Subgroup: Layer

Class: QgsLayerTree¶

class qgis.core.QgsLayerTree¶

Bases: qgis._core.QgsLayerTreeGroup

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.

New in version 3.0: Methods

`addChildNode`	Append an existing node.
`addGroup`	Append a new group node with given name.
`addLayer`	Append a new layer node for given map layer.
`blockSignals`
`checkedLayers`	Returns a list of any checked layers which belong to this node or its children.
`childEvent`
`children`	Get list of children of the node.
`clear`	Clear any information from this layer tree.
`clone`
`connectNotify`
`customEvent`
`customLayerOrder`	The order in which layers will be rendered on the canvas.
`customProperties`	Return list of keys stored in custom properties
`customProperty`	Read a custom property from layer.
`deleteLater`
`disconnect`
`disconnectNotify`
`dump`	Return text representation of the tree.
`dumpObjectInfo`
`dumpObjectTree`
`dynamicPropertyNames`
`event`
`eventFilter`
`findChild`	findChild(self, Tuple, name: str = ‘’, options: Union[Qt.FindChildOptions, Qt.FindChildOption] = Qt.FindChildrenRecursively) -> QObject
`findChildren`	findChildren(self, Tuple, name: str = ‘’, options: Union[Qt.FindChildOptions, Qt.FindChildOption] = Qt.FindChildrenRecursively) -> List[QObject]
`findGroup`	Find group node with specified name.
`findLayer`	Find layer node representing the map layer.
`findLayerIds`	Find layer IDs used in all layer nodes.
`findLayers`	Find all layer nodes.
`hasCustomLayerOrder`	Determines if the layer order should be derived from the layer tree or if a custom override order shall be used instead.
`inherits`
`insertChildNode`	Insert existing node at specified position.
`insertChildNodes`	Insert existing nodes at specified position.
`insertChildrenPrivate`
`insertGroup`	Insert a new group node with given name at specified position.
`insertLayer`	Insert a new layer node for given map layer at specified position.
`installEventFilter`
`isExpanded`	Return whether the node should be shown as expanded or collapsed in GUI
`isGroup`	Check whether the node is a valid group node
`isItemVisibilityCheckedRecursive`	Return whether this node is checked and all its children.
`isItemVisibilityUncheckedRecursive`	Return whether this node is unchecked and all its children.
`isLayer`	Check whether the node is a valid layer node
`isMutuallyExclusive`	Return whether the group is mutually exclusive (only one child can be checked at a time)
`isSignalConnected`
`isVisible`	Returns whether a node is really visible (ie checked and all its ancestors checked as well)
`isWidgetType`
`isWindowType`
`itemVisibilityChecked`	Returns whether a node is checked (independently of its ancestors or children)
`killTimer`
`layerOrder`	The order in which layers will be rendered on the canvas.
`metaObject`
`moveToThread`
`name`	Returns the group’s name.
`nodeType`	Find out about type of the node.
`nodeVisibilityChanged`
`objectName`
`parent`	Get pointer to the parent.
`property`
`pyqtConfigure`	Each keyword argument is either the name of a Qt property or a Qt signal.
`readChildrenFromXml`	Read children from XML and append them to the group.
`readCommonXml`
`readLayerOrderFromXml`	Load the layer order from an XML element.
`readXml`	Load the layer tree from an XML element.
`receivers`
`removeAllChildren`	Remove all child nodes.
`removeChildNode`	Remove a child node from this group.
`removeChildren`	Remove child nodes from index “from”.
`removeChildrenGroupWithoutLayers`	Remove all child group nodes without layers.
`removeChildrenPrivate`
`removeCustomProperty`	Remove a custom property from layer.
`removeEventFilter`
`removeLayer`	Remove map layer’s node from this group.
`resolveReferences`	Calls resolveReferences() on child tree nodes
`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.
`setCustomProperty`	Set a custom property for the node.
`setExpanded`	Set whether the node should be shown as expanded or collapsed in GUI
`setHasCustomLayerOrder`	Determines if the layer order should be derived from the layer tree or if a custom override order shall be used instead.
`setIsMutuallyExclusive`	Set whether the group is mutually exclusive (only one child can be checked at a time).
`setItemVisibilityChecked`	Check or uncheck a node (independently of its ancestors or children)
`setItemVisibilityCheckedParentRecursive`	Check or uncheck a node and all its parents
`setItemVisibilityCheckedRecursive`	Check or uncheck a node and all its children (taking into account exclusion rules)
`setName`	Sets the group’s name.
`setObjectName`
`setParent`
`setProperty`
`signalsBlocked`
`startTimer`
`takeChild`	Remove a child from a node
`thread`
`timerEvent`
`tr`
`updateChildVisibilityMutuallyExclusive`
`writeCommonXml`
`writeXml`

Attributes

`NodeGroup`
`NodeLayer`
`addedChildren`	Emitted when one or more nodes have been added to a node within the tree [signal]
`customLayerOrderChanged`	Emitted when the custom layer order has changed.
`customPropertyChanged`	Emitted when a custom property of a node within the tree has been changed or removed [signal]
`destroyed`	destroyed(self, QObject = None) [signal]
`expandedChanged`	Emitted when the collapsed/expanded state of a node within the tree has been changed [signal]
`hasCustomLayerOrderChanged`	Emitted when the hasCustomLayerOrder flag changes.
`layerOrderChanged`	Emitted when the layer order has changed.
`nameChanged`	Emitted when the name of the node is changed
`objectNameChanged`	objectNameChanged(self, str) [signal]
`removedChildren`	Emitted when one or more nodes has been removed from a node within the tree [signal]
`staticMetaObject`
`visibilityChanged`	Emitted when check state of a node within the tree has been changed [signal]
`willAddChildren`	Emitted when one or more nodes will be added to a node within the tree [signal]
`willRemoveChildren`	Emitted when one or more nodes will be removed from a node within the tree [signal]

childEvent()¶

clear(self)¶: Clear any information from this layer tree.

New in version 3.0.

clone(self) → 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

setCustomLayerOrder()

See also

layerOrder()

See also

hasCustomLayerOrder()

New in version 3.0.

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.

See also

customLayerOrder()

New in version 3.0.

hasCustomLayerOrderChanged¶: Emitted when the hasCustomLayerOrder flag changes.

See also

hasCustomLayerOrder()

New in version 3.0: [signal]

insertChildrenPrivate()¶

isGroup(node: QgsLayerTreeNode) → bool¶: Check whether the node is a valid group node

New in version 2.4.

isLayer(node: QgsLayerTreeNode) → bool¶: Check whether the node is a valid layer node

New in version 2.4.

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.

See also

customLayerOrder()

New in version 3.0.

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.

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.

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

customLayerOrder()

See also

layerOrder()

See also

hasCustomLayerOrder()

New in version 3.0.

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

customLayerOrder()

See also

layerOrder()

See also

hasCustomLayerOrder()

New in version 3.0.

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.

See also

setCustomLayerOrder()

New in version 3.0.

timerEvent()¶

updateChildVisibilityMutuallyExclusive()¶

writeCommonXml()¶

writeXml(self, parentElement: QDomElement, context: QgsReadWriteContext)¶