Contains settings related to how the label engine places and formats labels for line features (or polygon features which are labeled in a "perimeter" style mode). More...

#include <qgslabellinesettings.h>

Public Types
enum class	AnchorClipping : int { UseVisiblePartsOfLine , UseEntireLine }
	Clipping behavior for line anchor calculation. More...

enum class	AnchorTextPoint : int { StartOfText , CenterOfText , EndOfText , FollowPlacement }
	Anchor point of label text. More...

enum class	AnchorType : int { HintOnly , Strict }
	Line anchor types. More...

enum class	DirectionSymbolPlacement : int { SymbolLeftRight , SymbolAbove , SymbolBelow }
	Placement options for direction symbols. More...

Public Member Functions
bool	addDirectionSymbol () const
	Returns `true` if '<' or '>' (or custom strings set via leftDirectionSymbol and rightDirectionSymbol) will be automatically added to the label text, pointing in the direction of the line or polygon ring.

AnchorClipping	anchorClipping () const
	Returns the line anchor clipping mode, which dictates how line strings are clipped before calculating the line anchor placement.

AnchorTextPoint	anchorTextPoint () const
	Returns the line anchor text point, which dictates which part of the label text should be placed at the lineAnchorPercent().

AnchorType	anchorType () const
	Returns the line anchor type, which dictates how the lineAnchorPercent() setting is handled.

DirectionSymbolPlacement	directionSymbolPlacement () const
	Returns the placement for direction symbols.

QString	leftDirectionSymbol () const
	Returns the string to use for left direction arrows.

double	lineAnchorPercent () const
	Returns the percent along the line at which labels should be placed.

bool	mergeLines () const
	Returns `true` if connected line features with identical label text should be merged prior to generating label positions.

double	overrunDistance () const
	Returns the distance which labels are allowed to overrun past the start or end of line features.

QgsMapUnitScale	overrunDistanceMapUnitScale () const
	Returns the map unit scale for label overrun distance.

Qgis::RenderUnit	overrunDistanceUnit () const
	Returns the units for label overrun distance.

Qgis::LabelLinePlacementFlags	placementFlags () const
	Returns the line placement flags, which dictate how line labels can be placed above or below the lines.

bool	reverseDirectionSymbol () const
	Returns `true` if direction symbols should be reversed.

QString	rightDirectionSymbol () const
	Returns the string to use for right direction arrows.

void	setAddDirectionSymbol (bool enabled)
	Sets whether '<' or '>' (or custom strings set via leftDirectionSymbol and rightDirectionSymbol) will be automatically added to the label text, pointing in the direction of the line or polygon ring.

void	setAnchorClipping (AnchorClipping clipping)
	Sets the line anchor clipping mode, which dictates how line strings are clipped before calculating the line anchor placement.

void	setAnchorTextPoint (AnchorTextPoint point)
	Sets the line anchor text point, which dictates which part of the label text should be placed at the lineAnchorPercent().

void	setAnchorType (AnchorType type)
	Sets the line anchor type, which dictates how the lineAnchorPercent() setting is handled.

void	setDirectionSymbolPlacement (DirectionSymbolPlacement placement)
	Sets the placement for direction symbols.

void	setLeftDirectionSymbol (const QString &symbol)
	Sets the string to use for left direction arrows.

void	setLineAnchorPercent (double percent)
	Sets the percent along the line at which labels should be placed.

void	setMergeLines (bool merge)
	Sets whether connected line features with identical label text should be merged prior to generating label positions.

void	setOverrunDistance (double distance)
	Sets the distance which labels are allowed to overrun past the start or end of line features.

void	setOverrunDistanceMapUnitScale (const QgsMapUnitScale &scale)
	Sets the map unit scale for label overrun distance.

void	setOverrunDistanceUnit (const Qgis::RenderUnit &unit)
	Sets the unit for label overrun distance.

void	setPlacementFlags (Qgis::LabelLinePlacementFlags flags)
	Returns the line placement flags, which dictate how line labels can be placed above or below the lines.

void	setReverseDirectionSymbol (bool reversed)
	Sets whether the direction symbols should be reversed.

void	setRightDirectionSymbol (const QString &symbol)
	Sets the string to use for right direction arrows.

void	updateDataDefinedProperties (const QgsPropertyCollection &properties, QgsExpressionContext &context)
	Updates the line settings to respect any data defined properties set within the specified properties collection.

Detailed Description

Contains settings related to how the label engine places and formats labels for line features (or polygon features which are labeled in a "perimeter" style mode).

Since: QGIS 3.16

Definition at line 37 of file qgslabellinesettings.h.

Member Enumeration Documentation

◆ AnchorClipping

enum class QgsLabelLineSettings::AnchorClipping : int

strong

Clipping behavior for line anchor calculation.

Since: QGIS 3.20

Enumerator
UseVisiblePartsOfLine	Only visible parts of lines are considered when calculating the line anchor for labels.
UseEntireLine	Entire original feature line geometry is used when calculating the line anchor for labels.

Definition at line 69 of file qgslabellinesettings.h.

◆ AnchorTextPoint

enum class QgsLabelLineSettings::AnchorTextPoint : int

strong

Anchor point of label text.

Since: QGIS 3.26

Enumerator
StartOfText	Anchor using start of text.
CenterOfText	Anchor using center of text.
EndOfText	Anchor using end of text.
FollowPlacement	Automatically set the anchor point based on the lineAnchorPercent() value. Values <25% will use the start of text, values > 75% will use the end of text, and values in between will use the center of the text.

Definition at line 81 of file qgslabellinesettings.h.

◆ AnchorType

enum class QgsLabelLineSettings::AnchorType : int

strong

Line anchor types.

Enumerator
HintOnly	Line anchor is a hint for preferred placement only, but other placements close to the hint are permitted.
Strict	Line anchor is a strict placement, and other placements are not permitted.

Definition at line 57 of file qgslabellinesettings.h.

◆ DirectionSymbolPlacement

enum class QgsLabelLineSettings::DirectionSymbolPlacement : int

strong

Placement options for direction symbols.

Enumerator
SymbolLeftRight	Place direction symbols on left/right of label.
SymbolAbove	Place direction symbols on above label.
SymbolBelow	Place direction symbols on below label.

Definition at line 46 of file qgslabellinesettings.h.

Member Function Documentation

◆ addDirectionSymbol()

bool QgsLabelLineSettings::addDirectionSymbol ( ) const

inline

Returns true if '<' or '>' (or custom strings set via leftDirectionSymbol and rightDirectionSymbol) will be automatically added to the label text, pointing in the direction of the line or polygon ring.

See also: setAddDirectionSymbol(); leftDirectionSymbol(); rightDirectionSymbol(); directionSymbolPlacement(); reverseDirectionSymbol()

Definition at line 139 of file qgslabellinesettings.h.

◆ anchorClipping()

AnchorClipping QgsLabelLineSettings::anchorClipping ( ) const

inline

Returns the line anchor clipping mode, which dictates how line strings are clipped before calculating the line anchor placement.

See also: setAnchorClipping(); anchorType(); lineAnchorPercent()

Since: QGIS 3.20

Definition at line 332 of file qgslabellinesettings.h.

◆ anchorTextPoint()

AnchorTextPoint QgsLabelLineSettings::anchorTextPoint ( ) const

inline

Returns the line anchor text point, which dictates which part of the label text should be placed at the lineAnchorPercent().

See also: setAnchorTextPoint()

Since: QGIS 3.26

Definition at line 354 of file qgslabellinesettings.h.

◆ anchorType()

AnchorType QgsLabelLineSettings::anchorType ( ) const

inline

Returns the line anchor type, which dictates how the lineAnchorPercent() setting is handled.

See also: setAnchorType(); lineAnchorPercent(); anchorClipping()

Definition at line 310 of file qgslabellinesettings.h.

◆ directionSymbolPlacement()

DirectionSymbolPlacement QgsLabelLineSettings::directionSymbolPlacement ( ) const

inline

Returns the placement for direction symbols.

This setting controls whether to place direction symbols to the left/right, above or below label.

See also: setDirectionSymbolPlacement(); addDirectionSymbol()

Definition at line 212 of file qgslabellinesettings.h.

◆ leftDirectionSymbol()

QString QgsLabelLineSettings::leftDirectionSymbol ( ) const

inline

Returns the string to use for left direction arrows.

See also: setLeftDirectionSymbol(); addDirectionSymbol(); rightDirectionSymbol()

Definition at line 161 of file qgslabellinesettings.h.

◆ lineAnchorPercent()

double QgsLabelLineSettings::lineAnchorPercent ( ) const

inline

Returns the percent along the line at which labels should be placed.

By default, this is 0.5 which indicates that labels should be placed as close to the center of the line as possible. A value of 0.0 indicates that the labels should be placed as close to the start of the line as possible, while a value of 1.0 pushes labels towards the end of the line.

See also: setLineAnchorPercent(); anchorTextPoint(); anchorType(); anchorClipping()

Definition at line 285 of file qgslabellinesettings.h.

◆ mergeLines()

bool QgsLabelLineSettings::mergeLines ( ) const

inline

Returns true if connected line features with identical label text should be merged prior to generating label positions.

See also: setMergeLines()

Definition at line 112 of file qgslabellinesettings.h.

◆ overrunDistance()

double QgsLabelLineSettings::overrunDistance ( ) const

inline

Returns the distance which labels are allowed to overrun past the start or end of line features.

See also: setOverrunDistance(); overrunDistanceUnit(); overrunDistanceMapUnitScale()

Definition at line 230 of file qgslabellinesettings.h.

◆ overrunDistanceMapUnitScale()

QgsMapUnitScale QgsLabelLineSettings::overrunDistanceMapUnitScale ( ) const

inline

Returns the map unit scale for label overrun distance.

See also: setOverrunDistanceMapUnitScale(); overrunDistance(); overrunDistanceUnit()

Definition at line 262 of file qgslabellinesettings.h.

◆ overrunDistanceUnit()

Qgis::RenderUnit QgsLabelLineSettings::overrunDistanceUnit ( ) const

inline

Returns the units for label overrun distance.

See also: setOverrunDistanceUnit(); overrunDistance(); overrunDistanceMapUnitScale()

Definition at line 246 of file qgslabellinesettings.h.

◆ placementFlags()

Qgis::LabelLinePlacementFlags QgsLabelLineSettings::placementFlags ( ) const

inline

Returns the line placement flags, which dictate how line labels can be placed above or below the lines.

See also: setPlacementFlags()

Definition at line 96 of file qgslabellinesettings.h.

◆ reverseDirectionSymbol()

bool QgsLabelLineSettings::reverseDirectionSymbol ( ) const

inline

Returns true if direction symbols should be reversed.

See also: setReverseDirectionSymbol()

Definition at line 195 of file qgslabellinesettings.h.

◆ rightDirectionSymbol()

QString QgsLabelLineSettings::rightDirectionSymbol ( ) const

inline

Returns the string to use for right direction arrows.

See also: setRightDirectionSymbol(); addDirectionSymbol(); leftDirectionSymbol()

Definition at line 179 of file qgslabellinesettings.h.

◆ setAddDirectionSymbol()

void QgsLabelLineSettings::setAddDirectionSymbol ( bool enabled )

inline

Sets whether '<' or '>' (or custom strings set via leftDirectionSymbol and rightDirectionSymbol) will be automatically added to the label text, pointing in the direction of the line or polygon ring.

See also: addDirectionSymbol(); setLeftDirectionSymbol(); setRightDirectionSymbol(); setDirectionSymbolPlacement(); setReverseDirectionSymbol()

Definition at line 152 of file qgslabellinesettings.h.

◆ setAnchorClipping()

void QgsLabelLineSettings::setAnchorClipping ( AnchorClipping clipping )

inline

Sets the line anchor clipping mode, which dictates how line strings are clipped before calculating the line anchor placement.

See also: anchorClipping(); setAnchorType(); setLineAnchorPercent()

Since: QGIS 3.20

Definition at line 344 of file qgslabellinesettings.h.

◆ setAnchorTextPoint()

void QgsLabelLineSettings::setAnchorTextPoint ( AnchorTextPoint point )

inline

Sets the line anchor text point, which dictates which part of the label text should be placed at the lineAnchorPercent().

See also: anchorTextPoint()

Since: QGIS 3.26

Definition at line 364 of file qgslabellinesettings.h.

◆ setAnchorType()

void QgsLabelLineSettings::setAnchorType ( AnchorType type )

inline

Sets the line anchor type, which dictates how the lineAnchorPercent() setting is handled.

See also: anchorType(); setLineAnchorPercent(); setAnchorClipping()

Definition at line 320 of file qgslabellinesettings.h.

◆ setDirectionSymbolPlacement()

void QgsLabelLineSettings::setDirectionSymbolPlacement ( DirectionSymbolPlacement placement )

inline

Sets the placement for direction symbols.

This setting controls whether to place direction symbols to the left/right, above or below label.

See also: directionSymbolPlacement(); addDirectionSymbol()

Definition at line 222 of file qgslabellinesettings.h.

◆ setLeftDirectionSymbol()

void QgsLabelLineSettings::setLeftDirectionSymbol ( const QString & symbol )

inline

Sets the string to use for left direction arrows.

See also: leftDirectionSymbol(); addDirectionSymbol(); rightDirectionSymbol()

Definition at line 170 of file qgslabellinesettings.h.

◆ setLineAnchorPercent()

void QgsLabelLineSettings::setLineAnchorPercent ( double percent )

inline

Sets the percent along the line at which labels should be placed.

By default, this is 0.5 which indicates that labels should be placed as close to the center of the line as possible. A value of 0.0 indicates that the labels should be placed as close to the start of the line as possible, while a value of 1.0 pushes labels towards the end of the line.

See also: lineAnchorPercent(); setAnchorTextPoint(); setAnchorType(); setAnchorClipping()

Definition at line 300 of file qgslabellinesettings.h.

◆ setMergeLines()

void QgsLabelLineSettings::setMergeLines ( bool merge )

inline

Sets whether connected line features with identical label text should be merged prior to generating label positions.

See also: mergeLines()

Definition at line 120 of file qgslabellinesettings.h.

◆ setOverrunDistance()

void QgsLabelLineSettings::setOverrunDistance ( double distance )

inline

Sets the distance which labels are allowed to overrun past the start or end of line features.

See also: overrunDistance(); overrunDistanceUnit(); overrunDistanceMapUnitScale()

Definition at line 238 of file qgslabellinesettings.h.

◆ setOverrunDistanceMapUnitScale()

void QgsLabelLineSettings::setOverrunDistanceMapUnitScale ( const QgsMapUnitScale & scale )

inline

Sets the map unit scale for label overrun distance.

See also: overrunDistanceMapUnitScale(); overrunDistance(); overrunDistanceUnit()

Definition at line 270 of file qgslabellinesettings.h.

◆ setOverrunDistanceUnit()

void QgsLabelLineSettings::setOverrunDistanceUnit ( const Qgis::RenderUnit & unit )

inline

Sets the unit for label overrun distance.

See also: overrunDistanceUnit(); overrunDistance(); overrunDistanceMapUnitScale()

Definition at line 254 of file qgslabellinesettings.h.

◆ setPlacementFlags()

void QgsLabelLineSettings::setPlacementFlags ( Qgis::LabelLinePlacementFlags flags )

inline

Returns the line placement flags, which dictate how line labels can be placed above or below the lines.

See also: placementFlags()

Definition at line 104 of file qgslabellinesettings.h.

◆ setReverseDirectionSymbol()

void QgsLabelLineSettings::setReverseDirectionSymbol ( bool reversed )

inline

Sets whether the direction symbols should be reversed.

See also: reverseDirectionSymbol()

Definition at line 202 of file qgslabellinesettings.h.

◆ setRightDirectionSymbol()

void QgsLabelLineSettings::setRightDirectionSymbol ( const QString & symbol )

inline

Sets the string to use for right direction arrows.

See also: setLeftDirectionSymbol(); addDirectionSymbol(); rightDirectionSymbol()

Definition at line 188 of file qgslabellinesettings.h.

◆ updateDataDefinedProperties()

void QgsLabelLineSettings::updateDataDefinedProperties	(	const QgsPropertyCollection &	properties,
		QgsExpressionContext &	context
	)

Updates the line settings to respect any data defined properties set within the specified properties collection.

Definition at line 24 of file qgslabellinesettings.cpp.

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

/build/qgis-3.41.0+git20241119+45a0abf3bec+99sid/src/core/labeling/qgslabellinesettings.h
/build/qgis-3.41.0+git20241119+45a0abf3bec+99sid/src/core/labeling/qgslabellinesettings.cpp

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

◆ AnchorClipping

◆ AnchorTextPoint

◆ AnchorType

◆ DirectionSymbolPlacement

Member Function Documentation

◆ addDirectionSymbol()

◆ anchorClipping()

◆ anchorTextPoint()

◆ anchorType()

◆ directionSymbolPlacement()

◆ leftDirectionSymbol()

◆ lineAnchorPercent()

◆ mergeLines()

◆ overrunDistance()

◆ overrunDistanceMapUnitScale()

◆ overrunDistanceUnit()

◆ placementFlags()

◆ reverseDirectionSymbol()

◆ rightDirectionSymbol()

◆ setAddDirectionSymbol()

◆ setAnchorClipping()

◆ setAnchorTextPoint()

◆ setAnchorType()

◆ setDirectionSymbolPlacement()

◆ setLeftDirectionSymbol()

◆ setLineAnchorPercent()

◆ setMergeLines()

◆ setOverrunDistance()

◆ setOverrunDistanceMapUnitScale()

◆ setOverrunDistanceUnit()

◆ setPlacementFlags()

◆ setReverseDirectionSymbol()

◆ setRightDirectionSymbol()

◆ updateDataDefinedProperties()