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
  17 // NB: this header is included from string.h as well, but from the place
  18 //     where wxStringImpl is already declared and that's all we need
  19 #include "wx/string.h"
  20
  21 class WXDLLIMPEXP_BASE wxUniCharRef;
  22
  23 // This class represents single Unicode character. It can be converted to
  24 // and from char or wchar_t and implements commonly used character operations.
  25 class WXDLLIMPEXP_BASE wxUniChar
  26 {
  27 public:
  28     // NB: this is not wchar_t on purpose, it needs to represent the entire
  29     //     Unicode code points range and wchar_t may be too small for that
  30     //     (e.g. on Win32 where wchar_t* is encoded in UTF-16)
  31     typedef wxUint32 value_type;
  32
  33     wxUniChar() : m_value(0) {}
  34
  35     // Create the character from 8bit character value encoded in the current
  36     // locale's charset.
  37     wxUniChar(char c) { m_value = From8bit(c); }
  38     wxUniChar(unsigned char c) { m_value = From8bit((char)c); }
  39
  40     // Create the character from a wchar_t character value.
  41     wxUniChar(wchar_t c) { m_value = c; }
  42
  43     wxUniChar(int c) { m_value = c; }
  44
  45     wxUniChar(const wxUniCharRef& c);
  46
  47     // Returns Unicode code point value of the character
  48     value_type GetValue() const { return m_value; }
  49
  50     // Conversions to char and wchar_t types: all of those are needed to be
  51     // able to pass wxUniChars to verious standard narrow and wide character
  52     // functions
  53     operator char() const { return To8bit(m_value); }
  54     operator wchar_t() const { return m_value; }
  55     operator int() const { return m_value; }
  56
  57     // More conversions needed for other standard functions: uchar is for VC++
  58     // _mbxxx() ones (to which toxxx/isxxx() are mapped when _MBCS is defined)
  59     // and some wide character functions take wint_t which happens to be the
  60     // same as wchar_t for Windows compilers but not for g++ (except for the
  61     // special Apple version)
  62     operator unsigned char() const { return (unsigned char)To8bit(m_value); }
  63 #if defined(__GNUC__) && !defined(__DARWIN__)
  64     operator wint_t() const { return m_value; }
  65 #endif
  66
  67     // We need this operator for the "*p" part of expressions like "for (
  68     // const_iterator p = begin() + nStart; *p; ++p )". In this case,
  69     // compilation would fail without it because the conversion to bool would
  70     // be ambiguous (there are all these int types conversions...). (And adding
  71     // operator unspecified_bool_type() would only makes the ambiguity worse.)
  72     operator bool() const { return m_value != 0; }
  73     bool operator!() const { return !((bool)*this); }
  74 #if (defined(__VISUALC__) && __VISUALC__ < 1400) || \
  75     defined(__DIGITALMARS__) || defined(__BORLANDC__)
  76     // We need this for VC++ < 8 or DigitalMars and expressions like
  77     // "str[0] && *p":
  78     bool operator&&(bool v) const { return (bool)*this && v; }
  79 #endif
  80
  81     // Assignment operators:
  82     wxUniChar& operator=(const wxUniChar& c) { m_value = c.m_value; return *this; }
  83     wxUniChar& operator=(char c) { m_value = From8bit(c); return *this; }
  84     wxUniChar& operator=(wchar_t c) { m_value = c; return *this; }
  85
  86     // Comparison operators:
  87
  88     // define the given comparison operator for all the types
  89 #define wxDEFINE_UNICHAR_OPERATOR(op)                                         \
  90     bool operator op(const wxUniChar& c) const { return m_value op c.m_value; }\
  91     bool operator op(char c) const { return m_value op From8bit(c); }         \
  92     bool operator op(wchar_t c) const { return m_value op (value_type)c; }
  93
  94     wxFOR_ALL_COMPARISONS(wxDEFINE_UNICHAR_OPERATOR)
  95
  96 #undef wxDEFINE_UNICHAR_OPERATOR
  97
  98     // this is needed for expressions like 'Z'-c
  99     int operator-(const wxUniChar& c) const { return m_value - c.m_value; }
 100     int operator-(char c) const { return m_value - From8bit(c); }
 101     int operator-(wchar_t c) const { return m_value - (value_type)c; }
 102
 103 private:
 104     static value_type From8bit(char c);
 105     static char To8bit(value_type c);
 106
 107 private:
 108     value_type m_value;
 109 };
 110
 111
 112 // Writeable reference to a character in wxString.
 113 //
 114 // This class can be used in the same way wxChar is used, except that changing
 115 // its value updates the underlying string object.
 116 class WXDLLIMPEXP_BASE wxUniCharRef
 117 {
 118 private:
 119     typedef wxStringImpl::iterator iterator;
 120
 121     // create the reference
 122     wxUniCharRef(iterator pos) : m_pos(pos) {}
 123
 124 public:
 125     // NB: we have to make this public, because we don't have wxString
 126     //     declaration available here and so can't declare wxString::iterator
 127     //     as friend; so at least don't use a ctor but a static function
 128     //     that must be used explicitly (this is more than using 'explicit'
 129     //     keyword on ctor!):
 130     static wxUniCharRef CreateForString(iterator pos)
 131         { return wxUniCharRef(pos); }
 132
 133     wxUniChar::value_type GetValue() const { return UniChar().GetValue(); }
 134
 135     // Assignment operators:
 136     wxUniCharRef& operator=(const wxUniCharRef& c)
 137     {
 138         *m_pos = *c.m_pos;
 139         return *this;
 140     };
 141
 142     wxUniCharRef& operator=(const wxUniChar& c)
 143     {
 144         *m_pos = c;
 145         return *this;
 146     };
 147
 148     wxUniCharRef& operator=(char c) { return *this = wxUniChar(c); }
 149     wxUniCharRef& operator=(wchar_t c) { return *this = wxUniChar(c); }
 150
 151     // Conversions to the same types as wxUniChar is convertible too:
 152     operator char() const { return UniChar(); }
 153     operator wchar_t() const { return UniChar(); }
 154     operator int() const { return UniChar(); }
 155     operator unsigned char() const { return UniChar(); }
 156 #if defined(__GNUC__) && !defined(__DARWIN__)
 157     operator wint_t() const { return UniChar(); }
 158 #endif
 159
 160     // see wxUniChar::operator bool etc. for explanation
 161     operator bool() const { return (bool)UniChar(); }
 162     bool operator!() const { return !UniChar(); }
 163 #if (defined(__VISUALC__) && __VISUALC__ < 1400) || \
 164     defined(__DIGITALMARS__) || defined(__BORLANDC__)
 165     bool operator&&(bool v) const { return UniChar() && v; }
 166 #endif
 167
 168     // Comparison operators:
 169 #define wxDEFINE_UNICHARREF_OPERATOR(op)                                      \
 170     bool operator op(const wxUniCharRef& c) const { return UniChar() op c.UniChar(); }\
 171     bool operator op(const wxUniChar& c) const { return UniChar() op c; }     \
 172     bool operator op(char c) const { return UniChar() op c; }                 \
 173     bool operator op(wchar_t c) const { return UniChar() op c; }
 174
 175     wxFOR_ALL_COMPARISONS(wxDEFINE_UNICHARREF_OPERATOR)
 176
 177 #undef wxDEFINE_UNICHARREF_OPERATOR
 178
 179     // for expressions like c-'A':
 180     int operator-(const wxUniCharRef& c) const { return UniChar() - c.UniChar(); }
 181     int operator-(const wxUniChar& c) const { return UniChar() - c; }
 182     int operator-(char c) const { return UniChar() - c; }
 183     int operator-(wchar_t c) const { return UniChar() - c; }
 184
 185 private:
 186     wxUniChar UniChar() const { return *m_pos; }
 187     friend class WXDLLIMPEXP_BASE wxUniChar;
 188
 189 private:
 190     // pointer to the character in string
 191     iterator m_pos;
 192 };
 193
 194 inline wxUniChar::wxUniChar(const wxUniCharRef& c)
 195 {
 196     m_value = c.UniChar().m_value;
 197 }
 198
 199 // Comparison operators for the case when wxUniChar(Ref) is the second operand
 200 // implemented in terms of member comparison functions
 201
 202 #define wxCMP_REVERSE(c1, c2, op) c2 op c1
 203
 204 wxDEFINE_COMPARISONS(char, const wxUniChar&, wxCMP_REVERSE)
 205 wxDEFINE_COMPARISONS(char, const wxUniCharRef&, wxCMP_REVERSE)
 206
 207 wxDEFINE_COMPARISONS(wchar_t, const wxUniChar&, wxCMP_REVERSE)
 208 wxDEFINE_COMPARISONS(wchar_t, const wxUniCharRef&, wxCMP_REVERSE)
 209
 210 wxDEFINE_COMPARISONS(const wxUniChar&, const wxUniCharRef&, wxCMP_REVERSE)
 211
 212 #undef wxCMP_REVERSE
 213
 214 // for expressions like c-'A':
 215 inline int operator-(char c1, const wxUniCharRef& c2) { return -(c2 - c1); }
 216 inline int operator-(wchar_t c1, const wxUniCharRef& c2) { return -(c2 - c1); }
 217 inline int operator-(const wxUniChar& c1, const wxUniCharRef& c2) { return -(c2 - c1); }
 218
 219 #endif /* _WX_UNICHAR_H_ */