include/wx/convauto.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/convauto.h
   3 // Purpose:     wxConvAuto class declaration
   4 // Author:      Vadim Zeitlin
   5 // Created:     2006-04-03
   6 // RCS-ID:      $Id$
   7 // Copyright:   (c) 2006 Vadim Zeitlin
   8 // Licence:     wxWindows licence
   9 ///////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef _WX_CONVAUTO_H_
  12 #define _WX_CONVAUTO_H_
  13
  14 #include "wx/strconv.h"
  15 #include "wx/fontenc.h"
  16
  17 #if wxUSE_WCHAR_T
  18
  19 // ----------------------------------------------------------------------------
  20 // wxConvAuto: uses BOM to automatically detect input encoding
  21 // ----------------------------------------------------------------------------
  22
  23 class WXDLLIMPEXP_BASE wxConvAuto : public wxMBConv
  24 {
  25 public:
  26     // default ctor, the real conversion will be created on demand
  27     wxConvAuto(wxFontEncoding enc = wxFONTENCODING_DEFAULT)
  28     {
  29         Init();
  30
  31         m_encDefault = enc;
  32     }
  33
  34     // copy ctor doesn't initialize anything neither as conversion can only be
  35     // deduced on first use
  36     wxConvAuto(const wxConvAuto& other) : wxMBConv()
  37     {
  38         Init();
  39
  40         m_encDefault = other.m_encDefault;
  41     }
  42
  43     virtual ~wxConvAuto()
  44     {
  45         if ( m_ownsConv )
  46             delete m_conv;
  47     }
  48
  49     // get/set the fall-back encoding used when the input text doesn't have BOM
  50     // and isn't UTF-8
  51     //
  52     // special values are wxFONTENCODING_MAX meaning not to use any fall back
  53     // at all (but just fail to convert in this case) and wxFONTENCODING_SYSTEM
  54     // meaning to use the encoding of the system locale
  55     static wxFontEncoding GetFallbackEncoding() { return ms_defaultMBEncoding; }
  56     static void SetFallbackEncoding(wxFontEncoding enc);
  57     static void DisableFallbackEncoding()
  58     {
  59         SetFallbackEncoding(wxFONTENCODING_MAX);
  60     }
  61
  62
  63     // override the base class virtual function(s) to use our m_conv
  64     virtual size_t ToWChar(wchar_t *dst, size_t dstLen,
  65                            const char *src, size_t srcLen = wxNO_LEN) const;
  66
  67     virtual size_t FromWChar(char *dst, size_t dstLen,
  68                              const wchar_t *src, size_t srcLen = wxNO_LEN) const;
  69
  70     virtual size_t GetMBNulLen() const { return m_conv->GetMBNulLen(); }
  71
  72     virtual wxMBConv *Clone() const { return new wxConvAuto(*this); }
  73
  74 private:
  75     // all currently recognized BOM values
  76     enum BOMType
  77     {
  78         BOM_None,
  79         BOM_UTF32BE,
  80         BOM_UTF32LE,
  81         BOM_UTF16BE,
  82         BOM_UTF16LE,
  83         BOM_UTF8
  84     };
  85
  86     // return the BOM type of this buffer
  87     static BOMType DetectBOM(const char *src, size_t srcLen);
  88
  89     // common part of all ctors
  90     void Init()
  91     {
  92         // no need to initialize m_bomType and m_consumedBOM here, this will be
  93         // done when m_conv is created
  94         m_conv = NULL;
  95         m_ownsConv = false;
  96     }
  97
  98     // initialize m_conv with the UTF-8 conversion
  99     void InitWithUTF8()
 100     {
 101         m_conv = &wxConvUTF8;
 102         m_ownsConv = false;
 103     }
 104
 105     // create the correct conversion object for the given BOM type
 106     void InitFromBOM(BOMType bomType);
 107
 108     // create the correct conversion object for the BOM present in the
 109     // beginning of the buffer; adjust the buffer to skip the BOM if found
 110     void InitFromInput(const char **src, size_t *len);
 111
 112     // adjust src and len to skip over the BOM (identified by m_bomType) at the
 113     // start of the buffer
 114     void SkipBOM(const char **src, size_t *len) const;
 115
 116
 117     // fall-back multibyte encoding to use, may be wxFONTENCODING_SYSTEM or
 118     // wxFONTENCODING_MAX but not wxFONTENCODING_DEFAULT
 119     static wxFontEncoding ms_defaultMBEncoding;
 120
 121     // conversion object which we really use, NULL until the first call to
 122     // either ToWChar() or FromWChar()
 123     wxMBConv *m_conv;
 124
 125     // the multibyte encoding to use by default if input isn't Unicode
 126     wxFontEncoding m_encDefault;
 127
 128     // our BOM type
 129     BOMType m_bomType;
 130
 131     // true if we allocated m_conv ourselves, false if we just use an existing
 132     // global conversion
 133     bool m_ownsConv;
 134
 135     // true if we already skipped BOM when converting (and not just calculating
 136     // the size)
 137     bool m_consumedBOM;
 138
 139
 140     DECLARE_NO_ASSIGN_CLASS(wxConvAuto)
 141 };
 142
 143 #endif // wxUSE_WCHAR_T
 144
 145 #endif // _WX_CONVAUTO_H_
 146