QGIS API Documentation 3.41.0-Master (fda2aa46e9a)
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Public Types | Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
QgsLineSymbolLayer Class Referenceabstract

Abstract base class for line symbol layers. More...

#include <qgssymbollayer.h>

Inheritance diagram for QgsLineSymbolLayer:
Inheritance graph
[legend]

Public Types

enum  RenderRingFilter { AllRings , ExteriorRingOnly , InteriorRingsOnly }
 Options for filtering rings when the line symbol layer is being used to render a polygon's rings. More...
 
- Public Types inherited from QgsSymbolLayer
enum class  Property : int {
  Size = 0 , Angle , Name , FillColor ,
  StrokeColor , StrokeWidth , StrokeStyle , Offset ,
  Character , Width , Height , PreserveAspectRatio ,
  FillStyle , JoinStyle , SecondaryColor , LineAngle ,
  LineDistance , GradientType , CoordinateMode , GradientSpread ,
  GradientReference1X , GradientReference1Y , GradientReference2X , GradientReference2Y ,
  GradientReference1IsCentroid , GradientReference2IsCentroid , BlurRadius , ShapeburstUseWholeShape ,
  ShapeburstMaxDistance , ShapeburstIgnoreRings , File , DistanceX ,
  DistanceY , DisplacementX , DisplacementY , Opacity ,
  CustomDash , CapStyle , Placement , Interval ,
  OffsetAlongLine , AverageAngleLength , HorizontalAnchor , VerticalAnchor ,
  LayerEnabled , ArrowWidth , ArrowStartWidth , ArrowHeadLength ,
  ArrowHeadThickness , ArrowHeadType , ArrowType , OffsetX ,
  OffsetY , PointCount , RandomSeed , ClipPoints ,
  DensityArea , FontFamily , FontStyle , DashPatternOffset ,
  TrimStart , TrimEnd , LineStartWidthValue , LineEndWidthValue ,
  LineStartColorValue , LineEndColorValue , MarkerClipping , RandomOffsetX ,
  RandomOffsetY , LineClipping , SkipMultiples , ShowMarker
}
 Data definable properties. More...
 

Public Member Functions

 QgsLineSymbolLayer (const QgsLineSymbolLayer &other)=delete
 
void drawPreviewIcon (QgsSymbolRenderContext &context, QSize size) override
 
double dxfWidth (const QgsDxfExport &e, QgsSymbolRenderContext &context) const override
 Gets line width.
 
QgsMapUnitScale mapUnitScale () const override
 
double offset () const
 Returns the line's offset.
 
const QgsMapUnitScaleoffsetMapUnitScale () const
 Returns the map unit scale for the line's offset.
 
Qgis::RenderUnit offsetUnit () const
 Returns the units for the line's offset.
 
QgsLineSymbolLayeroperator= (const QgsLineSymbolLayer &other)=delete
 
Qgis::RenderUnit outputUnit () const override
 Returns the units to use for sizes and widths within the symbol layer.
 
virtual void renderPolygonStroke (const QPolygonF &points, const QVector< QPolygonF > *rings, QgsSymbolRenderContext &context)
 Renders the line symbol layer along the outline of polygon, using the given render context.
 
virtual void renderPolyline (const QPolygonF &points, QgsSymbolRenderContext &context)=0
 Renders the line symbol layer along the line joining points, using the given render context.
 
RenderRingFilter ringFilter () const
 Returns the line symbol layer's ring filter, which controls which rings are rendered when the line symbol is being used to draw a polygon's rings.
 
void setMapUnitScale (const QgsMapUnitScale &scale) override
 
void setOffset (double offset)
 Sets the line's offset.
 
void setOffsetMapUnitScale (const QgsMapUnitScale &scale)
 Sets the map unit scale for the line's offset.
 
void setOffsetUnit (Qgis::RenderUnit unit)
 Sets the unit for the line's offset.
 
void setOutputUnit (Qgis::RenderUnit unit) override
 Sets the units to use for sizes and widths within the symbol layer.
 
void setRingFilter (QgsLineSymbolLayer::RenderRingFilter filter)
 Sets the line symbol layer's ring filter, which controls which rings are rendered when the line symbol is being used to draw a polygon's rings.
 
virtual void setWidth (double width)
 Sets the width of the line symbol layer.
 
void setWidthMapUnitScale (const QgsMapUnitScale &scale)
 
void setWidthUnit (Qgis::RenderUnit unit)
 Sets the units for the line's width.
 
virtual double width () const
 Returns the estimated width for the line symbol layer.
 
virtual double width (const QgsRenderContext &context) const
 Returns the line symbol layer width, in painter units.
 
const QgsMapUnitScalewidthMapUnitScale () const
 
Qgis::RenderUnit widthUnit () const
 Returns the units for the line's width.
 
- Public Member Functions inherited from QgsSymbolLayer
 QgsSymbolLayer (const QgsSymbolLayer &other)=delete
 
virtual ~QgsSymbolLayer ()
 
virtual bool canCauseArtifactsBetweenAdjacentTiles () const
 Returns true if the symbol layer rendering can cause visible artifacts across a single feature when the feature is rendered as a series of adjacent map tiles each containing a portion of the feature's geometry.
 
virtual QgsSymbolLayerclone () const =0
 Shall be reimplemented by subclasses to create a deep copy of the instance.
 
virtual QColor color () const
 Returns the "representative" color of the symbol layer.
 
QgsPropertyCollectiondataDefinedProperties ()
 Returns a reference to the symbol layer's property collection, used for data defined overrides.
 
const QgsPropertyCollectiondataDefinedProperties () const
 Returns a reference to the symbol layer's property collection, used for data defined overrides.
 
virtual double dxfAngle (QgsSymbolRenderContext &context) const
 Gets angle.
 
virtual QColor dxfBrushColor (QgsSymbolRenderContext &context) const
 Gets brush/fill color.
 
virtual Qt::BrushStyle dxfBrushStyle () const
 Gets brush/fill style.
 
virtual QColor dxfColor (QgsSymbolRenderContext &context) const
 Gets color.
 
virtual QVector< qreal > dxfCustomDashPattern (Qgis::RenderUnit &unit) const
 Gets dash pattern.
 
virtual double dxfOffset (const QgsDxfExport &e, QgsSymbolRenderContext &context) const
 Gets offset.
 
virtual Qt::PenStyle dxfPenStyle () const
 Gets pen style.
 
virtual double dxfSize (const QgsDxfExport &e, QgsSymbolRenderContext &context) const
 Gets marker size.
 
bool enabled () const
 Returns true if symbol layer is enabled and will be drawn.
 
virtual double estimateMaxBleed (const QgsRenderContext &context) const
 Returns the estimated maximum distance which the layer style will bleed outside the drawn shape when drawn in the specified /a context.
 
virtual QColor fillColor () const
 Returns the fill color for the symbol layer.
 
virtual Qgis::SymbolLayerFlags flags () const
 Returns flags which control the symbol layer's behavior.
 
virtual bool hasDataDefinedProperties () const
 Returns true if the symbol layer (or any of its sub-symbols) contains data defined properties.
 
QString id () const
 Returns symbol layer identifier This id is unique in the whole project.
 
bool installMasks (QgsRenderContext &context, bool recursive, const QRectF &rect=QRectF())
 When rendering, install masks on context painter.
 
virtual bool isCompatibleWithSymbol (QgsSymbol *symbol) const
 Returns if the layer can be used below the specified symbol.
 
bool isLocked () const
 Returns true if the symbol layer colors are locked and the layer will ignore any symbol-level color changes.
 
virtual QString layerType () const =0
 Returns a string that represents this layer type.
 
virtual QList< QgsSymbolLayerReferencemasks () const
 Returns masks defined by this symbol layer.
 
virtual QString ogrFeatureStyle (double mmScaleFactor, double mapUnitScaleFactor) const
 
QgsSymbolLayeroperator= (const QgsSymbolLayer &other)=delete
 
QgsPaintEffectpaintEffect () const
 Returns the current paint effect for the layer.
 
virtual void prepareExpressions (const QgsSymbolRenderContext &context)
 Prepares all data defined property expressions for evaluation.
 
virtual void prepareMasks (const QgsSymbolRenderContext &context)
 Prepares all mask internal objects according to what is defined in context This should be called prior to calling startRender() method.
 
virtual QVariantMap properties () const =0
 Should be reimplemented by subclasses to return a string map that contains the configuration information for the symbol layer.
 
int renderingPass () const
 Specifies the rendering pass in which this symbol layer should be rendered.
 
virtual void setColor (const QColor &color)
 Sets the "representative" color for the symbol layer.
 
void setDataDefinedProperties (const QgsPropertyCollection &collection)
 Sets the symbol layer's property collection, used for data defined overrides.
 
virtual void setDataDefinedProperty (Property key, const QgsProperty &property)
 Sets a data defined property for the layer.
 
void setEnabled (bool enabled)
 Sets whether symbol layer is enabled and should be drawn.
 
virtual void setFillColor (const QColor &color)
 Sets the fill color for the symbol layer.
 
void setId (const QString &id)
 Set symbol layer identifier This id has to be unique in the whole project.
 
void setLocked (bool locked)
 Sets whether the layer's colors are locked.
 
void setPaintEffect (QgsPaintEffect *effect)
 Sets the current paint effect for the layer.
 
void setRenderingPass (int renderingPass)
 Specifies the rendering pass in which this symbol layer should be rendered.
 
virtual void setStrokeColor (const QColor &color)
 Sets the stroke color for the symbol layer.
 
virtual bool setSubSymbol (QgsSymbol *symbol)
 Sets layer's subsymbol. takes ownership of the passed symbol.
 
void setUserFlags (Qgis::SymbolLayerUserFlags flags)
 Sets user-controlled flags which control the symbol layer's behavior.
 
virtual void startFeatureRender (const QgsFeature &feature, QgsRenderContext &context)
 Called before the layer will be rendered for a particular feature.
 
virtual void startRender (QgsSymbolRenderContext &context)=0
 Called before a set of rendering operations commences on the supplied render context.
 
virtual void stopFeatureRender (const QgsFeature &feature, QgsRenderContext &context)
 Called after the layer has been rendered for a particular feature.
 
virtual void stopRender (QgsSymbolRenderContext &context)=0
 Called after a set of rendering operations has finished on the supplied render context.
 
virtual QColor strokeColor () const
 Returns the stroke color for the symbol layer.
 
virtual QgsSymbolsubSymbol ()
 Returns the symbol's sub symbol, if present.
 
virtual void toSld (QDomDocument &doc, QDomElement &element, const QVariantMap &props) const
 Saves the symbol layer as SLD.
 
Qgis::SymbolType type () const
 
virtual QSet< QString > usedAttributes (const QgsRenderContext &context) const
 Returns the set of attributes referenced by the layer.
 
Qgis::SymbolLayerUserFlags userFlags () const
 Returns user-controlled flags which control the symbol layer's behavior.
 
virtual bool usesMapUnits () const
 Returns true if the symbol layer has any components which use map unit based sizes.
 
virtual bool writeDxf (QgsDxfExport &e, double mmMapUnitScaleFactor, const QString &layerName, QgsSymbolRenderContext &context, QPointF shift=QPointF(0.0, 0.0)) const
 write as DXF
 

Protected Member Functions

 QgsLineSymbolLayer (bool locked=false)
 
- Protected Member Functions inherited from QgsSymbolLayer
 QgsSymbolLayer (Qgis::SymbolType type, bool locked=false)
 Constructor for QgsSymbolLayer.
 
void copyDataDefinedProperties (QgsSymbolLayer *destLayer) const
 Copies all data defined properties of this layer to another symbol layer.
 
void copyPaintEffect (QgsSymbolLayer *destLayer) const
 Copies paint effect of this layer to another symbol layer.
 
void removeMasks (QgsRenderContext &context, bool recursive)
 When rendering, remove previously installed masks from context painter if recursive is true masks are removed recursively for all children symbol layers.
 
void restoreOldDataDefinedProperties (const QVariantMap &stringMap)
 Restores older data defined properties from string map.
 
bool shouldRenderUsingSelectionColor (const QgsSymbolRenderContext &context) const
 Returns true if the symbol layer should be rendered using the selection color from the render context.
 

Protected Attributes

double mOffset = 0
 
QgsMapUnitScale mOffsetMapUnitScale
 
Qgis::RenderUnit mOffsetUnit = Qgis::RenderUnit::Millimeters
 
RenderRingFilter mRingFilter = AllRings
 
double mWidth = 0
 
QgsMapUnitScale mWidthMapUnitScale
 
Qgis::RenderUnit mWidthUnit = Qgis::RenderUnit::Millimeters
 
- Protected Attributes inherited from QgsSymbolLayer
QPainterPath mClipPath
 
QColor mColor
 
QgsPropertyCollection mDataDefinedProperties
 
bool mEnabled = true
 True if layer is enabled and should be drawn.
 
QgsFields mFields
 
QString mId
 
bool mLocked = false
 
std::unique_ptr< QgsPaintEffectmPaintEffect
 
int mRenderingPass = 0
 
Qgis::SymbolType mType
 
Qgis::SymbolLayerUserFlags mUserFlags
 User controlled flags.
 

Additional Inherited Members

- Static Public Member Functions inherited from QgsSymbolLayer
static const QgsPropertiesDefinitionpropertyDefinitions ()
 Returns the symbol layer property definitions.
 
- Static Protected Attributes inherited from QgsSymbolLayer
static const bool SELECT_FILL_BORDER = false
 Whether fill styles for selected features also highlight symbol stroke.
 
static const bool SELECT_FILL_STYLE = false
 Whether fill styles for selected features uses symbol layer style.
 
static const bool SELECTION_IS_OPAQUE = true
 Whether styles for selected features ignore symbol alpha.
 

Detailed Description

Abstract base class for line symbol layers.

Definition at line 1084 of file qgssymbollayer.h.

Member Enumeration Documentation

◆ RenderRingFilter

Options for filtering rings when the line symbol layer is being used to render a polygon's rings.

Enumerator
AllRings 

Render both exterior and interior rings.

ExteriorRingOnly 

Render the exterior ring only.

InteriorRingsOnly 

Render the interior rings only.

Definition at line 1089 of file qgssymbollayer.h.

Constructor & Destructor Documentation

◆ QgsLineSymbolLayer() [1/2]

QgsLineSymbolLayer::QgsLineSymbolLayer ( const QgsLineSymbolLayer other)
delete

◆ QgsLineSymbolLayer() [2/2]

QgsLineSymbolLayer::QgsLineSymbolLayer ( bool  locked = false)
protected

Definition at line 517 of file qgssymbollayer.cpp.

Member Function Documentation

◆ drawPreviewIcon()

void QgsLineSymbolLayer::drawPreviewIcon ( QgsSymbolRenderContext context,
QSize  size 
)
overridevirtual

Implements QgsSymbolLayer.

Definition at line 752 of file qgssymbollayer.cpp.

◆ dxfWidth()

double QgsLineSymbolLayer::dxfWidth ( const QgsDxfExport e,
QgsSymbolRenderContext context 
) const
overridevirtual

Gets line width.

Reimplemented from QgsSymbolLayer.

Reimplemented in QgsSimpleLineSymbolLayer.

Definition at line 824 of file qgssymbollayer.cpp.

◆ mapUnitScale()

QgsMapUnitScale QgsLineSymbolLayer::mapUnitScale ( ) const
overridevirtual

Reimplemented from QgsSymbolLayer.

Reimplemented in QgsTemplatedLineSymbolLayerBase, QgsSimpleLineSymbolLayer, and QgsRasterLineSymbolLayer.

Definition at line 746 of file qgssymbollayer.cpp.

◆ offset()

double QgsLineSymbolLayer::offset ( ) const
inline

Returns the line's offset.

Offset units can be retrieved by calling offsetUnit().

See also
setOffset()
offsetUnit()
offsetMapUnitScale()

Definition at line 1169 of file qgssymbollayer.h.

◆ offsetMapUnitScale()

const QgsMapUnitScale & QgsLineSymbolLayer::offsetMapUnitScale ( ) const
inline

Returns the map unit scale for the line's offset.

See also
setOffsetMapUnitScale()
offset()
offsetUnit()

Definition at line 1212 of file qgssymbollayer.h.

◆ offsetUnit()

Qgis::RenderUnit QgsLineSymbolLayer::offsetUnit ( ) const
inline

Returns the units for the line's offset.

See also
setOffsetUnit()
offset()
offsetMapUnitScale()

Definition at line 1196 of file qgssymbollayer.h.

◆ operator=()

QgsLineSymbolLayer & QgsLineSymbolLayer::operator= ( const QgsLineSymbolLayer other)
delete

◆ outputUnit()

Qgis::RenderUnit QgsLineSymbolLayer::outputUnit ( ) const
overridevirtual

Returns the units to use for sizes and widths within the symbol layer.

Individual symbol layer subclasses will interpret this in different ways, e.g., a marker symbol layer may use it to specify the units for the marker size, while a line symbol layer may use it to specify the units for the line width.

Returns
output unit, or QgsUnitTypes::RenderUnknownUnit if the symbol layer contains mixed units
See also
setOutputUnit()

Reimplemented from QgsSymbolLayer.

Reimplemented in QgsTemplatedLineSymbolLayerBase, QgsSimpleLineSymbolLayer, and QgsRasterLineSymbolLayer.

Definition at line 736 of file qgssymbollayer.cpp.

◆ renderPolygonStroke()

void QgsLineSymbolLayer::renderPolygonStroke ( const QPolygonF &  points,
const QVector< QPolygonF > *  rings,
QgsSymbolRenderContext context 
)
virtual

Renders the line symbol layer along the outline of polygon, using the given render context.

The exterior ring of the polygon is specified in points. Optionally, interior rings are set via the rings argument.

See also
renderPolyline()

Reimplemented in QgsTemplatedLineSymbolLayerBase, and QgsSimpleLineSymbolLayer.

Definition at line 771 of file qgssymbollayer.cpp.

◆ renderPolyline()

virtual void QgsLineSymbolLayer::renderPolyline ( const QPolygonF &  points,
QgsSymbolRenderContext context 
)
pure virtual

◆ ringFilter()

QgsLineSymbolLayer::RenderRingFilter QgsLineSymbolLayer::ringFilter ( ) const

Returns the line symbol layer's ring filter, which controls which rings are rendered when the line symbol is being used to draw a polygon's rings.

This setting has no effect when the line symbol is not being rendered for a polygon.

See also
setRingFilter()
Since
QGIS 3.6

Definition at line 522 of file qgssymbollayer.cpp.

◆ setMapUnitScale()

void QgsLineSymbolLayer::setMapUnitScale ( const QgsMapUnitScale scale)
overridevirtual

Reimplemented from QgsSymbolLayer.

Reimplemented in QgsTemplatedLineSymbolLayerBase, QgsSimpleLineSymbolLayer, and QgsRasterLineSymbolLayer.

Definition at line 741 of file qgssymbollayer.cpp.

◆ setOffset()

void QgsLineSymbolLayer::setOffset ( double  offset)
inline

Sets the line's offset.

Offset units are set via setOffsetUnit().

See also
offset()
setOffsetUnit()
setOffsetMapUnitScale()

Definition at line 1180 of file qgssymbollayer.h.

◆ setOffsetMapUnitScale()

void QgsLineSymbolLayer::setOffsetMapUnitScale ( const QgsMapUnitScale scale)
inline

Sets the map unit scale for the line's offset.

See also
offsetMapUnitScale()
setOffset()
setOffsetUnit()

Definition at line 1204 of file qgssymbollayer.h.

◆ setOffsetUnit()

void QgsLineSymbolLayer::setOffsetUnit ( Qgis::RenderUnit  unit)
inline

Sets the unit for the line's offset.

See also
offsetUnit()
setOffset()
setOffsetMapUnitScale()

Definition at line 1188 of file qgssymbollayer.h.

◆ setOutputUnit()

void QgsLineSymbolLayer::setOutputUnit ( Qgis::RenderUnit  unit)
overridevirtual

Sets the units to use for sizes and widths within the symbol layer.

Individual symbol layer subclasses will interpret this in different ways, e.g., a marker symbol layer may use it to specify the units for the marker size, while a line symbol layer may use it to specify the units for the line width.

Parameters
unitoutput units
See also
outputUnit()

Reimplemented from QgsSymbolLayer.

Reimplemented in QgsSimpleLineSymbolLayer, QgsTemplatedLineSymbolLayerBase, QgsMarkerLineSymbolLayer, and QgsRasterLineSymbolLayer.

Definition at line 730 of file qgssymbollayer.cpp.

◆ setRingFilter()

void QgsLineSymbolLayer::setRingFilter ( QgsLineSymbolLayer::RenderRingFilter  filter)

Sets the line symbol layer's ring filter, which controls which rings are rendered when the line symbol is being used to draw a polygon's rings.

This setting has no effect when the line symbol is not being rendered for a polygon.

See also
ringFilter()
Since
QGIS 3.6

Definition at line 527 of file qgssymbollayer.cpp.

◆ setWidth()

virtual void QgsLineSymbolLayer::setWidth ( double  width)
inlinevirtual

Sets the width of the line symbol layer.

Calling this method updates the width of the line symbol layer, without changing the existing width units. It has different effects depending on the line symbol layer subclass, e.g. for a simple line layer it changes the stroke width of the line, for a marker line layer it changes the size of the markers used to draw the line.

See also
width()
Warning
Since the width units vary, this method is useful for changing the relative width of a line symbol layer only.

Reimplemented in QgsMarkerLineSymbolLayer, and QgsHashedLineSymbolLayer.

Definition at line 1135 of file qgssymbollayer.h.

◆ setWidthMapUnitScale()

void QgsLineSymbolLayer::setWidthMapUnitScale ( const QgsMapUnitScale scale)
inline

Definition at line 1230 of file qgssymbollayer.h.

◆ setWidthUnit()

void QgsLineSymbolLayer::setWidthUnit ( Qgis::RenderUnit  unit)
inline

Sets the units for the line's width.

Parameters
unitwidth units
See also
widthUnit()

Definition at line 1222 of file qgssymbollayer.h.

◆ width() [1/2]

virtual double QgsLineSymbolLayer::width ( ) const
inlinevirtual

Returns the estimated width for the line symbol layer.

Warning
This returned value is inaccurate if the symbol layer has sub-symbols with different width units. Use the overload accepting a QgsRenderContext argument instead for accurate sizes in this case.
See also
setWidth()

Reimplemented in QgsMarkerLineSymbolLayer, and QgsHashedLineSymbolLayer.

Definition at line 1146 of file qgssymbollayer.h.

◆ width() [2/2]

double QgsLineSymbolLayer::width ( const QgsRenderContext context) const
virtual

Returns the line symbol layer width, in painter units.

This method returns an accurate width by calculating the actual rendered width of the symbol layer using the provided render context.

See also
setWidth()
Since
QGIS 3.4.5

Reimplemented in QgsMarkerLineSymbolLayer, and QgsHashedLineSymbolLayer.

Definition at line 819 of file qgssymbollayer.cpp.

◆ widthMapUnitScale()

const QgsMapUnitScale & QgsLineSymbolLayer::widthMapUnitScale ( ) const
inline

Definition at line 1231 of file qgssymbollayer.h.

◆ widthUnit()

Qgis::RenderUnit QgsLineSymbolLayer::widthUnit ( ) const
inline

Returns the units for the line's width.

See also
setWidthUnit()

Definition at line 1228 of file qgssymbollayer.h.

Member Data Documentation

◆ mOffset

double QgsLineSymbolLayer::mOffset = 0
protected

Definition at line 1263 of file qgssymbollayer.h.

◆ mOffsetMapUnitScale

QgsMapUnitScale QgsLineSymbolLayer::mOffsetMapUnitScale
protected

Definition at line 1265 of file qgssymbollayer.h.

◆ mOffsetUnit

Qgis::RenderUnit QgsLineSymbolLayer::mOffsetUnit = Qgis::RenderUnit::Millimeters
protected

Definition at line 1264 of file qgssymbollayer.h.

◆ mRingFilter

RenderRingFilter QgsLineSymbolLayer::mRingFilter = AllRings
protected

Definition at line 1267 of file qgssymbollayer.h.

◆ mWidth

double QgsLineSymbolLayer::mWidth = 0
protected

Definition at line 1260 of file qgssymbollayer.h.

◆ mWidthMapUnitScale

QgsMapUnitScale QgsLineSymbolLayer::mWidthMapUnitScale
protected

Definition at line 1262 of file qgssymbollayer.h.

◆ mWidthUnit

Qgis::RenderUnit QgsLineSymbolLayer::mWidthUnit = Qgis::RenderUnit::Millimeters
protected

Definition at line 1261 of file qgssymbollayer.h.


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