pal::Problem Class Reference

Representation of a labeling problem. More...

#include <problem.h>

Public Member Functions
	Problem (const Problem &other)=delete
	Problem (const QgsRectangle &extent)
	Constructor for Problem.
	~Problem ()
void	addCandidatePosition (std::unique_ptr< LabelPosition > position)
	Adds a candidate label position to the problem.
PalRtree< LabelPosition > &	allCandidatesIndex ()
	Returns the index containing all label candidates.
void	chainSearch (QgsRenderContext &context)
	Test with very-large scale neighborhood.
LabelPosition *	featureCandidate (int feature, int candidate) const
	Returns the candidate corresponding to the specified feature and candidate index.
int	featureCandidateCount (int feature) const
	Returns the number of candidates generated for the feature at the specified index.
std::size_t	featureCount () const
	Returns the total number of features considered during the labeling problem.
QList< LabelPosition * >	getSolution (bool returnInactive, QList< LabelPosition * > *unlabeled=nullptr)
	Solves the labeling problem, selecting the best candidate locations for all labels and returns a list of these calculated label positions.
void	init_sol_falp ()
Problem &	operator= (const Problem &other)=delete
std::vector< std::unique_ptr< LabelPosition > > *	positionsWithNoCandidates ()
	Returns a reference to the list of label positions which correspond to features with no candidates.
void	reduce ()
	Gets called AFTER extractProblem.

Friends
class	Pal

Detailed Description

Representation of a labeling problem.

Note

not available in Python bindings

Definition at line 74 of file problem.h.

Constructor & Destructor Documentation

Problem() [1/2]

Problem::Problem

(

const QgsRectangle &

extent

)

Constructor for Problem.

The extent argument specifies the bounds of the incoming coordinates.

Definition at line 46 of file problem.cpp.

~Problem()

Problem::~Problem ( )

default

Problem() [2/2]

pal::Problem::Problem ( const Problem & other )

delete

Member Function Documentation

addCandidatePosition()

void Problem::addCandidatePosition

(

std::unique_ptr< LabelPosition >

position

)

Adds a candidate label position to the problem.

Parameters

position

label candidate position. Ownership is transferred to Problem.

Definition at line 53 of file problem.cpp.

allCandidatesIndex()

PalRtree< LabelPosition > & pal::Problem::allCandidatesIndex ( )

inline

Returns the index containing all label candidates.

Definition at line 158 of file problem.h.

chainSearch()

void Problem::chainSearch

(

QgsRenderContext &

context

)

Test with very-large scale neighborhood.

Definition at line 547 of file problem.cpp.

featureCandidate()

LabelPosition * pal::Problem::featureCandidate ( int feature, int candidate ) const

inline

Returns the candidate corresponding to the specified feature and candidate index.

Definition at line 113 of file problem.h.

featureCandidateCount()

int pal::Problem::featureCandidateCount ( int feature ) const

inline

Returns the number of candidates generated for the feature at the specified index.

Definition at line 108 of file problem.h.

featureCount()

std::size_t pal::Problem::featureCount ( ) const

inline

Returns the total number of features considered during the labeling problem.

Definition at line 103 of file problem.h.

getSolution()

QList< LabelPosition * > Problem::getSolution	(	bool	returnInactive,
		QList< LabelPosition * > *	unlabeled = nullptr )

Solves the labeling problem, selecting the best candidate locations for all labels and returns a list of these calculated label positions.

If returnInactive is true, then the best positions for ALL labels will be returned, regardless of whether these labels overlap other labels.

If the optional unlabeled list is specified, it will be filled with a list of all feature labels which could not be placed in the returned solution (e.g. due to overlaps or other constraints).

Ownership of the returned labels is not transferred - it resides with the pal object.

Definition at line 624 of file problem.cpp.

init_sol_falp()

void Problem::init_sol_falp

(

)

Definition at line 155 of file problem.cpp.

operator=()

Problem & pal::Problem::operator= ( const Problem & other )

delete

positionsWithNoCandidates()

std::vector< std::unique_ptr< LabelPosition > > * pal::Problem::positionsWithNoCandidates ( )

inline

Returns a reference to the list of label positions which correspond to features with no candidates.

Ownership of positions added to this list is transferred to the problem.

Definition at line 150 of file problem.h.

reduce()

void Problem::reduce

(

)

Gets called AFTER extractProblem.

Definition at line 60 of file problem.cpp.

Friends And Related Symbol Documentation

Pal

friend class Pal

friend

Definition at line 76 of file problem.h.

---

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

• /build/qgis-3.99.0+git20251210+2fe06baccd8+99sid/src/core/pal/problem.h
• /build/qgis-3.99.0+git20251210+2fe06baccd8+99sid/src/core/pal/problem.cpp