Class: QgsMapLayerStore

class qgis.core.QgsMapLayerStore(parent: QObject = None)

Bases: PyQt5.QtCore.QObject

Constructor for QgsMapLayerStore.

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

New in version 3.0: Methods

addMapLayer Add a layer to the store.
addMapLayers Add a list of layers to the store.
childEvent
connectNotify
count Returns the number of layers contained in the store.
customEvent
disconnectNotify
isSignalConnected
mapLayer Retrieve a pointer to a layer by layer id.
mapLayers Returns a map of all layers by layer ID.
mapLayersByName Retrieve a list of matching layers by layer name.
receivers
removeAllMapLayers Removes all registered layers.
removeMapLayer Remove a layer from the store by layer id.
removeMapLayers Remove a set of layers from the store.
removeMapLayersById Remove a set of layers from the store by layer ID.
sender
senderSignalIndex
takeMapLayer Takes a layer from the store.
timerEvent
transferLayersFromStore Transfers all the map layers contained within another map layer store and adds them to this store.
validCount Returns the number of valid layers contained in the store.
validMapLayers Returns a map of all valid layers by layer ID.

Signals

allLayersRemoved Emitted when all layers are removed, before layersWillBeRemoved() and layerWillBeRemoved() signals are emitted.
layerRemoved Emitted after a layer was removed from the store.
layerWasAdded Emitted when a layer was added to the store.
layerWillBeRemoved Emitted when a layer is about to be removed from the store.
layersAdded Emitted when one or more layers were added to the store.
layersRemoved Emitted after one or more layers were removed from the store.
layersWillBeRemoved Emitted when one or more layers are about to be removed from the store.

Attributes

addMapLayer(self, layer: QgsMapLayer) → QgsMapLayer

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
Returns:None 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()

addMapLayers(self, layers: Iterable[QgsMapLayer]) → List[QgsMapLayer]

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.
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()

allLayersRemoved

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. [signal]

childEvent()
connectNotify()
count(self) → int

Returns the number of layers contained in the store.

customEvent()
disconnectNotify()
isSignalConnected()
layerRemoved

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() [signal]

layerWasAdded

Emitted when a layer was added to the store.

Note

Consider using layersAdded() instead

See also

layersAdded() [signal]

layerWillBeRemoved

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

layerRemoved() [signal]

layerWillBeRemoved(self, QgsMapLayer) 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

layerRemoved() [signal]

layersAdded

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

Parameters:layers – List of layers which have been added.

See also

layerWasAdded() [signal]

layersRemoved

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() [signal]

layersWillBeRemoved

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

layersRemoved() [signal]

layersWillBeRemoved(self, Iterable[QgsMapLayer]) 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

layersRemoved() [signal]

mapLayer(self, id: str) → QgsMapLayer

Retrieve a pointer to a layer by layer id.

Parameters:id – ID of layer to retrieve
Returns:matching layer, or None if no matching layer found

See also

mapLayers()

mapLayers(self) → object

Returns a map of all layers by layer ID.

See also

mapLayer()

See also

layers()

mapLayersByName(self, name: str) → List[QgsMapLayer]

Retrieve a list of matching layers by layer name.

Parameters:name – name of layers to match
Returns:list of matching layers

See also

mapLayer()

See also

mapLayers()

receivers()
removeAllMapLayers(self)

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()

removeMapLayer(self, id: str)

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()

removeMapLayer(self, layer: QgsMapLayer) 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. Null pointers are ignored.

See also

takeMapLayer()

removeMapLayers(self, layers: Iterable[QgsMapLayer])

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. Null pointers are ignored.

See also

takeMapLayer()

See also

removeMapLayer()

removeMapLayersById(self, layerIds: Iterable[str])

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()

See also

removeMapLayer()

Note

available in Python bindings as removeMapLayersById.

sender()
senderSignalIndex()
takeMapLayer(self, layer: QgsMapLayer) → QgsMapLayer

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()

timerEvent()
transferLayersFromStore(self, other: QgsMapLayerStore)

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.

validCount(self) → int

Returns the number of valid layers contained in the store.

New in version 3.6.

validMapLayers(self) → object

Returns a map of all valid layers by layer ID.

See also

mapLayer()

See also

layers()

New in version 3.6.