Reads and writes project states. More...

#include <qgsproject.h>

Inheritance diagram for QgsProject:

Public Slots
void	setDirty (bool b=true)
	Flag the project as dirty (modified). More...

void	setSnappingConfig (const QgsSnappingConfig &snappingConfig)
	The snapping configuration for this project. More...

Signals
void	avoidIntersectionsLayersChanged ()
	Emitted whenever avoidIntersectionsLayers has changed. More...

void	crsChanged ()
	Emitted when the CRS of the project has changed. More...

void	customVariablesChanged ()
	Emitted whenever the expression variables stored in the project have been changed. More...

void	ellipsoidChanged (const QString &ellipsoid)
	Emitted when the project ellipsoid is changed. More...

void	fileNameChanged ()
	Emitted when the file name of the project changes. More...

void	homePathChanged ()
	Emitted when the home path of the project changes. More...

void	labelingEngineSettingsChanged ()
	Emitted when global configuration of the labeling engine changes. More...

void	layerLoaded (int i, int n)
	Emitted when a layer from a projects was read. More...

void	layerRemoved (const QString &layerId)
	Emitted after a layer was removed from the registry. More...

void	layersAdded (const QList< QgsMapLayer *> &layers)
	Emitted when one or more layers were added to the registry. More...

void	layersRemoved (const QStringList &layerIds)
	Emitted after one or more layers were removed from the registry. More...

void	layersWillBeRemoved (const QStringList &layerIds)
	Emitted when one or more layers are about to be removed from the registry. More...

void	layersWillBeRemoved (const QList< QgsMapLayer *> &layers)
	Emitted when one or more layers are about to be removed from the registry. More...

void	layerWasAdded (QgsMapLayer *layer)
	Emitted when a layer was added to the registry. More...

void	layerWillBeRemoved (const QString &layerId)
	Emitted when a layer is about to be removed from the registry. More...

void	layerWillBeRemoved (QgsMapLayer *layer)
	Emitted when a layer is about to be removed from the registry. More...

void	legendLayersAdded (const QList< QgsMapLayer *> &layers)
	Emitted, when a layer was added to the registry and the legend. More...

void	loadingLayer (const QString &)

void	mapThemeCollectionChanged ()
	Emitted when the map theme collection changes. More...

void	missingDatumTransforms (const QStringList &missingTransforms)
	Emitted when datum transforms stored in the project are not available locally. More...

void	nonIdentifiableLayersChanged (QStringList nonIdentifiableLayers)
	Emitted when the list of layer which are excluded from map identification changes. More...

void	oldProjectVersionWarning (const QString &)
	emitted when an old project file is read. More...

void	projectSaved ()
	emitted when the project file has been written and closed More...

void	readMapLayer (QgsMapLayer *mapLayer, const QDomElement &layerNode)
	Emitted, after the basic initialization of a layer from the project file is done. More...

void	readProject (const QDomDocument &)
	emitted when project is being read More...

void	removeAll ()
	Emitted when all layers are removed, before layersWillBeRemoved() and layerWillBeRemoved() signals are emitted. More...

void	snappingConfigChanged (const QgsSnappingConfig &config)
	emitted whenever the configuration for snapping has changed More...

void	topologicalEditingChanged ()
	Emitted when the topological editing flag has changed. More...

void	transactionGroupsChanged ()
	Emitted whenever a new transaction group has been created or a transaction group has been removed. More...

void	transformContextChanged ()
	Emitted when the project transformContext() is changed. More...

void	writeMapLayer (QgsMapLayer *mapLayer, QDomElement &layerElem, QDomDocument &doc)
	Emitted, when a layer is being saved. More...

void	writeProject (QDomDocument &)
	emitted when project is being written More...

Public Member Functions
	QgsProject (QObject *parent=nullptr)
	Create a new QgsProject. More...

	~QgsProject () override

QgsMapLayer *	addMapLayer (QgsMapLayer *mapLayer, bool addToLegend=true, bool takeOwnership=true)
	Add a layer to the map of loaded layers. More...

QList< QgsMapLayer * >	addMapLayers (const QList< QgsMapLayer *> &mapLayers, bool addToLegend=true, bool takeOwnership=true)
	Add a list of layers to the map of loaded layers. More...

QgsAnnotationManager *	annotationManager ()
	Returns pointer to the project's annotation manager. More...

const QgsAnnotationManager *	annotationManager () const
	Returns a const pointer to the project's annotation manager. More...

QgsUnitTypes::AreaUnit	areaUnits () const
	Convenience function to query default area measurement units for project. More...

bool	autoTransaction () const
	Transactional editing means that on supported datasources (postgres databases) the edit state of all tables that originate from the same database are synchronized and executed in a server side transaction. More...

const QgsAuxiliaryStorage *	auxiliaryStorage () const
	Returns the current const auxiliary storage. More...

QgsAuxiliaryStorage *	auxiliaryStorage ()
	Returns the current auxiliary storage. More...

QList< QgsVectorLayer * >	avoidIntersectionsLayers () const
	A list of layers with which intersections should be avoided. More...

void	clear ()
	Clear the project - removes all settings and resets it back to an empty, default state. More...

int	count () const
	Returns the number of registered layers. More...

QgsLayerTreeGroup *	createEmbeddedGroup (const QString &groupName, const QString &projectFilePath, const QStringList &invisibleLayers)
	Create layer group instance defined in an arbitrary project file. More...

bool	createEmbeddedLayer (const QString &layerId, const QString &projectFilePath, QList< QDomNode > &brokenNodes, bool saveFlag=true)
	Creates a maplayer instance defined in an arbitrary project file. More...

QgsExpressionContext	createExpressionContext () const override
	This method needs to be reimplemented in all classes which implement this interface and return an expression context. More...

QgsCoordinateReferenceSystem	crs () const
	Returns the project's native coordinate reference system. More...

QVariantMap	customVariables () const
	A map of custom project variables. More...

QgsCoordinateReferenceSystem	defaultCrsForNewLayers () const
	Returns the default CRS for new layers based on the settings and the current project CRS. More...

QgsUnitTypes::DistanceUnit	distanceUnits () const
	Convenience function to query default distance measurement units for project. More...

void	dumpProperties () const
	Dump out current project properties to stderr. More...

QString	ellipsoid () const
	Returns a proj string representing the project's ellipsoid setting, e.g., "WGS84". More...

QStringList	entryList (const QString &scope, const QString &key) const
	Return keys with values – do not return keys that contain other keys. More...

QString	error () const
	Return error message from previous read/write. More...

bool	evaluateDefaultValues () const
	Should default values be evaluated on provider side when requested and not when committed. More...

QFileInfo	fileInfo () const
	Returns QFileInfo object for the project's associated file. More...

QString	fileName () const
	Returns the project's file name. More...

QString	homePath () const
	Return project's home path. More...

bool	isDirty () const
	Returns true if the project has been modified since the last write() More...

bool	isZipped () const
	Returns true if the project comes from a zip archive, false otherwise. More...

const QgsLabelingEngineSettings &	labelingEngineSettings () const
	Returns project's global labeling engine settings. More...

QString	layerIsEmbedded (const QString &id) const
	Returns project file path if layer is embedded from other project file. Returns empty string if layer is not embedded. More...

template<typename T >
QVector< T >	layers () const
	Returns a list of registered map layers with a specified layer type. More...

QgsMapLayerStore *	layerStore ()
	Returns a pointer to the project's internal layer store. More...

const QgsMapLayerStore *	layerStore () const
	Returns a pointer to the project's internal layer store. More...

QgsLayerTreeRegistryBridge *	layerTreeRegistryBridge () const
	Return pointer to the helper class that synchronizes map layer registry with layer tree. More...

QgsLayerTree *	layerTreeRoot () const
	Return pointer to the root (invisible) node of the project's layer tree. More...

const QgsLayoutManager *	layoutManager () const
	Returns the project's layout manager, which manages compositions within the project. More...

QgsLayoutManager *	layoutManager ()
	Returns the project's layout manager, which manages compositions within the project. More...

QgsMapLayer *	mapLayer (const QString &layerId) const
	Retrieve a pointer to a registered layer by layer ID. More...

QMap< QString, QgsMapLayer * >	mapLayers () const
	Returns a map of all registered layers by layer ID. More...

QList< QgsMapLayer * >	mapLayersByName (const QString &layerName) const
	Retrieve a list of matching registered layers by layer name. More...

QgsMapThemeCollection *	mapThemeCollection ()
	Returns pointer to the project's map theme collection. More...

QStringList	nonIdentifiableLayers () const
	Get the list of layers which currently should not be taken into account on map identification. More...

QgsPathResolver	pathResolver () const
	Return path resolver object with considering whether the project uses absolute or relative paths and using current project's path. More...

bool	read (const QString &filename)
	Reads given project file from the given file. More...

bool	read ()
	Reads the project from its currently associated file (see fileName() ). More...

bool	readBoolEntry (const QString &scope, const QString &key, bool def=false, bool *ok=nullptr) const

double	readDoubleEntry (const QString &scope, const QString &key, double def=0, bool *ok=nullptr) const

QString	readEntry (const QString &scope, const QString &key, const QString &def=QString(), bool *ok=nullptr) const

bool	readLayer (const QDomNode &layerNode)
	Reads the layer described in the associated DOM node. More...

QStringList	readListEntry (const QString &scope, const QString &key, const QStringList &def=QStringList(), bool *ok=nullptr) const
	Key value accessors. More...

int	readNumEntry (const QString &scope, const QString &key, int def=0, bool *ok=nullptr) const

QString	readPath (const QString &filename) const
	Turn filename read from the project file to an absolute path. More...

QgsRelationManager *	relationManager () const

void	reloadAllLayers ()
	Reload all registered layer's provider data caches, synchronising the layer with any changes in the datasource. More...

void	removeAllMapLayers ()
	Removes all registered layers. More...

bool	removeEntry (const QString &scope, const QString &key)
	Remove the given key. More...

void	removeMapLayer (const QString &layerId)
	Remove a layer from the registry by layer ID. More...

void	removeMapLayer (QgsMapLayer *layer)
	Remove a layer from the registry. More...

void	removeMapLayers (const QStringList &layerIds)
	Remove a set of layers from the registry by layer ID. More...

void	removeMapLayers (const QList< QgsMapLayer *> &layers)
	Remove a set of layers from the registry. More...

void	setAreaUnits (QgsUnitTypes::AreaUnit unit)
	Sets the default area measurement units for the project. More...

void	setAutoTransaction (bool autoTransaction)
	Transactional editing means that on supported datasources (postgres databases) the edit state of all tables that originate from the same database are synchronized and executed in a server side transaction. More...

void	setAvoidIntersectionsLayers (const QList< QgsVectorLayer *> &layers)
	A list of layers with which intersections should be avoided. More...

void	setBadLayerHandler (QgsProjectBadLayerHandler *handler)
	Change handler for missing layers. More...

void	setCrs (const QgsCoordinateReferenceSystem &crs)
	Sets the project's native coordinate reference system. More...

void	setCustomVariables (const QVariantMap &customVariables)
	A map of custom project variables. More...

void	setDistanceUnits (QgsUnitTypes::DistanceUnit unit)
	Sets the default distance measurement units for the project. More...

void	setEllipsoid (const QString &ellipsoid)
	Sets the project's ellipsoid from a proj string representation, e.g., "WGS84". More...

void	setEvaluateDefaultValues (bool evaluateDefaultValues)
	Defines if default values should be evaluated on provider side when requested and not when committed. More...

void	setFileName (const QString &name)
	Sets the file name associated with the project. More...

void	setLabelingEngineSettings (const QgsLabelingEngineSettings &settings)
	Sets project's global labeling engine settings. More...

void	setNonIdentifiableLayers (const QList< QgsMapLayer *> &layers)
	Set a list of layers which should not be taken into account on map identification. More...

void	setNonIdentifiableLayers (const QStringList &layerIds)
	Set a list of layers which should not be taken into account on map identification. More...

void	setTitle (const QString &title)
	Sets the project's title. More...

void	setTopologicalEditing (bool enabled)
	Convenience function to set topological editing. More...

void	setTransformContext (const QgsCoordinateTransformContext &context)
	Sets the project's coordinate transform context, which stores various information regarding which datum transforms should be used when transforming points from a source to destination coordinate reference system. More...

void	setTrustLayerMetadata (bool trust)
	Sets the trust option allowing to indicate if the extent has to be read from the XML document when data source has no metadata or if the data provider has to determine it. More...

QgsSnappingConfig	snappingConfig () const
	The snapping configuration for this project. More...

QStringList	subkeyList (const QString &scope, const QString &key) const
	Return keys with keys – do not return keys that contain only values. More...

QgsMapLayer *	takeMapLayer (QgsMapLayer *layer)
	Takes a layer from the registry. More...

QString	title () const
	Returns the project's title. More...

bool	topologicalEditing () const
	Convenience function to query topological editing status. More...

QMap< QPair< QString, QString >, QgsTransactionGroup * >	transactionGroups ()
	Map of transaction groups. More...

QgsCoordinateTransformContext	transformContext () const
	Returns a copy of the project's coordinate transform context, which stores various information regarding which datum transforms should be used when transforming points from a source to destination coordinate reference system. More...

bool	trustLayerMetadata () const
	Returns true if the trust option is activated, false otherwise. More...

bool	write (const QString &filename)
	Writes the project to a file. More...

bool	write ()
	Writes the project to its current associated file (see fileName() ). More...

bool	writeEntry (const QString &scope, const QString &key, bool value)
	Write a boolean entry to the project file. More...

bool	writeEntry (const QString &scope, const QString &key, double value)
	Write a double entry to the project file. More...

bool	writeEntry (const QString &scope, const QString &key, int value)
	Write an integer entry to the project file. More...

bool	writeEntry (const QString &scope, const QString &key, const QString &value)
	Write a string entry to the project file. More...

bool	writeEntry (const QString &scope, const QString &key, const QStringList &value)
	Write a string list entry to the project file. More...

QString	writePath (const QString &filename) const
	Prepare a filename to save it to the project file. More...

Public Member Functions inherited from QgsExpressionContextGenerator
virtual	~QgsExpressionContextGenerator ()=default

Static Public Member Functions
static QgsProject *	instance ()
	Returns the QgsProject singleton instance. More...

Properties
QList< QgsVectorLayer * >	avoidIntersectionsLayers

QgsCoordinateReferenceSystem	crs

QString	ellipsoid

QString	fileName

QString	homePath

QgsMapThemeCollection	mapThemeCollection

QStringList	nonIdentifiableLayers

QgsRelationManager	relationManager

QgsSnappingConfig	snappingConfig

Detailed Description

Reads and writes project states.

Note

Has two general kinds of state to make persistent. (I.e., to read and write.) First, QGIS proprietary information. Second plug-in information.

A singleton since there shall only be one active project at a time; and provides canonical location for plug-ins and main app to find/set properties.

Definition at line 82 of file qgsproject.h.

Constructor & Destructor Documentation

◆ QgsProject()

QgsProject::QgsProject ( QObject * parent = nullptr )

explicit

Create a new QgsProject.

Most of the time you want to use QgsProject::instance() instead as many components of QGIS work with the singleton.

Definition at line 328 of file qgsproject.cpp.

◆ ~QgsProject()

QgsProject::~QgsProject ( )

override

Definition at line 369 of file qgsproject.cpp.

Member Function Documentation

◆ addMapLayer()

QgsMapLayer * QgsProject::addMapLayer	(	QgsMapLayer *	mapLayer,
		bool	addToLegend = `true`,
		bool	takeOwnership = `true`
	)

Add a layer to the map of loaded layers.

The layersAdded() and layerWasAdded() signals will always be emitted. The legendLayersAdded() signal is emitted only if addToLegend is true. If you are adding multiple layers at once, you should use addMapLayers() instead.

Parameters

mapLayer	A layer to add to the registry
addToLegend	If true (by default), the layer will be added to the legend and to the main canvas. If you have a private layer you can set this parameter to false to hide it.
takeOwnership	Ownership will be transferred to the layer registry. If you specify false here you have take care of deleting the layer yourself. Not available in Python.

Returns: nullptr if unable to add layer, otherwise pointer to newly added layer

See also: addMapLayers

Note: As a side-effect QgsProject is made dirty.; Use addMapLayers if adding more than one layer at a time; takeOwnership is not available in the Python bindings - the registry will always take ownership

See also: addMapLayers()

Definition at line 2325 of file qgsproject.cpp.

◆ addMapLayers()

QList< QgsMapLayer * > QgsProject::addMapLayers	(	const QList< QgsMapLayer *> &	mapLayers,
		bool	addToLegend = `true`,
		bool	takeOwnership = `true`
	)

Add a list of layers to the map of loaded layers.

The layersAdded() and layerWasAdded() signals will always be emitted. The legendLayersAdded() signal is emitted only if addToLegend is true.

Parameters

mapLayers	A list of layer which should be added to the registry
addToLegend	If true (by default), the layers will be added to the legend and to the main canvas. If you have a private layer you can set this parameter to false to hide it.
takeOwnership	Ownership will be transferred to the layer registry. If you specify false here you have take care of deleting the layers yourself. Not available in Python.

Returns: a list of the map layers that were added successfully. If a layer is invalid, or already exists in the registry, it will not be part of the returned QList.

Note: As a side-effect QgsProject is made dirty.; takeOwnership is not available in the Python bindings - the registry will always take ownership

Since: QGIS 1.8

See also: addMapLayer()

Definition at line 2294 of file qgsproject.cpp.

◆ annotationManager() [1/2]

QgsAnnotationManager * QgsProject::annotationManager ( )

Returns pointer to the project's annotation manager.

Since: QGIS 3.0

Definition at line 2107 of file qgsproject.cpp.

◆ annotationManager() [2/2]

const QgsAnnotationManager * QgsProject::annotationManager ( ) const

Returns a const pointer to the project's annotation manager.

Since: QGIS 3.0

Definition at line 2112 of file qgsproject.cpp.

◆ areaUnits()

QgsUnitTypes::AreaUnit QgsProject::areaUnits ( ) const

Convenience function to query default area measurement units for project.

Since: QGIS 2.14

See also: distanceUnits()

Definition at line 2055 of file qgsproject.cpp.

◆ autoTransaction()

bool QgsProject::autoTransaction ( ) const

Transactional editing means that on supported datasources (postgres databases) the edit state of all tables that originate from the same database are synchronized and executed in a server side transaction.

Since: QGIS 2.16

Definition at line 2152 of file qgsproject.cpp.

◆ auxiliaryStorage() [1/2]

const QgsAuxiliaryStorage * QgsProject::auxiliaryStorage ( ) const

Returns the current const auxiliary storage.

Since: QGIS 3.0

Definition at line 2441 of file qgsproject.cpp.

◆ auxiliaryStorage() [2/2]

QgsAuxiliaryStorage * QgsProject::auxiliaryStorage ( )

Returns the current auxiliary storage.

Since: QGIS 3.0

Definition at line 2446 of file qgsproject.cpp.

◆ avoidIntersectionsLayers()

QList<QgsVectorLayer *> QgsProject::avoidIntersectionsLayers ( ) const

A list of layers with which intersections should be avoided.

Since: QGIS 3.0

◆ avoidIntersectionsLayersChanged

void QgsProject::avoidIntersectionsLayersChanged ( )

signal

Emitted whenever avoidIntersectionsLayers has changed.

Since: QGIS 3.0

◆ clear()

void QgsProject::clear ( )

Clear the project - removes all settings and resets it back to an empty, default state.

Since: QGIS 2.4

Definition at line 485 of file qgsproject.cpp.

◆ count()

int QgsProject::count ( ) const

Returns the number of registered layers.

Definition at line 2181 of file qgsproject.cpp.

◆ createEmbeddedGroup()

QgsLayerTreeGroup * QgsProject::createEmbeddedGroup	(	const QString &	groupName,
		const QString &	projectFilePath,
		const QStringList &	invisibleLayers
	)

Create layer group instance defined in an arbitrary project file.

Since: QGIS 2.4

Definition at line 1900 of file qgsproject.cpp.

◆ createEmbeddedLayer()

bool QgsProject::createEmbeddedLayer	(	const QString &	layerId,
		const QString &	projectFilePath,
		QList< QDomNode > &	brokenNodes,
		bool	saveFlag = `true`
	)

Creates a maplayer instance defined in an arbitrary project file.

Caller takes ownership

Returns: the layer or 0 in case of error

Note: not available in Python bindings

Definition at line 1815 of file qgsproject.cpp.

◆ createExpressionContext()

QgsExpressionContext QgsProject::createExpressionContext ( ) const

overridevirtual

This method needs to be reimplemented in all classes which implement this interface and return an expression context.

Since: QGIS 3.0

Implements QgsExpressionContextGenerator.

Definition at line 1197 of file qgsproject.cpp.

◆ crs()

QgsCoordinateReferenceSystem QgsProject::crs ( ) const

Returns the project's native coordinate reference system.

Since: QGIS 3.0

See also: setCrs(); ellipsoid()

◆ crsChanged

void QgsProject::crsChanged ( )

signal

Emitted when the CRS of the project has changed.

Since: QGIS 3.0

◆ customVariables()

QVariantMap QgsProject::customVariables ( ) const

A map of custom project variables.

To get all available variables including generated ones use QgsExpressionContextUtils::projectScope() instead.

Definition at line 1126 of file qgsproject.cpp.

◆ customVariablesChanged

void QgsProject::customVariablesChanged ( )

signal

Emitted whenever the expression variables stored in the project have been changed.

Since: QGIS 3.0

◆ defaultCrsForNewLayers()

QgsCoordinateReferenceSystem QgsProject::defaultCrsForNewLayers ( ) const

Returns the default CRS for new layers based on the settings and the current project CRS.

Definition at line 2380 of file qgsproject.cpp.

◆ distanceUnits()

QgsUnitTypes::DistanceUnit QgsProject::distanceUnits ( ) const

Convenience function to query default distance measurement units for project.

Since: QGIS 2.14

See also: setDistanceUnits(); areaUnits()

Definition at line 2037 of file qgsproject.cpp.

◆ dumpProperties()

void QgsProject::dumpProperties ( ) const

Dump out current project properties to stderr.

Definition at line 1763 of file qgsproject.cpp.

◆ ellipsoid()

QString QgsProject::ellipsoid ( ) const

Returns a proj string representing the project's ellipsoid setting, e.g., "WGS84".

See also: setEllipsoid(); crs()

Since: QGIS 3.0

◆ ellipsoidChanged

void QgsProject::ellipsoidChanged ( const QString & ellipsoid )

signal

Emitted when the project ellipsoid is changed.

Since: QGIS 3.0

See also: setEllipsoid(); ellipsoid()

◆ entryList()

QStringList QgsProject::entryList	(	const QString &	scope,
		const QString &	key
	)		const

Return keys with values – do not return keys that contain other keys.

Note: equivalent to QgsSettings entryList()

Definition at line 1729 of file qgsproject.cpp.

◆ error()

QString QgsProject::error ( ) const

Return error message from previous read/write.

Definition at line 1789 of file qgsproject.cpp.

◆ evaluateDefaultValues()

bool QgsProject::evaluateDefaultValues ( ) const

Should default values be evaluated on provider side when requested and not when committed.

Since: QGIS 2.16

Definition at line 2005 of file qgsproject.cpp.

◆ fileInfo()

QFileInfo QgsProject::fileInfo ( ) const

Returns QFileInfo object for the project's associated file.

See also: fileName()

Since: QGIS 2.9

Definition at line 441 of file qgsproject.cpp.

◆ fileName()

QString QgsProject::fileName ( ) const

Returns the project's file name.

This is the file which contains the project's XML representation.

See also: setFileName(); fileInfo()

◆ fileNameChanged

void QgsProject::fileNameChanged ( )

signal

Emitted when the file name of the project changes.

◆ homePath()

QString QgsProject::homePath ( ) const

Return project's home path.

Returns: home path of project (or null QString if not set)

◆ homePathChanged

void QgsProject::homePathChanged ( )

signal

Emitted when the home path of the project changes.

◆ instance()

QgsProject * QgsProject::instance ( )

static

Returns the QgsProject singleton instance.

Definition at line 383 of file qgsproject.cpp.

◆ isDirty()

bool QgsProject::isDirty ( ) const

Returns true if the project has been modified since the last write()

Definition at line 409 of file qgsproject.cpp.

◆ isZipped()

bool QgsProject::isZipped ( ) const

Returns true if the project comes from a zip archive, false otherwise.

Definition at line 2289 of file qgsproject.cpp.

◆ labelingEngineSettings()

const QgsLabelingEngineSettings & QgsProject::labelingEngineSettings ( ) const

Returns project's global labeling engine settings.

Since: QGIS 3.0

Definition at line 1161 of file qgsproject.cpp.

◆ labelingEngineSettingsChanged

void QgsProject::labelingEngineSettingsChanged ( )

signal

Emitted when global configuration of the labeling engine changes.

Since: QGIS 3.0

◆ layerIsEmbedded()

QString QgsProject::layerIsEmbedded ( const QString & id ) const

Returns project file path if layer is embedded from other project file. Returns empty string if layer is not embedded.

Definition at line 1805 of file qgsproject.cpp.

◆ layerLoaded

void QgsProject::layerLoaded	(	int	i,
		int	n
	)

signal

Emitted when a layer from a projects was read.

Parameters

i	current layer
n	number of layers

◆ layerRemoved

void QgsProject::layerRemoved ( const QString & layerId )

signal

Emitted after a layer was removed from the registry.

Parameters

layerId The ID of the layer removed.

Note: Consider using layersRemoved() instead

See also: layerWillBeRemoved()

◆ layers()

template<typename T >

QVector<T> QgsProject::layers ( ) const

inline

Returns a list of registered map layers with a specified layer type.

Example:

QVector<QgsVectorLayer*> vectorLayers = QgsProject::instance()->layers<QgsVectorLayer*>();

Note: not available in Python bindings

Since: QGIS 2.16

See also: mapLayers()

Definition at line 649 of file qgsproject.h.

◆ layersAdded

void QgsProject::layersAdded ( const QList< QgsMapLayer *> & layers )

signal

Emitted when one or more layers were added to the registry.

This signal is also emitted for layers added to the registry, but not to the legend.

Parameters

layers List of layers which have been added.

See also: legendLayersAdded(); layerWasAdded()

◆ layersRemoved

void QgsProject::layersRemoved ( const QStringList & layerIds )

signal

Emitted after one or more layers were removed from the registry.

Parameters

layerIds A list of IDs of the layers which were removed.

See also: layersWillBeRemoved()

◆ layerStore() [1/2]

QgsMapLayerStore * QgsProject::layerStore ( )

Returns a pointer to the project's internal layer store.

/since QGIS 3.0

Definition at line 1166 of file qgsproject.cpp.

◆ layerStore() [2/2]

const QgsMapLayerStore * QgsProject::layerStore ( ) const

Returns a pointer to the project's internal layer store.

/since QGIS 3.0

Definition at line 1171 of file qgsproject.cpp.

◆ layersWillBeRemoved [1/2]

void QgsProject::layersWillBeRemoved ( const QStringList & layerIds )

signal

Emitted when one or more layers are about to be removed from the registry.

Parameters

layerIds A list of IDs for the layers which are to be removed.

See also: layerWillBeRemoved(); layersRemoved()

◆ layersWillBeRemoved [2/2]

void QgsProject::layersWillBeRemoved ( const QList< QgsMapLayer *> & layers )

signal

Emitted when one or more layers are about to be removed from the registry.

Parameters

layers A list of layers which are to be removed.

See also: layerWillBeRemoved(); layersRemoved()

◆ layerTreeRegistryBridge()

QgsLayerTreeRegistryBridge* QgsProject::layerTreeRegistryBridge ( ) const

inline

Return pointer to the helper class that synchronizes map layer registry with layer tree.

Since: QGIS 2.4

Definition at line 456 of file qgsproject.h.

◆ layerTreeRoot()

QgsLayerTree * QgsProject::layerTreeRoot ( ) const

Return pointer to the root (invisible) node of the project's layer tree.

Since: QGIS 2.4

Definition at line 2097 of file qgsproject.cpp.

◆ layerWasAdded

void QgsProject::layerWasAdded ( QgsMapLayer * layer )

signal

Emitted when a layer was added to the registry.

Note: Consider using layersAdded() instead

See also: layersAdded()

◆ layerWillBeRemoved [1/2]

void QgsProject::layerWillBeRemoved ( const QString & layerId )

signal

Emitted when a layer is about to be removed from the registry.

Parameters

layerId The ID of the layer to be removed.

Note: Consider using layersWillBeRemoved() instead

See also: layersWillBeRemoved(); layerRemoved()

◆ layerWillBeRemoved [2/2]

void QgsProject::layerWillBeRemoved ( QgsMapLayer * layer )

signal

Emitted when a layer is about to be removed from the registry.

Parameters

layer The layer to be removed.

Note: Consider using layersWillBeRemoved() instead

See also: layersWillBeRemoved(); layerRemoved()

◆ layoutManager() [1/2]

const QgsLayoutManager * QgsProject::layoutManager ( ) const

Returns the project's layout manager, which manages compositions within the project.

Since: QGIS 3.0

Note: not available in Python bindings

Definition at line 2087 of file qgsproject.cpp.

◆ layoutManager() [2/2]

QgsLayoutManager * QgsProject::layoutManager ( )

Returns the project's layout manager, which manages compositions within the project.

Since: QGIS 3.0

Definition at line 2092 of file qgsproject.cpp.

◆ legendLayersAdded

void QgsProject::legendLayersAdded ( const QList< QgsMapLayer *> & layers )

signal

Emitted, when a layer was added to the registry and the legend.

Layers can also be private layers, which are signalled by layersAdded() and layerWasAdded() but will not be advertised by this signal.

Parameters

layers List of QgsMapLayer which were added to the legend.

◆ loadingLayer

void QgsProject::loadingLayer ( const QString & )

signal

◆ mapLayer()

QgsMapLayer * QgsProject::mapLayer ( const QString & layerId ) const

Retrieve a pointer to a registered layer by layer ID.

Parameters

layerId ID of layer to retrieve

Returns: matching layer, or nullptr if no matching layer found

See also: mapLayersByName(); mapLayers()

Definition at line 2186 of file qgsproject.cpp.

◆ mapLayers()

QMap< QString, QgsMapLayer * > QgsProject::mapLayers ( ) const

Returns a map of all registered layers by layer ID.

See also: mapLayer(); mapLayersByName(); layers()

Definition at line 2374 of file qgsproject.cpp.

◆ mapLayersByName()

QList< QgsMapLayer * > QgsProject::mapLayersByName ( const QString & layerName ) const

Retrieve a list of matching registered layers by layer name.

Parameters

layerName name of layers to match

Returns: list of matching layers

See also: mapLayer(); mapLayers()

Definition at line 2191 of file qgsproject.cpp.

◆ mapThemeCollection()

QgsMapThemeCollection* QgsProject::mapThemeCollection ( )

Returns pointer to the project's map theme collection.

Since: QGIS 2.12

Note: renamed in QGIS 3.0, formerly QgsVisibilityPresetCollection

◆ mapThemeCollectionChanged

void QgsProject::mapThemeCollectionChanged ( )

signal

Emitted when the map theme collection changes.

This only happens when the map theme collection is reset. Any pointer previously received from mapThemeCollection() must no longer be used after this signal is emitted. You must still connect to signals from the map theme collection if you want to be notified about new map themes being added and map themes being removed.

Since: QGIS 3.0

◆ missingDatumTransforms

void QgsProject::missingDatumTransforms ( const QStringList & missingTransforms )

signal

Emitted when datum transforms stored in the project are not available locally.

Since: QGIS 3.0

◆ nonIdentifiableLayers()

QStringList QgsProject::nonIdentifiableLayers ( ) const

Get the list of layers which currently should not be taken into account on map identification.

◆ nonIdentifiableLayersChanged

void QgsProject::nonIdentifiableLayersChanged ( QStringList nonIdentifiableLayers )

signal

Emitted when the list of layer which are excluded from map identification changes.

◆ oldProjectVersionWarning

void QgsProject::oldProjectVersionWarning ( const QString & )

signal

emitted when an old project file is read.

◆ pathResolver()

QgsPathResolver QgsProject::pathResolver ( ) const

Return path resolver object with considering whether the project uses absolute or relative paths and using current project's path.

Since: QGIS 3.0

Definition at line 1768 of file qgsproject.cpp.

◆ projectSaved

void QgsProject::projectSaved ( )

signal

emitted when the project file has been written and closed

◆ read() [1/2]

bool QgsProject::read ( const QString & filename )

Reads given project file from the given file.

Parameters

filename name of project file to read

Returns: true if project file has been read successfully

Definition at line 783 of file qgsproject.cpp.

◆ read() [2/2]

bool QgsProject::read ( )

Reads the project from its currently associated file (see fileName() ).

Returns: true if project file has been read successfully

Definition at line 790 of file qgsproject.cpp.

◆ readBoolEntry()

bool QgsProject::readBoolEntry	(	const QString &	scope,
		const QString &	key,
		bool	def = `false`,
		bool *	ok = `nullptr`
	)		const

Definition at line 1698 of file qgsproject.cpp.

◆ readDoubleEntry()

double QgsProject::readDoubleEntry	(	const QString &	scope,
		const QString &	key,
		double	def = `0`,
		bool *	ok = `nullptr`
	)		const

Definition at line 1678 of file qgsproject.cpp.

◆ readEntry()

QString QgsProject::readEntry	(	const QString &	scope,
		const QString &	key,
		const QString &	def = `QString()`,
		bool *	ok = `nullptr`
	)		const

Definition at line 1627 of file qgsproject.cpp.

◆ readLayer()

bool QgsProject::readLayer ( const QDomNode & layerNode )

Reads the layer described in the associated DOM node.

Note: This method is mainly for use by QgsProjectBadLayerHandler subclasses that may fix definition of bad layers with the user's help in GUI. Calling this method with corrected DOM node adds the layer back to the project.

Parameters

layerNode represents a QgsProject DOM node that encodes a specific layer.

Definition at line 1286 of file qgsproject.cpp.

◆ readListEntry()

QStringList QgsProject::readListEntry	(	const QString &	scope,
		const QString &	key,
		const QStringList &	def = `QStringList()`,
		bool *	ok = `nullptr`
	)		const

Key value accessors.

keys would be the familiar QgsSettings-like '/' delimited entries, implying a hierarchy of keys and corresponding values

Definition at line 1600 of file qgsproject.cpp.

◆ readMapLayer

void QgsProject::readMapLayer	(	QgsMapLayer *	mapLayer,
		const QDomElement &	layerNode
	)

signal

Emitted, after the basic initialization of a layer from the project file is done.

You can use this signal to read additional information from the project file.

Parameters

mapLayer	The map layer which is being initialized
layerNode	The layer node from the project file

◆ readNumEntry()

int QgsProject::readNumEntry	(	const QString &	scope,
		const QString &	key,
		int	def = `0`,
		bool *	ok = `nullptr`
	)		const

Definition at line 1651 of file qgsproject.cpp.

◆ readPath()

QString QgsProject::readPath ( const QString & filename ) const

Turn filename read from the project file to an absolute path.

Definition at line 1774 of file qgsproject.cpp.

◆ readProject

void QgsProject::readProject ( const QDomDocument & )

signal

emitted when project is being read

◆ relationManager()

QgsRelationManager* QgsProject::relationManager ( ) const

◆ reloadAllLayers()

void QgsProject::reloadAllLayers ( )

Reload all registered layer's provider data caches, synchronising the layer with any changes in the datasource.

See also: QgsMapLayer::reload()

Definition at line 2364 of file qgsproject.cpp.

◆ removeAll

void QgsProject::removeAll ( )

signal

Emitted when all layers are removed, before layersWillBeRemoved() and layerWillBeRemoved() signals are emitted.

The layersWillBeRemoved() and layerWillBeRemoved() signals will still be emitted following this signal. You can use this signal to do easy (and fast) cleanup.

◆ removeAllMapLayers()

void QgsProject::removeAllMapLayers ( )

Removes all registered layers.

If the registry has ownership of any layers these layers will also be deleted.

Note: As a side-effect the QgsProject instance is marked dirty.; Calling this method will cause the removeAll() signal to be emitted.

See also: removeMapLayer(); removeMapLayers()

Definition at line 2359 of file qgsproject.cpp.

◆ removeEntry()

bool QgsProject::removeEntry	(	const QString &	scope,
		const QString &	key
	)

Remove the given key.

Definition at line 1719 of file qgsproject.cpp.

◆ removeMapLayer() [1/2]

void QgsProject::removeMapLayer ( const QString & layerId )

Remove a layer from the registry by layer ID.

The specified layer will be removed from the registry. If the registry has ownership of the layer then it will also be deleted.

Parameters

layerId ID of the layer to remove

Note: As a side-effect the QgsProject instance is marked dirty.

See also: removeMapLayers(); removeAllMapLayers()

Definition at line 2344 of file qgsproject.cpp.

◆ removeMapLayer() [2/2]

void QgsProject::removeMapLayer ( QgsMapLayer * layer )

Remove a layer from the registry.

The specified layer will be removed from the registry. If the registry has ownership of the layer then it will also be deleted.

Parameters

layer The layer to remove. Null pointers are ignored.

Note: As a side-effect the QgsProject instance is marked dirty.

See also: removeMapLayers(); removeAllMapLayers()

Definition at line 2349 of file qgsproject.cpp.

◆ removeMapLayers() [1/2]

void QgsProject::removeMapLayers ( const QStringList & layerIds )

Remove a set of layers from the registry by layer ID.

The specified layers will be removed from the registry. If the registry has ownership of any layers these layers will also be deleted.

Parameters

layerIds list of IDs of the layers to remove

Note: As a side-effect the QgsProject instance is marked dirty.

Since: QGIS 1.8

See also: removeMapLayer(); removeAllMapLayers()

Definition at line 2334 of file qgsproject.cpp.

◆ removeMapLayers() [2/2]

void QgsProject::removeMapLayers ( const QList< QgsMapLayer *> & layers )

Remove a set of layers from the registry.

The specified layers will be removed from the registry. If the registry has ownership of any layers these layers will also be deleted.

Parameters

layers A list of layers to remove. Null pointers are ignored.

Note: As a side-effect the QgsProject instance is marked dirty.

See also: removeMapLayer(); removeAllMapLayers()

Definition at line 2339 of file qgsproject.cpp.

◆ setAreaUnits()

void QgsProject::setAreaUnits ( QgsUnitTypes::AreaUnit unit )

Sets the default area measurement units for the project.

Since: QGIS 3.0

See also: areaUnits(); setDistanceUnits()

Definition at line 2068 of file qgsproject.cpp.

◆ setAutoTransaction()

void QgsProject::setAutoTransaction ( bool autoTransaction )

Transactional editing means that on supported datasources (postgres databases) the edit state of all tables that originate from the same database are synchronized and executed in a server side transaction.

Make sure that this is only called when all layers are not in edit mode.

Since: QGIS 2.16

Definition at line 2157 of file qgsproject.cpp.

◆ setAvoidIntersectionsLayers()

void QgsProject::setAvoidIntersectionsLayers ( const QList< QgsVectorLayer *> & layers )

A list of layers with which intersections should be avoided.

Since: QGIS 3.0

Definition at line 1188 of file qgsproject.cpp.

◆ setBadLayerHandler()

void QgsProject::setBadLayerHandler ( QgsProjectBadLayerHandler * handler )

Change handler for missing layers.

Deletes old handler and takes ownership of the new one.

Definition at line 1799 of file qgsproject.cpp.

◆ setCrs()

void QgsProject::setCrs ( const QgsCoordinateReferenceSystem & crs )

Sets the project's native coordinate reference system.

Since: QGIS 3.0

See also: crs(); setEllipsoid()

Definition at line 451 of file qgsproject.cpp.

◆ setCustomVariables()

void QgsProject::setCustomVariables ( const QVariantMap & customVariables )

A map of custom project variables.

Be careful not to set generated variables.

Definition at line 1131 of file qgsproject.cpp.

◆ setDirty

void QgsProject::setDirty ( bool b = true )

slot

Flag the project as dirty (modified).

If this flag is set, the user will be asked to save changes to the project before closing the current project.

Since: QGIS 2.4

Note: promoted to public slot in 2.16

Definition at line 414 of file qgsproject.cpp.

◆ setDistanceUnits()

void QgsProject::setDistanceUnits ( QgsUnitTypes::DistanceUnit unit )

Sets the default distance measurement units for the project.

Since: QGIS 3.0

See also: distanceUnits(); setAreaUnits()

Definition at line 2050 of file qgsproject.cpp.

◆ setEllipsoid()

void QgsProject::setEllipsoid ( const QString & ellipsoid )

Sets the project's ellipsoid from a proj string representation, e.g., "WGS84".

See also: ellipsoid(); setCrs()

Since: QGIS 3.0

Definition at line 467 of file qgsproject.cpp.

◆ setEvaluateDefaultValues()

void QgsProject::setEvaluateDefaultValues ( bool evaluateDefaultValues )

Defines if default values should be evaluated on provider side when requested and not when committed.

Since: QGIS 2.16

Definition at line 2010 of file qgsproject.cpp.

◆ setFileName()

void QgsProject::setFileName ( const QString & name )

Sets the file name associated with the project.

This is the file which contains the project's XML representation.

Parameters

name	project file name

See also: fileName()

Definition at line 419 of file qgsproject.cpp.

◆ setLabelingEngineSettings()

void QgsProject::setLabelingEngineSettings ( const QgsLabelingEngineSettings & settings )

Sets project's global labeling engine settings.

Since: QGIS 3.0

Definition at line 1155 of file qgsproject.cpp.

◆ setNonIdentifiableLayers() [1/2]

void QgsProject::setNonIdentifiableLayers ( const QList< QgsMapLayer *> & layers )

Set a list of layers which should not be taken into account on map identification.

Definition at line 2117 of file qgsproject.cpp.

◆ setNonIdentifiableLayers() [2/2]

void QgsProject::setNonIdentifiableLayers ( const QStringList & layerIds )

Set a list of layers which should not be taken into account on map identification.

Definition at line 2140 of file qgsproject.cpp.

◆ setSnappingConfig

void QgsProject::setSnappingConfig ( const QgsSnappingConfig & snappingConfig )

slot

The snapping configuration for this project.

Since: QGIS 3.0

Definition at line 657 of file qgsproject.cpp.

◆ setTitle()

void QgsProject::setTitle ( const QString & title )

Sets the project's title.

Parameters

title new title

Since: QGIS 2.4

See also: title()

Definition at line 392 of file qgsproject.cpp.

◆ setTopologicalEditing()

void QgsProject::setTopologicalEditing ( bool enabled )

Convenience function to set topological editing.

Definition at line 2026 of file qgsproject.cpp.

◆ setTransformContext()

void QgsProject::setTransformContext ( const QgsCoordinateTransformContext & context )

Sets the project's coordinate transform context, which stores various information regarding which datum transforms should be used when transforming points from a source to destination coordinate reference system.

Since: QGIS 3.0

See also: transformContext(); transformContextChanged()

Definition at line 479 of file qgsproject.cpp.

◆ setTrustLayerMetadata()

void QgsProject::setTrustLayerMetadata ( bool trust )

Sets the trust option allowing to indicate if the extent has to be read from the XML document when data source has no metadata or if the data provider has to determine it.

Moreover, when this option is activated, primary key unicity is not checked for views and materialized views with Postgres provider.

Parameters

trust True to trust the project, false otherwise

Since: QGIS 3.0

Definition at line 2401 of file qgsproject.cpp.

◆ snappingConfig()

QgsSnappingConfig QgsProject::snappingConfig ( ) const

The snapping configuration for this project.

Since: QGIS 3.0

◆ snappingConfigChanged

void QgsProject::snappingConfigChanged ( const QgsSnappingConfig & config )

signal

emitted whenever the configuration for snapping has changed

◆ subkeyList()

QStringList QgsProject::subkeyList	(	const QString &	scope,
		const QString &	key
	)		const

Return keys with keys – do not return keys that contain only values.

Note: equivalent to QgsSettings subkeyList()

Definition at line 1746 of file qgsproject.cpp.

◆ takeMapLayer()

QgsMapLayer * QgsProject::takeMapLayer ( QgsMapLayer * layer )

Takes a layer from the registry.

If the layer was owned by the project, the layer will be returned without deleting it. The caller takes ownership of the layer and is responsible for deleting it.

See also: removeMapLayer()

Since: QGIS 3.0

Definition at line 2354 of file qgsproject.cpp.

◆ title()

QString QgsProject::title ( ) const

Returns the project's title.

See also: setTitle()

Definition at line 403 of file qgsproject.cpp.

◆ topologicalEditing()

bool QgsProject::topologicalEditing ( ) const

Convenience function to query topological editing status.

Definition at line 2032 of file qgsproject.cpp.

◆ topologicalEditingChanged

void QgsProject::topologicalEditingChanged ( )

signal

Emitted when the topological editing flag has changed.

Since: QGIS 3.0

◆ transactionGroups()

QMap< QPair< QString, QString >, QgsTransactionGroup * > QgsProject::transactionGroups ( )

Map of transaction groups.

QPair( providerKey, connString ) -> transactionGroup

Since: QGIS 2.16

Note: Not available in Python bindings

Definition at line 2170 of file qgsproject.cpp.

◆ transactionGroupsChanged

void QgsProject::transactionGroupsChanged ( )

signal

Emitted whenever a new transaction group has been created or a transaction group has been removed.

Since: QGIS 3.0

◆ transformContext()

QgsCoordinateTransformContext QgsProject::transformContext ( ) const

Returns a copy of the project's coordinate transform context, which stores various information regarding which datum transforms should be used when transforming points from a source to destination coordinate reference system.

Since: QGIS 3.0

See also: setTransformContext(); transformContextChanged()

Definition at line 474 of file qgsproject.cpp.

◆ transformContextChanged

void QgsProject::transformContextChanged ( )

signal

Emitted when the project transformContext() is changed.

Since: QGIS 3.0

See also: transformContext()

◆ trustLayerMetadata()

bool QgsProject::trustLayerMetadata ( ) const

inline

Returns true if the trust option is activated, false otherwise.

This option allows indicateing if the extent has to be read from the XML document when data source has no metadata or if the data provider has to determine it. Moreover, when this option is activated, primary key unicity is not checked for views and materialized views with Postgres provider.

Since: QGIS 3.0

Definition at line 834 of file qgsproject.h.

◆ write() [1/2]

bool QgsProject::write ( const QString & filename )

Writes the project to a file.

Parameters

filename destination file

Returns: true if project was written successfully

Note: calling this implicitly sets the project's filename (see setFileName() ); isDirty() will be set to false if project is successfully written

Since: QGIS 3.0

Definition at line 1307 of file qgsproject.cpp.

◆ write() [2/2]

bool QgsProject::write ( )

Writes the project to its current associated file (see fileName() ).

Returns: true if project was written successfully

Note: isDirty() will be set to false if project is successfully written

Definition at line 1314 of file qgsproject.cpp.