The QgsLegendRendererItem class is abstract interface for legend items returned from QgsMapLayerLegend implementation. More...

#include <qgslayertreemodellegendnode.h>

Inheritance diagram for QgsLayerTreeModelLegendNode:

[legend]

Classes
struct	ItemContext

struct	ItemMetrics

Public Types
enum	LegendNodeRoles { RuleKeyRole = Qt::UserRole, ParentRuleKeyRole }

Signals
void	dataChanged ()
	Emitted on internal data change so the layer tree model can forward the signal to views. More...

Public Member Functions
virtual QVariant	data (int role) const =0
	Returns data associated with the item. Must be implemented in derived class. More...

virtual ItemMetrics	draw (const QgsLegendSettings &settings, ItemContext *ctx)
	Entry point called from QgsLegendRenderer to do the rendering. More...

virtual QSizeF	drawSymbol (const QgsLegendSettings &settings, ItemContext *ctx, double itemHeight) const
	Draws symbol on the left side of the item. More...

virtual QSizeF	drawSymbolText (const QgsLegendSettings &settings, ItemContext *ctx, QSizeF symbolSize) const
	Draws label on the right side of the item. More...

void	exportSymbolTextToJson (const QgsLegendSettings &settings, QJsonObject &json) const
	Adds a label in a JSON object with the key "title". More...

virtual void	exportSymbolToJson (const QgsLegendSettings &settings, const QgsRenderContext &context, QJsonObject &json) const
	Adds a symbol in base64 string within a JSON object with the key "icon". More...

void	exportToJson (const QgsLegendSettings &settings, const QgsRenderContext &context, QJsonObject &json)
	Entry point called from QgsLegendRenderer to do the rendering in a JSON object. More...

virtual Qt::ItemFlags	flags () const
	Returns item flags associated with the item. Default implementation returns Qt::ItemIsEnabled. More...

virtual void	invalidateMapBasedData ()
	Notification from model that information from associated map view has changed. More...

virtual bool	isEmbeddedInParent () const

virtual bool	isScaleOK (double scale) const

QgsLayerTreeLayer *	layerNode () const
	Returns pointer to the parent layer node. More...

QgsLayerTreeModel *	model () const
	Returns pointer to model owning this legend node. More...

virtual bool	setData (const QVariant &value, int role)
	Sets some data associated with the item. Default implementation does nothing and returns `false`. More...

virtual void	setEmbeddedInParent (bool embedded)

virtual void	setUserLabel (const QString &userLabel)

virtual QString	userLabel () const

Protected Member Functions
	QgsLayerTreeModelLegendNode (QgsLayerTreeLayer nodeL, QObject parent=nullptr)
	Construct the node with pointer to its parent layer node. More...

QgsRenderContext *	createTemporaryRenderContext () const
	Returns a temporary context or `nullptr` if legendMapViewData are not valid. More...

Protected Attributes
bool	mEmbeddedInParent

QgsLayerTreeLayer *	mLayerNode = nullptr

QString	mUserLabel

Detailed Description

The QgsLegendRendererItem class is abstract interface for legend items returned from QgsMapLayerLegend implementation.

The objects are used in QgsLayerTreeModel. Custom implementations may offer additional interactivity and customized look.

Since: QGIS 2.6

Definition at line 49 of file qgslayertreemodellegendnode.h.

Member Enumeration Documentation

◆ LegendNodeRoles

enum QgsLayerTreeModelLegendNode::LegendNodeRoles

Enumerator
RuleKeyRole	Rule key of the node (QString)
ParentRuleKeyRole	Rule key of the parent legend node - for legends with tree hierarchy (QString). Added in 2.8.

Definition at line 62 of file qgslayertreemodellegendnode.h.

Constructor & Destructor Documentation

◆ QgsLayerTreeModelLegendNode()

QgsLayerTreeModelLegendNode::QgsLayerTreeModelLegendNode	(	QgsLayerTreeLayer *	nodeL,
		QObject *	parent = `nullptr`
	)

explicitprotected

Construct the node with pointer to its parent layer node.

Definition at line 38 of file qgslayertreemodellegendnode.cpp.

Member Function Documentation

◆ createTemporaryRenderContext()

QgsRenderContext * QgsLayerTreeModelLegendNode::createTemporaryRenderContext ( ) const

protected

Returns a temporary context or nullptr if legendMapViewData are not valid.

Definition at line 351 of file qgslayertreemodellegendnode.cpp.

◆ data()

virtual QVariant QgsLayerTreeModelLegendNode::data ( int role ) const

pure virtual

Returns data associated with the item. Must be implemented in derived class.

Implemented in QgsDataDefinedSizeLegendNode, QgsWmsLegendNode, QgsRasterSymbolLegendNode, QgsImageLegendNode, QgsSimpleLegendNode, and QgsSymbolLegendNode.

◆ dataChanged

void QgsLayerTreeModelLegendNode::dataChanged ( )

signal

Emitted on internal data change so the layer tree model can forward the signal to views.

◆ draw()

QgsLayerTreeModelLegendNode::ItemMetrics QgsLayerTreeModelLegendNode::draw	(	const QgsLegendSettings &	settings,
		ItemContext *	ctx
	)

virtual

Entry point called from QgsLegendRenderer to do the rendering.

Default implementation calls drawSymbol() and drawSymbolText() methods.

If ctx is nullptr, this is just first stage when preparing layout - without actual rendering.

Reimplemented in QgsDataDefinedSizeLegendNode.

Definition at line 63 of file qgslayertreemodellegendnode.cpp.

◆ drawSymbol()

QSizeF QgsLayerTreeModelLegendNode::drawSymbol	(	const QgsLegendSettings &	settings,
		ItemContext *	ctx,
		double	itemHeight
	)		const

virtual

Draws symbol on the left side of the item.

Parameters

settings	Legend layout configuration
ctx	Context for rendering - may be `nullptr` if only doing layout without actual rendering
itemHeight	Minimal height of the legend item - used for correct positioning when rendering

Returns: Real size of the symbol (may be bigger than "normal" symbol size from settings)

Reimplemented in QgsWmsLegendNode, QgsRasterSymbolLegendNode, QgsImageLegendNode, and QgsSymbolLegendNode.

Definition at line 85 of file qgslayertreemodellegendnode.cpp.

◆ drawSymbolText()

QSizeF QgsLayerTreeModelLegendNode::drawSymbolText	(	const QgsLegendSettings &	settings,
		ItemContext *	ctx,
		QSizeF	symbolSize
	)		const

virtual

Draws label on the right side of the item.

Parameters

settings	Legend layout configuration
ctx	Context for rendering - may be `nullptr` if only doing layout without actual rendering
symbolSize	Real size of the associated symbol - used for correct positioning when rendering