value = c; return *this; }
 129     wxUniChar& operator=(long int c) { m_value = c; return *this; }
 130     wxUniChar& operator=(unsigned long int c) { m_value = c; return *this; }
 131     wxUniChar& operator=(short int c) { m_value = c; return *this; }
 132     wxUniChar& operator=(unsigned short int c) { m_value = c; return *this; }
 133
 134     // Comparison operators:
 135
 136     // define the given comparison operator for all the types
 137 #define wxDEFINE_UNICHAR_OPERATOR(op)                                         \
 138     bool operator op(const wxUniChar& c) const { return m_value op c.m_value; }\
 139     bool operator op(char c) const { return m_value op From8bit(c); }         \
 140     bool operator op(unsigned char c) const { return m_value op From8bit((char)c); } \
 141     wxIF_WCHAR_T_TYPE( bool operator op(wchar_t c) const { return m_value op (value_type)c; } )    \
 142     bool operator op(int c) const { return m_value op (value_type)c; }        \
 143     bool operator op(unsigned int c) const { return m_value op (value_type)c; }        \
 144     bool operator op(short int c) const { return m_value op (value_type)c; }  \
 145     bool operator op(unsigned short int c) const { return m_value op (value_type)c; }  \
 146     bool operator op(long int c) const { return m_value op (value_type)c; }   \
 147     bool operator op(unsigned long int c) const { return m_value op (value_type)c; }
 148
 149     wxFOR_ALL_COMPARISONS(wxDEFINE_UNICHAR_OPERATOR)
 150
 151 #undef wxDEFINE_UNICHAR_OPERATOR
 152
 153     // this is needed for expressions like 'Z'-c
 154     int operator-(const wxUniChar& c) const { return m_value - c.m_value; }
 155     int operator-(char c) const { return m_value - From8bit(c); }
 156     int operator-(unsigned char c) const { return m_value - From8bit((char)c); }
 157     int operator-(wchar_t c) const { return m_value - (value_type)c; }
 158
 159
 160 private:
 161     // notice that we implement these functions inline for 7-bit ASCII
 162     // characters purely for performance reasons
 163     static value_type From8bit(char c)
 164     {
 165 #if wxUSE_UNICODE
 166         if ( (unsigned char)c < 0x80 )
 167             return c;
 168
 169         return FromHi8bit(c);
 170 #else
 171         return c;
 172 #endif
 173     }
 174
 175     static char To8bit(value_type c)
 176     {
 177 #if wxUSE_UNICODE
 178         if ( c < 0x80 )
 179             return wx_truncate_cast(char, c);
 180
 181         return ToHi8bit(c);
 182 #else
 183         return c;
 184 #endif
 185     }
 186
 187     // helpers of the functions above called to deal with non-ASCII chars
 188     static value_type FromHi8bit(char c);
 189     static char ToHi8bit(value_type v);
 190     static bool GetAsHi8bit(value_type v, char *c);
 191
 192 private:
 193     value_type m_value;
 194 };
 195
 196
 197 // Writeable reference to a character in wxString.
 198 //
 199 // This class can be used in the same way wxChar is used, except that changing
 200 // its value updates the underlying string object.
 201 class WXDLLIMPEXP_BASE wxUniCharRef
 202 {
 203 private:
 204     typedef wxStringImpl::iterator iterator;
 205
 206     // create the reference
 207 #if wxUSE_UNICODE_UTF8
 208     wxUniCharRef(wxString& str, iterator pos) : m_str(str), m_pos(pos) {}
 209 #else
 210     wxUniCharRef(iterator pos) : m_pos(pos) {}
 211 #endif
 212
 213 public:
 214     // NB: we have to make this public, because we don't have wxString
 215     //     declaration available here and so can't declare wxString::iterator
 216     //     as friend; so at least don't use a ctor but a static function
 217     //     that must be used explicitly (this is more than using 'explicit'
 218     //     keyword on ctor!):
 219 #if wxUSE_UNICODE_UTF8
 220     static wxUniCharRef CreateForString(wxString& str, iterator pos)
 221         { return wxUniCharRef(str, pos); }
 222 #else
 223     static wxUniCharRef CreateForString(iterator pos)
 224         { return wxUniCharRef(pos); }
 225 #endif
 226
 227     wxUniChar::value_type GetValue() const { return UniChar().GetValue(); }
 228
 229 #if wxUSE_UNICODE_UTF8
 230     wxUniChar::Utf8CharBuffer AsUTF8() const { return UniChar().AsUTF8(); }
 231 #endif // wxUSE_UNICODE_UTF8
 232
 233     bool IsAscii() const { return UniChar().IsAscii(); }
 234     bool GetAsChar(char *c) const { return UniChar().GetAsChar(c); }
 235
 236     // Assignment operators:
 237 #if wxUSE_UNICODE_UTF8
 238     wxUniCharRef& operator=(const wxUniChar& c);
 239 #else
 240     wxUniCharRef& operator=(const wxUniChar& c) { *m_pos = c; return *this; }
 241 #endif
 242
 243     wxUniCharRef& operator=(const wxUniCharRef& c)
 244         { if (&c != this) *this = c.UniChar(); return *this; }
 245
 246     wxUniCharRef& operator=(char c) { return *this = wxUniChar(c); }
 247     wxUniCharRef& operator=(unsigned char c) { return *this = wxUniChar(c); }
 248 #if wxWCHAR_T_IS_REAL_TYPE
 249     wxUniCharRef& operator=(wchar_t c) { return *this = wxUniChar(c); }
 250 #endif
 251     wxUniCharRef& operator=(int c) { return *this = wxUniChar(c); }
 252     wxUniCharRef& operator=(unsigned int c) { return *this = wxUniChar(c); }
 253     wxUniCharRef& operator=(short int c) { return *this = wxUniChar(c); }
 254     wxUniCharRef& operator=(unsigned short int c) { return *this = wxUniChar(c); }
 255     wxUniCharRef& operator=(long int c) { return *this = wxUniChar(c); }
 256     wxUniCharRef& operator=(unsigned long int c) { return *this = wxUniChar(c); }
 257
 258     // Conversions to the same types as wxUniChar is convertible too:
 259     operator char() const { return UniChar(); }
 260     operator unsigned char() const { return UniChar(); }
 261 #if wxWCHAR_T_IS_REAL_TYPE
 262     operator wchar_t() const { return UniChar(); }
 263 #endif
 264     operator int() const { return UniChar(); }
 265     operator unsigned int() const { return UniChar(); }
 266     operator short int() const { return UniChar(); }
 267     operator unsigned short int() const { return UniChar(); }
 268     operator long int() const { return UniChar(); }
 269     operator unsigned long int() const { return UniChar(); }
 270
 271     // see wxUniChar::operator bool etc. for explanation
 272     operator bool() const { return (bool)UniChar(); }
 273     bool operator!() const { return !UniChar(); }
 274     bool operator&&(bool v) const { return UniChar() && v; }
 275
 276     // Comparison operators:
 277 #define wxDEFINE_UNICHARREF_OPERATOR(op)                                      \
 278     bool operator op(const wxUniCharRef& c) const { return UniChar() op c.UniChar(); }\
 279     bool operator op(const wxUniChar& c) const { return UniChar() op c; }     \
 280     bool operator op(char c) const { return UniChar() op c; }                 \
 281     bool operator op(unsigned char c) const { return UniChar() op c; }        \
 282     wxIF_WCHAR_T_TYPE( bool operator op(wchar_t c) const { return UniChar() op c; } ) \
 283     bool operator op(int c) const { return UniChar() op c; }                  \
 284     bool operator op(unsigned int c) const { return UniChar() op c; }         \
 285     bool operator op(short int c) const { return UniChar() op c; }             \
 286     bool operator op(unsigned short int c) const { return UniChar() op c; }    \
 287     bool operator op(long int c) const { return UniChar() op c; }             \
 288     bool operator op(unsigned long int c) const { return UniChar() op c; }
 289
 290     wxFOR_ALL_COMPARISONS(wxDEFINE_UNICHARREF_OPERATOR)
 291
 292 #undef wxDEFINE_UNICHARREF_OPERATOR
 293
 294     // for expressions like c-'A':
 295     int operator-(const wxUniCharRef& c) const { return UniChar() - c.UniChar(); }
 296     int operator-(const wxUniChar& c) const { return UniChar() - c; }
 297     int operator-(char c) const { return UniChar() - c; }
 298     int operator-(unsigned char c) const { return UniChar() - c; }
 299     int operator-(wchar_t c) const { return UniChar() - c; }
 300
 301 private:
 302 #if wxUSE_UNICODE_UTF8
 303     wxUniChar UniChar() const;
 304 #else
 305     wxUniChar UniChar() const { return *m_pos; }
 306 #endif
 307
 308     friend class WXDLLIMPEXP_FWD_BASE wxUniChar;
 309
 310 private:
 311     // reference to the string and pointer to the character in string
 312 #if wxUSE_UNICODE_UTF8
 313     wxString& m_str;
 314 #endif
 315     iterator m_pos;
 316 };
 317
 318 inline wxUniChar::wxUniChar(const wxUniCharRef& c)
 319 {
 320     m_value = c.UniChar().m_value;
 321 }
 322
 323 inline wxUniChar& wxUniChar::operator=(const wxUniCharRef& c)
 324 {
 325     m_value = c.UniChar().m_value;
 326     return *this;
 327 }
 328
 329 // Comparison operators for the case when wxUniChar(Ref) is the second operand
 330 // implemented in terms of member comparison functions
 331
 332 wxDEFINE_COMPARISONS_BY_REV(char, const wxUniChar&)
 333 wxDEFINE_COMPARISONS_BY_REV(char, const wxUniCharRef&)
 334
 335 wxDEFINE_COMPARISONS_BY_REV(wchar_t, const wxUniChar&)
 336 wxDEFINE_COMPARISONS_BY_REV(wchar_t, const wxUniCharRef&)
 337
 338 wxDEFINE_COMPARISONS_BY_REV(const wxUniChar&, const wxUniCharRef&)
 339
 340 // for expressions like c-'A':
 341 inline int operator-(char c1, const wxUniCharRef& c2) { return -(c2 - c1); }
 342 inline int operator-(const wxUniChar& c1, const wxUniCharRef& c2) { return -(c2 - c1); }
 343 inline int operator-(wchar_t c1, const wxUniCharRef& c2) { return -(c2 - c1); }
 344
 345 #endif /* _WX_UNICHAR_H_ */