QGIS API Documentation  3.8.0-Zanzibar (11aff65)
qgsprocessingutils.h
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1 /***************************************************************************
2  qgsprocessingutils.h
3  ------------------------
4  begin : April 2017
5  copyright : (C) 2017 by Nyall Dawson
6  email : nyall dot dawson at gmail dot 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 QGSPROCESSINGUTILS_H
19 #define QGSPROCESSINGUTILS_H
20 
21 #include "qgis_core.h"
22 
23 #include "qgsrasterlayer.h"
24 #include "qgsmessagelog.h"
25 #include "qgsspatialindex.h"
26 #include "qgsprocessing.h"
27 #include "qgsfeaturesink.h"
28 #include "qgsfeaturesource.h"
29 
30 class QgsMeshLayer;
31 class QgsProject;
33 class QgsMapLayerStore;
37 
38 #include <QString>
39 #include <QVariant>
40 
47 class CORE_EXPORT QgsProcessingUtils
48 {
49  public:
50 
61  static QList< QgsRasterLayer * > compatibleRasterLayers( QgsProject *project, bool sort = true );
62 
78  static QList< QgsVectorLayer * > compatibleVectorLayers( QgsProject *project,
79  const QList< int > &sourceTypes = QList< int >(),
80  bool sort = true );
81 
95  static QList<QgsMeshLayer *> compatibleMeshLayers( QgsProject *project, bool sort = true );
96 
106  static QList< QgsMapLayer * > compatibleLayers( QgsProject *project, bool sort = true );
107 
113  {
114  UnknownType,
115  Vector,
116  Raster,
117  Mesh,
118  };
119 
132  static QgsMapLayer *mapLayerFromString( const QString &string, QgsProcessingContext &context, bool allowLoadingNewLayers = true, QgsProcessingUtils::LayerHint typeHint = QgsProcessingUtils::LayerHint::UnknownType );
133 
145  static QgsProcessingFeatureSource *variantToSource( const QVariant &value, QgsProcessingContext &context, const QVariant &fallbackValue = QVariant() ) SIP_FACTORY;
146 
151  static QString normalizeLayerSource( const QString &source );
152 
159  static QString variantToPythonLiteral( const QVariant &value );
160 
166  static QString stringToPythonLiteral( const QString &string );
167 
185 #ifndef SIP_RUN
186  static QgsFeatureSink *createFeatureSink( QString &destination,
187  QgsProcessingContext &context,
188  const QgsFields &fields,
189  QgsWkbTypes::Type geometryType,
191  const QVariantMap &createOptions = QVariantMap(),
192  QgsFeatureSink::SinkFlags sinkFlags = nullptr ) SIP_FACTORY;
193 #endif
194 
214  static void createFeatureSinkPython( QgsFeatureSink **sink SIP_OUT SIP_TRANSFERBACK, QString &destination SIP_INOUT, QgsProcessingContext &context, const QgsFields &fields, QgsWkbTypes::Type geometryType, const QgsCoordinateReferenceSystem &crs, const QVariantMap &createOptions = QVariantMap() ) SIP_THROW( QgsProcessingException ) SIP_PYNAME( createFeatureSink );
215 
216 
223  static QgsRectangle combineLayerExtents( const QList<QgsMapLayer *> &layers, const QgsCoordinateReferenceSystem &crs, QgsProcessingContext &context );
224 
230  Q_DECL_DEPRECATED static QgsRectangle combineLayerExtents( const QList<QgsMapLayer *> &layers, const QgsCoordinateReferenceSystem &crs = QgsCoordinateReferenceSystem() ) SIP_DEPRECATED;
231 
238  static QVariant generateIteratingDestination( const QVariant &input, const QVariant &id, QgsProcessingContext &context );
239 
244  static QString tempFolder();
245 
252  static QString generateTempFilename( const QString &basename );
253 
258  static QString formatHelpMapAsHtml( const QVariantMap &map, const QgsProcessingAlgorithm *algorithm );
259 
272  static QString convertToCompatibleFormat( const QgsVectorLayer *layer,
273  bool selectedFeaturesOnly,
274  const QString &baseName,
275  const QStringList &compatibleFormats,
276  const QString &preferredFormat,
277  QgsProcessingContext &context,
278  QgsProcessingFeedback *feedback );
279 
290  static QgsFields combineFields( const QgsFields &fieldsA, const QgsFields &fieldsB, const QString &fieldsBPrefix = QString() );
291 
297  static QList<int> fieldNamesToIndices( const QStringList &fieldNames, const QgsFields &fields );
298 
303  static QgsFields indicesToFields( const QList<int> &indices, const QgsFields &fields );
304 
305  private:
306  static bool canUseLayer( const QgsRasterLayer *layer );
307  static bool canUseLayer( const QgsMeshLayer *layer );
308  static bool canUseLayer( const QgsVectorLayer *layer,
309  const QList< int > &sourceTypes = QList< int >() );
310 
321  static QgsMapLayer *mapLayerFromStore( const QString &string, QgsMapLayerStore *store, QgsProcessingUtils::LayerHint typeHint = QgsProcessingUtils::LayerHint::UnknownType );
322 
333  static QgsMapLayer *loadMapLayerFromString( const QString &string, const QgsCoordinateTransformContext &transformContext, LayerHint typeHint = LayerHint::UnknownType );
334 
343  Q_DECL_DEPRECATED static QgsMapLayer *loadMapLayerFromString( const QString &string, LayerHint typeHint = LayerHint::UnknownType ) SIP_DEPRECATED ;
344 
345  static void parseDestinationString( QString &destination, QString &providerKey, QString &uri, QString &layerName, QString &format, QMap<QString, QVariant> &options, bool &useWriter, QString &extension );
346 
347  friend class TestQgsProcessing;
348  friend class QgsProcessingProvider;
349 
350 };
351 
360 {
361  public:
362 
364  enum Flag
365  {
366  FlagSkipGeometryValidityChecks = 1 << 1,
367  };
368  Q_DECLARE_FLAGS( Flags, Flag )
369 
370 
377  QgsProcessingFeatureSource( QgsFeatureSource *originalSource, const QgsProcessingContext &context, bool ownsOriginalSource = false );
378 
379  ~QgsProcessingFeatureSource() override;
380 
386  QgsFeatureIterator getFeatures( const QgsFeatureRequest &request, Flags flags ) const;
387 
388  QgsFeatureSource::FeatureAvailability hasFeatures() const override;
389 
390  QgsFeatureIterator getFeatures( const QgsFeatureRequest &request = QgsFeatureRequest() ) const override;
391  QgsCoordinateReferenceSystem sourceCrs() const override;
392  QgsFields fields() const override;
393  QgsWkbTypes::Type wkbType() const override;
394  long featureCount() const override;
395  QString sourceName() const override;
396  QSet<QVariant> uniqueValues( int fieldIndex, int limit = -1 ) const override;
397  QVariant minimumValue( int fieldIndex ) const override;
398  QVariant maximumValue( int fieldIndex ) const override;
399  QgsRectangle sourceExtent() const override;
400  QgsFeatureIds allFeatureIds() const override;
401 
405  QgsExpressionContextScope *createExpressionContextScope() const SIP_FACTORY;
406 
407  private:
408 
409  QgsFeatureSource *mSource = nullptr;
410  bool mOwnsSource = false;
411  QgsFeatureRequest::InvalidGeometryCheck mInvalidGeometryCheck = QgsFeatureRequest::GeometryNoCheck;
412  std::function< void( const QgsFeature & ) > mInvalidGeometryCallback;
413  std::function< void( const QgsFeature & ) > mTransformErrorCallback;
414 
415 };
416 
417 #ifndef SIP_RUN
418 
427 {
428  public:
429 
430 
444  QgsProcessingFeatureSink( QgsFeatureSink *originalSink, const QString &sinkName, QgsProcessingContext &context, bool ownsOriginalSink = false );
445  ~QgsProcessingFeatureSink() override;
446  bool addFeature( QgsFeature &feature, QgsFeatureSink::Flags flags = nullptr ) override;
447  bool addFeatures( QgsFeatureList &features, QgsFeatureSink::Flags flags = nullptr ) override;
448  bool addFeatures( QgsFeatureIterator &iterator, QgsFeatureSink::Flags flags = nullptr ) override;
449 
450  private:
451 
452  QgsProcessingContext &mContext;
453  QString mSinkName;
454  bool mOwnsSink = false;
455 
456 };
457 #endif
458 
459 #endif // QGSPROCESSINGUTILS_H
460 
461 
Wrapper for iterator of features from vector data provider or vector layer.
A rectangle specified with double values.
Definition: qgsrectangle.h:41
Base class for all map layer types.
Definition: qgsmaplayer.h:78
QSet< QgsFeatureId > QgsFeatureIds
Definition: qgsfeatureid.h:34
Base class for providing feedback from a processing algorithm.
A simple feature sink which proxies feature addition on to another feature sink.
FeatureAvailability
Possible return value for hasFeatures() to determine if a source is empty.
LayerHint
Layer type hints.
This class provides qgis with the ability to render raster datasets onto the mapcanvas.
QList< QgsFeature > QgsFeatureList
Definition: qgsfeature.h:571
An interface for objects which accept features via addFeature(s) methods.
QgsFeatureSource subclass which proxies methods to an underlying QgsFeatureSource, modifying results according to the settings in a QgsProcessingContext.
Container of fields for a vector layer.
Definition: qgsfields.h:42
#define SIP_MONKEYPATCH_SCOPEENUM
Definition: qgis_sip.h:244
Abstract base class for processing providers.
#define SIP_INOUT
Definition: qgis_sip.h:64
The feature class encapsulates a single feature including its id, geometry and a list of field/values...
Definition: qgsfeature.h:55
const QgsCoordinateReferenceSystem & crs
#define SIP_TRANSFERBACK
Definition: qgis_sip.h:41
Abstract base class for processing algorithms.
Utility functions for use with processing classes.
Type
The WKB type describes the number of dimensions a geometry has.
Definition: qgswkbtypes.h:68
This class wraps a request for features to a vector layer (or directly its vector data provider)...
Custom exception class for processing related exceptions.
Definition: qgsexception.h:82
Reads and writes project states.
Definition: qgsproject.h:89
#define SIP_FACTORY
Definition: qgis_sip.h:69
Single scope for storing variables and functions for use within a QgsExpressionContext.
Contains information about the context in which a coordinate transform is executed.
#define SIP_DEPRECATED
Definition: qgis_sip.h:99
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 allowing algorithms to be written in pure substantial changes are required in order to port existing x Processing algorithms for QGIS x The most significant changes are outlined not GeoAlgorithm For algorithms which operate on features one by consider subclassing the QgsProcessingFeatureBasedAlgorithm class This class allows much of the boilerplate code for looping over features from a vector layer to be bypassed and instead requires implementation of a processFeature method Ensure that your algorithm(or algorithm 's parent class) implements the new pure virtual createInstance(self) call
Flag
Flags controlling how QgsProcessingFeatureSource fetches features.
QgsProxyFeatureSink subclass which reports feature addition errors to a QgsProcessingContext.
An interface for objects which provide features via a getFeatures method.
#define SIP_OUT
Definition: qgis_sip.h:51
This class represents a coordinate reference system (CRS).
#define SIP_THROW(name)
Definition: qgis_sip.h:177
Represents a mesh layer supporting display of data on structured or unstructured meshes.
Definition: qgsmeshlayer.h:90
A storage object for map layers, in which the layers are owned by the store and have their lifetime b...
Represents a vector layer which manages a vector based data sets.
Contains information about the context in which a processing algorithm is executed.
#define SIP_PYNAME(name)
Definition: qgis_sip.h:74