A storage object for map layers, in which the layers are owned by the store and have their lifetime bound to the store. More...

#include <qgsmaplayerstore.h>

Inheritance diagram for QgsMapLayerStore:

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

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

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

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

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

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

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

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

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

Public Member Functions
	QgsMapLayerStore (QObject *parent=nullptr)
	Constructor for QgsMapLayerStore.

	~QgsMapLayerStore () override

QgsMapLayer *	addMapLayer (QgsMapLayer *layer, bool takeOwnership=true)
	Add a layer to the store.

QList< QgsMapLayer * >	addMapLayers (const QList< QgsMapLayer * > &layers, bool takeOwnership=true)
	Add a list of layers to the store.

int	count () const
	Returns the number of layers contained in the store.

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

QgsMapLayer *	mapLayer (const QString &id) const
	Retrieve a pointer to a layer by layer id.

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

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

void	removeAllMapLayers ()
	Removes all registered layers.

void	removeMapLayer (const QString &id)
	Remove a layer from the store by layer id.

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

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

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

QgsMapLayer *	takeMapLayer (QgsMapLayer *layer)
	Takes a layer from the store.

void	transferLayersFromStore (QgsMapLayerStore *other)
	Transfers all the map layers contained within another map layer store and adds them to this store.

int	validCount () const
	Returns the number of valid layers contained in the store.

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

Detailed Description

A storage object for map layers, in which the layers are owned by the store and have their lifetime bound to the store.

Definition at line 34 of file qgsmaplayerstore.h.

Constructor & Destructor Documentation

◆ QgsMapLayerStore()

QgsMapLayerStore::QgsMapLayerStore ( QObject * parent = nullptr )

explicit

Constructor for QgsMapLayerStore.

Definition at line 24 of file qgsmaplayerstore.cpp.

◆ ~QgsMapLayerStore()

QgsMapLayerStore::~QgsMapLayerStore ( )

override

Definition at line 28 of file qgsmaplayerstore.cpp.

Member Function Documentation

◆ addMapLayer()

QgsMapLayer * QgsMapLayerStore::addMapLayer	(	QgsMapLayer *	layer,
		bool	takeOwnership = `true`
	)

Add a layer to the store.

Ownership of the layer is transferred to the store.

The layersAdded() and layerWasAdded() signals will always be emitted. If you are adding multiple layers at once, you should use addMapLayers() instead.

Parameters

layer	A layer to add to the store
takeOwnership	Ownership will be transferred to the layer store. If you specify `false` here you have take care of deleting the layers yourself. Not available in Python.

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

See also: addMapLayers

Note: Use addMapLayers() if adding more than one layer at a time.

See also: addMapLayers()

Definition at line 120 of file qgsmaplayerstore.cpp.

◆ addMapLayers()

QList< QgsMapLayer * > QgsMapLayerStore::addMapLayers	(	const QList< QgsMapLayer * > &	layers,
		bool	takeOwnership = `true`
	)

Add a list of layers to the store.

Ownership of the layers is transferred to the store.

The layersAdded() and layerWasAdded() signals will always be emitted.

Parameters

layers	A list of layer which should be added to the store.
takeOwnership	Ownership will be transferred to the layer store. If you specify `false` here you have take care of deleting the layers yourself. Not available in Python.

Note: If a layer with the same id is already in the store it is not added again, but if the validity of the layer has changed from false to true, the layer data source is updated to the new one.

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

See also: addMapLayer()

Definition at line 78 of file qgsmaplayerstore.cpp.

◆ allLayersRemoved

void QgsMapLayerStore::allLayersRemoved ( )

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.

◆ count()

int QgsMapLayerStore::count ( ) const

Returns the number of layers contained in the store.

Definition at line 33 of file qgsmaplayerstore.cpp.

◆ layerRemoved

void QgsMapLayerStore::layerRemoved ( const QString & layerId )

signal

Emitted after a layer was removed from the store.

Parameters

layerId The ID of the layer removed.

Note: Consider using layersRemoved() instead

See also: layerWillBeRemoved()

◆ layers()

template<typename T >

QVector< T > QgsMapLayerStore::layers ( ) const

inline

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

Example

QVector<QgsVectorLayer*> vectorLayers = store->layers<QgsVectorLayer*>();

Note: not available in Python bindings

See also: mapLayers()

Definition at line 123 of file qgsmaplayerstore.h.

◆ layersAdded

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

signal

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

Parameters

layers List of layers which have been added.

See also: layerWasAdded()

◆ layersRemoved

void QgsMapLayerStore::layersRemoved ( const QStringList & layerIds )

signal

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

Parameters

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

See also: layersWillBeRemoved()

◆ layersWillBeRemoved [1/2]

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

signal

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

Parameters

layers A list of layers which are to be removed.

See also: layerWillBeRemoved(); layersRemoved()

◆ layersWillBeRemoved [2/2]

void QgsMapLayerStore::layersWillBeRemoved ( const QStringList & layerIds )

signal

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

Parameters

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

See also: layerWillBeRemoved(); layersRemoved()

◆ layerWasAdded

void QgsMapLayerStore::layerWasAdded ( QgsMapLayer * layer )

signal

Emitted when a layer was added to the store.

Note: Consider using layersAdded() instead

See also: layersAdded()

◆ layerWillBeRemoved [1/2]

void QgsMapLayerStore::layerWillBeRemoved ( const QString & layerId )

signal

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

Parameters

layerId The ID of the layer to be removed.

Note: Consider using layersWillBeRemoved() instead.

See also: layersWillBeRemoved(); layerRemoved()

◆ layerWillBeRemoved [2/2]

void QgsMapLayerStore::layerWillBeRemoved ( QgsMapLayer * layer )

signal

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

Parameters

layer The layer to be removed.

Note: Consider using layersWillBeRemoved() instead.

See also: layersWillBeRemoved(); layerRemoved()

◆ mapLayer()

QgsMapLayer * QgsMapLayerStore::mapLayer ( const QString & id ) const

Retrieve a pointer to a layer by layer id.

Parameters

id	ID of layer to retrieve

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

See also: mapLayersByName(); mapLayers()

Definition at line 54 of file qgsmaplayerstore.cpp.

◆ mapLayers()

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

Returns a map of all layers by layer ID.

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

Definition at line 268 of file qgsmaplayerstore.cpp.

◆ mapLayersByName()

QList< QgsMapLayer * > QgsMapLayerStore::mapLayersByName ( const QString & name ) const

Retrieve a list of matching layers by layer name.

Parameters

name	name of layers to match

Returns: list of matching layers

See also: mapLayer(); mapLayers()

Definition at line 62 of file qgsmaplayerstore.cpp.

◆ removeAllMapLayers()

void QgsMapLayerStore::removeAllMapLayers ( )

Removes all registered layers.

These layers will also be deleted.

Note: Calling this method will cause the removeAll() signal to be emitted.

See also: removeMapLayer(); removeMapLayers()

Definition at line 225 of file qgsmaplayerstore.cpp.

◆ removeMapLayer() [1/2]

void QgsMapLayerStore::removeMapLayer ( const QString & id )

Remove a layer from the store by layer id.

The specified layer will be removed from the store. The layer will also be deleted.

Parameters

id	ID of the layer to remove

See also: takeMapLayer(); removeMapLayers(); removeAllMapLayers()

Definition at line 187 of file qgsmaplayerstore.cpp.

◆ removeMapLayer() [2/2]

void QgsMapLayerStore::removeMapLayer ( QgsMapLayer * layer )

Remove a layer from the store.

The specified layer will be removed from the store. The layer will also be deleted.

Parameters

layer The layer to remove. nullptr values are ignored.

See also: takeMapLayer(); removeMapLayers(); removeAllMapLayers()

Definition at line 194 of file qgsmaplayerstore.cpp.

◆ removeMapLayers() [1/2]

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

Remove a set of layers from the store.

The specified layers will be removed from the store. These layers will also be deleted.

Parameters

layers A list of layers to remove. nullptr values are ignored.

See also: takeMapLayer(); removeMapLayer(); removeAllMapLayers()

Definition at line 143 of file qgsmaplayerstore.cpp.

◆ removeMapLayers() [2/2]

void QgsMapLayerStore::removeMapLayers ( const QStringList & layerIds )

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

The specified layers will be removed from the store. These layers will also be deleted.

Parameters

layerIds list of IDs of the layers to remove

See also: takeMapLayer(); removeMapLayer(); removeAllMapLayers()

Note: available in Python bindings as removeMapLayersById.

Definition at line 129 of file qgsmaplayerstore.cpp.

◆ takeMapLayer()

QgsMapLayer * QgsMapLayerStore::takeMapLayer ( QgsMapLayer * layer )

Takes a layer from the store.

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

See also: removeMapLayer()

Definition at line 202 of file qgsmaplayerstore.cpp.

◆ transferLayersFromStore()

void QgsMapLayerStore::transferLayersFromStore ( QgsMapLayerStore * other )

Transfers all the map layers contained within another map layer store and adds them to this store.

Note that other and this store must have the same thread affinity.

Definition at line 236 of file qgsmaplayerstore.cpp.

◆ validCount()

int QgsMapLayerStore::validCount ( ) const

Returns the number of valid layers contained in the store.

Since: QGIS 3.6

Definition at line 40 of file qgsmaplayerstore.cpp.

◆ validMapLayers()

QMap< QString, QgsMapLayer * > QgsMapLayerStore::validMapLayers ( ) const

Returns a map of all valid layers by layer ID.

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

Since: QGIS 3.6

Definition at line 276 of file qgsmaplayerstore.cpp.

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

/home/fischer/src/qgis-3.38/src/core/qgsmaplayerstore.h
/home/fischer/src/qgis-3.38/src/core/qgsmaplayerstore.cpp

Signals

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ QgsMapLayerStore()

◆ ~QgsMapLayerStore()

Member Function Documentation

◆ addMapLayer()

◆ addMapLayers()

◆ allLayersRemoved

◆ count()

◆ layerRemoved

◆ layers()

Example

◆ layersAdded

◆ layersRemoved

◆ layersWillBeRemoved [1/2]

◆ layersWillBeRemoved [2/2]

◆ layerWasAdded

◆ layerWillBeRemoved [1/2]

◆ layerWillBeRemoved [2/2]

◆ mapLayer()

◆ mapLayers()

◆ mapLayersByName()

◆ removeAllMapLayers()

◆ removeMapLayer() [1/2]

◆ removeMapLayer() [2/2]

◆ removeMapLayers() [1/2]

◆ removeMapLayers() [2/2]

◆ takeMapLayer()

◆ transferLayersFromStore()

◆ validCount()

◆ validMapLayers()