QgsLegendModel Class Reference

Item model implementation based on layer tree model for layout legend. More...

#include <qgslayoutitemlegend.h>

Inheritance diagram for QgsLegendModel:

Signals
void	refreshLegend ()
	Emitted to refresh the legend.
Signals inherited from QgsLayerTreeModel
void	hitTestCompleted ()
	Emitted when a hit test for visible legend items completes.
void	hitTestStarted ()
	Emitted when a hit test for visible legend items starts.
void	messageEmitted (const QString &message, Qgis::MessageLevel level=Qgis::MessageLevel::Info, int duration=5)
	Emits a message than can be displayed to the user in a GUI class.

Public Member Functions
	QgsLegendModel (QgsLayerTree *rootNode, QgsLayoutItemLegend *layout)
	Alternative constructor.
	QgsLegendModel (QgsLayerTree *rootNode, QObject *parent=nullptr, QgsLayoutItemLegend *layout=nullptr)
	Construct the model based on the given layer tree.
void	clearCachedData (QgsLayerTreeNode *node) const
	Clears any previously cached data for the specified node.
QVariant	data (const QModelIndex &index, int role) const override
Qt::ItemFlags	flags (const QModelIndex &index) const override
QList< QgsLayerTreeModelLegendNode * >	layerLegendNodes (QgsLayerTreeLayer *nodeLayer, bool skipNodeEmbeddedInParent=false) const
	Returns filtered list of active legend nodes attached to a particular layer node (by default it returns also legend node embedded in parent layer node (if any) unless skipNodeEmbeddedInParent is true)
Public Member Functions inherited from QgsLayerTreeModel
	QgsLayerTreeModel (QgsLayerTree *rootNode, QObject *parent=nullptr)
	Construct a new tree model with given layer tree (root node must not be nullptr).
	~QgsLayerTreeModel () override
void	addTargetScreenProperties (const QgsScreenProperties &properties)
	Adds additional target screen properties to use when generating icons for Qt::DecorationRole data.
int	autoCollapseLegendNodes () const
	Returns at what number of legend nodes the layer node should be collapsed. -1 means no auto-collapse (default).
int	columnCount (const QModelIndex &parent=QModelIndex()) const override
QModelIndex	currentIndex () const
	Gets index of the item marked as current. Item marked as current is underlined.
QVariant	data (const QModelIndex &index, int role=Qt::DisplayRole) const override
bool	dropMimeData (const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) override
const QgsLayerTreeFilterSettings *	filterSettings () const
	Returns the filter settings to use to filter legend nodes.
QgsLayerTreeModelLegendNode *	findLegendNode (const QString &layerId, const QString &ruleKey) const
	Searches through the layer tree to find a legend node with a matching layer ID and rule key.
Flags	flags () const
	Returns OR-ed combination of model flags.
Qt::ItemFlags	flags (const QModelIndex &index) const override
bool	hitTestInProgress () const
	Returns true if a hit test for visible legend items is currently in progress.
QModelIndex	index (int row, int column, const QModelIndex &parent=QModelIndex()) const override
QgsLayerTreeNode *	index2node (const QModelIndex &index) const
	Returns layer tree node for given index.
QList< QgsLayerTreeNode * >	indexes2nodes (const QModelIndexList &list, bool skipInternal=false) const
	Convert a list of indexes to a list of layer tree nodes.
QList< QgsLayerTreeModelLegendNode * >	layerLegendNodes (QgsLayerTreeLayer *nodeLayer, bool skipNodeEmbeddedInParent=false)
	Returns filtered list of active legend nodes attached to a particular layer node (by default it returns also legend node embedded in parent layer node (if any) unless skipNodeEmbeddedInParent is true)
QList< QgsLayerTreeModelLegendNode * >	layerOriginalLegendNodes (QgsLayerTreeLayer *nodeLayer)
	Returns original (unfiltered) list of legend nodes attached to a particular layer node.
QMap< QString, QString >	layerStyleOverrides () const
	Gets map of map layer style overrides (key: layer ID, value: style name) where a different style should be used instead of the current one.
QFont	layerTreeNodeFont (int nodeType) const
	Gets font for a particular type of layer tree node. nodeType should come from QgsLayerTreeNode::NodeType enumeration.
double	legendFilterByScale () const
	Returns the scale which restricts the legend nodes which are visible.
const QgsMapSettings *	legendFilterMapSettings () const
	Returns the current map settings used for the current legend filter (or nullptr if none is enabled)
void	legendMapViewData (double *mapUnitsPerPixel, int *dpi, double *scale) const
	Gets hints about map view - to be used in legend nodes.
QModelIndex	legendNode2index (QgsLayerTreeModelLegendNode *legendNode)
	Returns index for a given legend node.
QgsLayerTreeModelLegendNode *	legendNodeEmbeddedInParent (QgsLayerTreeLayer *nodeLayer) const
	Returns legend node that may be embedded in parent (i.e.
QMimeData *	mimeData (const QModelIndexList &indexes) const override
QStringList	mimeTypes () const override
QModelIndex	node2index (QgsLayerTreeNode *node) const
	Returns index for a given node. If the node does not belong to the layer tree, the result is undefined.
QModelIndex	parent (const QModelIndex &child) const override
void	refreshLayerLegend (QgsLayerTreeLayer *nodeLayer)
	Force a refresh of legend nodes of a layer node.
bool	removeRows (int row, int count, const QModelIndex &parent=QModelIndex()) override
QgsLayerTree *	rootGroup () const
	Returns pointer to the root node of the layer tree. Always a non nullptr value.
int	rowCount (const QModelIndex &parent=QModelIndex()) const override
void	setAutoCollapseLegendNodes (int nodeCount)
	Sets at what number of legend nodes the layer node should be collapsed. Setting -1 disables the auto-collapse (default).
void	setCurrentIndex (const QModelIndex &currentIndex)
	Sets index of the current item. May be used by view. Item marked as current is underlined.
bool	setData (const QModelIndex &index, const QVariant &value, int role=Qt::EditRole) override
void	setFilterSettings (const QgsLayerTreeFilterSettings *settings=nullptr)
	Sets the filter settings to use to filter legend nodes.
void	setFlag (Flag f, bool on=true)
	Enable or disable a model flag.
void	setFlags (QgsLayerTreeModel::Flags f)
	Sets OR-ed combination of model flags.
void	setLayerStyleOverrides (const QMap< QString, QString > &overrides)
	Sets map of map layer style overrides (key: layer ID, value: style name) where a different style should be used instead of the current one.
void	setLayerTreeNodeFont (int nodeType, const QFont &font)
	Sets font for a particular type of layer tree node. nodeType should come from QgsLayerTreeNode::NodeType enumeration.
Q_DECL_DEPRECATED void	setLegendFilter (const QgsMapSettings *settings, bool useExtent=true, const QgsGeometry &polygon=QgsGeometry(), bool useExpressions=true)
	Filter display of legend nodes for given map settings.
Q_DECL_DEPRECATED void	setLegendFilterByMap (const QgsMapSettings *settings)
	Force only display of legend nodes which are valid for given map settings.
void	setLegendFilterByScale (double scale)
	Force only display of legend nodes which are valid for a given scale.
void	setLegendMapViewData (double mapUnitsPerPixel, int dpi, double scale)
	Give the layer tree model hints about the currently associated map view so that legend nodes that use map units can be scaled correctly.
void	setRootGroup (QgsLayerTree *newRootGroup)
	Reset the model and use a new root group node.
Qt::DropActions	supportedDropActions () const override
QSet< QgsScreenProperties >	targetScreenProperties () const
	Returns the target screen properties to use when generating icons.
bool	testFlag (Flag f) const
	Check whether a flag is enabled.
void	waitForHitTestBlocking ()
	When a current hit test for visible legend items is in progress, calling this method will block until that hit test is complete.

Additional Inherited Members
Public Types inherited from QgsLayerTreeModel
enum	Flag {   ShowLegend = 0x0001 , ShowLegendAsTree = 0x0004 , DeferredLegendInvalidation = 0x0008 , UseEmbeddedWidgets = 0x0010 ,   UseTextFormatting = 0x0020 , AllowNodeReorder = 0x1000 , AllowNodeRename = 0x2000 , AllowNodeChangeVisibility = 0x4000 ,   AllowLegendChangeState = 0x8000 , ActionHierarchical = 0x10000 , UseThreadedHitTest = 0x20000 }
typedef QFlags< Flag >	Flags
Static Public Member Functions inherited from QgsLayerTreeModel
static QgsLayerTreeModelLegendNode *	index2legendNode (const QModelIndex &index)
	Returns legend node for given index.
static int	scaleIconSize (int standardSize)
	Scales an layer tree model icon size to compensate for display pixel density, making the icon size hi-dpi friendly, whilst still resulting in pixel-perfect sizes for low-dpi displays.
Protected Slots inherited from QgsLayerTreeModel
void	invalidateLegendMapBasedData ()
void	layerFlagsChanged ()
	Emitted when layer flags have changed.
void	layerLegendChanged ()
void	layerNeedsUpdate ()
void	legendNodeDataChanged ()
void	nodeAddedChildren (QgsLayerTreeNode *node, int indexFrom, int indexTo)
void	nodeCustomPropertyChanged (QgsLayerTreeNode *node, const QString &key)
void	nodeLayerLoaded ()
void	nodeLayerWillBeUnloaded ()
void	nodeNameChanged (QgsLayerTreeNode *node, const QString &name)
	Updates model when node's name has changed.
void	nodeRemovedChildren ()
void	nodeVisibilityChanged (QgsLayerTreeNode *node)
void	nodeWillAddChildren (QgsLayerTreeNode *node, int indexFrom, int indexTo)
void	nodeWillRemoveChildren (QgsLayerTreeNode *node, int indexFrom, int indexTo)
Protected Member Functions inherited from QgsLayerTreeModel
void	addLegendToLayer (QgsLayerTreeLayer *nodeL)
void	connectToLayer (QgsLayerTreeLayer *nodeLayer)
void	connectToLayers (QgsLayerTreeGroup *parentGroup)
void	connectToRootNode ()
QgsRenderContext *	createTemporaryRenderContext () const
	Returns a temporary render context.
void	disconnectFromLayer (QgsLayerTreeLayer *nodeLayer)
void	disconnectFromLayers (QgsLayerTreeGroup *parentGroup)
void	disconnectFromRootNode ()
QList< QgsLayerTreeModelLegendNode * >	filterLegendNodes (const QList< QgsLayerTreeModelLegendNode * > &nodes)
	Filter nodes from QgsMapLayerLegend according to the current filtering rules.
QModelIndex	indexOfParentLayerTreeNode (QgsLayerTreeNode *parentNode) const
void	legendCleanup ()
bool	legendEmbeddedInParent (QgsLayerTreeLayer *nodeLayer) const
QIcon	legendIconEmbeddedInParent (QgsLayerTreeLayer *nodeLayer) const
void	legendInvalidateMapBasedData ()
QVariant	legendNodeData (QgsLayerTreeModelLegendNode *node, int role) const
Qt::ItemFlags	legendNodeFlags (QgsLayerTreeModelLegendNode *node) const
QModelIndex	legendNodeIndex (int row, int column, QgsLayerTreeModelLegendNode *node) const
int	legendNodeRowCount (QgsLayerTreeModelLegendNode *node) const
QModelIndex	legendParent (QgsLayerTreeModelLegendNode *legendNode) const
QModelIndex	legendRootIndex (int row, int column, QgsLayerTreeLayer *nL) const
int	legendRootRowCount (QgsLayerTreeLayer *nL) const
void	recursivelyEmitDataChanged (const QModelIndex &index=QModelIndex())
	emit dataChanged() for layer tree node items
void	refreshScaleBasedLayers (const QModelIndex &index=QModelIndex(), double previousScale=0.0)
	Updates layer data for scale dependent layers, should be called when map scale changes.
void	removeLegendFromLayer (QgsLayerTreeLayer *nodeLayer)
LayerLegendTree *	tryBuildLegendTree (const QList< QgsLayerTreeModelLegendNode * > &nodes)
Static Protected Member Functions inherited from QgsLayerTreeModel
static QIcon	iconGroup ()
Protected Attributes inherited from QgsLayerTreeModel
int	mAutoCollapseLegendNodesCount = -1
	Minimal number of nodes when legend should be automatically collapsed. -1 = disabled.
QPersistentModelIndex	mCurrentIndex
	Current index - will be underlined.
QTimer	mDeferLegendInvalidationTimer
std::unique_ptr< QgsLayerTreeFilterSettings >	mFilterSettings
Flags	mFlags
	Sets of flags for the model.
QFont	mFontGroup
QFont	mFontLayer
QMap< QString, QSet< QString > >	mHitTestResults
QPointer< QgsMapHitTestTask >	mHitTestTask
QSet< QgsLayerTreeLayer * >	mInvalidatedNodes
	Keep track of layer nodes for which the legend size needs to be recalculated.
QMap< QString, QString >	mLayerStyleOverrides
	Overrides of map layers' styles: key = layer ID, value = style XML.
QHash< QgsLayerTreeLayer *, LayerLegendData >	mLegend
	Per layer data about layer's legend nodes.
double	mLegendFilterByScale = 0
	scale denominator for filtering of legend nodes (<= 0 means no filtering)
int	mLegendMapViewDpi = 0
double	mLegendMapViewMupp = 0
double	mLegendMapViewScale = 0
QgsLayerTree *	mRootNode = nullptr
	Pointer to the root node of the layer tree. Not owned by the model.
QSet< QgsScreenProperties >	mTargetScreenProperties

Detailed Description

Item model implementation based on layer tree model for layout legend.

Overrides some functionality of QgsLayerTreeModel to better fit the needs of layout legends.

Definition at line 42 of file qgslayoutitemlegend.h.

Constructor & Destructor Documentation

QgsLegendModel() [1/2]

QgsLegendModel::QgsLegendModel	(	QgsLayerTree *	rootNode,
		QObject *	parent = nullptr,
		QgsLayoutItemLegend *	layout = nullptr
	)

Construct the model based on the given layer tree.

Definition at line 1374 of file qgslayoutitemlegend.cpp.

QgsLegendModel() [2/2]

QgsLegendModel::QgsLegendModel	(	QgsLayerTree *	rootNode,
		QgsLayoutItemLegend *	layout
	)

Alternative constructor.

Definition at line 1384 of file qgslayoutitemlegend.cpp.

Member Function Documentation

clearCachedData()

void QgsLegendModel::clearCachedData

(

QgsLayerTreeNode *

node

)

const

Clears any previously cached data for the specified node.

Since

QGIS 3.14

Definition at line 1452 of file qgslayoutitemlegend.cpp.

data()

QVariant QgsLegendModel::data ( const QModelIndex &  index, int  role  ) const

override

Definition at line 1394 of file qgslayoutitemlegend.cpp.

flags()

Qt::ItemFlags QgsLegendModel::flags ( const QModelIndex &  index ) const

override

Definition at line 1431 of file qgslayoutitemlegend.cpp.

layerLegendNodes()

QList< QgsLayerTreeModelLegendNode * > QgsLegendModel::layerLegendNodes	(	QgsLayerTreeLayer *	nodeLayer,
		bool	skipNodeEmbeddedInParent = false
	)		const

Returns filtered list of active legend nodes attached to a particular layer node (by default it returns also legend node embedded in parent layer node (if any) unless skipNodeEmbeddedInParent is true)

Note

Parameter skipNodeEmbeddedInParent added in QGIS 2.18

Not available in Python bindings

See also

layerOriginalLegendNodes()

Since

QGIS 3.10

Definition at line 1440 of file qgslayoutitemlegend.cpp.

refreshLegend

void QgsLegendModel::refreshLegend ( )

signal

Emitted to refresh the legend.

Since

QGIS 3.10

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

• /build/qgis-3.41.0+git20241119+45a0abf3bec+99sid/src/core/layout/qgslayoutitemlegend.h
• /build/qgis-3.41.0+git20241119+45a0abf3bec+99sid/src/core/layout/qgslayoutitemlegend.cpp