Class: QgsLayerTree

class qgis.core.QgsLayerTree

Bases: QgsLayerTreeGroup

Create a new empty layer tree

Namespace with helper functions for layer tree operations.

Only generally useful routines should be here. Miscellaneous utility functions for work with the layer tree are in QgsLayerTreeUtils class.

Methods

childEvent

clear

Clear any information from this layer tree.

clone

rtype

QgsLayerTree

connectNotify

customEvent

customLayerOrder

The order in which layers will be rendered on the canvas.

disconnectNotify

hasCustomLayerOrder

Determines if the layer order should be derived from the layer tree or if a custom override order shall be used instead.

insertChildrenPrivate

isGroup

Check whether the node is a valid group node

isLayer

Check whether the node is a valid layer node

isSignalConnected

layerOrder

The order in which layers will be rendered on the canvas.

nodeVisibilityChanged

readCommonXml

readLayerOrderFromXml

Load the layer order from an XML element.

readXml

Load the layer tree from an XML element.

receivers

removeChildrenPrivate

sender

senderSignalIndex

setCustomLayerOrder

The order in which layers will be rendered on the canvas.

setCustomLayerOrderByIds

The order in which layers will be rendered on the canvas.

setHasCustomLayerOrder

Determines if the layer order should be derived from the layer tree or if a custom override order shall be used instead.

timerEvent

updateChildVisibilityMutuallyExclusive

writeCommonXml

writeXml

param parentElement

Signals

customLayerOrderChanged

Emitted when the custom layer order has changed.

hasCustomLayerOrderChanged

Emitted when the hasCustomLayerOrder flag changes.

layerOrderChanged

Emitted when the layer order has changed.

childEvent()
clear(self)

Clear any information from this layer tree.

New in version 3.0.

clone(self) → QgsLayerTree
Return type

QgsLayerTree

connectNotify()
customEvent()
customLayerOrder(self) → List[QgsMapLayer]

The order in which layers will be rendered on the canvas. Will only be used if the property hasCustomLayerOrder is True. If you need the current layer order that is active, prefer using layerOrder().

See also

layerOrder()

New in version 3.0.

Return type

List[QgsMapLayer]

customLayerOrderChanged

Emitted when the custom layer order has changed.

New in version 3.0: [signal]

disconnectNotify()
hasCustomLayerOrder(self) → bool

Determines if the layer order should be derived from the layer tree or if a custom override order shall be used instead.

New in version 3.0.

Return type

bool

hasCustomLayerOrderChanged

Emitted when the hasCustomLayerOrder flag changes.

New in version 3.0: [signal]

Parameters

hasCustomLayerOrder (bool) –

insertChildrenPrivate()
isGroup(node: QgsLayerTreeNode) → bool

Check whether the node is a valid group node

New in version 2.4.

Parameters

node (QgsLayerTreeNode) –

Return type

bool

isLayer(node: QgsLayerTreeNode) → bool

Check whether the node is a valid layer node

New in version 2.4.

Parameters

node (QgsLayerTreeNode) –

Return type

bool

isSignalConnected()
layerOrder(self) → List[QgsMapLayer]

The order in which layers will be rendered on the canvas. Depending on hasCustomLayerOrder, this will return either the override customLayerOrder or the layer order derived from the tree. This property is read only.

New in version 3.0.

Return type

List[QgsMapLayer]

layerOrderChanged

Emitted when the layer order has changed.

New in version 3.0: [signal]

nodeVisibilityChanged()
readCommonXml()
readLayerOrderFromXml(self, doc: QDomElement)

Load the layer order from an XML element. Make sure that this is only called after the layers are loaded.

New in version 3.0.

Parameters

doc (QDomElement) –

readXml(element: QDomElement, context: QgsReadWriteContext) → QgsLayerTree

Load the layer tree from an XML element. It is not required that layers are loaded at this point. resolveReferences() needs to be called after loading the layers and before using the tree.

New in version 3.0.

Parameters
Return type

QgsLayerTree

receivers()
removeChildrenPrivate()
sender()
senderSignalIndex()
setCustomLayerOrder(self, customLayerOrder: Iterable[QgsMapLayer])

The order in which layers will be rendered on the canvas. Will only be used if the property hasCustomLayerOrder is True. If you need the current layer order that is active, prefer using layerOrder().

See also

layerOrder()

New in version 3.0.

Parameters

customLayerOrder (Iterable[QgsMapLayer]) –

setCustomLayerOrderByIds(self, customLayerOrder: Iterable[str])

The order in which layers will be rendered on the canvas. Will only be used if the property hasCustomLayerOrder is True. If you need the current layer order that is active, prefer using layerOrder().

See also

layerOrder()

New in version 3.0.

Parameters

customLayerOrder (Iterable[str]) –

setHasCustomLayerOrder(self, hasCustomLayerOrder: bool)

Determines if the layer order should be derived from the layer tree or if a custom override order shall be used instead.

New in version 3.0.

Parameters

hasCustomLayerOrder (bool) –

timerEvent()
updateChildVisibilityMutuallyExclusive()
writeCommonXml()
writeXml(self, parentElement: QDomElement, context: QgsReadWriteContext)
Parameters