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 // wxNumberFormatter implementation
  26 // ============================================================================
  27
  28 // ----------------------------------------------------------------------------
  29 // Locale information accessors
  30 // ----------------------------------------------------------------------------
  31
  32 wxChar wxNumberFormatter::GetDecimalSeparator()
  33 {
  34     // Notice that while using static variable here is not MT-safe, the worst
  35     // that can happen is that we redo the initialization if we're called
  36     // concurrently from more than one thread so it's not a real problem.
  37     static wxChar s_decimalSeparator = 0;
  38
  39     // Remember the locale which was current when we initialized, we must redo
  40     // the initialization if the locale changed.
  41     static wxLocale *s_localeUsedForInit = NULL;
  42
  43     if ( !s_decimalSeparator || (s_localeUsedForInit != wxGetLocale()) )
  44     {
  45         const wxString
  46             s = wxLocale::GetInfo(wxLOCALE_DECIMAL_POINT, wxLOCALE_CAT_NUMBER);
  47         if ( s.empty() )
  48         {
  49             // We really must have something for decimal separator, so fall
  50             // back to the C locale default.
  51             s_decimalSeparator = '.';
  52         }
  53         else
  54         {
  55             // To the best of my knowledge there are no locales like this.
  56             wxASSERT_MSG( s.length() == 1,
  57                           "Multi-character decimal separator?" );
  58
  59             s_decimalSeparator = s[0];
  60         }
  61
  62         s_localeUsedForInit = wxGetLocale();
  63     }
  64
  65     return s_decimalSeparator;
  66 }
  67
  68 bool wxNumberFormatter::GetThousandsSeparatorIfUsed(wxChar *sep)
  69 {
  70     static wxChar s_thousandsSeparator = 0;
  71     static bool s_initialized = false;
  72     static wxLocale *s_localeUsedForInit = NULL;
  73
  74     if ( !s_initialized || (s_localeUsedForInit != wxGetLocale()) )
  75     {
  76         const wxString
  77             s = wxLocale::GetInfo(wxLOCALE_THOUSANDS_SEP, wxLOCALE_CAT_NUMBER);
  78         if ( !s.empty() )
  79         {
  80             wxASSERT_MSG( s.length() == 1,
  81                           "Multi-character thousands separator?" );
  82
  83             s_thousandsSeparator = s[0];
  84         }
  85         //else: Unlike above it's perfectly fine for the thousands separator to
  86         //      be empty if grouping is not used, so just leave it as 0.
  87
  88         s_initialized = true;
  89         s_localeUsedForInit = wxGetLocale();
  90     }
  91
  92     if ( !s_thousandsSeparator )
  93         return false;
  94
  95     if ( sep )
  96         *sep = s_thousandsSeparator;
  97
  98     return true;
  99 }
 100
 101 // ----------------------------------------------------------------------------
 102 // Conversion to string and helpers
 103 // ----------------------------------------------------------------------------
 104
 105 wxString wxNumberFormatter::PostProcessIntString(wxString s, int style)
 106 {
 107     if ( style & Style_WithThousandsSep )
 108         AddThousandsSeparators(s);
 109
 110     wxASSERT_MSG( !(style & Style_NoTrailingZeroes),
 111                   "Style_NoTrailingZeroes can't be used with integer values" );
 112
 113     return s;
 114 }
 115
 116 wxString wxNumberFormatter::ToString(long val, int style)
 117 {
 118     return PostProcessIntString(wxString::Format("%ld", val), style);
 119 }
 120
 121 #ifdef wxHAS_LONG_LONG_T_DIFFERENT_FROM_LONG
 122
 123 wxString wxNumberFormatter::ToString(wxLongLong_t val, int style)
 124 {
 125     return PostProcessIntString(wxString::Format("%" wxLongLongFmtSpec "d", val),
 126                                 style);
 127 }
 128
 129 #endif // wxHAS_LONG_LONG_T_DIFFERENT_FROM_LONG
 130
 131 wxString wxNumberFormatter::ToString(double val, int precision, int style)
 132 {
 133     const wxString fmt = wxString::Format("%%.%df", precision);
 134     wxString s = wxString::Format(fmt, val);
 135
 136     if ( style & Style_WithThousandsSep )
 137         AddThousandsSeparators(s);
 138
 139     if ( style & Style_NoTrailingZeroes )
 140         RemoveTrailingZeroes(s);
 141
 142     return s;
 143 }
 144
 145 void wxNumberFormatter::AddThousandsSeparators(wxString& s)
 146 {
 147     wxChar thousandsSep;
 148     if ( !GetThousandsSeparatorIfUsed(&thousandsSep) )
 149         return;
 150
 151     size_t pos = s.find(GetDecimalSeparator());
 152     if ( pos == wxString::npos )
 153     {
 154         // Start grouping at the end of an integer number.
 155         pos = s.length();
 156     }
 157
 158     // We currently group digits by 3 independently of the locale. This is not
 159     // the right thing to do and we should use lconv::grouping (under POSIX)
 160     // and GetLocaleInfo(LOCALE_SGROUPING) (under MSW) to get information about
 161     // the correct grouping to use. This is something that needs to be done at
 162     // wxLocale level first and then used here in the future (TODO).
 163     const size_t GROUP_LEN = 3;
 164
 165     while ( pos > GROUP_LEN )
 166     {
 167         pos -= GROUP_LEN;
 168         s.insert(pos, thousandsSep);
 169     }
 170 }
 171
 172 void wxNumberFormatter::RemoveTrailingZeroes(wxString& s)
 173 {
 174     const size_t posDecSep = s.find(GetDecimalSeparator());
 175     wxCHECK_RET( posDecSep != wxString::npos, "No decimal separator" );
 176     wxCHECK_RET( posDecSep, "Can't start with decimal separator" );
 177
 178     // Find the last character to keep.
 179     size_t posLastNonZero = s.find_last_not_of("0");
 180
 181     // If it's the decimal separator itself, don't keep it neither.
 182     if ( posLastNonZero == posDecSep )
 183         posLastNonZero--;
 184
 185     s.erase(posLastNonZero + 1);
 186 }
 187
 188 // ----------------------------------------------------------------------------
 189 // Conversion from strings
 190 // ----------------------------------------------------------------------------
 191
 192 void wxNumberFormatter::RemoveThousandsSeparators(wxString& s)
 193 {
 194     wxChar thousandsSep;
 195     if ( !GetThousandsSeparatorIfUsed(&thousandsSep) )
 196         return;
 197
 198     s.Replace(wxString(thousandsSep), wxString());
 199 }
 200
 201 bool wxNumberFormatter::FromString(wxString s, long *val)
 202 {
 203     RemoveThousandsSeparators(s);
 204     return s.ToLong(val);
 205 }
 206
 207 #ifdef wxHAS_LONG_LONG_T_DIFFERENT_FROM_LONG
 208
 209 bool wxNumberFormatter::FromString(wxString s, wxLongLong_t *val)
 210 {
 211     RemoveThousandsSeparators(s);
 212     return s.ToLongLong(val);
 213 }
 214
 215 #endif // wxHAS_LONG_LONG_T_DIFFERENT_FROM_LONG
 216
 217 bool wxNumberFormatter::FromString(wxString s, double *val)
 218 {
 219     RemoveThousandsSeparators(s);
 220     return s.ToDouble(val);
 221 }