docs/doxygen/overviews/fontencoding.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        fontencoding
   3 // Purpose:     topic overview
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows license
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /*!
  10
  11  @page fontencoding_overview Font encoding overview
  12
  13  wxWidgets has support for multiple font encodings.
  14  By encoding we mean here the mapping between the character codes and the
  15  letters. Probably the most well-known encoding is (7 bit) ASCII one which is
  16  used almost universally now to represent the letters of the English alphabet
  17  and some other common characters. However, it is not enough to represent the
  18  letters of foreign alphabets and here other encodings come into play. Please
  19  note that we will only discuss 8-bit fonts here and not
  20  #Unicode.
  21  Font encoding support is ensured by several classes:
  22  #wxFont itself, but also
  23  #wxFontEnumerator and
  24  #wxFontMapper. wxFont encoding support is reflected by
  25  a (new) constructor parameter @e encoding which takes one of the following
  26  values (elements of enumeration type @c wxFontEncoding):
  27
  28
  29
  30
  31
  32
  33  wxFONTENCODING_SYSTEM
  34
  35
  36
  37
  38  The default encoding of the underlying
  39  operating system (notice that this might be a "foreign" encoding for foreign
  40  versions of Windows 9x/NT).
  41
  42
  43
  44
  45
  46  wxFONTENCODING_DEFAULT
  47
  48
  49
  50
  51  The applications default encoding as
  52  returned by wxFont::GetDefaultEncoding. On
  53  program startup, the applications default encoding is the same as
  54  wxFONTENCODING_SYSTEM, but may be changed to make all the fonts created later
  55  to use it (by default).
  56
  57
  58
  59
  60
  61  wxFONTENCODING_ISO8859_1..15
  62
  63
  64
  65
  66  ISO8859 family encodings which are
  67  usually used by all non-Microsoft operating systems
  68
  69
  70
  71
  72
  73  wxFONTENCODING_KOI8
  74
  75
  76
  77
  78  Standard Cyrillic encoding for the Internet
  79  (but see also wxFONTENCODING_ISO8859_5 and wxFONTENCODING_CP1251)
  80
  81
  82
  83
  84
  85  wxFONTENCODING_CP1250
  86
  87
  88
  89
  90  Microsoft analogue of ISO8859-2
  91
  92
  93
  94
  95
  96  wxFONTENCODING_CP1251
  97
  98
  99
 100
 101  Microsoft analogue of ISO8859-5
 102
 103
 104
 105
 106
 107  wxFONTENCODING_CP1252
 108
 109
 110
 111
 112  Microsoft analogue of ISO8859-1
 113
 114
 115
 116
 117
 118  As you may see, Microsoft's encoding partly mirror the standard ISO8859 ones,
 119  but there are (minor) differences even between ISO8859-1 (Latin1, ISO encoding
 120  for Western Europe) and CP1251 (WinLatin1, standard code page for English
 121  versions of Windows) and there are more of them for other encodings.
 122  The situation is particularly complicated with Cyrillic encodings for which
 123  (more than) three incompatible encodings exist: KOI8 (the old standard, widely
 124  used on the Internet), ISO8859-5 (ISO standard for Cyrillic) and CP1251
 125  (WinCyrillic).
 126  This abundance of (incompatible) encodings should make it clear that using
 127  encodings is less easy than it might seem. The problems arise both from the
 128  fact that the standard encodings for the given language (say Russian, which is
 129  written in Cyrillic) are different on different platforms and because the
 130  fonts in the given encoding might just not be installed (this is especially a
 131  problem with Unix, or, in general, non-Win32 systems).
 132  To clarify, the #wxFontEnumerator
 133  class may be used to enumerate both all available encodings and to find the
 134  facename(s) in which the given encoding exists. If you can find the font in
 135  the correct encoding with wxFontEnumerator then your troubles are over, but,
 136  unfortunately, sometimes this is not enough. For example, there is no standard
 137  way (that I know of, please tell me if you do!) to find a font on a Windows system
 138  for KOI8 encoding (only for WinCyrillic one which is quite different), so
 139  #wxFontEnumerator will never return one, even if
 140  the user has installed a KOI8 font on his system.
 141  To solve this problem, a #wxFontMapper class is provided.
 142  This class stores the mapping between the encodings and the font face
 143  names which support them in #wxConfig object. Of
 144  course, it would be fairly useless if it tried to determine these mappings by
 145  itself, so, instead, it (optionally) asks the user and remembers his answers
 146  so that the next time the program will automatically choose the correct font.
 147  All these topics are illustrated by the @ref samplefont_overview;
 148  please refer to it and the documentation of the classes mentioned here for
 149  further explanations.
 150
 151  */
 152
 153