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