QGIS API Documentation  3.21.0-Master (5b68dc587e)
qgsprocessingprovider.h
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1 /***************************************************************************
2  qgsprocessingprovider.h
3  ------------------------
4  begin : December 2016
5  copyright : (C) 2016 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 QGSPROCESSINGPROVIDER_H
19 #define QGSPROCESSINGPROVIDER_H
20 
21 #include "qgis_core.h"
22 #include "qgis.h"
23 #include "qgsprocessingalgorithm.h"
24 #include <QIcon>
25 
35 class CORE_EXPORT QgsProcessingProvider : public QObject
36 {
37  Q_OBJECT
38 
39  public:
40 
45  enum Flag
46  {
47  FlagDeemphasiseSearchResults = 1 << 1,
48  };
49  Q_DECLARE_FLAGS( Flags, Flag )
50 
51 
54  QgsProcessingProvider( QObject *parent SIP_TRANSFERTHIS = nullptr );
55 
56  ~QgsProcessingProvider() override;
57 
59  QgsProcessingProvider( const QgsProcessingProvider &other ) = delete;
62 
67  virtual QIcon icon() const;
68 
73  virtual QString svgIconPath() const;
74 
80  virtual Flags flags() const;
81 
89  virtual QString id() const = 0;
90 
97  virtual QString helpId() const;
98 
105  virtual QString name() const = 0;
106 
117  virtual QString longName() const;
118 
127  virtual QString versionInfo() const;
128 
134  virtual bool canBeActivated() const { return true; }
135 
146  virtual QString warningMessage() const { return QString(); }
147 
151  virtual bool isActive() const { return true; }
152 
157  virtual QStringList supportedOutputRasterLayerExtensions() const;
158 
166  virtual QStringList supportedOutputVectorLayerExtensions() const;
167 
181  virtual QStringList supportedOutputTableExtensions() const;
182 
190  virtual bool isSupportedOutputValue( const QVariant &outputValue, const QgsProcessingDestinationParameter *parameter, QgsProcessingContext &context, QString &error SIP_OUT ) const;
191 
206  virtual QString defaultVectorFileExtension( bool hasGeometry = true ) const;
207 
219  virtual QString defaultRasterFileExtension() const;
220 
234  virtual bool supportsNonFileBasedOutput() const;
235 
245  virtual bool load() { refreshAlgorithms(); return true; }
246 
251  virtual void unload() {}
252 
256  void refreshAlgorithms();
257 
262  QList< const QgsProcessingAlgorithm * > algorithms() const;
263 
269  const QgsProcessingAlgorithm *algorithm( const QString &name ) const;
270 
271  signals:
272 
279 
280  protected:
281 
286  virtual void loadAlgorithms() = 0;
287 
291  bool addAlgorithm( QgsProcessingAlgorithm *algorithm SIP_TRANSFER );
292 
293  private:
294 
295  QMap< QString, const QgsProcessingAlgorithm * > mAlgorithms;
296 
297 #ifdef SIP_RUN
299 #endif
300 };
301 
302 Q_DECLARE_OPERATORS_FOR_FLAGS( QgsProcessingProvider::Flags )
303 
304 #endif // QGSPROCESSINGPROVIDER_H
305 
306 
Abstract base class for processing algorithms.
Contains information about the context in which a processing algorithm is executed.
Base class for all parameter definitions which represent file or layer destinations,...
Abstract base class for processing providers.
QgsProcessingProvider(const QgsProcessingProvider &other)=delete
Providers cannot be copied.
virtual QString name() const =0
Returns the provider name, which is used to describe the provider within the GUI.
Flag
Flags indicating how and when an provider operates and should be exposed to users.
virtual bool isActive() const
Returns true if the provider is active and able to run algorithms.
void algorithmsLoaded()
Emitted when the provider has loaded (or refreshed) its list of available algorithms.
QgsProcessingProvider & operator=(const QgsProcessingProvider &other)=delete
Providers cannot be copied.
virtual void unload()
Unloads the provider.
virtual QString id() const =0
Returns the unique provider id, used for identifying the provider.
virtual bool load()
Loads the provider.
virtual void loadAlgorithms()=0
Loads all algorithms belonging to this provider.
virtual bool canBeActivated() const
Returns true if the provider can be activated, or false if it cannot be activated (e....
virtual QString warningMessage() const
Returns an optional warning message to show users when running algorithms from this provider.
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
#define SIP_TRANSFERTHIS
Definition: qgis_sip.h:53
#define SIP_TRANSFER
Definition: qgis_sip.h:36
#define SIP_OUT
Definition: qgis_sip.h:58
Q_DECLARE_OPERATORS_FOR_FLAGS(QgsField::ConfigurationFlags) CORE_EXPORT QDataStream &operator<<(QDataStream &out
Writes the field to stream out. QGIS version compatibility is not guaranteed.