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     // Casts to char and wchar_t types:
  47     operator char() const { return To8bit(m_value); }
  48     operator unsigned char() const { return (unsigned char)To8bit(m_value); }
  49     operator wchar_t() const { return m_value; }
  50     operator int() const { return m_value; }
  51     operator unsigned int() const { return m_value; }
  52
  53     // We need this operator for the "*p" part of expressions like "for (
  54     // const_iterator p = begin() + nStart; *p; ++p )". In this case,
  55     // compilation would fail without it because the conversion to bool would
  56     // be ambiguous (there are all these int types conversions...). (And adding
  57     // operator unspecified_bool_type() would only makes the ambiguity worse.)
  58     operator bool() const { return m_value != 0; }
  59     bool operator!() const { return !((bool)*this); }
  60 #if (defined(__VISUALC__) && __VISUALC__ < 1400) || \
  61     defined(__DIGITALMARS__) || defined(__BORLANDC__)
  62     // We need this for VC++ < 8 or DigitalMars and expressions like
  63     // "str[0] && *p":
  64     bool operator&&(bool v) const { return (bool)*this && v; }
  65 #endif
  66
  67     // Assignment operators:
  68     wxUniChar& operator=(const wxUniChar& c) { m_value = c.m_value; return *this; }
  69     wxUniChar& operator=(char c) { m_value = From8bit(c); return *this; }
  70     wxUniChar& operator=(wchar_t c) { m_value = c; return *this; }
  71
  72     // Comparison operators:
  73
  74     // define the given comparison operator for all the types
  75 #define wxDEFINE_UNICHAR_OPERATOR(op)                                         \
  76     bool operator op(const wxUniChar& c) const { return m_value op c.m_value; }\
  77     bool operator op(char c) const { return m_value op From8bit(c); }         \
  78     bool operator op(wchar_t c) const { return m_value op (value_type)c; }
  79
  80     wxFOR_ALL_COMPARISONS(wxDEFINE_UNICHAR_OPERATOR)
  81
  82 #undef wxDEFINE_UNICHAR_OPERATOR
  83
  84     // this is needed for expressions like 'Z'-c
  85     int operator-(const wxUniChar& c) const { return m_value - c.m_value; }
  86     int operator-(char c) const { return m_value - From8bit(c); }
  87     int operator-(wchar_t c) const { return m_value - (value_type)c; }
  88
  89 private:
  90     static value_type From8bit(char c);
  91     static char To8bit(value_type c);
  92
  93 private:
  94     value_type m_value;
  95 };
  96
  97
  98 // Writeable reference to a character in wxString.
  99 //
 100 // This class can be used in the same way wxChar is used, except that changing
 101 // its value updates the underlying string object.
 102 class WXDLLIMPEXP_BASE wxUniCharRef
 103 {
 104 private:
 105     // create the reference
 106     // FIXME-UTF8: the interface will need changes for UTF-8 build
 107     wxUniCharRef(wxChar *pos) : m_pos(pos) {}
 108
 109 public:
 110     // NB: we have to make this public, because we don't have wxString
 111     //     declaration available here and so can't declare wxString::iterator
 112     //     as friend; so at least don't use a ctor but a static function
 113     //     that must be used explicitly (this is more than using 'explicit'
 114     //     keyword on ctor!):
 115     //
 116     // FIXME-UTF8: the interface will need changes for UTF-8 build
 117     static wxUniCharRef CreateForString(wxChar *pos)
 118         { return wxUniCharRef(pos); }
 119
 120     wxUniChar::value_type GetValue() const { return UniChar().GetValue(); }
 121
 122     // Assignment operators:
 123     wxUniCharRef& operator=(const wxUniCharRef& c)
 124     {
 125         *m_pos = *c.m_pos;
 126         return *this;
 127     };
 128
 129     wxUniCharRef& operator=(const wxUniChar& c)
 130     {
 131         *m_pos = c;
 132         return *this;
 133     };
 134
 135     wxUniCharRef& operator=(char c) { return *this = wxUniChar(c); }
 136     wxUniCharRef& operator=(wchar_t c) { return *this = wxUniChar(c); }
 137
 138     // Casts to wxUniChar type:
 139     operator char() const { return UniChar(); }
 140     operator unsigned char() const { return UniChar(); }
 141     operator wchar_t() const { return UniChar(); }
 142     operator int() const { return UniChar(); }
 143     operator unsigned int() const { return UniChar(); }
 144
 145     // see wxUniChar::operator bool etc. for explanation
 146     operator bool() const { return (bool)UniChar(); }
 147     bool operator!() const { return !UniChar(); }
 148 #if (defined(__VISUALC__) && __VISUALC__ < 1400) || \
 149     defined(__DIGITALMARS__) || defined(__BORLANDC__)
 150     bool operator&&(bool v) const { return UniChar() && v; }
 151 #endif
 152
 153     // Comparison operators:
 154 #define wxDEFINE_UNICHARREF_OPERATOR(op)                                      \
 155     bool operator op(const wxUniCharRef& c) const { return UniChar() op c.UniChar(); }\
 156     bool operator op(const wxUniChar& c) const { return UniChar() op c; }     \
 157     bool operator op(char c) const { return UniChar() op c; }                 \
 158     bool operator op(wchar_t c) const { return UniChar() op c; }
 159
 160     wxFOR_ALL_COMPARISONS(wxDEFINE_UNICHARREF_OPERATOR)
 161
 162 #undef wxDEFINE_UNICHARREF_OPERATOR
 163
 164     // for expressions like c-'A':
 165     int operator-(const wxUniCharRef& c) const { return UniChar() - c.UniChar(); }
 166     int operator-(const wxUniChar& c) const { return UniChar() - c; }
 167     int operator-(char c) const { return UniChar() - c; }
 168     int operator-(wchar_t c) const { return UniChar() - c; }
 169
 170 private:
 171     wxUniChar UniChar() const { return *m_pos; }
 172     friend class WXDLLIMPEXP_BASE wxUniChar;
 173
 174 private:
 175     // pointer to the character in string
 176     wxChar *m_pos;
 177 };
 178
 179 inline wxUniChar::wxUniChar(const wxUniCharRef& c)
 180 {
 181     m_value = c.UniChar().m_value;
 182 }
 183
 184 // Comparison operators for the case when wxUniChar(Ref) is the second operand
 185 // implemented in terms of member comparison functions
 186
 187 #define wxCMP_REVERSE(c1, c2, op) c2 op c1
 188
 189 wxDEFINE_COMPARISONS(char, const wxUniChar&, wxCMP_REVERSE)
 190 wxDEFINE_COMPARISONS(char, const wxUniCharRef&, wxCMP_REVERSE)
 191
 192 wxDEFINE_COMPARISONS(wchar_t, const wxUniChar&, wxCMP_REVERSE)
 193 wxDEFINE_COMPARISONS(wchar_t, const wxUniCharRef&, wxCMP_REVERSE)
 194
 195 wxDEFINE_COMPARISONS(const wxUniChar&, const wxUniCharRef&, wxCMP_REVERSE)
 196
 197 #undef wxCMP_REVERSE
 198
 199 // for expressions like c-'A':
 200 inline int operator-(char c1, const wxUniCharRef& c2) { return -(c2 - c1); }
 201 inline int operator-(wchar_t c1, const wxUniCharRef& c2) { return -(c2 - c1); }
 202 inline int operator-(const wxUniChar& c1, const wxUniCharRef& c2) { return -(c2 - c1); }
 203
 204 #endif /* _WX_UNICHAR_H_ */