interface/wx/fontmap.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        fontmap.h
   3 // Purpose:     interface of wxFontMapper
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows licence
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10     @class wxFontMapper
  11
  12     wxFontMapper manages user-definable correspondence between logical font
  13     names and the fonts present on the machine.
  14
  15     The default implementations of all functions will ask the user if they are
  16     not capable of finding the answer themselves and store the answer in a
  17     config file (configurable via SetConfigXXX functions). This behaviour may
  18     be disabled by giving the value of @false to "interactive" parameter.
  19
  20     However, the functions will always consult the config file to allow the
  21     user-defined values override the default logic and there is no way to
  22     disable this - which shouldn't be ever needed because if "interactive" was
  23     never @true, the config file is never created anyhow.
  24
  25     In case everything else fails (i.e. there is no record in config file
  26     and "interactive" is @false or user denied to choose any replacement),
  27     the class queries wxEncodingConverter for "equivalent" encodings
  28     (e.g. iso8859-2 and cp1250) and tries them.
  29
  30
  31     @section fontmapper_mbconv Using wxFontMapper in conjunction with wxMBConv classes
  32
  33     If you need to display text in encoding which is not available at host
  34     system (see wxFontMapper::IsEncodingAvailable), you may use these two
  35     classes to find font in some similar encoding (see wxFontMapper::GetAltForEncoding)
  36     and convert the text to this encoding (wxMBConv classes).
  37     Following code snippet demonstrates it:
  38
  39     @code
  40     if (!wxFontMapper::Get()->IsEncodingAvailable(enc, facename))
  41     {
  42         wxFontEncoding alternative;
  43         if (wxFontMapper::Get()->GetAltForEncoding(enc, &alternative,
  44                                                     facename, false))
  45         {
  46             wxCSConv convFrom(wxFontMapper::Get()->GetEncodingName(enc));
  47             wxCSConv convTo(wxFontMapper::Get()->GetEncodingName(alternative));
  48             text = wxString(text.mb_str(convFrom), convTo);
  49         }
  50         else
  51             ...failure (or we may try iso8859-1/7bit ASCII)...
  52     }
  53     ...display text...
  54     @endcode
  55
  56     @library{wxcore}
  57     @category{cfg}
  58
  59     @see wxEncodingConverter, @ref overview_nonenglish
  60 */
  61 class wxFontMapper
  62 {
  63 public:
  64     /**
  65         Default ctor.
  66
  67         @note
  68         The preferred way of creating a wxFontMapper instance is to call wxFontMapper::Get().
  69     */
  70     wxFontMapper();
  71
  72     /**
  73         Virtual dtor.
  74     */
  75     virtual ~wxFontMapper();
  76
  77     /**
  78         Returns the encoding for the given charset (in the form of RFC 2046) or
  79         @c wxFONTENCODING_SYSTEM if couldn't decode it.
  80
  81         Be careful when using this function with @a interactive set to @true
  82         (default value) as the function then may show a dialog box to the user which
  83         may lead to unexpected reentrancies and may also take a significantly longer
  84         time than a simple function call. For these reasons, it is almost always a bad
  85         idea to call this function from the event handlers for repeatedly generated
  86         events such as @c EVT_PAINT.
  87     */
  88     virtual wxFontEncoding CharsetToEncoding(const wxString& charset,
  89                                              bool interactive = true);
  90
  91     /**
  92         Get the current font mapper object. If there is no current object, creates one.
  93
  94         @see Set()
  95     */
  96     static wxFontMapper* Get();
  97
  98     /**
  99         Returns the array of all possible names for the given encoding.
 100
 101         The array is @NULL-terminated. IF it isn't empty, the first name in it is
 102         the canonical encoding name, i.e. the same string as returned by
 103         GetEncodingName().
 104     */
 105     static const wxChar** GetAllEncodingNames(wxFontEncoding encoding);
 106
 107     //@{
 108     /**
 109         Find an alternative for the given encoding (which is supposed to not be
 110         available on this system). If successful, return @true and fill info
 111         structure with the parameters required to create the font, otherwise
 112         return @false.
 113
 114         The first form is for wxWidgets' internal use while the second one
 115         is better suitable for general use -- it returns wxFontEncoding which
 116         can consequently be passed to wxFont constructor.
 117     */
 118     bool GetAltForEncoding(wxFontEncoding encoding,
 119                            wxNativeEncodingInfo* info,
 120                            const wxString& facename = wxEmptyString,
 121                            bool interactive = true);
 122     bool GetAltForEncoding(wxFontEncoding encoding,
 123                            wxFontEncoding* alt_encoding,
 124                            const wxString& facename = wxEmptyString,
 125                            bool interactive = true);
 126     //@}
 127
 128     /**
 129         Returns the @e n-th supported encoding.
 130
 131         Together with GetSupportedEncodingsCount() this method may be used
 132         to get all supported encodings.
 133     */
 134     static wxFontEncoding GetEncoding(size_t n);
 135
 136     /**
 137         Return user-readable string describing the given encoding.
 138     */
 139     static wxString GetEncodingDescription(wxFontEncoding encoding);
 140
 141     /**
 142         Return the encoding corresponding to the given internal name.
 143
 144         This function is the inverse of GetEncodingName() and is intentionally
 145         less general than CharsetToEncoding(), i.e. it doesn't try to make any
 146         guesses nor ever asks the user. It is meant just as a way of restoring
 147         objects previously serialized using GetEncodingName().
 148     */
 149     static wxFontEncoding GetEncodingFromName(const wxString& encoding);
 150
 151     /**
 152         Return internal string identifier for the encoding (see also
 153         wxFontMapper::GetEncodingDescription).
 154
 155         @see GetEncodingFromName()
 156     */
 157     static wxString GetEncodingName(wxFontEncoding encoding);
 158
 159     /**
 160         Returns the number of the font encodings supported by this class.
 161         Together with GetEncoding() this method may be used to get
 162         all supported encodings.
 163     */
 164     static size_t GetSupportedEncodingsCount();
 165
 166     /**
 167         Check whether given encoding is available in given face or not.
 168         If no facename is given, find @e any font in this encoding.
 169     */
 170     virtual bool IsEncodingAvailable(wxFontEncoding encoding,
 171                                      const wxString& facename = wxEmptyString);
 172
 173     /**
 174         Set the current font mapper object and return previous one (may be @NULL).
 175         This method is only useful if you want to plug-in an alternative font mapper
 176         into wxWidgets.
 177
 178         @see Get()
 179     */
 180     static wxFontMapper* Set(wxFontMapper* mapper);
 181
 182     /**
 183         Set the config object to use (may be @NULL to use default).
 184         By default, the global one (from wxConfigBase::Get() will be used)
 185         and the default root path for the config settings is the string returned
 186         by GetDefaultConfigPath().
 187     */
 188     void SetConfig(wxConfigBase* config);
 189
 190     /**
 191         Set the root config path to use (should be an absolute path).
 192     */
 193     void SetConfigPath(const wxString& prefix);
 194
 195     /**
 196         The parent window for modal dialogs.
 197     */
 198     void SetDialogParent(wxWindow* parent);
 199
 200     /**
 201         The title for the dialogs (note that default is quite reasonable).
 202     */
 203     void SetDialogTitle(const wxString& title);
 204 };
 205