QGIS API Documentation 3.39.0-Master (bca3cdb6021)
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Namespace with helper functions for layer tree operations. More...
#include <qgslayertree.h>
Signals | |
void | customLayerOrderChanged () |
Emitted when the custom layer order has changed. | |
void | hasCustomLayerOrderChanged (bool hasCustomLayerOrder) |
Emitted when the hasCustomLayerOrder flag changes. | |
void | layerOrderChanged () |
Emitted when the layer order has changed. | |
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. | |
Public Member Functions | |
QgsLayerTree () | |
Create a new empty layer tree. | |
void | clear () |
Clear any information from this layer tree. | |
QgsLayerTree * | clone () const override |
Create a copy of the node. Returns new instance. | |
QList< QgsMapLayer * > | customLayerOrder () const |
The order in which layers will be rendered on the canvas. | |
bool | hasCustomLayerOrder () const |
Determines if the layer order should be derived from the layer tree or if a custom override order shall be used instead. | |
QList< QgsMapLayer * > | layerOrder () const |
The order in which layers will be rendered on the canvas. | |
void | readLayerOrderFromXml (const QDomElement &doc) |
Load the layer order from an XML element. | |
void | setCustomLayerOrder (const QList< QgsMapLayer * > &customLayerOrder) |
The order in which layers will be rendered on the canvas. | |
void | setCustomLayerOrder (const QStringList &customLayerOrder) |
The order in which layers will be rendered on the canvas. | |
void | setHasCustomLayerOrder (bool hasCustomLayerOrder) |
Determines if the layer order should be derived from the layer tree or if a custom override order shall be used instead. | |
void | writeXml (QDomElement &parentElement, const QgsReadWriteContext &context) override |
Write layer tree to XML. | |
Public Member Functions inherited from QgsLayerTreeGroup | |
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 bool | isGroup (QgsLayerTreeNode *node) |
Check whether the node is a valid group node. | |
static bool | isLayer (const QgsLayerTreeNode *node) |
Check whether the node is a valid layer node. | |
static QgsLayerTree * | readXml (QDomElement &element, const QgsReadWriteContext &context) |
Load the layer tree from an XML element. | |
static QgsLayerTreeGroup * | toGroup (QgsLayerTreeNode *node) |
Cast node to a group. | |
static const QgsLayerTreeLayer * | toLayer (const QgsLayerTreeNode *node) |
Cast node to a layer. | |
static QgsLayerTreeLayer * | toLayer (QgsLayerTreeNode *node) |
Cast node to a layer. | |
Static Public Member Functions inherited from QgsLayerTreeGroup | |
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. | |
Additional Inherited Members | |
Public Types inherited from QgsLayerTreeNode | |
enum | NodeType { NodeGroup , NodeLayer } |
Enumeration of possible tree node types. More... | |
Protected Slots inherited from QgsLayerTreeGroup | |
void | nodeVisibilityChanged (QgsLayerTreeNode *node) |
Protected Member Functions inherited from QgsLayerTreeGroup | |
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 inherited from QgsLayerTreeGroup | |
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 | |
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.
Definition at line 31 of file qgslayertree.h.
QgsLayerTree::QgsLayerTree | ( | ) |
Create a new empty layer tree.
Definition at line 20 of file qgslayertree.cpp.
void QgsLayerTree::clear | ( | ) |
Clear any information from this layer tree.
Definition at line 153 of file qgslayertree.cpp.
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overridevirtual |
Create a copy of the node. Returns new instance.
Implements QgsLayerTreeNode.
Definition at line 148 of file qgslayertree.cpp.
QList< QgsMapLayer * > QgsLayerTree::customLayerOrder | ( | ) | const |
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().
Definition at line 39 of file qgslayertree.cpp.
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signal |
Emitted when the custom layer order has changed.
bool QgsLayerTree::hasCustomLayerOrder | ( | ) | const |
Determines if the layer order should be derived from the layer tree or if a custom override order shall be used instead.
Definition at line 91 of file qgslayertree.cpp.
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signal |
Emitted when the hasCustomLayerOrder flag changes.
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inlinestatic |
Check whether the node is a valid group node.
Definition at line 41 of file qgslayertree.h.
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inlinestatic |
Check whether the node is a valid layer node.
Definition at line 50 of file qgslayertree.h.
QList< QgsMapLayer * > QgsLayerTree::layerOrder | ( | ) | const |
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.
Definition at line 79 of file qgslayertree.cpp.
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signal |
Emitted when the layer order has changed.
void QgsLayerTree::readLayerOrderFromXml | ( | const QDomElement & | doc | ) |
Load the layer order from an XML element.
Make sure that this is only called after the layers are loaded.
Definition at line 244 of file qgslayertree.cpp.
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static |
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.
Definition at line 107 of file qgslayertree.cpp.
void QgsLayerTree::setCustomLayerOrder | ( | const QList< QgsMapLayer * > & | customLayerOrder | ) |
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().
Definition at line 44 of file qgslayertree.cpp.
void QgsLayerTree::setCustomLayerOrder | ( | const QStringList & | customLayerOrder | ) |
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().
Definition at line 58 of file qgslayertree.cpp.
void QgsLayerTree::setHasCustomLayerOrder | ( | bool | hasCustomLayerOrder | ) |
Determines if the layer order should be derived from the layer tree or if a custom override order shall be used instead.
Definition at line 96 of file qgslayertree.cpp.
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inlinestatic |
Cast node to a group.
Definition at line 60 of file qgslayertree.h.
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inlinestatic |
Cast node to a layer.
Definition at line 80 of file qgslayertree.h.
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inlinestatic |
Cast node to a layer.
Definition at line 70 of file qgslayertree.h.
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overridevirtual |
Write layer tree to XML.
Implements QgsLayerTreeNode.
Definition at line 118 of file qgslayertree.cpp.