QgsMapHitTest Class Reference

Runs a hit test with given map settings. More...

#include <qgsmaphittest.h>

Public Types
typedef QMap< QString, QString >	LayerFilterExpression
	Maps an expression string to a layer id.

Public Member Functions
	QgsMapHitTest (const QgsLayerTreeFilterSettings &settings)
	Constructor based off layer tree filter settings.
	QgsMapHitTest (const QgsMapSettings &settings, const QgsGeometry &polygon=QgsGeometry(), const QgsMapHitTest::LayerFilterExpression &layerFilterExpression=QgsMapHitTest::LayerFilterExpression())
	Constructor for QgsMapHitTest.
	QgsMapHitTest (const QgsMapSettings &settings, const QgsMapHitTest::LayerFilterExpression &layerFilterExpression)
	Constructor version used with only expressions to filter symbols (no extent or polygon intersection).
bool	legendKeyVisible (const QString &ruleKey, QgsVectorLayer *layer) const
	Tests whether a given legend key is visible for a specified layer.
QMap< QString, QSet< QString > >	results () const
	Returns the hit test results, which are a map of layer ID to visible symbol legend keys.
PRIVATE QMap< QString, std::pair< double, double > >	resultsRenderersUpdatedCanvas () const
	Returns the hit test results, for layers with UpdatedCanvas renderers (raster/mesh layers).
void	run ()
	Runs the map hit test.
bool	symbolVisible (QgsSymbol *symbol, QgsVectorLayer *layer) const
	Tests whether a symbol is visible for a specified layer.

Friends
class	QgsMapHitTestTask

Detailed Description

Runs a hit test with given map settings.

Based on the hit test it returns which symbols will be visible on the map - this is useful for content based legend.

Definition at line 48 of file qgsmaphittest.h.

Member Typedef Documentation

LayerFilterExpression

typedef QMap<QString, QString> QgsMapHitTest::LayerFilterExpression

Maps an expression string to a layer id.

Definition at line 52 of file qgsmaphittest.h.

Constructor & Destructor Documentation

QgsMapHitTest() [1/3]

QgsMapHitTest::QgsMapHitTest	(	const QgsMapSettings &	settings,
		const QgsGeometry &	polygon = QgsGeometry(),
		const QgsMapHitTest::LayerFilterExpression &	layerFilterExpression = QgsMapHitTest::LayerFilterExpression() )

Constructor for QgsMapHitTest.

Parameters

settings	Map settings used to evaluate symbols
polygon	Polygon geometry to refine the hit test
layerFilterExpression	Expression string for each layer id to evaluate in order to refine the symbol selection

Definition at line 34 of file qgsmaphittest.cpp.

QgsMapHitTest() [2/3]

QgsMapHitTest::QgsMapHitTest	(	const QgsMapSettings &	settings,
		const QgsMapHitTest::LayerFilterExpression &	layerFilterExpression )

Constructor version used with only expressions to filter symbols (no extent or polygon intersection).

Definition at line 41 of file qgsmaphittest.cpp.

QgsMapHitTest() [3/3]

QgsMapHitTest::QgsMapHitTest

(

const QgsLayerTreeFilterSettings &

settings

)

Constructor based off layer tree filter settings.

Since

QGIS 3.32

Definition at line 48 of file qgsmaphittest.cpp.

Member Function Documentation

legendKeyVisible()

bool QgsMapHitTest::legendKeyVisible	(	const QString &	ruleKey,
		QgsVectorLayer *	layer ) const

Tests whether a given legend key is visible for a specified layer.

Parameters

ruleKey	legend rule key
layer	vector layer

See also

symbolVisible()

Definition at line 155 of file qgsmaphittest.cpp.

results()

QMap< QString, QSet< QString > > QgsMapHitTest::results

(

)

const

Returns the hit test results, which are a map of layer ID to visible symbol legend keys.

Note

Not available in Python bindings

Since

QGIS 3.32

Definition at line 126 of file qgsmaphittest.cpp.

resultsRenderersUpdatedCanvas()

PRIVATE QMap< QString, std::pair< double, double > > QgsMapHitTest::resultsRenderersUpdatedCanvas ( ) const

inline

Returns the hit test results, for layers with UpdatedCanvas renderers (raster/mesh layers).

Results are given as QMap of layer IDs to pairs of (min, max) values.

Since

QGIS 4.0

Definition at line 102 of file qgsmaphittest.h.

run()

void QgsMapHitTest::run

(

)

Runs the map hit test.

Definition at line 54 of file qgsmaphittest.cpp.

symbolVisible()

PRIVATE bool QgsMapHitTest::symbolVisible	(	QgsSymbol *	symbol,
		QgsVectorLayer *	layer ) const

Tests whether a symbol is visible for a specified layer.

Parameters

symbol	symbol to find
layer	vector layer

See also

legendKeyVisible()

Definition at line 143 of file qgsmaphittest.cpp.

Friends And Related Symbol Documentation

QgsMapHitTestTask

friend class QgsMapHitTestTask

friend

Definition at line 222 of file qgsmaphittest.h.

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

• /build/qgis-3.99.0+git20260124+a8882ad4560+99sid/src/core/qgsmaphittest.h
• /build/qgis-3.99.0+git20260124+a8882ad4560+99sid/src/core/qgsmaphittest.cpp