QGIS API Documentation  3.21.0-Master (5b68dc587e)
qgsfeaturepickermodelbase.h
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1 /***************************************************************************
2  qgsfeaturefiltermodel.h - QgsFeatureFilterModel
3  ---------------------
4  begin : 10.3.2017
5  copyright : (C) 2017 by Matthias Kuhn
6  email : [email protected]
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 QGSFEATUREFILTERMODELBASE_H
16 #define QGSFEATUREFILTERMODELBASE_H
17 
18 #include "qgsconditionalstyle.h"
20 
21 #include <QAbstractItemModel>
22 #include <QTimer>
23 
32 class CORE_EXPORT QgsFeaturePickerModelBase : public QAbstractItemModel SIP_ABSTRACT
33 {
34  Q_OBJECT
35 
36  Q_PROPERTY( QgsVectorLayer *sourceLayer READ sourceLayer WRITE setSourceLayer NOTIFY sourceLayerChanged )
37  Q_PROPERTY( QString displayExpression READ displayExpression WRITE setDisplayExpression NOTIFY displayExpressionChanged )
38  Q_PROPERTY( QString filterValue READ filterValue WRITE setFilterValue NOTIFY filterValueChanged )
39  Q_PROPERTY( QString filterExpression READ filterExpression WRITE setFilterExpression NOTIFY filterExpressionChanged )
40  Q_PROPERTY( bool allowNull READ allowNull WRITE setAllowNull NOTIFY allowNullChanged )
41  Q_PROPERTY( bool fetchGeometry READ fetchGeometry WRITE setFetchGeometry NOTIFY fetchGeometryChanged )
42  Q_PROPERTY( int fetchLimit READ fetchLimit WRITE setFetchLimit NOTIFY fetchLimitChanged )
43  Q_PROPERTY( int extraIdentifierValueIndex READ extraIdentifierValueIndex NOTIFY extraIdentifierValueIndexChanged )
44 
45  public:
46 
50  enum Role
51  {
52  IdentifierValueRole = Qt::UserRole,
56  FeatureIdRole
57  };
58 
62  explicit QgsFeaturePickerModelBase( QObject *parent = nullptr );
63  ~QgsFeaturePickerModelBase() override;
64 
68  QgsVectorLayer *sourceLayer() const;
69 
73  void setSourceLayer( QgsVectorLayer *sourceLayer );
74 
81  QString displayExpression() const;
82 
89  void setDisplayExpression( const QString &displayExpression );
90 
96  QString filterValue() const;
97 
103  void setFilterValue( const QString &filterValue );
104 
105  QModelIndex index( int row, int column, const QModelIndex &parent ) const override;
106  QModelIndex parent( const QModelIndex &child ) const override;
107  int rowCount( const QModelIndex &parent ) const override;
108  int columnCount( const QModelIndex &parent ) const override
109  {
110  Q_UNUSED( parent )
111  return 1;
112  }
113  QVariant data( const QModelIndex &index, int role ) const override;
114 
119  QString filterExpression() const;
120 
125  void setFilterExpression( const QString &filterExpression );
126 
130  bool isLoading() const;
131 
136  virtual void setExtraIdentifierValueToNull() = 0;
137 
141  int extraIdentifierValueIndex() const;
142 
146  bool extraValueDoesNotExist() const;
147 
151  bool allowNull() const;
152 
156  void setAllowNull( bool allowNull );
157 
161  bool fetchGeometry() const;
162 
166  void setFetchGeometry( bool fetchGeometry );
167 
171  int fetchLimit() const;
172 
177  void setFetchLimit( int fetchLimit );
178 
179  signals:
180 
188 
193 
201 
208 
214 
219 
224 
230 
235 
240 
244  void beginUpdate();
245 
249  void endUpdate();
250 
255 
260 
265 
266 
267  private slots:
268  void updateCompleter();
269  void scheduledReload();
270 
271  protected:
272 
277  QVariant extraIdentifierValue() const;
278 
283  void setExtraIdentifierValue( const QVariant &extraIdentifierValue );
284 
286  virtual void requestToReloadCurrentFeature( QgsFeatureRequest &request ) = 0;
287 
289  void setExtraIdentifierValueUnguarded( const QVariant &identifierValue );
290 
291 #ifndef SIP_RUN
292 
297  virtual QSet<QString> requestedAttributes() const {return {};}
298 
300  virtual QgsFeatureExpressionValuesGatherer *createValuesGatherer( const QgsFeatureRequest &request ) const = 0;
301 
303  virtual QgsFeatureExpressionValuesGatherer::Entry createEntry( const QVariant &identifier ) const = 0;
304 
306  virtual QVariant entryIdentifier( const QgsFeatureExpressionValuesGatherer::Entry &entry ) const = 0;
307 
309  virtual bool compareEntries( const QgsFeatureExpressionValuesGatherer::Entry &a, const QgsFeatureExpressionValuesGatherer::Entry &b ) const = 0;
310 
312  virtual QVariant nullIdentifier() const = 0;
313 
318  virtual bool identifierIsNull( const QVariant &identifier ) const = 0;
319 
320  QVector<QgsFeatureExpressionValuesGatherer::Entry> mEntries;
321 #endif
322 
325 
327  int mExtraValueIndex = -1;
328 
329  private:
330  void setExtraIdentifierValueIndex( int index, bool force = false );
331  void setExtraValueDoesNotExist( bool extraValueDoesNotExist );
332  void reload();
333  void reloadCurrentFeature();
334  QSet<QString> requestedAttributesForStyle() const;
335 
336  QgsConditionalStyle featureStyle( const QgsFeature &feature ) const;
337 
338  QgsVectorLayer *mSourceLayer = nullptr;
339  QgsExpression mDisplayExpression;
340  QString mFilterValue;
341  QString mFilterExpression;
342 
343  mutable QgsExpressionContext mExpressionContext;
344  mutable QMap< QgsFeatureId, QgsConditionalStyle > mEntryStylesMap;
345 
346  QgsFeatureExpressionValuesGatherer *mGatherer = nullptr;
347  bool mFetchGeometry = true;
348  int mFetchLimit = 100;
349 
350  QTimer mReloadTimer;
351  bool mShouldReloadCurrentFeature = false;
352  bool mKeepCurrentEntry = false; // need to keep the current value after a reload or if the value does not exist
353  bool mExtraValueDoesNotExist = false;
354  bool mAllowNull = false;
355  bool mIsSettingExtraIdentifierValue = false;
356 
357  friend class TestQgsFeatureListComboBox;
358 };
359 
360 #endif // QGSFEATUREFILTERMODELBASE_H
Conditional styling for a rule.
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
Class for parsing and evaluation of expressions (formerly called "search strings").
Provides a list of features based on filter conditions.
void extraIdentifierValueIndexChanged(int index)
The index at which the extra identifier value is available within the model.
void beginUpdate()
Notification that the model is about to be changed because a job was completed.
virtual QVariant entryIdentifier(const QgsFeatureExpressionValuesGatherer::Entry &entry) const =0
Returns the identifier of the given entry.
void filterValueChanged()
This value will be used to filter the features available from this model.
virtual void setExtraIdentifierValueToNull()=0
Allows specifying one value that does not need to match the filter criteria but will still be availab...
virtual void requestToReloadCurrentFeature(QgsFeatureRequest &request)=0
Update the request to match the current feature to be reloaded.
void filterExpressionChanged()
An additional filter expression to apply, next to the filterValue.
int columnCount(const QModelIndex &parent) const override
void extraIdentifierValueChanged()
Allows specifying one value that does not need to match the filter criteria but will still be availab...
void filterJobCompleted()
Indicates that a filter job has been completed and new data may be available.
QVariant mExtraIdentifierValue
The current identifier value.
virtual QgsFeatureExpressionValuesGatherer * createValuesGatherer(const QgsFeatureRequest &request) const =0
Creates the value gatherer.
virtual QgsFeatureExpressionValuesGatherer::Entry createEntry(const QVariant &identifier) const =0
Creates an entry with just the identifier so the feature can be retrieved in a next iteration.
virtual bool identifierIsNull(const QVariant &identifier) const =0
Returns true if the entry is null The identifier can be either the feature ID or the list of identifi...
void fetchLimitChanged()
Emitted when the fetching limit for the feature request changes.
void sourceLayerChanged()
The source layer from which features will be fetched.
virtual QSet< QString > requestedAttributes() const
Returns the attributes to be fetched in the request.
Role
Extra roles that can be used to fetch data from this model.
@ IdentifierValuesRole
Used to retrieve the identifierValues (primary keys) of a feature.
@ FeatureRole
Used to retrieve the feature, it might be incomplete if the request doesn't fetch all attributes or g...
@ ValueRole
Used to retrieve the displayExpression of a feature.
void allowNullChanged()
Add a NULL entry to the list.
virtual bool compareEntries(const QgsFeatureExpressionValuesGatherer::Entry &a, const QgsFeatureExpressionValuesGatherer::Entry &b) const =0
Returns true if the 2 entries refers to the same feature.
void currentFeatureChanged()
Emitted when the current feature in the model has changed This emitted both when the extra value chan...
void fetchGeometryChanged()
Emitted when the fetching of the geometry changes.
void isLoadingChanged()
Indicator if the model is currently performing any feature iteration in the background.
QVector< QgsFeatureExpressionValuesGatherer::Entry > mEntries
virtual QVariant nullIdentifier() const =0
Returns a null identifier.
void endUpdate()
Notification that the model change is finished.
void displayExpressionChanged()
The display expression will be used for.
void extraValueDoesNotExistChanged()
Flag indicating that the extraIdentifierValue does not exist in the data.
This class wraps a request for features to a vector layer (or directly its vector data provider).
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition: qgsfeature.h:56
Represents a vector layer which manages a vector based data sets.
#define SIP_ABSTRACT
Definition: qgis_sip.h:199