QgsMapHitTest Class Reference

Class that 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. More...

#include <qgsmaphittest.h>

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

Public Member Functions
	QgsMapHitTest (const QgsMapSettings &settings, const QgsGeometry &polygon=QgsGeometry(), const QgsMapHitTest::LayerFilterExpression &layerFilterExpression=QgsMapHitTest::LayerFilterExpression())
	QgsMapHitTest (const QgsMapSettings &settings, const QgsMapHitTest::LayerFilterExpression &layerFilterExpression)
	Constructor version used with only expressions to filter symbols (no extent or polygon intersection) More...
bool	legendKeyVisible (const QString &ruleKey, QgsVectorLayer *layer) const
	Tests whether a given legend key is visible for a specified layer. More...
void	run ()
	Runs the map hit test. More...
bool	symbolVisible (QgsSymbol *symbol, QgsVectorLayer *layer) const
	Tests whether a symbol is visible for a specified layer. More...

Detailed Description

Class that 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.

Since

QGIS 2.6

Definition at line 37 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 41 of file qgsmaphittest.h.

Constructor & Destructor Documentation

QgsMapHitTest() [1/2]

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

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 31 of file qgsmaphittest.cpp.

QgsMapHitTest() [2/2]

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 42 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()

Since

QGIS 2.14

Definition at line 97 of file qgsmaphittest.cpp.

run()

void QgsMapHitTest::run

(

)

Runs the map hit test.

Definition at line 49 of file qgsmaphittest.cpp.

symbolVisible()

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()

Since

QGIS 2.12

Definition at line 89 of file qgsmaphittest.cpp.

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

• /build/qgis-3.26.3+32focal/src/core/qgsmaphittest.h
• /build/qgis-3.26.3+32focal/src/core/qgsmaphittest.cpp