A class to render labels. More...

#include <qgslabel.h>

Classes
struct	labelpoint

Public Types
enum	LabelField { Text = 0, Family, Size, SizeType, Bold, Italic, Underline, Color, XCoordinate, YCoordinate, XOffset, YOffset, Angle, Alignment, BufferEnabled, BufferSize, BufferColor, BufferBrush, BorderWidth, BorderColor, BorderStyle, MultilineEnabled, StrikeOut, LabelFieldCount }

Public Member Functions
	QgsLabel (const QgsFields &fields)

	~QgsLabel ()

void	addRequiredFields (QgsAttributeList &fields) const
	add vector of required fields to existing list of fields More...

QgsFields &	fields ()
	Available vector fields. More...

QString	fieldValue (int attr, QgsFeature &feature)
	Get field value if : 1) field name is not empty 2) field exists 3) value is defined otherwise returns empty string. More...

bool	isInScaleRange (double scale) const
	Return true if the label is visible at the given scale. More...

QgsLabelAttributes *	labelAttributes ()
	Pointer to default attributes. More...

QString	labelField (int attr) const
	label field More...

float	maxScale () const

float	minScale () const

void	readXML (const QDomNode &node)
	Reads the renderer configuration from an XML file. More...

void	renderLabel (QgsRenderContext &renderContext, QgsFeature &feature, bool selected, QgsLabelAttributes *classAttributes=nullptr)
	render label More...

bool	scaleBasedVisibility () const

void	setFields (const QgsFields &fields)
	Set available fields. More...

void	setLabelField (int attr, int fieldIndex)
	Set label field. More...

void	setMaxScale (float theMaxScale)
	Accessor and mutator for the maximum scale member. More...

void	setMinScale (float theMinScale)
	Accessor and mutator for the minimum scale member. More...

void	setScaleBasedVisibility (bool theVisibilityFlag)
	Accessor and mutator for the scale based visilibility flag. More...

void	writeXML (QDomNode &label_node, QDomDocument &document) const
	Writes the contents of the renderer to a configuration file. More...

Detailed Description

A class to render labels.

Label rendering properties can be either specified directly or in most cases determined dynamically based on the value of an attribute.

Definition at line 51 of file qgslabel.h.

Member Enumeration Documentation

◆ LabelField

enum QgsLabel::LabelField

Enumerator
Text
Family
Size
SizeType
Bold
Italic
Underline
Color
XCoordinate
YCoordinate
XOffset
YOffset
Angle
Alignment
BufferEnabled
BufferSize
BufferColor
BufferBrush
BorderWidth
BorderColor
BorderStyle
MultilineEnabled
StrikeOut
LabelFieldCount

Definition at line 59 of file qgslabel.h.

Constructor & Destructor Documentation

◆ QgsLabel()

QgsLabel::QgsLabel ( const QgsFields & fields )

Definition at line 47 of file qgslabel.cpp.

◆ ~QgsLabel()

QgsLabel::~QgsLabel ( )

Definition at line 61 of file qgslabel.cpp.

Member Function Documentation

◆ addRequiredFields()

void QgsLabel::addRequiredFields ( QgsAttributeList & fields ) const

add vector of required fields to existing list of fields

Definition at line 459 of file qgslabel.cpp.

◆ fields()

QgsFields & QgsLabel::fields ( )

Available vector fields.

Definition at line 486 of file qgslabel.cpp.

◆ fieldValue()

QString QgsLabel::fieldValue	(	int	attr,
		QgsFeature &	feature
	)

Get field value if : 1) field name is not empty 2) field exists 3) value is defined otherwise returns empty string.

Definition at line 66 of file qgslabel.cpp.

◆ isInScaleRange()

bool QgsLabel::isInScaleRange ( double scale ) const

Return true if the label is visible at the given scale.

Definition at line 1418 of file qgslabel.cpp.

◆ labelAttributes()

QgsLabelAttributes * QgsLabel::labelAttributes ( )

Pointer to default attributes.

Note: this replaces the to-be-deprecated layerAttributes method.; introduced in QGIS 1.4

Definition at line 510 of file qgslabel.cpp.

◆ labelField()

QString QgsLabel::labelField ( int attr ) const

label field

Definition at line 499 of file qgslabel.cpp.

◆ maxScale()

float QgsLabel::maxScale ( ) const

Definition at line 1413 of file qgslabel.cpp.

◆ minScale()

float QgsLabel::minScale ( ) const

Definition at line 1403 of file qgslabel.cpp.

◆ readXML()

void QgsLabel::readXML ( const QDomNode & node )

Reads the renderer configuration from an XML file.

Parameters

node	the Dom node to read

Definition at line 745 of file qgslabel.cpp.

◆ renderLabel()

void QgsLabel::renderLabel	(	QgsRenderContext &	renderContext,
		QgsFeature &	feature,
		bool	selected,
		QgsLabelAttributes *	classAttributes = `nullptr`
	)

render label

Parameters

renderContext	the render context
feature	feature to render the label for
selected	feature is selected
classAttributes	attributes to create the label from

Definition at line 72 of file qgslabel.cpp.

◆ scaleBasedVisibility()

bool QgsLabel::scaleBasedVisibility ( ) const

Definition at line 1393 of file qgslabel.cpp.

◆ setFields()

void QgsLabel::setFields ( const QgsFields & fields )

Set available fields.

Definition at line 481 of file qgslabel.cpp.

◆ setLabelField()

void QgsLabel::setLabelField	(	int	attr,
		int	fieldIndex
	)

Set label field.

Definition at line 491 of file qgslabel.cpp.

◆ setMaxScale()

void QgsLabel::setMaxScale ( float theMaxScale )

Accessor and mutator for the maximum scale member.

Definition at line 1408 of file qgslabel.cpp.

◆ setMinScale()

void QgsLabel::setMinScale ( float theMinScale )

Accessor and mutator for the minimum scale member.

Definition at line 1398 of file qgslabel.cpp.

◆ setScaleBasedVisibility()

void QgsLabel::setScaleBasedVisibility ( bool theVisibilityFlag )

Accessor and mutator for the scale based visilibility flag.

Definition at line 1388 of file qgslabel.cpp.

◆ writeXML()

void QgsLabel::writeXML	(	QDomNode &	label_node,
		QDomDocument &	document
	)		const

Writes the contents of the renderer to a configuration file.

Definition at line 1038 of file qgslabel.cpp.

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

/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgslabel.h
/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgslabel.cpp

Classes

Public Types

Public Member Functions