src/common/numformatter.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/common/numformatter.cpp
   3 // Purpose:     wxNumberFormatter
   4 // Author:      Fulvio Senore, Vadim Zeitlin
   5 // Created:     2010-11-06
   6 // Copyright:   (c) 2010 wxWidgets team
   7 // Licence:     wxWindows licence
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10 // ----------------------------------------------------------------------------
  11 // headers
  12 // ----------------------------------------------------------------------------
  13
  14 // For compilers that support precompilation, includes "wx.h".
  15 #include "wx/wxprec.h"
  16
  17 #ifdef __BORLANDC__
  18     #pragma hdrstop
  19 #endif
  20
  21 #include "wx/numformatter.h"
  22 #include "wx/intl.h"
  23
  24 // ----------------------------------------------------------------------------
  25 // local helpers
  26 // ----------------------------------------------------------------------------
  27
  28 namespace
  29 {
  30
  31 // Contains information about the locale which was used to initialize our
  32 // cached values of the decimal and thousands separators. Notice that it isn't
  33 // enough to store just wxLocale because the user code may call setlocale()
  34 // directly and storing just C locale string is not enough because we can use
  35 // the OS API directly instead of the CRT ones on some platforms. So just store
  36 // both.
  37 class LocaleId
  38 {
  39 public:
  40     LocaleId()
  41     {
  42 #if wxUSE_INTL
  43         m_wxloc = NULL;
  44 #endif // wxUSE_INTL
  45         m_cloc = NULL;
  46     }
  47
  48     ~LocaleId()
  49     {
  50         Free();
  51     }
  52
  53 #if wxUSE_INTL
  54     // Return true if this is the first time this function is called for this
  55     // object or if the program locale has changed since the last time it was
  56     // called. Otherwise just return false indicating that updating locale-
  57     // dependent information is not necessary.
  58     bool NotInitializedOrHasChanged()
  59     {
  60         wxLocale * const wxloc = wxGetLocale();
  61         const char * const cloc = setlocale(LC_ALL, NULL);
  62         if ( m_wxloc || m_cloc )
  63         {
  64             if ( m_wxloc == wxloc && strcmp(m_cloc, cloc) == 0 )
  65                 return false;
  66
  67             Free();
  68         }
  69         //else: Not initialized yet.
  70
  71         m_wxloc = wxloc;
  72         m_cloc = wxCRT_StrdupA(cloc);
  73
  74         return true;
  75     }
  76 #endif // wxUSE_INTL
  77
  78 private:
  79     void Free()
  80     {
  81 #if wxUSE_INTL
  82         free(m_cloc);
  83 #endif // wxUSE_INTL
  84     }
  85
  86 #if wxUSE_INTL
  87     // Non-owned pointer to wxLocale which was used.
  88     wxLocale *m_wxloc;
  89 #endif // wxUSE_INTL
  90
  91     // Owned pointer to the C locale string.
  92     char *m_cloc;
  93
  94     wxDECLARE_NO_COPY_CLASS(LocaleId);
  95 };
  96
  97 } // anonymous namespace
  98
  99 // ============================================================================
 100 // wxNumberFormatter implementation
 101 // ============================================================================
 102
 103 // ----------------------------------------------------------------------------
 104 // Locale information accessors
 105 // ----------------------------------------------------------------------------
 106
 107 wxChar wxNumberFormatter::GetDecimalSeparator()
 108 {
 109 #if wxUSE_INTL
 110     // Notice that while using static variable here is not MT-safe, the worst
 111     // that can happen is that we redo the initialization if we're called
 112     // concurrently from more than one thread so it's not a real problem.
 113     static wxChar s_decimalSeparator = 0;
 114
 115     // Remember the locale which was current when we initialized, we must redo
 116     // the initialization if the locale changed.
 117     static LocaleId s_localeUsedForInit;
 118
 119     if ( s_localeUsedForInit.NotInitializedOrHasChanged() )
 120     {
 121         const wxString
 122             s = wxLocale::GetInfo(wxLOCALE_DECIMAL_POINT, wxLOCALE_CAT_NUMBER);
 123         if ( s.empty() )
 124         {
 125             // We really must have something for decimal separator, so fall
 126             // back to the C locale default.
 127             s_decimalSeparator = '.';
 128         }
 129         else
 130         {
 131             // To the best of my knowledge there are no locales like this.
 132             wxASSERT_MSG( s.length() == 1,
 133                           "Multi-character decimal separator?" );
 134
 135             s_decimalSeparator = s[0];
 136         }
 137     }
 138
 139     return s_decimalSeparator;
 140 #else // !wxUSE_INTL
 141     return wxT('.');
 142 #endif // wxUSE_INTL/!wxUSE_INTL
 143 }
 144
 145 bool wxNumberFormatter::GetThousandsSeparatorIfUsed(wxChar *sep)
 146 {
 147 #if wxUSE_INTL
 148     static wxChar s_thousandsSeparator = 0;
 149     static LocaleId s_localeUsedForInit;
 150
 151     if ( s_localeUsedForInit.NotInitializedOrHasChanged() )
 152     {
 153         const wxString
 154             s = wxLocale::GetInfo(wxLOCALE_THOUSANDS_SEP, wxLOCALE_CAT_NUMBER);
 155         if ( !s.empty() )
 156         {
 157             wxASSERT_MSG( s.length() == 1,
 158                           "Multi-character thousands separator?" );
 159
 160             s_thousandsSeparator = s[0];
 161         }
 162         //else: Unlike above it's perfectly fine for the thousands separator to
 163         //      be empty if grouping is not used, so just leave it as 0.
 164     }
 165
 166     if ( !s_thousandsSeparator )
 167         return false;
 168
 169     if ( sep )
 170         *sep = s_thousandsSeparator;
 171
 172     return true;
 173 #else // !wxUSE_INTL
 174     wxUnusedVar(sep);
 175     return false;
 176 #endif // wxUSE_INTL/!wxUSE_INTL
 177 }
 178
 179 // ----------------------------------------------------------------------------
 180 // Conversion to string and helpers
 181 // ----------------------------------------------------------------------------
 182
 183 wxString wxNumberFormatter::PostProcessIntString(wxString s, int style)
 184 {
 185     if ( style & Style_WithThousandsSep )
 186         AddThousandsSeparators(s);
 187
 188     wxASSERT_MSG( !(style & Style_NoTrailingZeroes),
 189                   "Style_NoTrailingZeroes can't be used with integer values" );
 190
 191     return s;
 192 }
 193
 194 wxString wxNumberFormatter::ToString(long val, int style)
 195 {
 196     return PostProcessIntString(wxString::Format("%ld", val), style);
 197 }
 198
 199 #ifdef wxHAS_LONG_LONG_T_DIFFERENT_FROM_LONG
 200
 201 wxString wxNumberFormatter::ToString(wxLongLong_t val, int style)
 202 {
 203     return PostProcessIntString(wxString::Format("%" wxLongLongFmtSpec "d", val),
 204                                 style);
 205 }
 206
 207 #endif // wxHAS_LONG_LONG_T_DIFFERENT_FROM_LONG
 208
 209 wxString wxNumberFormatter::ToString(double val, int precision, int style)
 210 {
 211     const wxString fmt = wxString::Format("%%.%df", precision);
 212     wxString s = wxString::Format(fmt, val);
 213
 214     if ( style & Style_WithThousandsSep )
 215         AddThousandsSeparators(s);
 216
 217     if ( style & Style_NoTrailingZeroes )
 218         RemoveTrailingZeroes(s);
 219
 220     return s;
 221 }
 222
 223 void wxNumberFormatter::AddThousandsSeparators(wxString& s)
 224 {
 225     wxChar thousandsSep;
 226     if ( !GetThousandsSeparatorIfUsed(&thousandsSep) )
 227         return;
 228
 229     size_t pos = s.find(GetDecimalSeparator());
 230     if ( pos == wxString::npos )
 231     {
 232         // Start grouping at the end of an integer number.
 233         pos = s.length();
 234     }
 235
 236     // We currently group digits by 3 independently of the locale. This is not
 237     // the right thing to do and we should use lconv::grouping (under POSIX)
 238     // and GetLocaleInfo(LOCALE_SGROUPING) (under MSW) to get information about
 239     // the correct grouping to use. This is something that needs to be done at
 240     // wxLocale level first and then used here in the future (TODO).
 241     const size_t GROUP_LEN = 3;
 242
 243     while ( pos > GROUP_LEN )
 244     {
 245         pos -= GROUP_LEN;
 246         s.insert(pos, thousandsSep);
 247     }
 248 }
 249
 250 void wxNumberFormatter::RemoveTrailingZeroes(wxString& s)
 251 {
 252     const size_t posDecSep = s.find(GetDecimalSeparator());
 253     wxCHECK_RET( posDecSep != wxString::npos,
 254                  wxString::Format("No decimal separator in \"%s\"", s) );
 255     wxCHECK_RET( posDecSep, "Can't start with decimal separator" );
 256
 257     // Find the last character to keep.
 258     size_t posLastNonZero = s.find_last_not_of("0");
 259
 260     // If it's the decimal separator itself, don't keep it neither.
 261     if ( posLastNonZero == posDecSep )
 262         posLastNonZero--;
 263
 264     s.erase(posLastNonZero + 1);
 265 }
 266
 267 // ----------------------------------------------------------------------------
 268 // Conversion from strings
 269 // ----------------------------------------------------------------------------
 270
 271 void wxNumberFormatter::RemoveThousandsSeparators(wxString& s)
 272 {
 273     wxChar thousandsSep;
 274     if ( !GetThousandsSeparatorIfUsed(&thousandsSep) )
 275         return;
 276
 277     s.Replace(wxString(thousandsSep), wxString());
 278 }
 279
 280 bool wxNumberFormatter::FromString(wxString s, long *val)
 281 {
 282     RemoveThousandsSeparators(s);
 283     return s.ToLong(val);
 284 }
 285
 286 #ifdef wxHAS_LONG_LONG_T_DIFFERENT_FROM_LONG
 287
 288 bool wxNumberFormatter::FromString(wxString s, wxLongLong_t *val)
 289 {
 290     RemoveThousandsSeparators(s);
 291     return s.ToLongLong(val);
 292 }
 293
 294 #endif // wxHAS_LONG_LONG_T_DIFFERENT_FROM_LONG
 295
 296 bool wxNumberFormatter::FromString(wxString s, double *val)
 297 {
 298     RemoveThousandsSeparators(s);
 299     return s.ToDouble(val);
 300 }