src/common/numformatter.cpp

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