Dogcows Code - chaz/openbox/blob - otk/ustring.hh

   1 // -*- mode: C++; indent-tabs-mode: nil; c-basic-offset: 2; -*-
   2 #ifndef   __ustring_hh
   3 #define   __ustring_hh
   4
   5 /*! @file ustring.hh
   6   @brief Provides a simple UTF-8 encoded string
   7 */
   8
   9 extern "C" {
  10 #ifdef HAVE_STDINT_H
  11 #  include <stdint.h>
  12 #else
  13 #  ifdef HAVE_SYS_TYPES_H
  14 #    include <sys/types.h>
  15 #  endif
  16 #endif
  17 }
  18
  19 #include <string>
  20
  21 namespace otk {
  22
  23 #ifdef HAVE_STDINT_H
  24 typedef uint32_t unichar;
  25 #else
  26 typedef u_int32_t unichar;
  27 #endif
  28
  29 #ifndef DOXYGEN_IGNORE
  30
  31 //! The number of bytes to skip to find the next character in the string
  32 const char g_utf8_skip[256] = {
  33   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
  34   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
  35   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
  36   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
  37   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
  38   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
  39   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
  40   3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,6,6,1,1
  41 };
  42
  43 //! The iterator type for ustring
  44 /*!
  45   Note this is not a random access iterator but a bidirectional one, since all
  46   index operations need to iterate over the UTF-8 data.  Use std::advance() to
  47   move to a certain position.
  48   <p>
  49   A writeable iterator isn't provided because:  The number of bytes of the old
  50   UTF-8 character and the new one to write could be different. Therefore, any
  51   write operation would invalidate all other iterators pointing into the same
  52   string.
  53 */
  54 template <class T>
  55 class ustring_Iterator
  56 {
  57 public:
  58   typedef std::bidirectional_iterator_tag   iterator_category;
  59   typedef unichar                           value_type;
  60   typedef std::string::difference_type      difference_type;
  61   typedef value_type                        reference;
  62   typedef void                              pointer;
  63
  64   inline ustring_Iterator() {}
  65   inline ustring_Iterator(const ustring_Iterator<std::string::iterator>&
  66                           other) : _pos(other.base()) {}
  67
  68   inline value_type operator*() const {
  69     // get a unicode character from the iterator's position
  70
  71     // get an iterator to the internal string
  72     std::string::const_iterator pos = _pos;
  73
  74     unichar result = static_cast<unsigned char>(*pos);
  75
  76     // if its not a 7-bit ascii character
  77     if((result & 0x80) != 0) {
  78       // len is the number of bytes this character takes up in the string
  79       unsigned char len = g_utf8_skip[result];
  80       result &= 0x7F >> len;
  81
  82       while(--len != 0) {
  83         result <<= 6;
  84         result |= static_cast<unsigned char>(*++pos) & 0x3F;
  85       }
  86     }
  87
  88     return result;
  89   }
  90
  91   inline ustring_Iterator<T> &     operator++() {
  92     pos_ += g_utf8_skip[static_cast<unsigned char>(*pos_)];
  93     return *this;
  94   }
  95   inline ustring_Iterator<T> &     operator--() {
  96     do { --_pos; } while((*_pos & '\xC0') == '\x80');
  97     return *this;
  98   }
  99
 100   explicit inline ustring_Iterator(T pos) : _pos(pos) {}
 101   inline T base() const { return _pos; }
 102
 103 private:
 104   T _pos;
 105 };
 106
 107 #endif // DOXYGEN_IGNORE
 108
 109 //! This class provides a simple wrapper to a std::string that is encoded as
 110 //! UTF-8.
 111 /*!
 112   This class does <b>not</b> handle extended 8-bit ASCII charsets like
 113   ISO-8859-1.
 114   <p>
 115   More info on Unicode and UTF-8 can be found here:
 116   http://www.cl.cam.ac.uk/~mgk25/unicode.html
 117   <p>
 118   This does not subclass std::string, because std::string was intended to be a
 119   final class.  For instance, it does not have a virtual destructor.
 120 */
 121 class ustring {
 122   std::string _string;
 123
 124 public:
 125   typedef std::string::size_type                        size_type;
 126   typedef std::string::difference_type                  difference_type;
 127
 128   typedef unichar                                       value_type;
 129   typedef unichar &                                     reference;
 130   typedef const unichar &                               const_reference;
 131
 132   typedef ustring_Iterator<std::string::iterator>       iterator;
 133   typedef ustring_Iterator<std::string::const_iterator> const_iterator;
 134
 135   static const size_type npos = std::string::npos;
 136
 137   ustring();
 138   ~ustring();
 139
 140   // make new strings
 141
 142   ustring(const ustring& other);
 143   ustring& operator=(const ustring& other);
 144   ustring(const std::string& src);
 145   ustring::ustring(const char* src);
 146
 147   // sizes
 148
 149   ustring::size_type size() const;
 150   ustring::size_type length() const;
 151   ustring::size_type bytes() const;
 152   ustring::size_type capacity() const;
 153   ustring::size_type max_size() const;
 154
 155   // internal data
 156
 157   const char* data()  const;
 158   const char* c_str() const;
 159
 160 };
 161
 162 }
 163
 164 #endif // __ustring_hh