QGIS API Documentation 3.34.0-Prizren (ffbdd678812)
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Classes | Public Member Functions | List of all members
QgsGroupLayer Class Reference

A map layer which consists of a set of child layers, where all component layers are rendered as a single flattened object during map renders. More...

#include <qgsgrouplayer.h>

Inheritance diagram for QgsGroupLayer:
Inheritance graph
[legend]

Classes

struct  LayerOptions
 Setting options for loading group layers. More...
 

Public Member Functions

 QgsGroupLayer (const QString &name, const QgsGroupLayer::LayerOptions &options)
 Constructor for a new QgsGroupLayer with the specified layer name.
 
 ~QgsGroupLayer () override
 
QList< QgsMapLayer * > childLayers () const
 Returns the child layers contained by the group.
 
QgsGroupLayerclone () const override
 Returns a new instance equivalent to this one except for the id which is still unique.
 
QgsMapLayerRenderercreateMapRenderer (QgsRenderContext &rendererContext) override
 Returns new instance of QgsMapLayerRenderer that will be used for rendering of given context.
 
const QgsDataProviderdataProvider () const override
 Returns the layer's data provider in a const-correct manner, it may be nullptr.
 
QgsDataProviderdataProvider () override
 Returns the layer's data provider, it may be nullptr.
 
QgsRectangle extent () const override
 Returns the extent of the layer.
 
QString htmlMetadata () const override
 Obtain a formatted HTML string containing assorted metadata for this layer.
 
QgsPaintEffectpaintEffect () const
 Returns the current paint effect for the group layer.
 
void prepareLayersForRemovalFromGroup ()
 Prepares all child layers in the group prior to removal from the group.
 
bool readSymbology (const QDomNode &node, QString &errorMessage, QgsReadWriteContext &context, StyleCategories categories=AllStyleCategories) override
 Read the symbology for the current layer from the DOM node supplied.
 
bool readXml (const QDomNode &layerNode, QgsReadWriteContext &context) override
 Called by readLayerXML(), used by children to read state specific to them from project files.
 
void resolveReferences (QgsProject *project) override
 Resolve references to other layers (kept as layer IDs after reading XML) into layer objects.
 
void setChildLayers (const QList< QgsMapLayer * > &layers)
 Sets the child layers contained by the group.
 
void setPaintEffect (QgsPaintEffect *effect)
 Sets the current paint effect for the renderer.
 
void setTransformContext (const QgsCoordinateTransformContext &context) override
 Sets the coordinate transform context to transformContext.
 
bool writeSymbology (QDomNode &node, QDomDocument &doc, QString &errorMessage, const QgsReadWriteContext &, StyleCategories categories=AllStyleCategories) const override
 Write the style for the layer into the document provided.
 
bool writeXml (QDomNode &layer_node, QDomDocument &doc, const QgsReadWriteContext &context) const override
 Called by writeLayerXML(), used by children to write state specific to them to project files.
 
- Public Member Functions inherited from QgsMapLayer
 QgsMapLayer (Qgis::LayerType type=Qgis::LayerType::Vector, const QString &name=QString(), const QString &source=QString())
 Constructor for QgsMapLayer.
 
 QgsMapLayer (QgsMapLayer const &)=delete
 QgsMapLayer cannot be copied.
 
 ~QgsMapLayer () override
 
QString abstract () const
 Returns the abstract of the layer used by QGIS Server in GetCapabilities request.
 
virtual bool accept (QgsStyleEntityVisitorInterface *visitor) const
 Accepts the specified symbology visitor, causing it to visit all symbols associated with the layer.
 
QString attribution () const
 Returns the attribution of the layer used by QGIS Server in GetCapabilities request.
 
QString attributionUrl () const
 Returns the attribution URL of the layer used by QGIS Server in GetCapabilities request.
 
int autoRefreshInterval () const
 Returns the auto refresh interval (in milliseconds).
 
Qgis::AutoRefreshMode autoRefreshMode () const
 Returns the layer's automatical refresh mode.
 
QPainter::CompositionMode blendMode () const
 Returns the current blending mode for a layer.
 
QgsCoordinateReferenceSystem crs () const
 Returns the layer's spatial reference system.
 
template<class T >
customEnumProperty (const QString &key, const T &defaultValue)
 Returns the property value for a property based on an enum.
 
template<class T >
customFlagProperty (const QString &key, const T &defaultValue)
 Returns the property value for a property based on a flag.
 
const QgsObjectCustomPropertiescustomProperties () const
 Read all custom properties from layer.
 
Q_INVOKABLE QVariant customProperty (const QString &value, const QVariant &defaultValue=QVariant()) const
 Read a custom property from layer.
 
Q_INVOKABLE QStringList customPropertyKeys () const
 Returns list of all keys within custom properties.
 
QString dataUrl () const
 Returns the DataUrl of the layer used by QGIS Server in GetCapabilities request.
 
QString dataUrlFormat () const
 Returns the DataUrl format of the layer used by QGIS Server in GetCapabilities request.
 
virtual bool deleteStyleFromDatabase (const QString &styleId, QString &msgError)
 Deletes a style from the database.
 
virtual QSet< QgsMapLayerDependencydependencies () const
 Gets the list of dependencies.
 
virtual QgsMapLayerElevationPropertieselevationProperties ()
 Returns the layer's elevation properties.
 
virtual QgsError error () const
 Gets current status error.
 
void exportNamedMetadata (QDomDocument &doc, QString &errorMsg) const
 Export the current metadata of this layer as named metadata in a QDomDocument.
 
virtual void exportNamedStyle (QDomDocument &doc, QString &errorMsg, const QgsReadWriteContext &context=QgsReadWriteContext(), QgsMapLayer::StyleCategories categories=QgsMapLayer::AllStyleCategories) const
 Export the properties of this layer as named style in a QDomDocument.
 
virtual void exportSldStyle (QDomDocument &doc, QString &errorMsg) const
 Export the properties of this layer as SLD style in a QDomDocument.
 
virtual void exportSldStyleV2 (QDomDocument &doc, QString &errorMsg, const QgsSldExportContext &exportContext) const
 Export the properties of this layer as SLD style in a QDomDocument.
 
QgsMapLayer::LayerFlags flags () const
 Returns the flags for this layer.
 
virtual QString getStyleFromDatabase (const QString &styleId, QString &msgError)
 Returns the named style corresponding to style id provided.
 
Q_DECL_DEPRECATED bool hasAutoRefreshEnabled () const
 Returns true if auto refresh is enabled for the layer.
 
virtual bool hasMapTips () const
 Returns true if the layer contains map tips.
 
bool hasScaleBasedVisibility () const
 Returns whether scale based visibility is enabled for the layer.
 
QString id () const
 Returns the layer's unique ID, which is used to access this layer from QgsProject.
 
bool importNamedMetadata (QDomDocument &document, QString &errorMessage)
 Import the metadata of this layer from a QDomDocument.
 
virtual bool importNamedStyle (QDomDocument &doc, QString &errorMsg, QgsMapLayer::StyleCategories categories=QgsMapLayer::AllStyleCategories)
 Import the properties of this layer from a QDomDocument.
 
virtual bool isEditable () const
 Returns true if the layer can be edited.
 
bool isInScaleRange (double scale) const
 Tests whether the layer should be visible at the specified scale.
 
virtual bool isModified () const
 Returns true if the layer has been modified since last commit/save.
 
bool isRefreshOnNotifyEnabled () const
 Returns true if the refresh on provider nofification is enabled.
 
virtual bool isSpatial () const
 Returns true if the layer is considered a spatial layer, ie it has some form of geometry associated with it.
 
virtual bool isTemporary () const
 Returns true if the layer is considered a temporary layer.
 
bool isValid () const
 Returns the status of the layer.
 
QString keywordList () const
 Returns the keyword list of the layer used by QGIS Server in GetCapabilities request.
 
QgsMapLayerLegendlegend () const
 Can be nullptr.
 
QString legendPlaceholderImage () const
 Returns path to the placeholder image or an empty string if a generated legend is shown.
 
QString legendUrl () const
 Returns the URL for the layer's legend.
 
QString legendUrlFormat () const
 Returns the format for a URL based layer legend.
 
virtual int listStylesInDatabase (QStringList &ids, QStringList &names, QStringList &descriptions, QString &msgError)
 Lists all the style in db split into related to the layer and not related to.
 
virtual QString loadDefaultMetadata (bool &resultFlag)
 Retrieve the default metadata for this layer if one exists (either as a .qmd file on disk or as a record in the users metadata table in their personal qgis.db)
 
virtual QString loadDefaultStyle (bool &resultFlag)
 Retrieve the default style for this layer if one exists (either as a .qml file on disk or as a record in the users style table in their personal qgis.db)
 
virtual QString loadNamedMetadata (const QString &uri, bool &resultFlag)
 Retrieve a named metadata for this layer if one exists (either as a .qmd file on disk or as a record in the users style table in their personal qgis.db)
 
bool loadNamedMetadataFromDatabase (const QString &db, const QString &uri, QString &qmd)
 Retrieve a named metadata for this layer from a sqlite database.
 
virtual QString loadNamedStyle (const QString &theURI, bool &resultFlag, bool loadFromLocalDb, QgsMapLayer::StyleCategories categories=QgsMapLayer::AllStyleCategories)
 Loads a named style from file/local db/datasource db.
 
virtual QString loadNamedStyle (const QString &uri, bool &resultFlag, QgsMapLayer::StyleCategories categories=QgsMapLayer::AllStyleCategories)
 Retrieve a named style for this layer if one exists (either as a .qml file on disk or as a record in the users style table in their personal qgis.db)
 
virtual bool loadNamedStyleFromDatabase (const QString &db, const QString &uri, QString &qml)
 Retrieve a named style for this layer from a sqlite database.
 
virtual QString loadSldStyle (const QString &uri, bool &resultFlag)
 Attempts to style the layer using the formatting from an SLD type file.
 
bool mapTipsEnabled () const
 Returns true if map tips are enabled for this layer.
 
QString mapTipTemplate () const
 The mapTip is a pretty, html representation for feature information.
 
double maximumScale () const
 Returns the maximum map scale (i.e.
 
virtual const QgsLayerMetadatametadata () const
 Returns a reference to the layer's metadata store.
 
virtual QString metadataUri () const
 Retrieve the metadata URI for this layer (either as a .qmd file on disk or as a record in the users style table in their personal qgis.db)
 
Q_DECL_DEPRECATED QString metadataUrl () const
 Returns the metadata URL of the layer used by QGIS Server in GetCapabilities request.
 
Q_DECL_DEPRECATED QString metadataUrlFormat () const
 Returns the metadata format of the layer used by QGIS Server in GetCapabilities request.
 
Q_DECL_DEPRECATED QString metadataUrlType () const
 Returns the metadata type of the layer used by QGIS Server in GetCapabilities request.
 
double minimumScale () const
 Returns the minimum map scale (i.e.
 
QString name () const
 Returns the display name of the layer.
 
virtual double opacity () const
 Returns the opacity for the layer, where opacity is a value between 0 (totally transparent) and 1.0 (fully opaque).
 
QgsMapLayeroperator= (QgsMapLayer const &)=delete
 QgsMapLayer cannot be copied.
 
QString originalXmlProperties () const
 Returns the XML properties of the original layer as they were when the layer was first read from the project file.
 
virtual Qgis::MapLayerProperties properties () const
 Returns the map layer properties of this layer.
 
QString providerType () const
 Returns the provider type (provider key) for this layer.
 
QString publicSource (bool hidePassword=false) const
 Gets a version of the internal layer definition that has sensitive bits removed (for example, the password).
 
bool readLayerXml (const QDomElement &layerElement, QgsReadWriteContext &context, QgsMapLayer::ReadFlags flags=QgsMapLayer::ReadFlags(), QgsDataProvider *preloadedProvider=nullptr)
 Sets state from DOM document.
 
bool readOnly () const
 Returns if this layer is read only.
 
virtual bool readSld (const QDomNode &node, QString &errorMessage)
 
virtual bool readStyle (const QDomNode &node, QString &errorMessage, QgsReadWriteContext &context, StyleCategories categories=AllStyleCategories)
 Read the style for the current layer from the DOM node supplied.
 
QString refreshOnNotifyMessage () const
 Returns the message that should be notified by the provider to triggerRepaint.
 
virtual Q_INVOKABLE void reload ()
 Synchronises with changes in the datasource.
 
void removeCustomProperty (const QString &key)
 Remove a custom property from layer.
 
QgsAbstract3DRendererrenderer3D () const
 Returns 3D renderer associated with the layer.
 
virtual QString saveDefaultMetadata (bool &resultFlag)
 Save the current metadata of this layer as the default metadata (either as a .qmd file on disk or as a record in the users style table in their personal qgis.db)
 
virtual Q_DECL_DEPRECATED QString saveDefaultStyle (bool &resultFlag)
 Save the properties of this layer as the default style (either as a .qml file on disk or as a record in the users style table in their personal qgis.db)
 
virtual QString saveDefaultStyle (bool &resultFlag, StyleCategories categories)
 Save the properties of this layer as the default style (either as a .qml file on disk or as a record in the users style table in their personal qgis.db)
 
QString saveNamedMetadata (const QString &uri, bool &resultFlag)
 Save the current metadata of this layer as a named metadata (either as a .qmd file on disk or as a record in the users style table in their personal qgis.db)
 
virtual QString saveNamedStyle (const QString &uri, bool &resultFlag, StyleCategories categories=AllStyleCategories)
 Save the properties of this layer as a named style (either as a .qml file on disk or as a record in the users style table in their personal qgis.db)
 
virtual QString saveSldStyle (const QString &uri, bool &resultFlag) const
 Saves the properties of this layer to an SLD format file.
 
virtual QString saveSldStyleV2 (bool &resultFlag, const QgsSldExportContext &exportContext) const
 Saves the properties of this layer to an SLD format file.
 
virtual void saveStyleToDatabase (const QString &name, const QString &description, bool useAsDefault, const QString &uiFileContent, QString &msgError, QgsMapLayer::StyleCategories categories=QgsMapLayer::AllStyleCategories)
 Saves named and sld style of the layer to the style table in the db.
 
virtual QgsMapLayerSelectionPropertiesselectionProperties ()
 Returns the layer's selection properties.
 
QgsMapLayerServerPropertiesserverProperties ()
 Returns QGIS Server Properties for the map layer.
 
const QgsMapLayerServerPropertiesserverProperties () const
 Returns QGIS Server Properties const for the map layer.
 
void setAbstract (const QString &abstract)
 Sets the abstract of the layer used by QGIS Server in GetCapabilities request.
 
void setAttribution (const QString &attrib)
 Sets the attribution of the layer used by QGIS Server in GetCapabilities request.
 
void setAttributionUrl (const QString &attribUrl)
 Sets the attribution URL of the layer used by QGIS Server in GetCapabilities request.
 
Q_DECL_DEPRECATED void setAutoRefreshEnabled (bool enabled)
 Sets whether auto refresh is enabled for the layer.
 
void setAutoRefreshInterval (int interval)
 Sets the auto refresh interval (in milliseconds) for the layer.
 
void setAutoRefreshMode (Qgis::AutoRefreshMode mode)
 Sets the automatic refresh mode for the layer.
 
void setBlendMode (QPainter::CompositionMode blendMode)
 Set the blending mode used for rendering a layer.
 
void setCrs (const QgsCoordinateReferenceSystem &srs, bool emitSignal=true)
 Sets layer's spatial reference system.
 
template<class T >
void setCustomEnumProperty (const QString &key, const T &value)
 Set the value of a property based on an enum.
 
template<class T >
void setCustomFlagProperty (const QString &key, const T &value)
 Set the value of a property based on a flag.
 
void setCustomProperties (const QgsObjectCustomProperties &properties)
 Set custom properties for layer.
 
Q_INVOKABLE void setCustomProperty (const QString &key, const QVariant &value)
 Set a custom property for layer.
 
void setDataSource (const QString &dataSource, const QString &baseName, const QString &provider, bool loadDefaultStyleFlag=false)
 Updates the data source of the layer.
 
void setDataSource (const QString &dataSource, const QString &baseName, const QString &provider, const QgsDataProvider::ProviderOptions &options, bool loadDefaultStyleFlag=false)
 Updates the data source of the layer.
 
void setDataSource (const QString &dataSource, const QString &baseName, const QString &provider, const QgsDataProvider::ProviderOptions &options, QgsDataProvider::ReadFlags flags)
 Updates the data source of the layer.
 
void setDataUrl (const QString &dataUrl)
 Sets the DataUrl of the layer used by QGIS Server in GetCapabilities request.
 
void setDataUrlFormat (const QString &dataUrlFormat)
 Sets the DataUrl format of the layer used by QGIS Server in GetCapabilities request.
 
void setFlags (QgsMapLayer::LayerFlags flags)
 Returns the flags for this layer.
 
void setKeywordList (const QString &keywords)
 Sets the keyword list of the layer used by QGIS Server in GetCapabilities request.
 
virtual void setLayerOrder (const QStringList &layers)
 Reorders the previously selected sublayers of this layer from bottom to top.
 
void setLegend (QgsMapLayerLegend *legend)
 Assign a legend controller to the map layer.
 
void setLegendPlaceholderImage (const QString &imgPath)
 Set placeholder image for legend.
 
void setLegendUrl (const QString &legendUrl)
 Sets the URL for the layer's legend.
 
void setLegendUrlFormat (const QString &legendUrlFormat)
 Sets the format for a URL based layer legend.
 
void setMapTipsEnabled (bool enabled)
 Enable or disable map tips for this layer.
 
void setMapTipTemplate (const QString &mapTipTemplate)
 The mapTip is a pretty, html representation for feature information.
 
virtual void setMetadata (const QgsLayerMetadata &metadata)
 Sets the layer's metadata store.
 
Q_DECL_DEPRECATED void setMetadataUrl (const QString &metaUrl)
 Sets the metadata URL of the layer used by QGIS Server in GetCapabilities request.
 
Q_DECL_DEPRECATED void setMetadataUrlFormat (const QString &metaUrlFormat)
 Sets the metadata format of the layer used by QGIS Server in GetCapabilities request.
 
Q_DECL_DEPRECATED void setMetadataUrlType (const QString &metaUrlType)
 Set the metadata type of the layer used by QGIS Server in GetCapabilities request MetadataUrlType indicates the standard to which the metadata complies.
 
void setName (const QString &name)
 Set the display name of the layer.
 
virtual void setOpacity (double opacity)
 Sets the opacity for the layer, where opacity is a value between 0 (totally transparent) and 1.0 (fully opaque).
 
void setOriginalXmlProperties (const QString &originalXmlProperties)
 Sets the original XML properties for the layer to originalXmlProperties.
 
void setRenderer3D (QgsAbstract3DRenderer *renderer)
 Sets 3D renderer for the layer.
 
void setShortName (const QString &shortName)
 Sets the short name of the layer used by QGIS Server to identify the layer.
 
virtual void setSubLayerVisibility (const QString &name, bool visible)
 Set the visibility of the given sublayer name.
 
void setTitle (const QString &title)
 Sets the title of the layer used by QGIS Server in GetCapabilities request.
 
QString shortName () const
 Returns the short name of the layer used by QGIS Server to identify the layer.
 
QString source () const
 Returns the source for the layer.
 
QgsMapLayerStyleManagerstyleManager () const
 Gets access to the layer's style manager.
 
virtual QString styleURI () const
 Retrieve the style URI for this layer (either as a .qml file on disk or as a record in the users style table in their personal qgis.db)
 
virtual QStringList subLayers () const
 Returns the sublayers of this layer.
 
virtual bool supportsEditing () const
 Returns whether the layer supports editing or not.
 
virtual QgsMapLayerTemporalPropertiestemporalProperties ()
 Returns the layer's temporal properties.
 
virtual QDateTime timestamp () const
 Time stamp of data source in the moment when data/metadata were loaded by provider.
 
QString title () const
 Returns the title of the layer used by QGIS Server in GetCapabilities request.
 
QgsCoordinateTransformContext transformContext () const
 Returns the layer data provider coordinate transform context or a default transform context if the layer does not have a valid data provider.
 
Qgis::LayerType type () const
 Returns the type of the layer.
 
QUndoStack * undoStack ()
 Returns pointer to layer's undo stack.
 
QUndoStack * undoStackStyles ()
 Returns pointer to layer's style undo stack.
 
QgsRectangle wgs84Extent (bool forceRecalculate=false) const
 Returns the WGS84 extent (EPSG:4326) of the layer according to ReadFlag::FlagTrustLayerMetadata.
 
bool writeLayerXml (QDomElement &layerElement, QDomDocument &document, const QgsReadWriteContext &context) const
 Stores state in DOM node.
 
virtual bool writeStyle (QDomNode &node, QDomDocument &doc, QString &errorMessage, const QgsReadWriteContext &context, StyleCategories categories=AllStyleCategories) const
 Write just the symbology information for the layer into the document.
 

Additional Inherited Members

- Public Types inherited from QgsMapLayer
enum  LayerFlag { Identifiable = 1 << 0 , Removable = 1 << 1 , Searchable = 1 << 2 , Private = 1 << 3 }
 Flags for the map layer. More...
 
enum  PropertyType { Style = 0 , Metadata }
 Maplayer has a style and a metadata property. More...
 
enum  ReadFlag { FlagDontResolveLayers = 1 << 0 , FlagTrustLayerMetadata = 1 << 1 , FlagReadExtentFromXml = 1 << 2 , FlagForceReadOnly = 1 << 3 }
 Flags which control project read behavior. More...
 
enum  StyleCategory {
  LayerConfiguration = 1 << 0 , Symbology = 1 << 1 , Symbology3D = 1 << 2 , Labeling = 1 << 3 ,
  Fields = 1 << 4 , Forms = 1 << 5 , Actions = 1 << 6 , MapTips = 1 << 7 ,
  Diagrams = 1 << 8 , AttributeTable = 1 << 9 , Rendering = 1 << 10 , CustomProperties = 1 << 11 ,
  GeometryOptions = 1 << 12 , Relations = 1 << 13 , Temporal = 1 << 14 , Legend = 1 << 15 ,
  Elevation = 1 << 16 , Notes = 1 << 17 , AllStyleCategories
}
 Categories of style to distinguish appropriate sections for import/export. More...
 
- Public Slots inherited from QgsMapLayer
void emitStyleChanged ()
 Triggers an emission of the styleChanged() signal.
 
QgsProjectproject () const
 Returns the parent project if this map layer is added to a project.
 
virtual bool setDependencies (const QSet< QgsMapLayerDependency > &layers)
 Sets the list of dependencies.
 
void setMaximumScale (double scale)
 Sets the maximum map scale (i.e.
 
void setMinimumScale (double scale)
 Sets the minimum map scale (i.e.
 
void setRefreshOnNofifyMessage (const QString &message)
 Set the notification message that triggers repaint If refresh on notification is enabled, the notification will triggerRepaint only if the notification message is equal to.
 
void setRefreshOnNotifyEnabled (bool enabled)
 Set whether provider notification is connected to triggerRepaint.
 
void setScaleBasedVisibility (bool enabled)
 Sets whether scale based visibility is enabled for the layer.
 
void trigger3DUpdate ()
 Will advise any 3D maps that this layer requires to be updated in the scene.
 
void triggerRepaint (bool deferredUpdate=false)
 Will advise the map canvas (and any other interested party) that this layer requires to be repainted.
 
- Signals inherited from QgsMapLayer
void autoRefreshIntervalChanged (int interval)
 Emitted when the auto refresh interval changes.
 
void beforeResolveReferences (QgsProject *project)
 Emitted when all layers are loaded and references can be resolved, just before the references of this layer are resolved.
 
void blendModeChanged (QPainter::CompositionMode blendMode)
 Signal emitted when the blend mode is changed, through QgsMapLayer::setBlendMode()
 
void configChanged ()
 Emitted whenever the configuration is changed.
 
void crsChanged ()
 Emit a signal that layer's CRS has been reset.
 
void customPropertyChanged (const QString &key)
 Emitted when a custom property of the layer has been changed or removed.
 
void dataChanged ()
 Data of layer changed.
 
void dataSourceChanged ()
 Emitted whenever the layer's data source has been changed.
 
void dependenciesChanged ()
 Emitted when dependencies are changed.
 
void editingStarted ()
 Emitted when editing on this layer has started.
 
void editingStopped ()
 Emitted when edited changes have been successfully written to the data provider.
 
void flagsChanged ()
 Emitted when layer's flags have been modified.
 
void isValidChanged ()
 Emitted when the validity of this layer changed.
 
void layerModified ()
 Emitted when modifications has been done on layer.
 
void legendChanged ()
 Signal emitted when legend of the layer has changed.
 
void mapTipsEnabledChanged ()
 Emitted when map tips are enabled or disabled for the layer.
 
void mapTipTemplateChanged ()
 Emitted when the map tip template changes.
 
void metadataChanged ()
 Emitted when the layer's metadata is changed.
 
void nameChanged ()
 Emitted when the name has been changed.
 
void opacityChanged (double opacity)
 Emitted when the layer's opacity is changed, where opacity is a value between 0 (transparent) and 1 (opaque).
 
void recalculateExtents () const
 This is used to send a request that any mapcanvas using this layer update its extents.
 
void renderer3DChanged ()
 Signal emitted when 3D renderer associated with the layer has changed.
 
void rendererChanged ()
 Signal emitted when renderer is changed.
 
void repaintRequested (bool deferredUpdate=false)
 By emitting this signal the layer tells that either appearance or content have been changed and any view showing the rendered layer should refresh itself.
 
void request3DUpdate ()
 Signal emitted when a layer requires an update in any 3D maps.
 
void statusChanged (const QString &status)
 Emit a signal with status (e.g. to be caught by QgisApp and display a msg on status bar)
 
void styleChanged ()
 Signal emitted whenever a change affects the layer's style.
 
void styleLoaded (QgsMapLayer::StyleCategories categories)
 Emitted when a style has been loaded.
 
void willBeDeleted ()
 Emitted in the destructor when the layer is about to be deleted, but it is still in a perfectly valid state: the last chance for other pieces of code for some cleanup if they use the layer.
 
- Static Public Member Functions inherited from QgsMapLayer
static QString extensionPropertyType (PropertyType type)
 Returns the extension of a Property.
 
static QString formatLayerName (const QString &name)
 A convenience function to capitalize and format a layer name.
 
static QString generateId (const QString &layerName)
 Generates an unique identifier for this layer, the generate ID is prefixed by layerName.
 
static QgsDataProvider::ReadFlags providerReadFlags (const QDomNode &layerNode, QgsMapLayer::ReadFlags layerReadFlags)
 Returns provider read flag deduced from layer read flags layerReadFlags and a dom node layerNode that describes a layer (corresponding to `‘maplayer’' tag in a DOM document project file read by QgsProject).
 
- Protected Member Functions inherited from QgsMapLayer
void appendError (const QgsErrorMessage &error)
 Add error message.
 
void clone (QgsMapLayer *layer) const
 Copies attributes like name, short name, ... into another layer.
 
QString crsHtmlMetadata () const
 Returns a HTML fragment containing the layer's CRS metadata, for use in the htmlMetadata() method.
 
virtual QString decodedSource (const QString &source, const QString &dataProvider, const QgsReadWriteContext &context) const
 Called by readLayerXML(), used by derived classes to decode provider's specific data source from project files.
 
virtual QString encodedSource (const QString &source, const QgsReadWriteContext &context) const
 Called by writeLayerXML(), used by derived classes to encode provider's specific data source to project files.
 
QString generalHtmlMetadata () const
 Returns an HTML fragment containing general metadata information, for use in the htmlMetadata() method.
 
Q_DECL_DEPRECATED bool hasDependencyCycle (const QSet< QgsMapLayerDependency > &) const
 Checks whether a new set of dependencies will introduce a cycle this method is now deprecated and always return false, because circular dependencies are now correctly managed.
 
void invalidateWgs84Extent ()
 Invalidates the WGS84 extent.
 
void readCommonStyle (const QDomElement &layerElement, const QgsReadWriteContext &context, StyleCategories categories=AllStyleCategories)
 Read style data common to all layer types.
 
void readCustomProperties (const QDomNode &layerNode, const QString &keyStartsWith=QString())
 Read custom properties from project file.
 
void readStyleManager (const QDomNode &layerNode)
 Read style manager's configuration (if any). To be called by subclasses.
 
void setError (const QgsError &error)
 Sets error message.
 
virtual void setExtent (const QgsRectangle &rect)
 Sets the extent.
 
void setProviderType (const QString &providerType)
 Sets the providerType (provider key)
 
void setValid (bool valid)
 Sets whether layer is valid or not.
 
void writeCommonStyle (QDomElement &layerElement, QDomDocument &document, const QgsReadWriteContext &context, StyleCategories categories=AllStyleCategories) const
 Write style data common to all layer types.
 
void writeCustomProperties (QDomNode &layerNode, QDomDocument &doc) const
 Write custom properties to project file.
 
void writeStyleManager (QDomNode &layerNode, QDomDocument &doc) const
 Write style manager's configuration (if exists). To be called by subclasses.
 
- Protected Attributes inherited from QgsMapLayer
QString mAbstract
 Description of the layer.
 
QString mAttribution
 Attribution of the layer.
 
QString mAttributionUrl
 
int mBlockStyleChangedSignal = 0
 If non-zero, the styleChanged signal should not be emitted.
 
QString mDataSource
 Data source description string, varies by layer type.
 
QString mDataUrl
 DataUrl of the layer.
 
QString mDataUrlFormat
 
QSet< QgsMapLayerDependencymDependencies
 List of layers that may modify this layer on modification.
 
QgsError mError
 Error.
 
bool mIsRefreshOnNofifyEnabled = false
 
QString mKeywordList
 
QString mLayerName
 Name of the layer - used for display.
 
double mLayerOpacity = 1.0
 Layer opacity.
 
QString mLegendUrl
 WMS legend.
 
QString mLegendUrlFormat
 
std::unique_ptr< QgsDataProvidermPreloadedProvider
 Optionally used when loading a project, it is released when the layer is effectively created.
 
QString mProviderKey
 Data provider key (name of the data provider)
 
QgsMapLayer::ReadFlags mReadFlags = QgsMapLayer::ReadFlags()
 Read flags. It's up to the subclass to respect these when restoring state from XML.
 
QString mRefreshOnNofifyMessage
 
QString mShortName
 
bool mShouldValidateCrs = true
 true if the layer's CRS should be validated and invalid CRSes are not permitted.
 
QString mTitle
 
bool mValid = false
 Indicates if the layer is valid and can be drawn.
 
- Properties inherited from QgsMapLayer
int autoRefreshInterval
 
QgsCoordinateReferenceSystem crs
 
bool isValid
 
bool mapTipsEnabled
 
QString mapTipTemplate
 
QgsLayerMetadata metadata
 
QString name
 
double opacity
 
Qgis::LayerType type
 

Detailed Description

A map layer which consists of a set of child layers, where all component layers are rendered as a single flattened object during map renders.

Child layers are never owned by QgsGroupLayer. References to layers in a group are stored as weak references only, which wills be automatically cleaned up whenever the linked child layer is deleted.

Since
QGIS 3.24

Definition at line 41 of file qgsgrouplayer.h.

Constructor & Destructor Documentation

◆ QgsGroupLayer()

QgsGroupLayer::QgsGroupLayer ( const QString &  name,
const QgsGroupLayer::LayerOptions options 
)

Constructor for a new QgsGroupLayer with the specified layer name.

The options argument specifies load-time layer options.

Definition at line 30 of file qgsgrouplayer.cpp.

◆ ~QgsGroupLayer()

QgsGroupLayer::~QgsGroupLayer ( )
override

Definition at line 45 of file qgsgrouplayer.cpp.

Member Function Documentation

◆ childLayers()

QList< QgsMapLayer * > QgsGroupLayer::childLayers ( ) const

Returns the child layers contained by the group.

See also
setChildLayers()

Definition at line 330 of file qgsgrouplayer.cpp.

◆ clone()

QgsGroupLayer * QgsGroupLayer::clone ( ) const
overridevirtual

Returns a new instance equivalent to this one except for the id which is still unique.

Returns
a new layer instance
Since
QGIS 3.0

Implements QgsMapLayer.

Definition at line 51 of file qgsgrouplayer.cpp.

◆ createMapRenderer()

QgsMapLayerRenderer * QgsGroupLayer::createMapRenderer ( QgsRenderContext rendererContext)
overridevirtual

Returns new instance of QgsMapLayerRenderer that will be used for rendering of given context.

Since
QGIS 2.4

Implements QgsMapLayer.

Definition at line 63 of file qgsgrouplayer.cpp.

◆ dataProvider() [1/2]

const QgsDataProvider * QgsGroupLayer::dataProvider ( ) const
overridevirtual

Returns the layer's data provider in a const-correct manner, it may be nullptr.

Note
not available in Python bindings

Reimplemented from QgsMapLayer.

Definition at line 231 of file qgsgrouplayer.cpp.

◆ dataProvider() [2/2]

QgsDataProvider * QgsGroupLayer::dataProvider ( )
overridevirtual

Returns the layer's data provider, it may be nullptr.

Reimplemented from QgsMapLayer.

Definition at line 224 of file qgsgrouplayer.cpp.

◆ extent()

QgsRectangle QgsGroupLayer::extent ( ) const
overridevirtual

Returns the extent of the layer.

Reimplemented from QgsMapLayer.

Definition at line 70 of file qgsgrouplayer.cpp.

◆ htmlMetadata()

QString QgsGroupLayer::htmlMetadata ( ) const
overridevirtual

Obtain a formatted HTML string containing assorted metadata for this layer.

Since
QGIS 3.0

Reimplemented from QgsMapLayer.

Definition at line 238 of file qgsgrouplayer.cpp.

◆ paintEffect()

QgsPaintEffect * QgsGroupLayer::paintEffect ( ) const

Returns the current paint effect for the group layer.

See also
setPaintEffect()

Definition at line 337 of file qgsgrouplayer.cpp.

◆ prepareLayersForRemovalFromGroup()

void QgsGroupLayer::prepareLayersForRemovalFromGroup ( )

Prepares all child layers in the group prior to removal from the group.

This method should be called before removing a group layer from a project, to ensure that the existing child layers are in a state which is compatible with non-group layer children.

Since
QGIS 3.30

Definition at line 351 of file qgsgrouplayer.cpp.

◆ readSymbology()

bool QgsGroupLayer::readSymbology ( const QDomNode &  node,
QString &  errorMessage,
QgsReadWriteContext context,
StyleCategories  categories = AllStyleCategories 
)
overridevirtual

Read the symbology for the current layer from the DOM node supplied.

Parameters
nodenode that will contain the symbology definition for this layer.
errorMessagereference to string that will be updated with any error messages
contextreading context (used for transform from relative to absolute paths)
categoriesthe style categories to be read
Returns
true in case of success.

Implements QgsMapLayer.

Definition at line 183 of file qgsgrouplayer.cpp.

◆ readXml()

bool QgsGroupLayer::readXml ( const QDomNode &  layer_node,
QgsReadWriteContext context 
)
overridevirtual

Called by readLayerXML(), used by children to read state specific to them from project files.

Reimplemented from QgsMapLayer.

Definition at line 88 of file qgsgrouplayer.cpp.

◆ resolveReferences()

void QgsGroupLayer::resolveReferences ( QgsProject project)
overridevirtual

Resolve references to other layers (kept as layer IDs after reading XML) into layer objects.

Since
QGIS 3.0

Reimplemented from QgsMapLayer.

Definition at line 254 of file qgsgrouplayer.cpp.

◆ setChildLayers()

void QgsGroupLayer::setChildLayers ( const QList< QgsMapLayer * > &  layers)

Sets the child layers contained by the group.

This method does not take ownership of the layers, but rather assigns them to the group. Layers should be already added to the parent QgsProject wherever appropriate.

See also
childLayers()

Definition at line 278 of file qgsgrouplayer.cpp.

◆ setPaintEffect()

void QgsGroupLayer::setPaintEffect ( QgsPaintEffect effect)

Sets the current paint effect for the renderer.

Ownership is transferred to the renderer.

See also
paintEffect()

Definition at line 344 of file qgsgrouplayer.cpp.

◆ setTransformContext()

void QgsGroupLayer::setTransformContext ( const QgsCoordinateTransformContext transformContext)
overridevirtual

Sets the coordinate transform context to transformContext.

Since
QGIS 3.8

Implements QgsMapLayer.

Definition at line 77 of file qgsgrouplayer.cpp.

◆ writeSymbology()

bool QgsGroupLayer::writeSymbology ( QDomNode &  node,
QDomDocument &  doc,
QString &  errorMessage,
const QgsReadWriteContext context,
StyleCategories  categories = AllStyleCategories 
) const
overridevirtual

Write the style for the layer into the document provided.

Parameters
nodethe node that will have the style element added to it.
docthe document that will have the QDomNode added.
errorMessagereference to string that will be updated with any error messages
contextwriting context (used for transform from absolute to relative paths)
categoriesthe style categories to be written
Note
There is a confusion of terms with the GUI. This method actually writes what is called a style in the application.
Returns
true in case of success.

Implements QgsMapLayer.

Definition at line 151 of file qgsgrouplayer.cpp.

◆ writeXml()

bool QgsGroupLayer::writeXml ( QDomNode &  layer_node,
QDomDocument &  document,
const QgsReadWriteContext context 
) const
overridevirtual

Called by writeLayerXML(), used by children to write state specific to them to project files.

Reimplemented from QgsMapLayer.

Definition at line 122 of file qgsgrouplayer.cpp.


The documentation for this class was generated from the following files: