Layer tree group node serves as a container for layers and further groups. More...

#include <qgslayertreegroup.h>

Inheritance diagram for QgsLayerTreeGroup:

[legend]

Public Member Functions
	QgsLayerTreeGroup (const QgsLayerTreeGroup &other)

	QgsLayerTreeGroup (const QString &name=QString(), bool checked=true)
	Constructor.

void	addChildNode (QgsLayerTreeNode *node)
	Append an existing node.

QgsLayerTreeGroup *	addGroup (const QString &name)
	Append a new group node with given name.

QgsLayerTreeLayer *	addLayer (QgsMapLayer *layer)
	Append a new layer node for given map layer.

QgsLayerTreeGroup *	clone () const override
	Returns a clone of the group.

QgsGroupLayer *	convertToGroupLayer (const QgsGroupLayer::LayerOptions &options)
	Converts the group to a QgsGroupLayer.

QString	dump () const override
	Returns text representation of the tree.

QgsLayerTreeGroup *	findGroup (const QString &name)
	Find group node with specified name.

QList< QgsLayerTreeGroup * >	findGroups (bool recursive=false) const
	Find group layer nodes.

QgsLayerTreeLayer *	findLayer (const QString &layerId) const
	Find layer node representing the map layer specified by its ID.

QgsLayerTreeLayer *	findLayer (QgsMapLayer *layer) const
	Find layer node representing the map layer.

QStringList	findLayerIds () const
	Find layer IDs used in all layer nodes.

QList< QgsLayerTreeLayer * >	findLayers () const
	Find all layer nodes.

QgsGroupLayer *	groupLayer ()
	Returns a reference to the associated group layer, if the layer tree group will be treated as group layer during map rendering.

void	insertChildNode (int index, QgsLayerTreeNode *node)
	Insert existing node at specified position.

void	insertChildNodes (int index, const QList< QgsLayerTreeNode * > &nodes)
	Insert existing nodes at specified position.

QgsLayerTreeGroup *	insertGroup (int index, const QString &name)
	Insert a new group node with given name at specified position.

QgsLayerTreeLayer *	insertLayer (int index, QgsMapLayer *layer)
	Insert a new layer node for given map layer at specified position.

bool	isMutuallyExclusive () const
	Returns whether the group is mutually exclusive (only one child can be checked at a time)

QList< QgsMapLayer * >	layerOrderRespectingGroupLayers () const
	Returns an ordered list of map layers in the group, ignoring any layers which are child layers of QgsGroupLayers.

QString	name () const override
	Returns the group's name.

void	readChildrenFromXml (QDomElement &element, const QgsReadWriteContext &context)
	Read children from XML and append them to the group.

void	removeAllChildren ()
	Remove all child nodes.

void	removeChildNode (QgsLayerTreeNode *node)
	Remove a child node from this group.

void	removeChildren (int from, int count)
	Remove child nodes from index "from".

void	removeChildrenGroupWithoutLayers ()
	Remove all child group nodes without layers.

void	removeLayer (QgsMapLayer *layer)
	Remove map layer's node from this group.

void	reorderGroupLayers (const QList< QgsMapLayer * > &order)
	Reorders layers in the group to match the order specified by order.

void	resolveReferences (const QgsProject *project, bool looseMatching=false) override
	Calls resolveReferences() on child tree nodes.

void	setGroupLayer (QgsGroupLayer *layer)
	Sets the associated group layer, if the layer tree group will be treated as group layer during map rendering.

void	setIsMutuallyExclusive (bool enabled, int initialChildIndex=-1)
	Set whether the group is mutually exclusive (only one child can be checked at a time).

void	setItemVisibilityCheckedRecursive (bool checked) override
	Check or uncheck a node and all its children (taking into account exclusion rules)

void	setName (const QString &n) override
	Sets the group's name.

void	writeXml (QDomElement &parentElement, const QgsReadWriteContext &context) override
	Write group (tree) as XML element <layer-tree-group> and add it to the given parent element.

Public Member Functions inherited from QgsLayerTreeNode
	~QgsLayerTreeNode () override

QList< QgsLayerTreeNode * >	abandonChildren ()
	Removes the children, disconnect all the forwarded and external signals and sets their parent to `nullptr`.

QList< QgsMapLayer * >	checkedLayers () const
	Returns a list of any checked layers which belong to this node or its children.

QList< QgsLayerTreeNode * >	children ()
	Gets list of children of the node. Children are owned by the parent.

QList< QgsLayerTreeNode * >	children () const
	Gets list of children of the node. Children are owned by the parent.

QStringList	customProperties () const
	Returns list of keys stored in custom properties.

QVariant	customProperty (const QString &key, const QVariant &defaultValue=QVariant()) const
	Read a custom property from layer. Properties are stored in a map and saved in project file.

int	depth () const
	Returns the depth of this node, i.e.

bool	isExpanded () const
	Returns whether the node should be shown as expanded or collapsed in GUI.

bool	isItemVisibilityCheckedRecursive () const
	Returns whether this node is checked and all its children.

bool	isItemVisibilityUncheckedRecursive () const
	Returns whether this node is unchecked and all its children.

bool	isVisible () const
	Returns whether a node is really visible (ie checked and all its ancestors checked as well)

bool	itemVisibilityChecked () const
	Returns whether a node is checked (independently of its ancestors or children)

NodeType	nodeType () const
	Find out about type of the node. It is usually shorter to use convenience functions from QgsLayerTree namespace for that.

QgsLayerTreeNode *	parent ()
	Gets pointer to the parent. If parent is `nullptr`, the node is a root node.

void	removeCustomProperty (const QString &key)
	Remove a custom property from layer. Properties are stored in a map and saved in project file.

void	setCustomProperty (const QString &key, const QVariant &value)
	Sets a custom property for the node. Properties are stored in a map and saved in project file.

void	setExpanded (bool expanded)
	Sets whether the node should be shown as expanded or collapsed in GUI.

void	setItemVisibilityChecked (bool checked)
	Check or uncheck a node (independently of its ancestors or children)

void	setItemVisibilityCheckedParentRecursive (bool checked)
	Check or uncheck a node and all its parents.

bool	takeChild (QgsLayerTreeNode *node)
	Remove a child from a node.

Static Public Member Functions
static QgsLayerTreeGroup *	readXml (QDomElement &element, const QgsProject *project, const QgsReadWriteContext &context)
	Read group (tree) from XML element <layer-tree-group> and return the newly created group (or `nullptr` on error).

static QgsLayerTreeGroup *	readXml (QDomElement &element, const QgsReadWriteContext &context)
	Read group (tree) from XML element <layer-tree-group> and return the newly created group (or `nullptr` on error).

Static Public Member Functions inherited from QgsLayerTreeNode
static QgsLayerTreeNode *	readXml (QDomElement &element, const QgsProject *project)
	Read layer tree from XML.

static QgsLayerTreeNode *	readXml (QDomElement &element, const QgsReadWriteContext &context)
	Read layer tree from XML.

Protected Slots
void	nodeVisibilityChanged (QgsLayerTreeNode *node)

Protected Member Functions
virtual void	makeOrphan () override
	Sets parent to `nullptr` and disconnects all external and forwarded signals.

void	updateChildVisibilityMutuallyExclusive ()
	Set check state of children - if mutually exclusive.

Protected Member Functions inherited from QgsLayerTreeNode
	QgsLayerTreeNode (const QgsLayerTreeNode &other)

	QgsLayerTreeNode (NodeType t, bool checked=true)
	Constructor.

void	insertChildrenPrivate (int index, const QList< QgsLayerTreeNode * > &nodes)
	Low-level insertion of children to the node. The children must not have any parent yet!

void	readCommonXml (QDomElement &element)
	Read common XML elements.

void	removeChildrenPrivate (int from, int count, bool destroy=true)
	Low-level removal of children from the node.

void	writeCommonXml (QDomElement &element)
	Write common XML elements.

Protected Attributes
bool	mChangingChildVisibility = false

bool	mMutuallyExclusive = false
	Whether the group is mutually exclusive (i.e. only one child can be checked at a time)

int	mMutuallyExclusiveChildIndex = -1
	Keeps track which child has been most recently selected (so if the whole group is unchecked and checked again, we know which child to check)

QString	mName

Protected Attributes inherited from QgsLayerTreeNode
bool	mChecked

QList< QgsLayerTreeNode * >	mChildren
	list of children - node is responsible for their deletion

bool	mExpanded
	whether the node should be shown in GUI as expanded

NodeType	mNodeType
	type of the node - determines which subclass is used

QgsLayerTreeNode *	mParent = nullptr
	pointer to the parent node - `nullptr` in case of root node

QgsObjectCustomProperties	mProperties
	custom properties attached to the node

Additional Inherited Members
Public Types inherited from QgsLayerTreeNode
enum	NodeType { NodeGroup , NodeLayer }
	Enumeration of possible tree node types. More...

Signals inherited from QgsLayerTreeNode
void	addedChildren (QgsLayerTreeNode *node, int indexFrom, int indexTo)
	Emitted when one or more nodes have been added to a node within the tree.

void	customPropertyChanged (QgsLayerTreeNode *node, const QString &key)
	Emitted when a custom property of a node within the tree has been changed or removed.

void	expandedChanged (QgsLayerTreeNode *node, bool expanded)
	Emitted when the collapsed/expanded state of a node within the tree has been changed.

void	nameChanged (QgsLayerTreeNode *node, QString name)
	Emitted when the name of the node is changed.

void	removedChildren (QgsLayerTreeNode *node, int indexFrom, int indexTo)
	Emitted when one or more nodes has been removed from a node within the tree.

void	visibilityChanged (QgsLayerTreeNode *node)
	Emitted when check state of a node within the tree has been changed.

void	willAddChildren (QgsLayerTreeNode *node, int indexFrom, int indexTo)
	Emitted when one or more nodes will be added to a node within the tree.

void	willRemoveChildren (QgsLayerTreeNode *node, int indexFrom, int indexTo)
	Emitted when one or more nodes will be removed from a node within the tree.

Detailed Description

Layer tree group node serves as a container for layers and further groups.

Group names do not need to be unique within one tree nor within one parent.

While a layer tree group is typically used for hierarchical organisation of a QgsProject, they can optionally be associated with a QgsGroupLayer for map rendering purposes.

Definition at line 39 of file qgslayertreegroup.h.

Constructor & Destructor Documentation

◆ QgsLayerTreeGroup() [1/2]

QgsLayerTreeGroup::QgsLayerTreeGroup	(	const QString &	name = `QString()`,
		bool	checked = `true`
	)

Constructor.

Definition at line 29 of file qgslayertreegroup.cpp.

◆ QgsLayerTreeGroup() [2/2]

QgsLayerTreeGroup::QgsLayerTreeGroup ( const QgsLayerTreeGroup & other )

Definition at line 36 of file qgslayertreegroup.cpp.

Member Function Documentation

◆ addChildNode()

void QgsLayerTreeGroup::addChildNode ( QgsLayerTreeNode * node )

Append an existing node.

The node must not have a parent yet. The node will be owned by this group.

Definition at line 145 of file qgslayertreegroup.cpp.

◆ addGroup()

QgsLayerTreeGroup * QgsLayerTreeGroup::addGroup ( const QString & name )

Append a new group node with given name.

Newly created node is owned by this group.

Definition at line 77 of file qgslayertreegroup.cpp.

◆ addLayer()

QgsLayerTreeLayer * QgsLayerTreeGroup::addLayer ( QgsMapLayer * layer )

Append a new layer node for given map layer.

The newly created node is owned by this group.

Definition at line 96 of file qgslayertreegroup.cpp.

◆ clone()

QgsLayerTreeGroup * QgsLayerTreeGroup::clone ( ) const

overridevirtual

Returns a clone of the group.

The children are cloned too.

Implements QgsLayerTreeNode.

Definition at line 431 of file qgslayertreegroup.cpp.

◆ convertToGroupLayer()

QgsGroupLayer * QgsLayerTreeGroup::convertToGroupLayer ( const QgsGroupLayer::LayerOptions & options )

Converts the group to a QgsGroupLayer.

This method will convert the layer tree group to an equivalent QgsGroupLayer, and return the result. The caller takes ownership of the returned layer, and it is the caller's responsibility to add the layer to the associated QgsProject.

If the group is already associated with a group layer (see groupLayer()), nullptr will be returned.

See also: groupLayer(); setGroupLayer()

Since: QGIS 3.24

Definition at line 501 of file qgslayertreegroup.cpp.

◆ dump()

QString QgsLayerTreeGroup::dump ( ) const

overridevirtual

Returns text representation of the tree.

For debugging purposes only.

Implements QgsLayerTreeNode.

Definition at line 420 of file qgslayertreegroup.cpp.

◆ findGroup()

QgsLayerTreeGroup * QgsLayerTreeGroup::findGroup ( const QString & name )

Find group node with specified name.

Searches recursively the whole sub-tree.

Definition at line 312 of file qgslayertreegroup.cpp.

◆ findGroups()

QList< QgsLayerTreeGroup * > QgsLayerTreeGroup::findGroups ( bool recursive = false ) const

Find group layer nodes.

Searches recursively the whole sub-tree, if recursive is set.

Definition at line 332 of file qgslayertreegroup.cpp.

◆ findLayer() [1/2]

QgsLayerTreeLayer * QgsLayerTreeGroup::findLayer ( const QString & layerId ) const

Find layer node representing the map layer specified by its ID.

Searches recursively the whole sub-tree.

Definition at line 231 of file qgslayertreegroup.cpp.

◆ findLayer() [2/2]

QgsLayerTreeLayer * QgsLayerTreeGroup::findLayer ( QgsMapLayer * layer ) const

Find layer node representing the map layer.

Searches recursively the whole sub-tree.

Definition at line 223 of file qgslayertreegroup.cpp.

◆ findLayerIds()

QStringList QgsLayerTreeGroup::findLayerIds ( ) const

Find layer IDs used in all layer nodes.

Searches recursively the whole sub-tree.

Definition at line 527 of file qgslayertreegroup.cpp.

◆ findLayers()

QList< QgsLayerTreeLayer * > QgsLayerTreeGroup::findLayers ( ) const

Find all layer nodes.

Searches recursively the whole sub-tree.

Definition at line 251 of file qgslayertreegroup.cpp.

◆ groupLayer()

QgsGroupLayer * QgsLayerTreeGroup::groupLayer ( )

Returns a reference to the associated group layer, if the layer tree group will be treated as group layer during map rendering.

See also: setGroupLayer(); convertToGroupLayer()

Since: QGIS 3.24

Definition at line 483 of file qgslayertreegroup.cpp.

◆ insertChildNode()

void QgsLayerTreeGroup::insertChildNode	(	int	index,
		QgsLayerTreeNode *	node
	)

Insert existing node at specified position.

The node must not have a parent yet. The node will be owned by this group.

Definition at line 108 of file qgslayertreegroup.cpp.

◆ insertChildNodes()

void QgsLayerTreeGroup::insertChildNodes	(	int	index,
		const QList< QgsLayerTreeNode * > &	nodes
	)

Insert existing nodes at specified position.

The nodes must not have a parent yet. The nodes will be owned by this group.

Definition at line 115 of file qgslayertreegroup.cpp.

◆ insertGroup()

QgsLayerTreeGroup * QgsLayerTreeGroup::insertGroup	(	int	index,
		const QString &	name
	)

Insert a new group node with given name at specified position.

The newly created node is owned by this group.

Definition at line 70 of file qgslayertreegroup.cpp.

◆ insertLayer()

QgsLayerTreeLayer * QgsLayerTreeGroup::insertLayer	(	int	index,
		QgsMapLayer *	layer
	)

Insert a new layer node for given map layer at specified position.

The newly created node is owned by this group.

Definition at line 84 of file qgslayertreegroup.cpp.

◆ isMutuallyExclusive()

bool QgsLayerTreeGroup::isMutuallyExclusive ( ) const

Returns whether the group is mutually exclusive (only one child can be checked at a time)

Definition at line 450 of file qgslayertreegroup.cpp.

◆ layerOrderRespectingGroupLayers()

QList< QgsMapLayer * > QgsLayerTreeGroup::layerOrderRespectingGroupLayers ( ) const

Returns an ordered list of map layers in the group, ignoring any layers which are child layers of QgsGroupLayers.

Searches recursively the whole sub-tree.

Note: Not available in Python bindings

Since: QGIS 3.24

Definition at line 284 of file qgslayertreegroup.cpp.

◆ makeOrphan()

void QgsLayerTreeGroup::makeOrphan ( )

overrideprotectedvirtual

Sets parent to nullptr and disconnects all external and forwarded signals.

Reimplemented from QgsLayerTreeNode.

Definition at line 582 of file qgslayertreegroup.cpp.

◆ name()

QString QgsLayerTreeGroup::name ( ) const

overridevirtual

Returns the group's name.

Implements QgsLayerTreeNode.

Definition at line 55 of file qgslayertreegroup.cpp.

◆ nodeVisibilityChanged

void QgsLayerTreeGroup::nodeVisibilityChanged ( QgsLayerTreeNode * node )

protectedslot

Definition at line 540 of file qgslayertreegroup.cpp.

◆ readChildrenFromXml()

void QgsLayerTreeGroup::readChildrenFromXml	(	QDomElement &	element,
		const QgsReadWriteContext &	context
	)

Read children from XML and append them to the group.

Does not resolve textual references to layers. Call resolveReferences() afterwards to do it.

Definition at line 404 of file qgslayertreegroup.cpp.

◆ readXml() [1/2]

QgsLayerTreeGroup * QgsLayerTreeGroup::readXml	(	QDomElement &	element,
		const QgsProject *	project,
		const QgsReadWriteContext &	context
	)

static

Read group (tree) from XML element <layer-tree-group> and return the newly created group (or nullptr on error).

Also resolves textual references to layers from the project (calls resolveReferences() internally).

Definition at line 374 of file qgslayertreegroup.cpp.

◆ readXml() [2/2]

QgsLayerTreeGroup * QgsLayerTreeGroup::readXml	(	QDomElement &	element,
		const QgsReadWriteContext &	context
	)

static

Read group (tree) from XML element <layer-tree-group> and return the newly created group (or nullptr on error).

Does not resolve textual references to layers. Call resolveReferences() afterwards to do it.

Definition at line 349 of file qgslayertreegroup.cpp.

◆ removeAllChildren()

void QgsLayerTreeGroup::removeAllChildren ( )

Remove all child nodes.

The nodes will be deleted.

Definition at line 218 of file qgslayertreegroup.cpp.

◆ removeChildNode()

void QgsLayerTreeGroup::removeChildNode ( QgsLayerTreeNode * node )

Remove a child node from this group.

The node will be deleted.

Definition at line 152 of file qgslayertreegroup.cpp.

◆ removeChildren()

void QgsLayerTreeGroup::removeChildren	(	int	from,
		int	count
	)

Remove child nodes from index "from".

The nodes will be deleted.

Definition at line 179 of file qgslayertreegroup.cpp.

◆ removeChildrenGroupWithoutLayers()

void QgsLayerTreeGroup::removeChildrenGroupWithoutLayers ( )

Remove all child group nodes without layers.

The groupnodes will be deleted.

Definition at line 199 of file qgslayertreegroup.cpp.

◆ removeLayer()

void QgsLayerTreeGroup::removeLayer ( QgsMapLayer * layer )

Remove map layer's node from this group.

The node will be deleted.

Definition at line 161 of file qgslayertreegroup.cpp.

◆ reorderGroupLayers()

void QgsLayerTreeGroup::reorderGroupLayers ( const QList< QgsMapLayer * > & order )

Reorders layers in the group to match the order specified by order.

Only layers which are direct children of this group will be reordered, other layers will be ignored.

Note: This method does not recursively reorder child groups.; Matching layers will be moved to the start of the group, with any existing non-matching layers and group nodes moved to sit after the re-ordered matching layers.

Since: QGIS 3.30

Definition at line 264 of file qgslayertreegroup.cpp.

◆ resolveReferences()

void QgsLayerTreeGroup::resolveReferences	(	const QgsProject *	project,
		bool	looseMatching = `false`
	)

overridevirtual

Calls resolveReferences() on child tree nodes.

Implements QgsLayerTreeNode.

Definition at line 436 of file qgslayertreegroup.cpp.

◆ setGroupLayer()

void QgsLayerTreeGroup::setGroupLayer ( QgsGroupLayer * layer )

Sets the associated group layer, if the layer tree group will be treated as group layer during map rendering.

This method does not take ownership of the group layer, and only a weak reference to the layer is stored.

See also: groupLayer(); convertToGroupLayer()

Since: QGIS 3.24

Definition at line 488 of file qgslayertreegroup.cpp.

◆ setIsMutuallyExclusive()

void QgsLayerTreeGroup::setIsMutuallyExclusive	(	bool	enabled,
		int	initialChildIndex = `-1`
	)

Set whether the group is mutually exclusive (only one child can be checked at a time).

The initial child index determines which child should be initially checked. The default value of -1 will determine automatically (either first one currently checked or none)

Definition at line 455 of file qgslayertreegroup.cpp.

◆ setItemVisibilityCheckedRecursive()

void QgsLayerTreeGroup::setItemVisibilityCheckedRecursive ( bool checked )

overridevirtual

Check or uncheck a node and all its children (taking into account exclusion rules)

Reimplemented from QgsLayerTreeNode.

Definition at line 625 of file qgslayertreegroup.cpp.

◆ setName()

void QgsLayerTreeGroup::setName ( const QString & n )

overridevirtual

Sets the group's name.

Implements QgsLayerTreeNode.

Definition at line 60 of file qgslayertreegroup.cpp.

◆ updateChildVisibilityMutuallyExclusive()

void QgsLayerTreeGroup::updateChildVisibilityMutuallyExclusive ( )

protected

Set check state of children - if mutually exclusive.

Definition at line 563 of file qgslayertreegroup.cpp.

◆ writeXml()

void QgsLayerTreeGroup::writeXml	(	QDomElement &	parentElement,
		const QgsReadWriteContext &	context
	)

overridevirtual

Write group (tree) as XML element <layer-tree-group> and add it to the given parent element.

Implements QgsLayerTreeNode.

Definition at line 382 of file qgslayertreegroup.cpp.

Member Data Documentation

◆ mChangingChildVisibility

bool QgsLayerTreeGroup::mChangingChildVisibility = false

protected

Definition at line 291 of file qgslayertreegroup.h.

◆ mMutuallyExclusive

bool QgsLayerTreeGroup::mMutuallyExclusive = false

protected

Whether the group is mutually exclusive (i.e. only one child can be checked at a time)

Definition at line 294 of file qgslayertreegroup.h.

◆ mMutuallyExclusiveChildIndex

int QgsLayerTreeGroup::mMutuallyExclusiveChildIndex = -1

protected

Keeps track which child has been most recently selected (so if the whole group is unchecked and checked again, we know which child to check)

Definition at line 300 of file qgslayertreegroup.h.

◆ mName

QString QgsLayerTreeGroup::mName

protected

Definition at line 289 of file qgslayertreegroup.h.

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

/build/qgis-3.41.0+git20241116+25ec5511245+99sid/src/core/layertree/qgslayertreegroup.h
/build/qgis-3.41.0+git20241116+25ec5511245+99sid/src/core/layertree/qgslayertreegroup.cpp

Public Member Functions

Static Public Member Functions

Protected Slots

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QgsLayerTreeGroup() [1/2]

◆ QgsLayerTreeGroup() [2/2]

Member Function Documentation

◆ addChildNode()

◆ addGroup()

◆ addLayer()

◆ clone()

◆ convertToGroupLayer()

◆ dump()

◆ findGroup()

◆ findGroups()

◆ findLayer() [1/2]

◆ findLayer() [2/2]

◆ findLayerIds()

◆ findLayers()

◆ groupLayer()

◆ insertChildNode()

◆ insertChildNodes()

◆ insertGroup()

◆ insertLayer()

◆ isMutuallyExclusive()

◆ layerOrderRespectingGroupLayers()

◆ makeOrphan()

◆ name()

◆ nodeVisibilityChanged

◆ readChildrenFromXml()

◆ readXml() [1/2]

◆ readXml() [2/2]

◆ removeAllChildren()

◆ removeChildNode()

◆ removeChildren()

◆ removeChildrenGroupWithoutLayers()

◆ removeLayer()

◆ reorderGroupLayers()

◆ resolveReferences()

◆ setGroupLayer()

◆ setIsMutuallyExclusive()

◆ setItemVisibilityCheckedRecursive()

◆ setName()

◆ updateChildVisibilityMutuallyExclusive()

◆ writeXml()

Member Data Documentation

◆ mChangingChildVisibility

◆ mMutuallyExclusive

◆ mMutuallyExclusiveChildIndex

◆ mName