QGIS API Documentation  2.99.0-Master (b698612)
qgis.h
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1 /***************************************************************************
2  qgis.h - QGIS namespace
3  -------------------
4  begin : Sat Jun 30 2002
5  copyright : (C) 2002 by Gary E.Sherman
6  email : sherman at mrcc.com
7  ***************************************************************************/
8 
9 /***************************************************************************
10  * *
11  * This program is free software; you can redistribute it and/or modify *
12  * it under the terms of the GNU General Public License as published by *
13  * the Free Software Foundation; either version 2 of the License, or *
14  * (at your option) any later version. *
15  * *
16  ***************************************************************************/
17 
18 #ifndef QGIS_H
19 #define QGIS_H
20 
21 #include <QEvent>
22 #include "qgis_sip.h"
23 #include <QString>
24 #include <QRegExp>
25 #include <QMetaType>
26 #include <QVariant>
27 #include <QDateTime>
28 #include <QDate>
29 #include <QTime>
30 #include <QHash>
31 #include <stdlib.h>
32 #include <cfloat>
33 #include <cmath>
34 #include <qnumeric.h>
35 
36 #include "qgswkbtypes.h"
37 #include "qgis_core.h"
38 #include "qgis_sip.h"
39 
40 #ifdef SIP_RUN
41 % ModuleHeaderCode
42 #include <qgis.h>
43 % End
44 
45 % ModuleCode
46 int QgisEvent = QEvent::User + 1;
47 % End
48 #endif
49 
50 
54 class CORE_EXPORT Qgis
55 {
56  public:
57  // Version constants
58  //
60  static const QString QGIS_VERSION;
62  static const int QGIS_VERSION_INT;
64  static const QString QGIS_RELEASE_NAME;
66  static const char *QGIS_DEV_VERSION;
67 
68  // Enumerations
69  //
70 
74  enum DataType
75  {
76  UnknownDataType = 0,
77  Byte = 1,
78  UInt16 = 2,
79  Int16 = 3,
80  UInt32 = 4,
81  Int32 = 5,
82  Float32 = 6,
83  Float64 = 7,
84  CInt16 = 8,
85  CInt32 = 9,
86  CFloat32 = 10,
87  CFloat64 = 11,
88  ARGB32 = 12,
89  ARGB32_Premultiplied = 13
90  };
91 
94  static const double DEFAULT_SEARCH_RADIUS_MM;
95 
97  static const float DEFAULT_MAPTOPIXEL_THRESHOLD;
98 
102  static const QColor DEFAULT_HIGHLIGHT_COLOR;
103 
106  static const double DEFAULT_HIGHLIGHT_BUFFER_MM;
107 
110  static const double DEFAULT_HIGHLIGHT_MIN_WIDTH_MM;
111 
116  static const double SCALE_PRECISION;
117 
121  static const double DEFAULT_Z_COORDINATE;
122 
123 };
124 
125 // hack to workaround warnings when casting void pointers
126 // retrieved from QLibrary::resolve to function pointers.
127 // It's assumed that this works on all systems supporting
128 // QLibrary
129 #define cast_to_fptr(f) f
130 
131 
139 // based on Boojum's code from http://stackoverflow.com/questions/3556687/prevent-firing-signals-in-qt
140 template<class Object> class QgsSignalBlocker SIP_SKIP SIP_SKIP // clazy:exclude=rule-of-three
141 {
142  public:
143 
147  explicit QgsSignalBlocker( Object *object )
148  : mObject( object )
149  , mPreviousState( object->blockSignals( true ) )
150  {}
151 
153  {
154  mObject->blockSignals( mPreviousState );
155  }
156 
158  Object *operator->() { return mObject; }
159 
160  private:
161 
162  Object *mObject = nullptr;
163  bool mPreviousState;
164 
165 };
166 
179 // based on Boojum's code from http://stackoverflow.com/questions/3556687/prevent-firing-signals-in-qt
180 template<class Object> inline QgsSignalBlocker<Object> whileBlocking( Object *object ) SIP_SKIP SIP_SKIP
181 {
182  return QgsSignalBlocker<Object>( object );
183 }
184 
186 CORE_EXPORT uint qHash( const QVariant &variant );
187 
191 inline QString qgsDoubleToString( double a, int precision = 17 )
192 {
193  if ( precision )
194  return QString::number( a, 'f', precision ).remove( QRegExp( "\\.?0+$" ) );
195  else
196  return QString::number( a, 'f', precision );
197 }
198 
203 inline bool qgsDoubleNear( double a, double b, double epsilon = 4 * DBL_EPSILON )
204 {
205  const double diff = a - b;
206  return diff > -epsilon && diff <= epsilon;
207 }
208 
213 inline bool qgsFloatNear( float a, float b, float epsilon = 4 * FLT_EPSILON )
214 {
215  const float diff = a - b;
216  return diff > -epsilon && diff <= epsilon;
217 }
218 
220 inline bool qgsDoubleNearSig( double a, double b, int significantDigits = 10 )
221 {
222  // The most simple would be to print numbers as %.xe and compare as strings
223  // but that is probably too costly
224  // Then the fastest would be to set some bits directly, but little/big endian
225  // has to be considered (maybe TODO)
226  // Is there a better way?
227  int aexp, bexp;
228  double ar = frexp( a, &aexp );
229  double br = frexp( b, &bexp );
230 
231  return aexp == bexp &&
232  qRound( ar * pow( 10.0, significantDigits ) ) == qRound( br * pow( 10.0, significantDigits ) );
233 }
234 
236 inline double qgsRound( double x )
237 {
238  return x < 0.0 ? std::ceil( x - 0.5 ) : std::floor( x + 0.5 );
239 }
240 
246 inline double qgsRound( double number, double places )
247 {
248  int scaleFactor = pow( 10, places );
249  return static_cast<double>( static_cast<qlonglong>( number * scaleFactor + 0.5 ) ) / scaleFactor;
250 }
251 
260 CORE_EXPORT double qgsPermissiveToDouble( QString string, bool &ok );
261 
270 CORE_EXPORT int qgsPermissiveToInt( QString string, bool &ok );
271 
276 CORE_EXPORT bool qgsVariantLessThan( const QVariant &lhs, const QVariant &rhs );
277 
282 CORE_EXPORT bool qgsVariantGreaterThan( const QVariant &lhs, const QVariant &rhs );
283 
284 CORE_EXPORT QString qgsVsiPrefix( const QString &path );
285 
290 void CORE_EXPORT *qgsMalloc( size_t size ) SIP_SKIP;
291 
298 void CORE_EXPORT *qgsCalloc( size_t nmemb, size_t size ) SIP_SKIP;
299 
303 void CORE_EXPORT qgsFree( void *ptr ) SIP_SKIP;
304 
308 extern CORE_EXPORT const QString GEOWKT;
309 extern CORE_EXPORT const QString PROJECT_SCALES;
310 
312 extern CORE_EXPORT const QString GEOPROJ4;
314 const long GEOSRID = 4326;
316 const long GEOCRS_ID = 3452;
318 const long GEO_EPSG_CRS_ID = 4326;
320 extern CORE_EXPORT const QString GEO_EPSG_CRS_AUTHID;
321 
324 const int USER_CRS_START_ID = 100000;
325 
327 extern CORE_EXPORT const QString GEO_NONE;
328 
329 //
330 // Constants for point symbols
331 //
332 
334 const double DEFAULT_POINT_SIZE = 2.0;
335 const double DEFAULT_LINE_WIDTH = 0.26;
336 
338 const double DEFAULT_SEGMENT_EPSILON = 1e-8;
339 
340 typedef QMap<QString, QString> QgsStringMap SIP_SKIP;
341 
348 typedef unsigned long long qgssize;
349 
350 #ifndef SIP_RUN
351 #if (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)) || defined(__clang__)
352 #define Q_NOWARN_DEPRECATED_PUSH \
353  _Pragma("GCC diagnostic push") \
354  _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"");
355 #define Q_NOWARN_DEPRECATED_POP \
356  _Pragma("GCC diagnostic pop");
357 #elif defined(_MSC_VER)
358 #define Q_NOWARN_DEPRECATED_PUSH \
359  __pragma(warning(push)) \
360  __pragma(warning(disable:4996))
361 #define Q_NOWARN_DEPRECATED_POP \
362  __pragma(warning(pop))
363 #else
364 #define Q_NOWARN_DEPRECATED_PUSH
365 #define Q_NOWARN_DEPRECATED_POP
366 #endif
367 #endif
368 
369 #ifndef QGISEXTERN
370 #ifdef Q_OS_WIN
371 # define QGISEXTERN extern "C" __declspec( dllexport )
372 # ifdef _MSC_VER
373 // do not warn about C bindings returning QString
374 # pragma warning(disable:4190)
375 # endif
376 #else
377 # if defined(__GNUC__) || defined(__clang__)
378 # define QGISEXTERN extern "C" __attribute__ ((visibility ("default")))
379 # else
380 # define QGISEXTERN extern "C"
381 # endif
382 #endif
383 #endif
384 #endif
385 
386 #if defined(__clang__)
387 #define FALLTHROUGH //[[clang::fallthrough]]
388 #else
389 #define FALLTHROUGH
390 #endif
391 
392 
CORE_EXPORT QString qgsVsiPrefix(const QString &path)
Definition: qgis.cpp:209
static const QString QGIS_VERSION
Version string.
Definition: qgis.h:60
static const char * QGIS_DEV_VERSION
The development version.
Definition: qgis.h:66
bool qgsFloatNear(float a, float b, float epsilon=4 *FLT_EPSILON)
Compare two floats (but allow some difference)
Definition: qgis.h:213
DataType
Raster data types.
Definition: qgis.h:74
static const QColor DEFAULT_HIGHLIGHT_COLOR
Default highlight color.
Definition: qgis.h:102
void CORE_EXPORT * qgsCalloc(size_t nmemb, size_t size)
Allocates memory for an array of nmemb elements of size bytes each and returns a pointer to the alloc...
Definition: qgis.cpp:116
static const int QGIS_VERSION_INT
Version number used for comparing versions using the "Check QGIS Version" function.
Definition: qgis.h:62
QMap< QString, QString > QgsStringMap
Definition: qgis.h:340
~QgsSignalBlocker()
Definition: qgis.h:152
bool qgsDoubleNear(double a, double b, double epsilon=4 *DBL_EPSILON)
Compare two doubles (but allow some difference)
Definition: qgis.h:203
The Qgis class provides global constants for use throughout the application.
Definition: qgis.h:54
CORE_EXPORT bool qgsVariantLessThan(const QVariant &lhs, const QVariant &rhs)
Compares two QVariant values and returns whether the first is less than the second.
Definition: qgis.cpp:136
static const double DEFAULT_Z_COORDINATE
Default Z coordinate value for 2.5d geometry This value have to be assigned to the Z coordinate for t...
Definition: qgis.h:121
double qgsRound(double x)
A round function which returns a double to guard against overflows.
Definition: qgis.h:236
QgsSignalBlocker(Object *object)
Constructor for QgsSignalBlocker.
Definition: qgis.h:147
CORE_EXPORT const QString GEO_NONE
Constant that holds the string representation for "No ellips/No CRS".
Definition: qgis.cpp:71
const double DEFAULT_SEGMENT_EPSILON
Default snapping tolerance for segments.
Definition: qgis.h:338
#define SIP_SKIP
Definition: qgis_sip.h:107
QString qgsDoubleToString(double a, int precision=17)
Returns a string representation of a double.
Definition: qgis.h:191
const long GEOCRS_ID
Magic number for a geographic coord sys in QGIS srs.db tbl_srs.srs_id.
Definition: qgis.h:316
static const double DEFAULT_SEARCH_RADIUS_MM
Identify search radius in mm.
Definition: qgis.h:94
CORE_EXPORT double qgsPermissiveToDouble(QString string, bool &ok)
Converts a string to a double in a permissive way, e.g., allowing for incorrect numbers of digits bet...
Definition: qgis.cpp:87
CORE_EXPORT const QString GEOPROJ4
PROJ4 string that represents a geographic coord sys.
Definition: qgis.cpp:50
RAII signal blocking class.
Definition: qgis.h:140
void CORE_EXPORT qgsFree(void *ptr)
Frees the memory space pointed to by ptr.
Definition: qgis.cpp:131
unsigned long long qgssize
Qgssize is used instead of size_t, because size_t is stdlib type, unknown by SIP, and it would be har...
Definition: qgis.h:348
const double DEFAULT_POINT_SIZE
Magic number that determines the default point size for point symbols.
Definition: qgis.h:334
static const float DEFAULT_MAPTOPIXEL_THRESHOLD
Default threshold between map coordinates and device coordinates for map2pixel simplification.
Definition: qgis.h:97
const int USER_CRS_START_ID
Magick number that determines whether a projection crsid is a system (srs.db) or user (~/...
Definition: qgis.h:324
QgsSignalBlocker< Object > whileBlocking(Object *object)
Temporarily blocks signals from a QObject while calling a single method from the object.
Definition: qgis.h:180
const long GEOSRID
Magic number for a geographic coord sys in POSTGIS SRID.
Definition: qgis.h:314
static const QString QGIS_RELEASE_NAME
Release name.
Definition: qgis.h:64
bool qgsDoubleNearSig(double a, double b, int significantDigits=10)
Compare two doubles using specified number of significant digits.
Definition: qgis.h:220
const double DEFAULT_LINE_WIDTH
Definition: qgis.h:335
CORE_EXPORT const QString PROJECT_SCALES
Definition: qgis.cpp:65
CORE_EXPORT uint qHash(const QVariant &variant)
Hash for QVariant.
Definition: qgis.cpp:226
static const double DEFAULT_HIGHLIGHT_MIN_WIDTH_MM
Default highlight line/stroke minimum width in mm.
Definition: qgis.h:110
static const double DEFAULT_HIGHLIGHT_BUFFER_MM
Default highlight buffer in mm.
Definition: qgis.h:106
CORE_EXPORT int qgsPermissiveToInt(QString string, bool &ok)
Converts a string to an integer in a permissive way, e.g., allowing for incorrect numbers of digits b...
Definition: qgis.cpp:94
CORE_EXPORT bool qgsVariantGreaterThan(const QVariant &lhs, const QVariant &rhs)
Compares two QVariant values and returns whether the first is greater than the second.
Definition: qgis.cpp:204
void CORE_EXPORT * qgsMalloc(size_t size)
Allocates size bytes and returns a pointer to the allocated memory.
Definition: qgis.cpp:101
Object * operator->()
Returns pointer to blocked QObject.
Definition: qgis.h:158
const long GEO_EPSG_CRS_ID
Magic number for a geographic coord sys in EpsgCrsId ID format.
Definition: qgis.h:318
static const double SCALE_PRECISION
Fudge factor used to compare two scales.
Definition: qgis.h:116
CORE_EXPORT const QString GEO_EPSG_CRS_AUTHID
Geographic coord sys from EPSG authority.
Definition: qgis.cpp:69
CORE_EXPORT const QString GEOWKT
Wkt string that represents a geographic coord sys.
Definition: qgis.cpp:52