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::ToString(long val, int style)
  98 {
  99     wxString s = wxString::Format("%ld", val);
 100
 101     if ( style & Style_WithThousandsSep )
 102         AddThousandsSeparators(s);
 103
 104     wxASSERT_MSG( !(style & Style_NoTrailingZeroes),
 105                   "Style_NoTrailingZeroes can't be used with integer values" );
 106
 107     return s;
 108 }
 109
 110 wxString wxNumberFormatter::ToString(double val, int precision, int style)
 111 {
 112     const wxString fmt = wxString::Format("%%.%df", precision);
 113     wxString s = wxString::Format(fmt, val);
 114
 115     if ( style & Style_WithThousandsSep )
 116         AddThousandsSeparators(s);
 117
 118     if ( style & Style_NoTrailingZeroes )
 119         RemoveTrailingZeroes(s);
 120
 121     return s;
 122 }
 123
 124 void wxNumberFormatter::AddThousandsSeparators(wxString& s)
 125 {
 126     wxChar thousandsSep;
 127     if ( !GetThousandsSeparatorIfUsed(&thousandsSep) )
 128         return;
 129
 130     size_t pos = s.find(GetDecimalSeparator());
 131     if ( pos == wxString::npos )
 132     {
 133         // Start grouping at the end of an integer number.
 134         pos = s.length();
 135     }
 136
 137     // We currently group digits by 3 independently of the locale. This is not
 138     // the right thing to do and we should use lconv::grouping (under POSIX)
 139     // and GetLocaleInfo(LOCALE_SGROUPING) (under MSW) to get information about
 140     // the correct grouping to use. This is something that needs to be done at
 141     // wxLocale level first and then used here in the future (TODO).
 142     const size_t GROUP_LEN = 3;
 143
 144     while ( pos > GROUP_LEN )
 145     {
 146         pos -= GROUP_LEN;
 147         s.insert(pos, thousandsSep);
 148     }
 149 }
 150
 151 void wxNumberFormatter::RemoveTrailingZeroes(wxString& s)
 152 {
 153     const size_t posDecSep = s.find(GetDecimalSeparator());
 154     wxCHECK_RET( posDecSep != wxString::npos, "No decimal separator" );
 155     wxCHECK_RET( posDecSep, "Can't start with decimal separator" );
 156
 157     // Find the last character to keep.
 158     size_t posLastNonZero = s.find_last_not_of("0");
 159
 160     // If it's the decimal separator itself, don't keep it neither.
 161     if ( posLastNonZero == posDecSep )
 162         posLastNonZero--;
 163
 164     s.erase(posLastNonZero + 1);
 165 }
 166
 167 // ----------------------------------------------------------------------------
 168 // Conversion from strings
 169 // ----------------------------------------------------------------------------
 170
 171 void wxNumberFormatter::RemoveThousandsSeparators(wxString& s)
 172 {
 173     wxChar thousandsSep;
 174     if ( !GetThousandsSeparatorIfUsed(&thousandsSep) )
 175         return;
 176
 177     s.Replace(wxString(thousandsSep), wxString());
 178 }
 179
 180 bool wxNumberFormatter::FromString(wxString s, long *val)
 181 {
 182     RemoveThousandsSeparators(s);
 183     return s.ToLong(val);
 184 }
 185
 186 bool wxNumberFormatter::FromString(wxString s, double *val)
 187 {
 188     RemoveThousandsSeparators(s);
 189     return s.ToDouble(val);
 190 }