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 class WXDLLIMPEXP_BASE wxUniCharRef;
  18
  19 // This class represents single Unicode character. It can be converted to
  20 // and from char or wchar_t and implements commonly used character operations.
  21 class WXDLLIMPEXP_BASE wxUniChar
  22 {
  23 public:
  24     // NB: this is not wchar_t on purpose, it needs to represent the entire
  25     //     Unicode code points range and wchar_t may be too small for that
  26     //     (e.g. on Win32 where wchar_t* is encoded in UTF-16)
  27     typedef wxUint32 value_type;
  28
  29     wxUniChar() : m_value(0) {}
  30
  31     // Create the character from 8bit character value encoded in the current
  32     // locale's charset.
  33     wxUniChar(char c) { m_value = From8bit(c); }
  34     wxUniChar(unsigned char c) { m_value = From8bit((char)c); }
  35
  36     // Create the character from a wchar_t character value.
  37     wxUniChar(wchar_t c) { m_value = c; }
  38
  39     wxUniChar(int c) { m_value = c; }
  40
  41     wxUniChar(const wxUniCharRef& c);
  42
  43     // Returns Unicode code point value of the character
  44     value_type GetValue() const { return m_value; }
  45
  46     // Conversions to char and wchar_t types: all of those are needed to be
  47     // able to pass wxUniChars to verious standard narrow and wide character
  48     // functions
  49     operator char() const { return To8bit(m_value); }
  50     operator wchar_t() const { return m_value; }
  51     operator int() const { return m_value; }
  52
  53     // More conversions needed for other standard functions: uchar is for VC++
  54     // _mbxxx() ones (to which toxxx/isxxx() are mapped when _MBCS is defined)
  55     // and wint_t is either uint or ushort and it's easier for us to just
  56     // define both at this stage than have a separate test for what wint_t is
  57     operator unsigned char() const { return (unsigned char)To8bit(m_value); }
  58     operator unsigned short() const { return m_value; }
  59     operator unsigned int() const { return m_value; }
  60
  61     // We need this operator for the "*p" part of expressions like "for (
  62     // const_iterator p = begin() + nStart; *p; ++p )". In this case,
  63     // compilation would fail without it because the conversion to bool would
  64     // be ambiguous (there are all these int types conversions...). (And adding
  65     // operator unspecified_bool_type() would only makes the ambiguity worse.)
  66     operator bool() const { return m_value != 0; }
  67     bool operator!() const { return !((bool)*this); }
  68 #if (defined(__VISUALC__) && __VISUALC__ < 1400) || \
  69     defined(__DIGITALMARS__) || defined(__BORLANDC__)
  70     // We need this for VC++ < 8 or DigitalMars and expressions like
  71     // "str[0] && *p":
  72     bool operator&&(bool v) const { return (bool)*this && v; }
  73 #endif
  74
  75     // Assignment operators:
  76     wxUniChar& operator=(const wxUniChar& c) { m_value = c.m_value; return *this; }
  77     wxUniChar& operator=(char c) { m_value = From8bit(c); return *this; }
  78     wxUniChar& operator=(wchar_t c) { m_value = c; return *this; }
  79
  80     // Comparison operators:
  81
  82     // define the given comparison operator for all the types
  83 #define wxDEFINE_UNICHAR_OPERATOR(op)                                         \
  84     bool operator op(const wxUniChar& c) const { return m_value op c.m_value; }\
  85     bool operator op(char c) const { return m_value op From8bit(c); }         \
  86     bool operator op(wchar_t c) const { return m_value op (value_type)c; }
  87
  88     wxFOR_ALL_COMPARISONS(wxDEFINE_UNICHAR_OPERATOR)
  89
  90 #undef wxDEFINE_UNICHAR_OPERATOR
  91
  92     // this is needed for expressions like 'Z'-c
  93     int operator-(const wxUniChar& c) const { return m_value - c.m_value; }
  94     int operator-(char c) const { return m_value - From8bit(c); }
  95     int operator-(wchar_t c) const { return m_value - (value_type)c; }
  96
  97 private:
  98     static value_type From8bit(char c);
  99     static char To8bit(value_type c);
 100
 101 private:
 102     value_type m_value;
 103 };
 104
 105
 106 // Writeable reference to a character in wxString.
 107 //
 108 // This class can be used in the same way wxChar is used, except that changing
 109 // its value updates the underlying string object.
 110 class WXDLLIMPEXP_BASE wxUniCharRef
 111 {
 112 private:
 113     // create the reference
 114     // FIXME-UTF8: the interface will need changes for UTF-8 build
 115     wxUniCharRef(wxChar *pos) : m_pos(pos) {}
 116
 117 public:
 118     // NB: we have to make this public, because we don't have wxString
 119     //     declaration available here and so can't declare wxString::iterator
 120     //     as friend; so at least don't use a ctor but a static function
 121     //     that must be used explicitly (this is more than using 'explicit'
 122     //     keyword on ctor!):
 123     //
 124     // FIXME-UTF8: the interface will need changes for UTF-8 build
 125     static wxUniCharRef CreateForString(wxChar *pos)
 126         { return wxUniCharRef(pos); }
 127
 128     wxUniChar::value_type GetValue() const { return UniChar().GetValue(); }
 129
 130     // Assignment operators:
 131     wxUniCharRef& operator=(const wxUniCharRef& c)
 132     {
 133         *m_pos = *c.m_pos;
 134         return *this;
 135     };
 136
 137     wxUniCharRef& operator=(const wxUniChar& c)
 138     {
 139         *m_pos = c;
 140         return *this;
 141     };
 142
 143     wxUniCharRef& operator=(char c) { return *this = wxUniChar(c); }
 144     wxUniCharRef& operator=(wchar_t c) { return *this = wxUniChar(c); }
 145
 146     // Conversions to the same types as wxUniChar is convertible too:
 147     operator char() const { return UniChar(); }
 148     operator wchar_t() const { return UniChar(); }
 149     operator int() const { return UniChar(); }
 150     operator unsigned char() const { return UniChar(); }
 151     operator unsigned short() const { return UniChar(); }
 152     operator unsigned int() const { return UniChar(); }
 153
 154     // see wxUniChar::operator bool etc. for explanation
 155     operator bool() const { return (bool)UniChar(); }
 156     bool operator!() const { return !UniChar(); }
 157 #if (defined(__VISUALC__) && __VISUALC__ < 1400) || \
 158     defined(__DIGITALMARS__) || defined(__BORLANDC__)
 159     bool operator&&(bool v) const { return UniChar() && v; }
 160 #endif
 161
 162     // Comparison operators:
 163 #define wxDEFINE_UNICHARREF_OPERATOR(op)                                      \
 164     bool operator op(const wxUniCharRef& c) const { return UniChar() op c.UniChar(); }\
 165     bool operator op(const wxUniChar& c) const { return UniChar() op c; }     \
 166     bool operator op(char c) const { return UniChar() op c; }                 \
 167     bool operator op(wchar_t c) const { return UniChar() op c; }
 168
 169     wxFOR_ALL_COMPARISONS(wxDEFINE_UNICHARREF_OPERATOR)
 170
 171 #undef wxDEFINE_UNICHARREF_OPERATOR
 172
 173     // for expressions like c-'A':
 174     int operator-(const wxUniCharRef& c) const { return UniChar() - c.UniChar(); }
 175     int operator-(const wxUniChar& c) const { return UniChar() - c; }
 176     int operator-(char c) const { return UniChar() - c; }
 177     int operator-(wchar_t c) const { return UniChar() - c; }
 178
 179 private:
 180     wxUniChar UniChar() const { return *m_pos; }
 181     friend class WXDLLIMPEXP_BASE wxUniChar;
 182
 183 private:
 184     // pointer to the character in string
 185     wxChar *m_pos;
 186 };
 187
 188 inline wxUniChar::wxUniChar(const wxUniCharRef& c)
 189 {
 190     m_value = c.UniChar().m_value;
 191 }
 192
 193 // Comparison operators for the case when wxUniChar(Ref) is the second operand
 194 // implemented in terms of member comparison functions
 195
 196 #define wxCMP_REVERSE(c1, c2, op) c2 op c1
 197
 198 wxDEFINE_COMPARISONS(char, const wxUniChar&, wxCMP_REVERSE)
 199 wxDEFINE_COMPARISONS(char, const wxUniCharRef&, wxCMP_REVERSE)
 200
 201 wxDEFINE_COMPARISONS(wchar_t, const wxUniChar&, wxCMP_REVERSE)
 202 wxDEFINE_COMPARISONS(wchar_t, const wxUniCharRef&, wxCMP_REVERSE)
 203
 204 wxDEFINE_COMPARISONS(const wxUniChar&, const wxUniCharRef&, wxCMP_REVERSE)
 205
 206 #undef wxCMP_REVERSE
 207
 208 // for expressions like c-'A':
 209 inline int operator-(char c1, const wxUniCharRef& c2) { return -(c2 - c1); }
 210 inline int operator-(wchar_t c1, const wxUniCharRef& c2) { return -(c2 - c1); }
 211 inline int operator-(const wxUniChar& c1, const wxUniCharRef& c2) { return -(c2 - c1); }
 212
 213 #endif /* _WX_UNICHAR_H_ */