QGIS API Documentation 3.41.0-Master (181b2f43d8e)
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Public Member Functions | Protected Attributes | List of all members
QgsLabelFeature Class Reference

The QgsLabelFeature class describes a feature that should be used within the labeling engine. More...

#include <qgslabelfeature.h>

Inheritance diagram for QgsLabelFeature:
Inheritance graph
[legend]

Public Member Functions

 QgsLabelFeature (QgsFeatureId id, geos::unique_ptr geometry, QSizeF size)
 Constructor for QgsLabelFeature.
 
virtual ~QgsLabelFeature ()
 
bool allowDegradedPlacement () const
 Returns true if the label can be placed in inferior fallback positions if it cannot otherwise be placed.
 
bool alwaysShow () const
 Whether label should be always shown (sets very high label priority)
 
QgsPointXY anchorPosition () const
 In case of quadrand or aligned positioning, this is set to the anchor point.
 
Qgis::LabelLinePlacementFlags arrangementFlags () const
 Returns the feature's arrangement flags.
 
double distLabel () const
 Applies to "around point" placement strategy or linestring features.
 
QgsFeature feature () const
 Returns the original feature associated with this label.
 
double fixedAngle () const
 Angle in radians of the fixed angle (relevant only if hasFixedAngle() returns true)
 
QgsPointXY fixedPosition () const
 Coordinates of the fixed position (relevant only if hasFixedPosition() returns true)
 
GEOSGeometrygeometry () const
 Gets access to the associated geometry.
 
bool hasFixedAngle () const
 Whether the label should use a fixed angle instead of using angle from automatic placement.
 
bool hasFixedPosition () const
 Whether the label should use a fixed position instead of being automatically placed.
 
bool hasFixedQuadrant () const
 Returns whether the quadrant for the label is fixed.
 
QgsFeatureId id () const
 Identifier of the label (unique within the parent label provider)
 
bool labelAllParts () const
 Returns true if all parts of the feature should be labeled.
 
QString labelText () const
 Text of the label.
 
pal::Layerlayer () const
 Gets PAL layer of the label feature. Should be only used internally in PAL.
 
double lineAnchorPercent () const
 Returns the percent along the line at which labels should be placed, for line labels only.
 
QgsLabelLineSettings::AnchorTextPoint lineAnchorTextPoint () const
 Returns the line anchor text point, which dictates which part of the label text should be placed at the lineAnchorPercent().
 
QgsLabelLineSettings::AnchorType lineAnchorType () const
 Returns the line anchor type, which dictates how the lineAnchorPercent() setting is handled.
 
double maximumDistance () const
 Returns the maximum distance which labels are allowed to be from their corresponding points.
 
double minimumSize () const
 Returns the minimum size (in map unit) for a feature to be labelled.
 
const QgsLabelObstacleSettingsobstacleSettings () const
 Returns the label's obstacle settings.
 
Qgis::LabelOffsetType offsetType () const
 Returns the offset type, which determines how offsets and distance to label behaves.
 
QgsCoordinateReferenceSystem originalFeatureCrs () const
 Returns the original layer CRS of the feature associated with the label.
 
QRectF outerBounds () const
 Returns the extreme outer bounds of the label feature, including any surrounding content like borders or background shapes.
 
Qgis::LabelOverlapHandling overlapHandling () const
 Returns the technique to use for handling overlapping labels for the feature.
 
double overrunDistance () const
 Returns the permissible distance (in map units) which labels are allowed to overrun the start or end of linear features.
 
double overrunSmoothDistance () const
 Returns the distance (in map units) with which the ends of linear features are averaged over when calculating the direction at which to overrun labels.
 
QgsGeometry permissibleZone () const
 Returns the label's permissible zone geometry.
 
const GEOSPreparedGeometry * permissibleZonePrepared () const
 Returns a GEOS prepared geometry representing the label's permissibleZone().
 
Qgis::LabelPolygonPlacementFlags polygonPlacementFlags () const
 Returns the polygon placement flags, which dictate how polygon labels can be placed.
 
QgsPointXY positionOffset () const
 Applies only to "offset from point" placement strategy.
 
QVector< Qgis::LabelPredefinedPointPositionpredefinedPositionOrder () const
 Returns the priority ordered list of predefined positions for label candidates.
 
Qgis::LabelPrioritization prioritization () const
 Returns the label prioritization technique.
 
double priority () const
 Returns the feature's labeling priority.
 
QgsAbstractLabelProviderprovider () const
 Returns provider of this instance.
 
QPointF quadOffset () const
 Applies to "offset from point" placement strategy and "around point" (in case hasFixedQuadrant() returns true).
 
double repeatDistance () const
 Applies only to linestring features - after what distance (in map units) the labels should be repeated (0 = no repetitions)
 
void setAllowDegradedPlacement (bool allow)
 Sets whether the label can be placed in inferior fallback positions if it cannot otherwise be placed.
 
void setAlwaysShow (bool enabled)
 Sets whether label should be always shown (sets very high label priority)
 
void setAnchorPosition (const QgsPointXY &anchorPosition)
 In case of quadrand or aligned positioning, this is set to the anchor point.
 
void setArrangementFlags (Qgis::LabelLinePlacementFlags flags)
 Sets the feature's arrangement flags.
 
void setDistLabel (double dist)
 Applies to "around point" placement strategy or linestring features.
 
void setFeature (const QgsFeature &feature)
 Sets the original feature associated with this label.
 
void setFixedAngle (double angle)
 Sets the angle in radians of the fixed angle (relevant only if hasFixedAngle() returns true).
 
void setFixedPosition (const QgsPointXY &point)
 Sets coordinates of the fixed position (relevant only if hasFixedPosition() returns true)
 
void setHasFixedAngle (bool enabled)
 Sets whether the label should use a fixed angle instead of using angle from automatic placement.
 
void setHasFixedPosition (bool enabled)
 Sets whether the label should use a fixed position instead of being automatically placed.
 
void setHasFixedQuadrant (bool enabled)
 Sets whether the quadrant for the label must be respected.
 
void setLabelAllParts (bool labelAllParts)
 Sets whether all parts of the feature should be labeled.
 
void setLabelText (const QString &text)
 Sets text of the label.
 
void setLayer (pal::Layer *layer)
 Assign PAL layer to the label feature. Should be only used internally in PAL.
 
void setLineAnchorPercent (double percent)
 Sets the percent along the line at which labels should be placed, for line labels only.
 
void setLineAnchorTextPoint (QgsLabelLineSettings::AnchorTextPoint point)
 Sets the line anchor text point, which dictates which part of the label text should be placed at the lineAnchorPercent().
 
void setLineAnchorType (QgsLabelLineSettings::AnchorType type)
 Sets the line anchor type, which dictates how the lineAnchorPercent() setting is handled.
 
void setMaximumDistance (double distance)
 Sets the maximum distance which labels are allowed to be from their corresponding points.
 
void setMinimumSize (double size)
 Sets the minimum size (in map unit) for a feature to be labelled.
 
void setObstacleSettings (const QgsLabelObstacleSettings &settings)
 Sets the label's obstacle settings.
 
void setOffsetType (Qgis::LabelOffsetType type)
 Sets the offset type, which determines how offsets and distance to label behaves.
 
void setOriginalFeatureCrs (const QgsCoordinateReferenceSystem &crs)
 Sets the original layer crs of the feature associated with the label.
 
void setOuterBounds (const QRectF &bounds)
 Sets the extreme outer bounds of the label feature, including any surrounding content like borders or background shapes.
 
void setOverlapHandling (Qgis::LabelOverlapHandling handling)
 Sets the technique to use for handling overlapping labels for the feature.
 
void setOverrunDistance (double distance)
 Sets the permissible distance (in map units) which labels are allowed to overrun the start or end of linear features.
 
void setOverrunSmoothDistance (double distance)
 Sets the distance (in map units) with which the ends of linear features are averaged over when calculating the direction at which to overrun labels.
 
void setPermissibleZone (const QgsGeometry &geometry)
 Sets the label's permissible zone geometry.
 
void setPolygonPlacementFlags (Qgis::LabelPolygonPlacementFlags flags)
 Sets the polygon placement flags, which dictate how polygon labels can be placed.
 
void setPositionOffset (const QgsPointXY &offset)
 Applies only to "offset from point" placement strategy.
 
void setPredefinedPositionOrder (const QVector< Qgis::LabelPredefinedPointPosition > &order)
 Sets the priority ordered list of predefined positions for label candidates.
 
void setPrioritization (Qgis::LabelPrioritization prioritization)
 Sets the label prioritization technique.
 
void setPriority (double priority)
 Sets the priority for labeling the feature.
 
void setQuadOffset (QPointF quadOffset)
 Set which side of the point to use.
 
void setRepeatDistance (double dist)
 Applies only to linestring features - set after what distance (in map units) the labels should be repeated (0 = no repetitions)
 
void setRotatedSize (QSizeF size)
 Sets an alternate label size to be used when a label rotation angle is between 45 to 135 and 235 to 313 degrees and the text rotation mode is set to rotation-based.
 
void setSymbol (const QgsSymbol *symbol)
 Sets the feature symbol associated with this label.
 
void setSymbolSize (QSizeF size)
 Sets the size of the rendered symbol associated with this feature.
 
void setVisualMargin (const QgsMargins &margin)
 Sets the visual margin for the label feature.
 
void setZIndex (double zIndex)
 Sets the label's z-index.
 
QSizeF size (double angle=0.0) const
 Size of the label (in map units).
 
const QgsSymbolsymbol () const
 Returns the feature symbol associated with this label.
 
const QSizeF & symbolSize () const
 Returns the size of the rendered symbol associated with this feature, if applicable.
 
const QgsMarginsvisualMargin () const
 Returns the visual margin for the label feature.
 
double zIndex () const
 Returns the label's z-index.
 

Protected Attributes

bool mAlwaysShow = false
 whether to always show label - even in case of collisions
 
Qgis::LabelLinePlacementFlags mArrangementFlags = Qgis::LabelLinePlacementFlags()
 
double mDistLabel = 0
 distance of label from the feature (only for "around point" placement or linestrings)
 
double mFixedAngle = 0
 fixed rotation for the label (instead of automatic choice)
 
QgsPointXY mFixedPosition
 fixed position for the label (instead of automatic placement)
 
geos::unique_ptr mGeometry
 Geometry of the feature to be labelled.
 
bool mHasFixedAngle = false
 whether mFixedAngle should be respected
 
bool mHasFixedPosition = false
 whether mFixedPosition should be respected
 
bool mHasFixedQuadrant = false
 whether mQuadOffset should be respected (only for "around point" placement)
 
QgsFeatureId mId
 Associated ID unique within the parent label provider.
 
QString mLabelText
 text of the label
 
pal::LayermLayer = nullptr
 Pointer to PAL layer (assigned when registered to PAL)
 
double mMaximumDistance = 0
 Maximum distance of label from the feature.
 
Qgis::LabelOffsetType mOffsetType = Qgis::LabelOffsetType::FromPoint
 Offset type for certain placement modes.
 
QRectF mOuterBounds
 Extreme outer bounds of the label feature, including any surrounding content like borders or background shapes.
 
double mOverrunDistance = 0
 Distance to allow label to overrun linear features.
 
double mOverrunSmoothDistance = 0
 Distance to smooth angle of line start and end when calculating overruns.
 
QgsGeometry mPermissibleZone
 Optional geometry to use for label's permissible zone.
 
Qgis::LabelPolygonPlacementFlags mPolygonPlacementFlags = Qgis::LabelPolygonPlacementFlag::AllowPlacementInsideOfPolygon
 
QgsPointXY mPositionOffset
 offset of label from the feature (only for "offset from point" placement)
 
QVector< Qgis::LabelPredefinedPointPositionmPredefinedPositionOrder
 Ordered list of predefined positions for label (only for OrderedPositionsAroundPoint placement)
 
double mPriority = -1
 Priority of the label.
 
QPointF mQuadOffset
 whether the side of the label is fixed (only for "around point" placement)
 
double mRepeatDistance = 0
 distance after which label should be repeated (only for linestrings)
 
QSizeF mRotatedSize
 Width and height of the label when rotated between 45 to 135 and 235 to 315 degrees;.
 
QSizeF mSize
 Width and height of the label.
 
QSizeF mSymbolSize
 Size of associated rendered symbol, if applicable.
 
QgsMargins mVisualMargin
 Visual margin of label contents.
 
double mZIndex = 0
 Z-index of label (higher z-index labels are rendered on top of lower z-index labels)
 

Detailed Description

The QgsLabelFeature class describes a feature that should be used within the labeling engine.

Those may be the usual textual labels, diagrams, or any other custom type of map annotations (generated by custom label providers).

Instances only contain data relevant to the labeling engine (geometry, label size etc.) necessary for the layout. Rendering of labels is done by label providers.

Individual label providers may create subclasses of QgsLabelFeature in order to add more data to the instances that will be later used for drawing of labels.

Note
this class is not a part of public API yet. See notes in QgsLabelingEngine
not available in Python bindings

Definition at line 55 of file qgslabelfeature.h.

Constructor & Destructor Documentation

◆ QgsLabelFeature()

QgsLabelFeature::QgsLabelFeature ( QgsFeatureId  id,
geos::unique_ptr  geometry,
QSizeF  size 
)

Constructor for QgsLabelFeature.

The feature id argument links the label feature back to the original layer feature.

The geometry argument specifies the geometry associated with the feature, which is used by the labeling engine to generate candidate placements for the label. For a vector layer feature this will generally be the feature's geometry.

The size argument dictates the size of the label's content (e.g. text width and height).

Definition at line 20 of file qgslabelfeature.cpp.

◆ ~QgsLabelFeature()

QgsLabelFeature::~QgsLabelFeature ( )
virtual

Definition at line 27 of file qgslabelfeature.cpp.

Member Function Documentation

◆ allowDegradedPlacement()

bool QgsLabelFeature::allowDegradedPlacement ( ) const
inline

Returns true if the label can be placed in inferior fallback positions if it cannot otherwise be placed.

For instance, this will permit a curved line label to fallback to a horizontal label at the end of the line if the label cannot otherwise be placed on the line in a curved manner.

See also
setAllowDegradedPlacement()
Since
QGIS 3.26

Definition at line 663 of file qgslabelfeature.h.

◆ alwaysShow()

bool QgsLabelFeature::alwaysShow ( ) const
inline

Whether label should be always shown (sets very high label priority)

Definition at line 376 of file qgslabelfeature.h.

◆ anchorPosition()

QgsPointXY QgsLabelFeature::anchorPosition ( ) const

In case of quadrand or aligned positioning, this is set to the anchor point.

This can be used for proper vector based output like DXF.

Since
QGIS 3.12

Definition at line 71 of file qgslabelfeature.cpp.

◆ arrangementFlags()

Qgis::LabelLinePlacementFlags QgsLabelFeature::arrangementFlags ( ) const
inline

Returns the feature's arrangement flags.

See also
setArrangementFlags

Definition at line 384 of file qgslabelfeature.h.

◆ distLabel()

double QgsLabelFeature::distLabel ( ) const
inline

Applies to "around point" placement strategy or linestring features.

Distance of the label from the feature (in map units)

See also
setDistLabel()
maximumDistance()

Definition at line 306 of file qgslabelfeature.h.

◆ feature()

QgsFeature QgsLabelFeature::feature ( ) const

Returns the original feature associated with this label.

See also
setFeature()
Since
QGIS 3.10

Definition at line 57 of file qgslabelfeature.cpp.

◆ fixedAngle()

double QgsLabelFeature::fixedAngle ( ) const
inline

Angle in radians of the fixed angle (relevant only if hasFixedAngle() returns true)

See also
setFixedAngle()

Definition at line 233 of file qgslabelfeature.h.

◆ fixedPosition()

QgsPointXY QgsLabelFeature::fixedPosition ( ) const
inline

Coordinates of the fixed position (relevant only if hasFixedPosition() returns true)

Definition at line 203 of file qgslabelfeature.h.

◆ geometry()

GEOSGeometry * QgsLabelFeature::geometry ( ) const
inline

Gets access to the associated geometry.

Definition at line 78 of file qgslabelfeature.h.

◆ hasFixedAngle()

bool QgsLabelFeature::hasFixedAngle ( ) const
inline

Whether the label should use a fixed angle instead of using angle from automatic placement.

Definition at line 225 of file qgslabelfeature.h.

◆ hasFixedPosition()

bool QgsLabelFeature::hasFixedPosition ( ) const
inline

Whether the label should use a fixed position instead of being automatically placed.

Definition at line 199 of file qgslabelfeature.h.

◆ hasFixedQuadrant()

bool QgsLabelFeature::hasFixedQuadrant ( ) const
inline

Returns whether the quadrant for the label is fixed.

Applies to "around point" placement strategy.

See also
setHasFixedQuadrant
quadOffset

Definition at line 247 of file qgslabelfeature.h.

◆ id()

QgsFeatureId QgsLabelFeature::id ( ) const
inline

Identifier of the label (unique within the parent label provider)

Definition at line 75 of file qgslabelfeature.h.

◆ labelAllParts()

bool QgsLabelFeature::labelAllParts ( ) const
inline

Returns true if all parts of the feature should be labeled.

See also
setLabelAllParts()
Since
QGIS 3.10

Definition at line 571 of file qgslabelfeature.h.

◆ labelText()

QString QgsLabelFeature::labelText ( ) const
inline

Text of the label.

Used also if "merge connected lines to avoid duplicate labels" is enabled to identify which features may be merged.

Definition at line 415 of file qgslabelfeature.h.

◆ layer()

pal::Layer * QgsLabelFeature::layer ( ) const
inline

Gets PAL layer of the label feature. Should be only used internally in PAL.

Definition at line 420 of file qgslabelfeature.h.

◆ lineAnchorPercent()

double QgsLabelFeature::lineAnchorPercent ( ) const
inline

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

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()
lineAnchorType()
Since
QGIS 3.16

Definition at line 512 of file qgslabelfeature.h.

◆ lineAnchorTextPoint()

QgsLabelLineSettings::AnchorTextPoint QgsLabelFeature::lineAnchorTextPoint ( ) const

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

See also
setLineAnchorTextPoint()
Since
QGIS 3.26

Definition at line 101 of file qgslabelfeature.cpp.

◆ lineAnchorType()

QgsLabelLineSettings::AnchorType QgsLabelFeature::lineAnchorType ( ) const
inline

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

See also
setLineAnchorType()
lineAnchorPercent()

Definition at line 535 of file qgslabelfeature.h.

◆ maximumDistance()

double QgsLabelFeature::maximumDistance ( ) const
inline

Returns the maximum distance which labels are allowed to be from their corresponding points.

This setting works alongside distLabel() to define a permissible range of distances at which labels can be placed from their points.

The default value is 0, which indicates that no maximum is set and the that distLabel() always be respected.

See also
setMaximumDistance()
distLabel()
Since
QGIS 3.38

Definition at line 331 of file qgslabelfeature.h.

◆ minimumSize()

double QgsLabelFeature::minimumSize ( ) const
inline

Returns the minimum size (in map unit) for a feature to be labelled.

Note
At the moment this is only used when labeling merged lines
See also
minimumSize()
Since
QGIS 3.20

Definition at line 626 of file qgslabelfeature.h.

◆ obstacleSettings()

const QgsLabelObstacleSettings & QgsLabelFeature::obstacleSettings ( ) const

Returns the label's obstacle settings.

See also
setObstacleSettings()
Since
QGIS 3.12

Definition at line 118 of file qgslabelfeature.cpp.

◆ offsetType()

Qgis::LabelOffsetType QgsLabelFeature::offsetType ( ) const
inline

Returns the offset type, which determines how offsets and distance to label behaves.

Support depends on which placement mode is used for generating label candidates.

See also
setOffsetType()

Definition at line 289 of file qgslabelfeature.h.

◆ originalFeatureCrs()

QgsCoordinateReferenceSystem QgsLabelFeature::originalFeatureCrs ( ) const

Returns the original layer CRS of the feature associated with the label.

See also
setOriginalFeatureCrs()
Since
QGIS 3.20

Definition at line 128 of file qgslabelfeature.cpp.

◆ outerBounds()

QRectF QgsLabelFeature::outerBounds ( ) const
inline

Returns the extreme outer bounds of the label feature, including any surrounding content like borders or background shapes.

See also
setOuterBounds()
Since
QGIS 3.30

Definition at line 120 of file qgslabelfeature.h.

◆ overlapHandling()

Qgis::LabelOverlapHandling QgsLabelFeature::overlapHandling ( ) const
inline

Returns the technique to use for handling overlapping labels for the feature.

See also
setOverlapHandling()
Since
QGIS 3.26

Definition at line 643 of file qgslabelfeature.h.

◆ overrunDistance()

double QgsLabelFeature::overrunDistance ( ) const

Returns the permissible distance (in map units) which labels are allowed to overrun the start or end of linear features.

See also
setOverrunDistance()
overrunSmoothDistance()
Since
QGIS 3.10

Definition at line 81 of file qgslabelfeature.cpp.

◆ overrunSmoothDistance()

double QgsLabelFeature::overrunSmoothDistance ( ) const

Returns the distance (in map units) with which the ends of linear features are averaged over when calculating the direction at which to overrun labels.

See also
setOverrunSmoothDistance()
overrunDistance()
Since
QGIS 3.10

Definition at line 91 of file qgslabelfeature.cpp.

◆ permissibleZone()

QgsGeometry QgsLabelFeature::permissibleZone ( ) const
inline

Returns the label's permissible zone geometry.

If a valid geometry is returned, the feature's label MUST be fully contained within this zone, and the feature will not be labeled if no candidates can be generated which are not contained within the zone.

See also
setPermissibleZone()
permissibleZonePrepared()

Definition at line 97 of file qgslabelfeature.h.

◆ permissibleZonePrepared()

const GEOSPreparedGeometry * QgsLabelFeature::permissibleZonePrepared ( ) const
inline

Returns a GEOS prepared geometry representing the label's permissibleZone().

See also
permissibleZone()

Definition at line 104 of file qgslabelfeature.h.

◆ polygonPlacementFlags()

Qgis::LabelPolygonPlacementFlags QgsLabelFeature::polygonPlacementFlags ( ) const
inline

Returns the polygon placement flags, which dictate how polygon labels can be placed.

See also
setPolygonPlacementFlags()
Since
QGIS 3.14

Definition at line 399 of file qgslabelfeature.h.

◆ positionOffset()

QgsPointXY QgsLabelFeature::positionOffset ( ) const
inline

Applies only to "offset from point" placement strategy.

What offset (in map units) to use from the point

Definition at line 275 of file qgslabelfeature.h.

◆ predefinedPositionOrder()

QVector< Qgis::LabelPredefinedPointPosition > QgsLabelFeature::predefinedPositionOrder ( ) const
inline

Returns the priority ordered list of predefined positions for label candidates.

This property is only used for OrderedPositionsAroundPoint placements.

See also
setPredefinedPositionOrder()

Definition at line 354 of file qgslabelfeature.h.

◆ prioritization()

Qgis::LabelPrioritization QgsLabelFeature::prioritization ( ) const
inline

Returns the label prioritization technique.

See also
setPrioritization()
Since
QGIS 3.38

Definition at line 671 of file qgslabelfeature.h.

◆ priority()

double QgsLabelFeature::priority ( ) const
inline

Returns the feature's labeling priority.

Returns
feature's priority, as a value between 0 (highest priority) and 1 (lowest priority). Returns -1.0 if feature will use the layer's default priority.
See also
setPriority

Definition at line 172 of file qgslabelfeature.h.

◆ provider()

QgsAbstractLabelProvider * QgsLabelFeature::provider ( ) const

Returns provider of this instance.

Definition at line 816 of file qgslabelingengine.cpp.

◆ quadOffset()

QPointF QgsLabelFeature::quadOffset ( ) const
inline

Applies to "offset from point" placement strategy and "around point" (in case hasFixedQuadrant() returns true).

Determines which side of the point to use. For X coordinate, values -1, 0, 1 mean left, center, right. For Y coordinate, values -1, 0, 1 mean above, center, below.

Definition at line 263 of file qgslabelfeature.h.

◆ repeatDistance()

double QgsLabelFeature::repeatDistance ( ) const
inline

Applies only to linestring features - after what distance (in map units) the labels should be repeated (0 = no repetitions)

Definition at line 367 of file qgslabelfeature.h.

◆ setAllowDegradedPlacement()

void QgsLabelFeature::setAllowDegradedPlacement ( bool  allow)
inline

Sets whether the label can be placed in inferior fallback positions if it cannot otherwise be placed.

For instance, this will permit a curved line label to fallback to a horizontal label at the end of the line if the label cannot otherwise be placed on the line in a curved manner.

See also
allowDegradedPlacement()
Since
QGIS 3.26

Definition at line 691 of file qgslabelfeature.h.

◆ setAlwaysShow()

void QgsLabelFeature::setAlwaysShow ( bool  enabled)
inline

Sets whether label should be always shown (sets very high label priority)

Definition at line 378 of file qgslabelfeature.h.

◆ setAnchorPosition()

void QgsLabelFeature::setAnchorPosition ( const QgsPointXY anchorPosition)

In case of quadrand or aligned positioning, this is set to the anchor point.

This can be used for proper vector based output like DXF.

Since
QGIS 3.12

Definition at line 138 of file qgslabelfeature.cpp.

◆ setArrangementFlags()

void QgsLabelFeature::setArrangementFlags ( Qgis::LabelLinePlacementFlags  flags)
inline

Sets the feature's arrangement flags.

Parameters
flagsarrangement flags
See also
arrangementFlags

Definition at line 391 of file qgslabelfeature.h.

◆ setDistLabel()

void QgsLabelFeature::setDistLabel ( double  dist)
inline

Applies to "around point" placement strategy or linestring features.

Set distance of the label from the feature (in map units)

See also
distLabel()
setMaximumDistance()

Definition at line 315 of file qgslabelfeature.h.

◆ setFeature()

void QgsLabelFeature::setFeature ( const QgsFeature feature)

Sets the original feature associated with this label.

See also
feature()
Since
QGIS 3.10

Definition at line 76 of file qgslabelfeature.cpp.

◆ setFixedAngle()

void QgsLabelFeature::setFixedAngle ( double  angle)
inline

Sets the angle in radians of the fixed angle (relevant only if hasFixedAngle() returns true).

See also
fixedAngle()

Definition at line 239 of file qgslabelfeature.h.

◆ setFixedPosition()

void QgsLabelFeature::setFixedPosition ( const QgsPointXY point)
inline

Sets coordinates of the fixed position (relevant only if hasFixedPosition() returns true)

Definition at line 206 of file qgslabelfeature.h.

◆ setHasFixedAngle()

void QgsLabelFeature::setHasFixedAngle ( bool  enabled)
inline

Sets whether the label should use a fixed angle instead of using angle from automatic placement.

Definition at line 227 of file qgslabelfeature.h.

◆ setHasFixedPosition()

void QgsLabelFeature::setHasFixedPosition ( bool  enabled)
inline

Sets whether the label should use a fixed position instead of being automatically placed.

Definition at line 201 of file qgslabelfeature.h.

◆ setHasFixedQuadrant()

void QgsLabelFeature::setHasFixedQuadrant ( bool  enabled)
inline

Sets whether the quadrant for the label must be respected.

This can be used to fix the quadrant for specific features when using an "around point" placement.

See also
hasFixedQuadrant
quadOffset

Definition at line 255 of file qgslabelfeature.h.

◆ setLabelAllParts()

void QgsLabelFeature::setLabelAllParts ( bool  labelAllParts)
inline

Sets whether all parts of the feature should be labeled.

See also
labelAllParts()
Since
QGIS 3.10

Definition at line 578 of file qgslabelfeature.h.

◆ setLabelText()

void QgsLabelFeature::setLabelText ( const QString &  text)
inline

Sets text of the label.

Definition at line 417 of file qgslabelfeature.h.

◆ setLayer()

void QgsLabelFeature::setLayer ( pal::Layer layer)
inline

Assign PAL layer to the label feature. Should be only used internally in PAL.

Definition at line 422 of file qgslabelfeature.h.

◆ setLineAnchorPercent()

void QgsLabelFeature::setLineAnchorPercent ( double  percent)
inline

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

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()
setLineAnchorType()
Since
QGIS 3.16

Definition at line 526 of file qgslabelfeature.h.

◆ setLineAnchorTextPoint()

void QgsLabelFeature::setLineAnchorTextPoint ( QgsLabelLineSettings::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
lineAnchorTextPoint()
Since
QGIS 3.26

Definition at line 564 of file qgslabelfeature.h.

◆ setLineAnchorType()

void QgsLabelFeature::setLineAnchorType ( QgsLabelLineSettings::AnchorType  type)
inline

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

See also
lineAnchorType()
setLineAnchorPercent()

Definition at line 544 of file qgslabelfeature.h.

◆ setMaximumDistance()

void QgsLabelFeature::setMaximumDistance ( double  distance)
inline

Sets the maximum distance which labels are allowed to be from their corresponding points.

This setting works alongside distLabel() to define a permissible range of distances at which labels can be placed from their points.

The default value is 0, which indicates that no maximum is set and the that distLabel() always be respected.

See also
maximumDistance()
setDistLabel()
Since
QGIS 3.38

Definition at line 347 of file qgslabelfeature.h.

◆ setMinimumSize()

void QgsLabelFeature::setMinimumSize ( double  size)
inline

Sets the minimum size (in map unit) for a feature to be labelled.

Note
At the moment this is only used when labeling merged lines
See also
setMinimumSize()
Since
QGIS 3.20

Definition at line 635 of file qgslabelfeature.h.

◆ setObstacleSettings()

void QgsLabelFeature::setObstacleSettings ( const QgsLabelObstacleSettings settings)

Sets the label's obstacle settings.

See also
obstacleSettings()
Since
QGIS 3.12

Definition at line 123 of file qgslabelfeature.cpp.

◆ setOffsetType()

void QgsLabelFeature::setOffsetType ( Qgis::LabelOffsetType  type)
inline

Sets the offset type, which determines how offsets and distance to label behaves.

Support depends on which placement mode is used for generating label candidates.

See also
offsetType()

Definition at line 297 of file qgslabelfeature.h.

◆ setOriginalFeatureCrs()

void QgsLabelFeature::setOriginalFeatureCrs ( const QgsCoordinateReferenceSystem crs)

Sets the original layer crs of the feature associated with the label.

See also
originalFeatureCrs()
Since
QGIS 3.20

Definition at line 133 of file qgslabelfeature.cpp.

◆ setOuterBounds()

void QgsLabelFeature::setOuterBounds ( const QRectF &  bounds)
inline

Sets the extreme outer bounds of the label feature, including any surrounding content like borders or background shapes.

See also
outerBounds()
Since
QGIS 3.30

Definition at line 129 of file qgslabelfeature.h.

◆ setOverlapHandling()

void QgsLabelFeature::setOverlapHandling ( Qgis::LabelOverlapHandling  handling)
inline

Sets the technique to use for handling overlapping labels for the feature.

See also
overlapHandling()
Since
QGIS 3.26

Definition at line 651 of file qgslabelfeature.h.

◆ setOverrunDistance()

void QgsLabelFeature::setOverrunDistance ( double  distance)

Sets the permissible distance (in map units) which labels are allowed to overrun the start or end of linear features.

See also
overrunDistance()
setOverrunSmoothDistance()
Since
QGIS 3.10

Definition at line 86 of file qgslabelfeature.cpp.

◆ setOverrunSmoothDistance()

void QgsLabelFeature::setOverrunSmoothDistance ( double  distance)

Sets the distance (in map units) with which the ends of linear features are averaged over when calculating the direction at which to overrun labels.

See also
overrunSmoothDistance()
setOverrunDistance()
Since
QGIS 3.10

Definition at line 96 of file qgslabelfeature.cpp.

◆ setPermissibleZone()

void QgsLabelFeature::setPermissibleZone ( const QgsGeometry geometry)

Sets the label's permissible zone geometry.

If set, the feature's label MUST be fully contained within this zone, and the feature will not be labeled if no candidates can be generated which are not contained within the zone.

Parameters
geometrypermissible zone geometry. If an invalid QgsGeometry is passed then no zone limit will be applied to the label candidates (this is the default behavior).
See also
permissibleZone()

Definition at line 36 of file qgslabelfeature.cpp.

◆ setPolygonPlacementFlags()

void QgsLabelFeature::setPolygonPlacementFlags ( Qgis::LabelPolygonPlacementFlags  flags)
inline

Sets the polygon placement flags, which dictate how polygon labels can be placed.

See also
polygonPlacementFlags()
Since
QGIS 3.14

Definition at line 407 of file qgslabelfeature.h.

◆ setPositionOffset()

void QgsLabelFeature::setPositionOffset ( const QgsPointXY offset)
inline

Applies only to "offset from point" placement strategy.

Set what offset (in map units) to use from the point

Definition at line 281 of file qgslabelfeature.h.

◆ setPredefinedPositionOrder()

void QgsLabelFeature::setPredefinedPositionOrder ( const QVector< Qgis::LabelPredefinedPointPosition > &  order)
inline

Sets the priority ordered list of predefined positions for label candidates.

This property is only used for OrderedPositionsAroundPoint placements.

See also
predefinedPositionOrder()

Definition at line 361 of file qgslabelfeature.h.

◆ setPrioritization()

void QgsLabelFeature::setPrioritization ( Qgis::LabelPrioritization  prioritization)
inline

Sets the label prioritization technique.

See also
prioritization()
Since
QGIS 3.26

Definition at line 679 of file qgslabelfeature.h.

◆ setPriority()

void QgsLabelFeature::setPriority ( double  priority)
inline

Sets the priority for labeling the feature.

Parameters
priorityfeature's priority, as a value between 0 (highest priority) and 1 (lowest priority). Set to -1.0 to use the layer's default priority for this feature.
See also
priority

Definition at line 181 of file qgslabelfeature.h.

◆ setQuadOffset()

void QgsLabelFeature::setQuadOffset ( QPointF  quadOffset)
inline

Set which side of the point to use.

See also
quadOffset

Definition at line 269 of file qgslabelfeature.h.

◆ setRepeatDistance()

void QgsLabelFeature::setRepeatDistance ( double  dist)
inline

Applies only to linestring features - set after what distance (in map units) the labels should be repeated (0 = no repetitions)

Definition at line 373 of file qgslabelfeature.h.

◆ setRotatedSize()

void QgsLabelFeature::setRotatedSize ( QSizeF  size)
inline

Sets an alternate label size to be used when a label rotation angle is between 45 to 135 and 235 to 313 degrees and the text rotation mode is set to rotation-based.

Since
QGIS 3.10

Definition at line 585 of file qgslabelfeature.h.

◆ setSymbol()

void QgsLabelFeature::setSymbol ( const QgsSymbol symbol)
inline

Sets the feature symbol associated with this label.

Ownership of symbol is not transferred to the label feature, .

See also
symbol()
Since
QGIS 3.10

Definition at line 458 of file qgslabelfeature.h.

◆ setSymbolSize()

void QgsLabelFeature::setSymbolSize ( QSizeF  size)
inline

Sets the size of the rendered symbol associated with this feature.

This size is taken into account in certain label placement modes to avoid placing labels over the rendered symbol for this feature.

See also
symbolSize()

Definition at line 155 of file qgslabelfeature.h.

◆ setVisualMargin()

void QgsLabelFeature::setVisualMargin ( const QgsMargins margin)
inline

Sets the visual margin for the label feature.

The visual margin represents a margin within the label which should not be considered when calculating the positions of candidates for the label feature. It is used in certain label placement modes to adjust the position of candidates so that they all appear to be at visually equal distances from a point feature. For instance, this can be used to place labels which sit above a point so that their baseline rather then the descender of the label is at a preset distance from the point.

Parameters
marginvisual margins for label
See also
visualMargin()

Definition at line 141 of file qgslabelfeature.h.

◆ setZIndex()

void QgsLabelFeature::setZIndex ( double  zIndex)
inline

Sets the label's z-index.

Higher z-index labels are rendered on top of lower z-index labels.

Parameters
zIndexz-index for label
See also
zIndex()

Definition at line 196 of file qgslabelfeature.h.

◆ size()

QSizeF QgsLabelFeature::size ( double  angle = 0.0) const

Size of the label (in map units).

An optional angle (in radians) can be specified to return the size taking into account the rotation.

Definition at line 62 of file qgslabelfeature.cpp.

◆ symbol()

const QgsSymbol * QgsLabelFeature::symbol ( ) const
inline

Returns the feature symbol associated with this label.

See also
setSymbol()
Since
QGIS 3.10

Definition at line 449 of file qgslabelfeature.h.

◆ symbolSize()

const QSizeF & QgsLabelFeature::symbolSize ( ) const
inline

Returns the size of the rendered symbol associated with this feature, if applicable.

This size is taken into account in certain label placement modes to avoid placing labels over the rendered symbol for this feature. The size will only be set for labels associated with a point feature.

See also
symbolSize()

Definition at line 164 of file qgslabelfeature.h.

◆ visualMargin()

const QgsMargins & QgsLabelFeature::visualMargin ( ) const
inline

Returns the visual margin for the label feature.

See also
setVisualMargin() for details

Definition at line 147 of file qgslabelfeature.h.

◆ zIndex()

double QgsLabelFeature::zIndex ( ) const
inline

Returns the label's z-index.

Higher z-index labels are rendered on top of lower z-index labels.

See also
setZIndex()

Definition at line 188 of file qgslabelfeature.h.

Member Data Documentation

◆ mAlwaysShow

bool QgsLabelFeature::mAlwaysShow = false
protected

whether to always show label - even in case of collisions

Definition at line 744 of file qgslabelfeature.h.

◆ mArrangementFlags

Qgis::LabelLinePlacementFlags QgsLabelFeature::mArrangementFlags = Qgis::LabelLinePlacementFlags()
protected

Definition at line 753 of file qgslabelfeature.h.

◆ mDistLabel

double QgsLabelFeature::mDistLabel = 0
protected

distance of label from the feature (only for "around point" placement or linestrings)

Definition at line 732 of file qgslabelfeature.h.

◆ mFixedAngle

double QgsLabelFeature::mFixedAngle = 0
protected

fixed rotation for the label (instead of automatic choice)

Definition at line 724 of file qgslabelfeature.h.

◆ mFixedPosition

QgsPointXY QgsLabelFeature::mFixedPosition
protected

fixed position for the label (instead of automatic placement)

Definition at line 720 of file qgslabelfeature.h.

◆ mGeometry

geos::unique_ptr QgsLabelFeature::mGeometry
protected

Geometry of the feature to be labelled.

Definition at line 700 of file qgslabelfeature.h.

◆ mHasFixedAngle

bool QgsLabelFeature::mHasFixedAngle = false
protected

whether mFixedAngle should be respected

Definition at line 722 of file qgslabelfeature.h.

◆ mHasFixedPosition

bool QgsLabelFeature::mHasFixedPosition = false
protected

whether mFixedPosition should be respected

Definition at line 718 of file qgslabelfeature.h.

◆ mHasFixedQuadrant

bool QgsLabelFeature::mHasFixedQuadrant = false
protected

whether mQuadOffset should be respected (only for "around point" placement)

Definition at line 726 of file qgslabelfeature.h.

◆ mId

QgsFeatureId QgsLabelFeature::mId
protected

Associated ID unique within the parent label provider.

Definition at line 698 of file qgslabelfeature.h.

◆ mLabelText

QString QgsLabelFeature::mLabelText
protected

text of the label

Definition at line 746 of file qgslabelfeature.h.

◆ mLayer

pal::Layer* QgsLabelFeature::mLayer = nullptr
protected

Pointer to PAL layer (assigned when registered to PAL)

Definition at line 695 of file qgslabelfeature.h.

◆ mMaximumDistance

double QgsLabelFeature::mMaximumDistance = 0
protected

Maximum distance of label from the feature.

Definition at line 735 of file qgslabelfeature.h.

◆ mOffsetType

Qgis::LabelOffsetType QgsLabelFeature::mOffsetType = Qgis::LabelOffsetType::FromPoint
protected

Offset type for certain placement modes.

Definition at line 738 of file qgslabelfeature.h.

◆ mOuterBounds

QRectF QgsLabelFeature::mOuterBounds
protected

Extreme outer bounds of the label feature, including any surrounding content like borders or background shapes.

Definition at line 708 of file qgslabelfeature.h.

◆ mOverrunDistance

double QgsLabelFeature::mOverrunDistance = 0
protected

Distance to allow label to overrun linear features.

Definition at line 749 of file qgslabelfeature.h.

◆ mOverrunSmoothDistance

double QgsLabelFeature::mOverrunSmoothDistance = 0
protected

Distance to smooth angle of line start and end when calculating overruns.

Definition at line 751 of file qgslabelfeature.h.

◆ mPermissibleZone

QgsGeometry QgsLabelFeature::mPermissibleZone
protected

Optional geometry to use for label's permissible zone.

Definition at line 702 of file qgslabelfeature.h.

◆ mPolygonPlacementFlags

Definition at line 754 of file qgslabelfeature.h.

◆ mPositionOffset

QgsPointXY QgsLabelFeature::mPositionOffset
protected

offset of label from the feature (only for "offset from point" placement)

Definition at line 730 of file qgslabelfeature.h.

◆ mPredefinedPositionOrder

QVector< Qgis::LabelPredefinedPointPosition > QgsLabelFeature::mPredefinedPositionOrder
protected

Ordered list of predefined positions for label (only for OrderedPositionsAroundPoint placement)

Definition at line 740 of file qgslabelfeature.h.

◆ mPriority

double QgsLabelFeature::mPriority = -1
protected

Priority of the label.

Definition at line 714 of file qgslabelfeature.h.

◆ mQuadOffset

QPointF QgsLabelFeature::mQuadOffset
protected

whether the side of the label is fixed (only for "around point" placement)

Definition at line 728 of file qgslabelfeature.h.

◆ mRepeatDistance

double QgsLabelFeature::mRepeatDistance = 0
protected

distance after which label should be repeated (only for linestrings)

Definition at line 742 of file qgslabelfeature.h.

◆ mRotatedSize

QSizeF QgsLabelFeature::mRotatedSize
protected

Width and height of the label when rotated between 45 to 135 and 235 to 315 degrees;.

Definition at line 706 of file qgslabelfeature.h.

◆ mSize

QSizeF QgsLabelFeature::mSize
protected

Width and height of the label.

Definition at line 704 of file qgslabelfeature.h.

◆ mSymbolSize

QSizeF QgsLabelFeature::mSymbolSize
protected

Size of associated rendered symbol, if applicable.

Definition at line 712 of file qgslabelfeature.h.

◆ mVisualMargin

QgsMargins QgsLabelFeature::mVisualMargin
protected

Visual margin of label contents.

Definition at line 710 of file qgslabelfeature.h.

◆ mZIndex

double QgsLabelFeature::mZIndex = 0
protected

Z-index of label (higher z-index labels are rendered on top of lower z-index labels)

Definition at line 716 of file qgslabelfeature.h.


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