QGIS API Documentation  3.23.0-Master (eb871beae0)
qgsbasicnumericformat.cpp
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1 /***************************************************************************
2  qgsbasicnumericformat.cpp
3  ----------------------------
4  begin : January 2020
5  copyright : (C) 2020 by Nyall Dawson
6  email : nyall dot dawson at gmail dot com
7 
8  ***************************************************************************
9  * *
10  * This program is free software; you can redistribute it and/or modify *
11  * it under the terms of the GNU General Public License as published by *
12  * the Free Software Foundation; either version 2 of the License, or *
13  * (at your option) any later version. *
14  * *
15  ***************************************************************************/
16 
17 #include "qgsbasicnumericformat.h"
18 #include "qgis.h"
19 #include <memory>
20 #include <iostream>
21 #include <locale>
22 #include <iomanip>
23 
24 struct formatter : std::numpunct<wchar_t>
25 {
26  formatter( QChar thousands, bool showThousands, QChar decimal )
27  : mThousands( thousands.unicode() )
28  , mDecimal( decimal.unicode() )
29  , mShowThousands( showThousands )
30  {}
31  wchar_t do_decimal_point() const override { return mDecimal; }
32  wchar_t do_thousands_sep() const override { return mThousands; }
33  std::string do_grouping() const override { return mShowThousands ? "\3" : "\0"; }
34 
35  wchar_t mThousands;
36  wchar_t mDecimal;
37  bool mShowThousands = true;
38 };
39 
41 {
42 }
43 
45 {
46  return QStringLiteral( "basic" );
47 }
48 
50 {
51  return QObject::tr( "Number" );
52 }
53 
55 {
56  return 1;
57 }
58 
59 QString QgsBasicNumericFormat::formatDouble( double value, const QgsNumericFormatContext &context ) const
60 {
61  const QChar decimal = mDecimalSeparator.isNull() ? context.decimalSeparator() : mDecimalSeparator;
62  std::basic_stringstream<wchar_t> os;
63  os.imbue( std::locale( os.getloc(), new formatter( mThousandsSeparator.isNull() ? context.thousandsSeparator() : mThousandsSeparator,
64  mShowThousandsSeparator,
65  decimal ) ) );
66 
67  if ( !mUseScientific )
68  {
69  switch ( mRoundingType )
70  {
71  case DecimalPlaces:
72  os << std::fixed << std::setprecision( mNumberDecimalPlaces );
73  os << value;
74  break;
75 
76  case SignificantFigures:
77  {
78  if ( qgsDoubleNear( value, 0 ) )
79  {
80  os << std::fixed << std::setprecision( mNumberDecimalPlaces - 1 ) << value;
81  }
82  else
83  {
84  // digits before decimal point
85  const int d = std::floor( std::log10( value < 0 ? -value : value ) ) + 1;
86  const double order = std::pow( 10.0, mNumberDecimalPlaces - d );
87  os << std::fixed << std::setprecision( std::max( mNumberDecimalPlaces - d, 0 ) ) << std::round( value * order ) / order;
88  }
89  break;
90  }
91  }
92  }
93  else
94  {
95  os << std::scientific << std::setprecision( mNumberDecimalPlaces );
96  os << value;
97  }
98 
99  QString res = QString::fromStdWString( os.str() );
100 
101  if ( mShowPlusSign && value > 0 )
102  res.prepend( context.positiveSign() );
103 
104  if ( !mShowTrailingZeros && res.contains( decimal ) )
105  {
106  int trimPoint = res.length() - 1;
107  int ePoint = 0;
108  if ( mUseScientific )
109  {
110  while ( res.at( trimPoint ).toUpper() != context.exponential().toUpper() )
111  trimPoint--;
112  ePoint = trimPoint;
113  trimPoint--;
114  }
115 
116  while ( res.at( trimPoint ) == context.zeroDigit() )
117  trimPoint--;
118 
119  if ( res.at( trimPoint ) == decimal )
120  trimPoint--;
121 
122  const QString original = res;
123  res.truncate( trimPoint + 1 );
124  if ( mUseScientific )
125  res += original.mid( ePoint );
126  }
127 
128  return res;
129 }
130 
132 {
133  return new QgsBasicNumericFormat( *this );
134 }
135 
136 QgsNumericFormat *QgsBasicNumericFormat::create( const QVariantMap &configuration, const QgsReadWriteContext &context ) const
137 {
138  std::unique_ptr< QgsBasicNumericFormat > res = std::make_unique< QgsBasicNumericFormat >();
139  res->setConfiguration( configuration, context );
140  return res.release();
141 }
142 
144 {
145  QVariantMap res;
146  res.insert( QStringLiteral( "decimals" ), mNumberDecimalPlaces );
147  res.insert( QStringLiteral( "show_thousand_separator" ), mShowThousandsSeparator );
148  res.insert( QStringLiteral( "show_plus" ), mShowPlusSign );
149  res.insert( QStringLiteral( "show_trailing_zeros" ), mShowTrailingZeros );
150  res.insert( QStringLiteral( "rounding_type" ), static_cast< int >( mRoundingType ) );
151  res.insert( QStringLiteral( "thousand_separator" ), mThousandsSeparator );
152  res.insert( QStringLiteral( "decimal_separator" ), mDecimalSeparator );
153  return res;
154 }
155 
156 void QgsBasicNumericFormat::setConfiguration( const QVariantMap &configuration, const QgsReadWriteContext & )
157 {
158  mNumberDecimalPlaces = configuration.value( QStringLiteral( "decimals" ), 6 ).toInt();
159  mShowThousandsSeparator = configuration.value( QStringLiteral( "show_thousand_separator" ), true ).toBool();
160  mShowPlusSign = configuration.value( QStringLiteral( "show_plus" ), false ).toBool();
161  mShowTrailingZeros = configuration.value( QStringLiteral( "show_trailing_zeros" ), false ).toBool();
162  mRoundingType = static_cast< RoundingType >( configuration.value( QStringLiteral( "rounding_type" ), static_cast< int >( DecimalPlaces ) ).toInt() );
163  mThousandsSeparator = configuration.value( QStringLiteral( "thousand_separator" ), QChar() ).toChar();
164  mDecimalSeparator = configuration.value( QStringLiteral( "decimal_separator" ), QChar() ).toChar();
165 }
166 
168 {
169  return mNumberDecimalPlaces;
170 }
171 
172 void QgsBasicNumericFormat::setNumberDecimalPlaces( int numberDecimalPlaces )
173 {
174  mNumberDecimalPlaces = numberDecimalPlaces;
175 }
176 
178 {
179  return mShowThousandsSeparator;
180 }
181 
182 void QgsBasicNumericFormat::setShowThousandsSeparator( bool showThousandsSeparator )
183 {
184  mShowThousandsSeparator = showThousandsSeparator;
185 }
186 
188 {
189  return mShowPlusSign;
190 }
191 
192 void QgsBasicNumericFormat::setShowPlusSign( bool showPlusSign )
193 {
194  mShowPlusSign = showPlusSign;
195 }
196 
198 {
199  return mShowTrailingZeros;
200 }
201 
202 void QgsBasicNumericFormat::setShowTrailingZeros( bool showTrailingZeros )
203 {
204  mShowTrailingZeros = showTrailingZeros;
205 }
206 
208 {
209  return mRoundingType;
210 }
211 
213 {
214  mRoundingType = type;
215 }
216 
218 {
219  return mThousandsSeparator;
220 }
221 
223 {
224  mThousandsSeparator = character;
225 }
226 
228 {
229  return mDecimalSeparator;
230 }
231 
233 {
234  mDecimalSeparator = character;
235 }
QgsNumericFormat * create(const QVariantMap &configuration, const QgsReadWriteContext &context) const override
Creates a new copy of the format, using the supplied configuration.
QChar thousandsSeparator() const
Returns any override for the thousands separator character.
RoundingType
Sets rounding type and behavior of the numberDecimalPlaces() setting.
@ DecimalPlaces
Maximum number of decimal places.
@ SignificantFigures
Maximum number of significant figures.
void setThousandsSeparator(QChar character)
Sets an override character for the thousands separator character.
QgsBasicNumericFormat()
Default constructor.
void setShowTrailingZeros(bool show)
Sets whether trailing zeros will be shown (up to the specified numberDecimalPlaces()).
void setShowThousandsSeparator(bool show)
Sets whether the thousands grouping separator will be shown.
bool showThousandsSeparator() const
Returns true if the thousands grouping separator will be shown.
QString id() const override
Returns a unique id for this numeric format.
virtual void setConfiguration(const QVariantMap &configuration, const QgsReadWriteContext &context)
Sets the format's configuration.
RoundingType roundingType() const
Returns the rounding type, which controls the behavior of the numberDecimalPlaces() setting.
QString visibleName() const override
Returns the translated, user-visible name for this format.
int sortKey() override
Returns a sorting key value, where formats with a lower sort key will be shown earlier in lists.
bool showTrailingZeros() const
Returns true if trailing zeros will be shown (up to the specified numberDecimalPlaces()).
void setRoundingType(RoundingType type)
Sets the rounding type, which controls the behavior of the numberDecimalPlaces() setting.
QgsNumericFormat * clone() const override
Clones the format, returning a new object.
bool showPlusSign() const
Returns true if a leading plus sign will be shown for positive values.
QChar decimalSeparator() const
Returns any override for the decimal separator character.
void setShowPlusSign(bool show)
Sets whether a leading plus sign will be shown for positive values.
QString formatDouble(double value, const QgsNumericFormatContext &context) const override
Returns a formatted string representation of a numeric double value.
virtual void setNumberDecimalPlaces(int places)
Sets the maximum number of decimal places to show.
int numberDecimalPlaces() const
Returns the maximum number of decimal places to show.
QVariantMap configuration(const QgsReadWriteContext &context) const override
Returns the current configuration of the formatter.
void setDecimalSeparator(QChar character)
Sets an override character for the decimal separator character.
A context for numeric formats.
QChar thousandsSeparator() const
Returns the thousands separator character.
QChar zeroDigit() const
Returns the zero digit character.
QChar exponential() const
Returns the exponential character.
QChar decimalSeparator() const
Returns the decimal separator character.
QChar positiveSign() const
Returns the positive sign character.
A numeric formatter allows for formatting a numeric value for display, using a variety of different f...
The class is used as a container of context for various read/write operations on other objects.
bool qgsDoubleNear(double a, double b, double epsilon=4 *std::numeric_limits< double >::epsilon())
Compare two doubles (but allow some difference)
Definition: qgis.h:1504
wchar_t do_decimal_point() const override
std::string do_grouping() const override
wchar_t do_thousands_sep() const override
formatter(QChar thousands, bool showThousands, QChar decimal)