mirror of
https://github.com/qgis/QGIS.git
synced 2025-02-24 00:47:57 -05:00
5bc36503e4
(instead of checking only AddFeatures) git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@9708 c8812cc2-4d05-0410-92ff-de0c093fc19c
244 lines
8.4 KiB
Plaintext
244 lines
8.4 KiB
Plaintext
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class QgsVectorDataProvider : QgsDataProvider
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{
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%TypeHeaderCode
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#include <qgsvectordataprovider.h>
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%End
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public:
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// If you add to this, please also add to capabilitiesString()
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/**
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* enumeration with capabilities that providers might implement
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*/
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enum Capability
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{
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NoCapabilities = 0,
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AddFeatures = 1,
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DeleteFeatures = 2,
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ChangeAttributeValues = 4,
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AddAttributes = 8,
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DeleteAttributes = 16,
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SaveAsShapefile = 32,
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CreateSpatialIndex = 64,
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SelectAtId = 128,
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ChangeGeometries = 256,
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SelectGeometryAtId = 512,
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RandomSelectGeometryAtId = 1024,
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SequentialSelectGeometryAtId = 2048
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};
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/** bitmask of all provider's editing capabilities */
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static const int EditingCapabilities;
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/**
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* Constructor of the vector provider
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* @param uri uniform resource locator (URI) for a dataset
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*/
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QgsVectorDataProvider(QString uri = QString());
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/**
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* Destructor
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*/
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virtual ~QgsVectorDataProvider();
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/**
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* Returns the permanent storage type for this layer as a friendly name.
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*/
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virtual QString storageType() const;
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/** Select features based on a bounding rectangle. Features can be retrieved with calls to nextFeature.
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* @param fetchAttributes list of attributes which should be fetched
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* @param rect spatial filter
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* @param fetchGeometry true if the feature geometry should be fetched
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* @param useIntersect true if an accurate intersection test should be used,
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* false if a test based on bounding box is sufficient
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*/
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virtual void select(QList<int> fetchAttributes = QList<int>(),
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QgsRectangle rect = QgsRectangle(),
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bool fetchGeometry = true,
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bool useIntersect = false) = 0;
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/**
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* Update the feature count based on current spatial filter. If not
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* overridden in the data provider this function returns -1
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*/
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virtual long updateFeatureCount();
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/**
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* Gets the feature at the given feature ID.
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* @param featureId id of the feature
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* @param feature feature which will receive the data
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* @param fetchGeoemtry if true, geometry will be fetched from the provider
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* @param fetchAttributes a list containing the indexes of the attribute fields to copy
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* @return True when feature was found, otherwise false
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*/
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virtual bool featureAtId(int featureId,
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QgsFeature& feature,
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bool fetchGeometry = true,
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QList<int> fetchAttributes = QList<int>());
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/**
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* Get the next feature resulting from a select operation.
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* @param feature feature which will receive data from the provider
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* @return true when there was a feature to fetch, false when end was hit
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*/
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virtual bool nextFeature(QgsFeature& feature) = 0;
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/**
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* Get feature type.
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* @return int representing the feature type
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*/
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virtual QGis::WkbType geometryType() const = 0;
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/**
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* Number of features in the layer
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* @return long containing number of features
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*/
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virtual long featureCount() const = 0;
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/**
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* Number of attribute fields for a feature in the layer
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*/
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virtual uint fieldCount() const = 0;
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/**
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* Return a map of indexes with field names for this layer
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* @return map of fields
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*/
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virtual const QMap<int, QgsField> & fields() const = 0;
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/**
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* Return a short comment for the data that this provider is
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* providing access to (e.g. the comment for postgres table).
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*/
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virtual QString dataComment() const;
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/** Restart reading features from previous select operation */
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virtual void rewind() = 0;
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/**
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* Returns the minimum value of an attributs
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* @param index the index of the attribute
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*
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* Default implementation walks all numeric attributes and caches minimal
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* and maximal values. If provider has facilities to retrieve minimal
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* value directly, override this function.
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*/
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virtual QVariant minimumValue(int index);
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/**
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* Returns the maximum value of an attributs
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* @param index the index of the attribute
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*
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* Default implementation walks all numeric attributes and caches minimal
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* and maximal values. If provider has facilities to retrieve maximal
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* value directly, override this function.
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*/
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virtual QVariant maximumValue(int index);
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/**
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* Return unique values of an attribute
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* @param index the index of the attribute
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* @param values reference to the list to fill
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*
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* Default implementation simply iterates the features
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*/
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virtual void uniqueValues(int index, QList<QVariant> &uniqueValues /Out/);
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/**
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* Adds a list of features
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* @return true in case of success and false in case of failure
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*/
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virtual bool addFeatures(QList<QgsFeature> & flist /In,Out/);
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/**
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* Deletes a feature
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* @param id list containing feature ids to delete
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* @return true in case of success and false in case of failure
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*/
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virtual bool deleteFeatures(const QSet<int> & id);
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/**
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* Adds new attributes
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* @param attributes map with attribute name as key and type as value
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* @return true in case of success and false in case of failure
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*/
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virtual bool addAttributes(const QMap<QString, QString> & attributes);
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/**
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* Deletes existing attributes
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* @param attributes a set containing indexes of attributes
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* @return true in case of success and false in case of failure
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*/
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virtual bool deleteAttributes(const QSet<int> & attributes);
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/**
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* Changes attribute values of existing features.
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* @param attr_map a map containing changed attributes
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* @return true in case of success and false in case of failure
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*/
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virtual bool changeAttributeValues(const QMap<int, QMap<int, QVariant> > & attr_map);
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/**
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* Returns the default value for field specified by @c fieldId
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*/
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virtual QVariant defaultValue(int fieldId);
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/**
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* Changes geometries of existing features
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* @param geometry_map A std::map containing the feature IDs to change the geometries of.
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* the second map parameter being the new geometries themselves
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* @return true in case of success and false in case of failure
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*/
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virtual bool changeGeometryValues(QMap<int, QgsGeometry> & geometry_map);
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/**
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* Creates a spatial index on the datasource (if supported by the provider type).
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* @return true in case of success
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*/
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virtual bool createSpatialIndex();
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/** Returns a bitmask containing the supported capabilities
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Note, some capabilities may change depending on whether
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a spatial filter is active on this provider, so it may
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be prudent to check this value per intended operation.
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*/
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virtual int capabilities() const;
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/**
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* Returns the above in friendly format.
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*/
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QString capabilitiesString() const;
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/**
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* Set encoding used for accessing data from layer
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*/
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virtual void setEncoding(const QString& e);
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/**
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* Get encoding which is used for accessing data
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*/
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QString encoding() const;
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/**
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* Returns the index of a field name or -1 if the field does not exist
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*/
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int fieldNameIndex(const QString& fieldName) const;
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/**
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* Return list of indexes to fetch all attributes in nextFeature()
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*/
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QList<int> attributeIndexes();
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/**Returns the names of the numerical types*/
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const QMap<QString,QVariant::Type> &supportedNativeTypes() const;
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/**
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* Set whether provider should return also features that don't have
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* associated geometry. FALSE by default
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*/
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void enableGeometrylessFeatures(bool fetch);
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};
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