source: ntrip/trunk/BNC/qwt/qwt_scale_engine.h@ 5681

Last change on this file since 5681 was 4271, checked in by mervart, 12 years ago
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1/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
2 * Qwt Widget Library
3 * Copyright (C) 1997 Josef Wilgen
4 * Copyright (C) 2002 Uwe Rathmann
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the Qwt License, Version 1.0
8 *****************************************************************************/
9
10#ifndef QWT_SCALE_ENGINE_H
11#define QWT_SCALE_ENGINE_H
12
13#include "qwt_global.h"
14#include "qwt_scale_div.h"
15#include "qwt_interval.h"
16
17class QwtScaleTransformation;
18
19/*!
20 \brief Arithmetic including a tolerance
21*/
22class QWT_EXPORT QwtScaleArithmetic
23{
24public:
25 static double ceilEps( double value, double intervalSize );
26 static double floorEps( double value, double intervalSize );
27
28 static double divideEps( double interval, double steps );
29
30 static double ceil125( double x );
31 static double floor125( double x );
32};
33
34/*!
35 \brief Base class for scale engines.
36
37 A scale engine tries to find "reasonable" ranges and step sizes
38 for scales.
39
40 The layout of the scale can be varied with setAttribute().
41
42 Qwt offers implementations for logarithmic (log10)
43 and linear scales. Contributions for other types of scale engines
44 (date/time, log2 ... ) are welcome.
45*/
46
47class QWT_EXPORT QwtScaleEngine
48{
49public:
50 /*!
51 Layout attributes
52 \sa setAttribute(), testAttribute(), reference(),
53 lowerMargin(), upperMargin()
54 */
55
56 enum Attribute
57 {
58 //! No attributes
59 NoAttribute = 0x00,
60
61 //! Build a scale which includes the reference() value.
62 IncludeReference = 0x01,
63
64 //! Build a scale which is symmetric to the reference() value.
65 Symmetric = 0x02,
66
67 /*!
68 The endpoints of the scale are supposed to be equal the
69 outmost included values plus the specified margins
70 (see setMargins()).
71 If this attribute is *not* set, the endpoints of the scale will
72 be integer multiples of the step size.
73 */
74 Floating = 0x04,
75
76 //! Turn the scale upside down.
77 Inverted = 0x08
78 };
79
80 //! Layout attributes
81 typedef QFlags<Attribute> Attributes;
82
83 explicit QwtScaleEngine();
84 virtual ~QwtScaleEngine();
85
86 void setAttribute( Attribute, bool on = true );
87 bool testAttribute( Attribute ) const;
88
89 void setAttributes( Attributes );
90 Attributes attributes() const;
91
92 void setReference( double reference );
93 double reference() const;
94
95 void setMargins( double lower, double upper );
96 double lowerMargin() const;
97 double upperMargin() const;
98
99 /*!
100 Align and divide an interval
101
102 \param maxNumSteps Max. number of steps
103 \param x1 First limit of the interval (In/Out)
104 \param x2 Second limit of the interval (In/Out)
105 \param stepSize Step size (Return value)
106 */
107 virtual void autoScale( int maxNumSteps,
108 double &x1, double &x2, double &stepSize ) const = 0;
109
110 /*!
111 \brief Calculate a scale division
112
113 \param x1 First interval limit
114 \param x2 Second interval limit
115 \param maxMajSteps Maximum for the number of major steps
116 \param maxMinSteps Maximum number of minor steps
117 \param stepSize Step size. If stepSize == 0.0, the scaleEngine
118 calculates one.
119 */
120 virtual QwtScaleDiv divideScale( double x1, double x2,
121 int maxMajSteps, int maxMinSteps,
122 double stepSize = 0.0 ) const = 0;
123
124 //! \return a transformation
125 virtual QwtScaleTransformation *transformation() const = 0;
126
127protected:
128 bool contains( const QwtInterval &, double val ) const;
129 QList<double> strip( const QList<double>&, const QwtInterval & ) const;
130 double divideInterval( double interval, int numSteps ) const;
131
132 QwtInterval buildInterval( double v ) const;
133
134private:
135 class PrivateData;
136 PrivateData *d_data;
137};
138
139/*!
140 \brief A scale engine for linear scales
141
142 The step size will fit into the pattern
143 \f$\left\{ 1,2,5\right\} \cdot 10^{n}\f$, where n is an integer.
144*/
145
146class QWT_EXPORT QwtLinearScaleEngine: public QwtScaleEngine
147{
148public:
149 virtual void autoScale( int maxSteps,
150 double &x1, double &x2, double &stepSize ) const;
151
152 virtual QwtScaleDiv divideScale( double x1, double x2,
153 int numMajorSteps, int numMinorSteps,
154 double stepSize = 0.0 ) const;
155
156 virtual QwtScaleTransformation *transformation() const;
157
158protected:
159 QwtInterval align( const QwtInterval&, double stepSize ) const;
160
161 void buildTicks(
162 const QwtInterval &, double stepSize, int maxMinSteps,
163 QList<double> ticks[QwtScaleDiv::NTickTypes] ) const;
164
165 QList<double> buildMajorTicks(
166 const QwtInterval &interval, double stepSize ) const;
167
168 void buildMinorTicks(
169 const QList<double>& majorTicks,
170 int maxMinMark, double step,
171 QList<double> &, QList<double> & ) const;
172};
173
174/*!
175 \brief A scale engine for logarithmic (base 10) scales
176
177 The step size is measured in *decades*
178 and the major step size will be adjusted to fit the pattern
179 \f$\left\{ 1,2,3,5\right\} \cdot 10^{n}\f$, where n is a natural number
180 including zero.
181
182 \warning the step size as well as the margins are measured in *decades*.
183*/
184
185class QWT_EXPORT QwtLog10ScaleEngine: public QwtScaleEngine
186{
187public:
188 virtual void autoScale( int maxSteps,
189 double &x1, double &x2, double &stepSize ) const;
190
191 virtual QwtScaleDiv divideScale( double x1, double x2,
192 int numMajorSteps, int numMinorSteps,
193 double stepSize = 0.0 ) const;
194
195 virtual QwtScaleTransformation *transformation() const;
196
197protected:
198 QwtInterval log10( const QwtInterval& ) const;
199 QwtInterval pow10( const QwtInterval& ) const;
200
201 QwtInterval align( const QwtInterval&, double stepSize ) const;
202
203 void buildTicks(
204 const QwtInterval &, double stepSize, int maxMinSteps,
205 QList<double> ticks[QwtScaleDiv::NTickTypes] ) const;
206
207 QList<double> buildMajorTicks(
208 const QwtInterval &interval, double stepSize ) const;
209
210 QList<double> buildMinorTicks(
211 const QList<double>& majorTicks,
212 int maxMinMark, double step ) const;
213};
214
215Q_DECLARE_OPERATORS_FOR_FLAGS( QwtScaleEngine::Attributes )
216
217#endif
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