QGIS API Documentation 3.32.0-Lima (311a8cb8a6)
qgsfractionnumericformat.h
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1/***************************************************************************
2 qgsfractionnumericformat.h
3 --------------------------
4 begin : March 2020
5 copyright : (C) 2020 by Nyall Dawson
6 email : nyall dot dawson at gmail dot com
7 ***************************************************************************
8 * *
9 * This program is free software; you can redistribute it and/or modify *
10 * it under the terms of the GNU General Public License as published by *
11 * the Free Software Foundation; either version 2 of the License, or *
12 * (at your option) any later version. *
13 * *
14 ***************************************************************************/
15#ifndef QGSFRACTIONNUMERICFORMAT_H
16#define QGSFRACTIONNUMERICFORMAT_H
17
18#include "qgis_core.h"
19#include "qgis_sip.h"
20#include "qgis.h"
21#include "qgsnumericformat.h"
22#include <cmath>
23
31{
32 public:
33
38
39 QString id() const override;
40 QString visibleName() const override;
41 int sortKey() override;
42 QString formatDouble( double value, const QgsNumericFormatContext &context ) const override;
43 QgsNumericFormat *clone() const override SIP_FACTORY;
44 QgsNumericFormat *create( const QVariantMap &configuration, const QgsReadWriteContext &context ) const override SIP_FACTORY;
45 QVariantMap configuration( const QgsReadWriteContext &context ) const override;
46 double suggestSampleValue() const override;
47
54 bool useDedicatedUnicodeCharacters() const;
55
62 void setUseDedicatedUnicodeCharacters( bool enabled );
63
69 bool useUnicodeSuperSubscript() const;
70
76 void setUseUnicodeSuperSubscript( bool enabled );
77
82 bool showThousandsSeparator() const;
83
88 void setShowThousandsSeparator( bool show );
89
94 bool showPlusSign() const;
95
100 void setShowPlusSign( bool show );
101
108 QChar thousandsSeparator() const;
109
116 void setThousandsSeparator( QChar character );
117
131 static bool doubleToVulgarFraction( const double value, unsigned long long &numerator SIP_OUT, unsigned long long &denominator SIP_OUT, int &sign SIP_OUT, const double tolerance = 1e-10 )
132 {
133 sign = value < 0 ? -1 : 1;
134 double g = std::fabs( value );
135 unsigned long long a = 0;
136 unsigned long long b = 1;
137 unsigned long long c = 1;
138 unsigned long long d = 0;
139 unsigned long long s;
140 unsigned int iteration = 0;
141 do
142 {
143 s = std::floor( g );
144 numerator = a + s * c;
145 denominator = b + s * d;
146 a = c;
147 b = d;
148 c = numerator;
149 d = denominator;
150 g = 1.0 / ( g - s );
151 if ( qgsDoubleNear( static_cast< double >( sign )*static_cast< double >( numerator ) / denominator, value, tolerance ) )
152 {
153 return true;
154 }
155 }
156 while ( iteration++ < 100 ); // limit to 100 iterations, should be sufficient for realistic purposes
157 return false;
158 }
159
164 static QString toUnicodeSuperscript( const QString &input );
165
170 static QString toUnicodeSubscript( const QString &input );
171
172 protected:
173
177 virtual void setConfiguration( const QVariantMap &configuration, const QgsReadWriteContext &context );
178
179 private:
180
181 bool mUseDedicatedUnicode = false;
182 bool mUseUnicodeSuperSubscript = true;
183 bool mShowThousandsSeparator = true;
184 bool mShowPlusSign = false;
185 QChar mThousandsSeparator;
186};
187
188#endif // QGSFRACTIONNUMERICFORMAT_H
A numeric formatter which returns a vulgar fractional representation of a decimal value (e....
static bool doubleToVulgarFraction(const double value, unsigned long long &numerator, unsigned long long &denominator, int &sign, const double tolerance=1e-10)
Converts a double value to a vulgar fraction (e.g.
A context for numeric formats.
A numeric formatter allows for formatting a numeric value for display, using a variety of different f...
virtual QgsNumericFormat * create(const QVariantMap &configuration, const QgsReadWriteContext &context) const =0
Creates a new copy of the format, using the supplied configuration.
virtual QString formatDouble(double value, const QgsNumericFormatContext &context) const =0
Returns a formatted string representation of a numeric double value.
virtual QgsNumericFormat * clone() const =0
Clones the format, returning a new object.
virtual int sortKey()
Returns a sorting key value, where formats with a lower sort key will be shown earlier in lists.
virtual QString visibleName() const =0
Returns the translated, user-visible name for this format.
virtual QString id() const =0
Returns a unique id for this numeric format.
virtual double suggestSampleValue() const
Returns a suggested sample value which nicely represents the current format configuration.
virtual QVariantMap configuration(const QgsReadWriteContext &context) const =0
Returns the current configuration of the formatter.
The class is used as a container of context for various read/write operations on other objects.
As part of the API refactoring and improvements which landed in the Processing API was substantially reworked from the x version This was done in order to allow much of the underlying Processing framework to be ported into c
bool qgsDoubleNear(double a, double b, double epsilon=4 *std::numeric_limits< double >::epsilon())
Compare two doubles (but allow some difference)
Definition: qgis.h:3988
#define SIP_OUT
Definition: qgis_sip.h:58
#define SIP_FACTORY
Definition: qgis_sip.h:76