QgsLineSymbol Class Reference

A line symbol type, for rendering LineString and MultiLineString geometries. More...

#include <qgssymbol.h>

Inheritance diagram for QgsLineSymbol:

Public Member Functions
	QgsLineSymbol (const QgsSymbolLayerList &layers=QgsSymbolLayerList())
	Constructor for QgsLineSymbol, with the specified list of initial symbol layers. More...
QgsLineSymbol *	clone () const override
	Returns a deep copy of this symbol. More...
QgsProperty	dataDefinedWidth () const
	Returns data defined width for whole symbol (including all symbol layers). More...
void	renderPolyline (const QPolygonF &points, const QgsFeature *f, QgsRenderContext &context, int layer=-1, bool selected=false)
	Renders the symbol along the line joining points, using the given render context. More...
void	setDataDefinedWidth (const QgsProperty &property)
	Set data defined width for whole symbol (including all symbol layers). More...
void	setWidth (double width)
	Sets the width for the whole line symbol. More...
double	width () const
	Returns the estimated width for the whole symbol, which is the maximum width of all marker symbol layers in the symbol. More...
double	width (const QgsRenderContext &context) const
	Returns the symbol width, in painter units. More...
Public Member Functions inherited from QgsSymbol
virtual	~QgsSymbol ()
bool	appendSymbolLayer (QgsSymbolLayer *layer)
	Appends a symbol layer at the end of the current symbol layer list. More...
QImage	asImage (QSize size, QgsRenderContext *customContext=nullptr)
	Returns an image of the symbol at the specified size. More...
QImage	bigSymbolPreviewImage (QgsExpressionContext *expressionContext=nullptr)
	Returns a large (roughly 100x100 pixel) preview image for the symbol. More...
bool	changeSymbolLayer (int index, QgsSymbolLayer *layer)
	Deletes the current layer at the specified index and replaces it with layer. More...
bool	clipFeaturesToExtent () const
	Returns whether features drawn by the symbol will be clipped to the render context's extent. More...
QColor	color () const
	Returns the symbol's color. More...
bool	deleteSymbolLayer (int index)
	Removes and deletes the symbol layer at the specified index. More...
void	drawPreviewIcon (QPainter *painter, QSize size, QgsRenderContext *customContext=nullptr, bool selected=false, const QgsExpressionContext *expressionContext=nullptr)
	Draws an icon of the symbol that occupies an area given by size using the specified painter. More...
QString	dump () const
	Returns a string dump of the symbol's properties. More...
void	exportImage (const QString &path, const QString &format, QSize size)
	Export the symbol as an image format, to the specified path and with the given size. More...
bool	forceRHR () const
	Returns true if polygon features drawn by the symbol will be reoriented to follow the standard right-hand-rule orientation, in which the area that is bounded by the polygon is to the right of the boundary. More...
bool	hasDataDefinedProperties () const
	Returns whether the symbol utilizes any data defined properties. More...
bool	insertSymbolLayer (int index, QgsSymbolLayer *layer)
	Inserts a symbol layer to specified index. More...
Q_DECL_DEPRECATED const QgsVectorLayer *	layer () const
QgsMapUnitScale	mapUnitScale () const
	Returns the map unit scale for the symbol. More...
qreal	opacity () const
	Returns the opacity for the symbol. More...
QgsUnitTypes::RenderUnit	outputUnit () const
	Returns the units to use for sizes and widths within the symbol. More...
void	renderFeature (const QgsFeature &feature, QgsRenderContext &context, int layer=-1, bool selected=false, bool drawVertexMarker=false, int currentVertexMarkerType=0, double currentVertexMarkerSize=0.0) SIP_THROW(QgsCsException)
	Render a feature. More...
RenderHints	renderHints () const
	Returns the rendering hint flags for the symbol. More...
void	setClipFeaturesToExtent (bool clipFeaturesToExtent)
	Sets whether features drawn by the symbol should be clipped to the render context's extent. More...
void	setColor (const QColor &color)
	Sets the color for the symbol. More...
void	setForceRHR (bool force)
	Sets whether polygon features drawn by the symbol should be reoriented to follow the standard right-hand-rule orientation, in which the area that is bounded by the polygon is to the right of the boundary. More...
Q_DECL_DEPRECATED void	setLayer (const QgsVectorLayer *layer)
void	setMapUnitScale (const QgsMapUnitScale &scale)
	Sets the map unit scale for the symbol. More...
void	setOpacity (qreal opacity)
	Sets the opacity for the symbol. More...
void	setOutputUnit (QgsUnitTypes::RenderUnit unit)
	Sets the units to use for sizes and widths within the symbol. More...
void	setRenderHints (RenderHints hints)
	Sets rendering hint flags for the symbol. More...
void	startRender (QgsRenderContext &context, const QgsFields &fields=QgsFields())
	Begins the rendering process for the symbol. More...
void	stopRender (QgsRenderContext &context)
	Ends the rendering process. More...
QgsSymbolLayer *	symbolLayer (int layer)
	Returns the symbol layer at the specified index. More...
int	symbolLayerCount () const
	Returns the total number of symbol layers contained in the symbol. More...
QgsSymbolLayerList	symbolLayers ()
	Returns the list of symbol layers contained in the symbol. More...
QgsSymbolRenderContext *	symbolRenderContext ()
	Returns the symbol render context. More...
QgsSymbolLayer *	takeSymbolLayer (int index)
	Removes a symbol layer from the list and returns a pointer to it. More...
void	toSld (QDomDocument &doc, QDomElement &element, QgsStringMap props) const
	Converts the symbol to a SLD representation. More...
SymbolType	type () const
	Returns the symbol's type. More...
QSet< QString >	usedAttributes (const QgsRenderContext &context) const
	Returns a list of attributes required to render this feature. More...

Static Public Member Functions
static QgsLineSymbol *	createSimple (const QgsStringMap &properties)
	Create a line symbol with one symbol layer: SimpleLine with specified properties. More...
Static Public Member Functions inherited from QgsSymbol
static QgsSymbol *	defaultSymbol (QgsWkbTypes::GeometryType geomType)
	Returns a new default symbol for the specified geometry type. More...

Additional Inherited Members
Public Types inherited from QgsSymbol
enum	RenderHint { DynamicRotation = 2 }
	Flags controlling behavior of symbols during rendering. More...
enum	ScaleMethod { ScaleArea, ScaleDiameter }
	Scale method. More...
enum	SymbolType { Marker, Line, Fill, Hybrid }
	Type of the symbol. More...
Protected Member Functions inherited from QgsSymbol
	QgsSymbol (SymbolType type, const QgsSymbolLayerList &layers)
QgsSymbolLayerList	cloneLayers () const
	Retrieve a cloned list of all layers that make up this symbol. More...
void	renderUsingLayer (QgsSymbolLayer *layer, QgsSymbolRenderContext &context)
	Renders a context using a particular symbol layer without passing in a geometry. More...
void	renderVertexMarker (QPointF pt, QgsRenderContext &context, int currentVertexMarkerType, double currentVertexMarkerSize)
	Render editing vertex marker at specified point. More...
Static Protected Member Functions inherited from QgsSymbol
static QPolygonF	_getLineString (QgsRenderContext &context, const QgsCurve &curve, bool clipToExtent=true)
	Creates a line string in screen coordinates from a QgsCurve in map coordinates. More...
static QPointF	_getPoint (QgsRenderContext &context, const QgsPoint &point)
	Creates a point in screen coordinates from a QgsPoint in map coordinates. More...
static void	_getPolygon (QPolygonF &pts, QList< QPolygonF > &holes, QgsRenderContext &context, const QgsPolygon &polygon, bool clipToExtent=true, bool correctRingOrientation=false)
	Creates a polygon in screen coordinates from a QgsPolygonXYin map coordinates. More...
static QPolygonF	_getPolygonRing (QgsRenderContext &context, const QgsCurve &curve, bool clipToExtent, bool isExteriorRing=false, bool correctRingOrientation=false)
	Creates a polygon ring in screen coordinates from a QgsCurve in map coordinates. More...
Protected Attributes inherited from QgsSymbol
bool	mClipFeaturesToExtent = true
bool	mForceRHR = false
Q_DECL_DEPRECATED const QgsVectorLayer *	mLayer = nullptr
QgsSymbolLayerList	mLayers
qreal	mOpacity = 1.0
	Symbol opacity (in the range 0 - 1) More...
RenderHints	mRenderHints = nullptr
SymbolType	mType

Detailed Description

A line symbol type, for rendering LineString and MultiLineString geometries.

Definition at line 1060 of file qgssymbol.h.

Constructor & Destructor Documentation

QgsLineSymbol()

QgsLineSymbol::QgsLineSymbol

(

const QgsSymbolLayerList &

layers = QgsSymbolLayerList()

)

Constructor for QgsLineSymbol, with the specified list of initial symbol layers.

Ownership of the layers are transferred to the symbol.

Definition at line 1724 of file qgssymbol.cpp.

Member Function Documentation

clone()

QgsLineSymbol * QgsLineSymbol::clone ( ) const

overridevirtual

Returns a deep copy of this symbol.

Ownership is transferred to the caller.

Implements QgsSymbol.

Definition at line 1951 of file qgssymbol.cpp.

createSimple()

QgsLineSymbol * QgsLineSymbol::createSimple ( const QgsStringMap &  properties )

static

Create a line symbol with one symbol layer: SimpleLine with specified properties.

This is a convenience method for easier creation of line symbols.

Definition at line 1240 of file qgssymbol.cpp.

dataDefinedWidth()

QgsProperty QgsLineSymbol::dataDefinedWidth

(

)

const

Returns data defined width for whole symbol (including all symbol layers).

Returns

data defined width, or invalid property if size is not set at the line level. Caller takes responsibility for deleting the returned object.

See also

setDataDefinedWidth

Since

QGIS 3.0

Definition at line 1829 of file qgssymbol.cpp.

renderPolyline()

void QgsLineSymbol::renderPolyline	(	const QPolygonF &	points,
		const QgsFeature *	f,
		QgsRenderContext &	context,
		int	layer = -1,
		bool	selected = false
	)

Renders the symbol along the line joining points, using the given render context.

The f argument is used to pass the feature currently being rendered (when available).

If only a single symbol layer from the symbol should be rendered, it should be specified in the layer argument. A layer of -1 indicates that all symbol layers should be rendered.

If selected is true then the symbol will be drawn using the "selected feature" style and colors instead of the symbol's normal style.

Definition at line 1883 of file qgssymbol.cpp.

setDataDefinedWidth()

void QgsLineSymbol::setDataDefinedWidth

(

const QgsProperty &

property

)

Set data defined width for whole symbol (including all symbol layers).

See also

dataDefinedWidth()

Since

QGIS 3.0

Definition at line 1793 of file qgssymbol.cpp.

setWidth()

void QgsLineSymbol::setWidth

(

double

width

)

Sets the width for the whole line symbol.

Individual symbol layer sizes will be scaled to maintain their current relative size to the whole symbol size.

See also

width()

Definition at line 1731 of file qgssymbol.cpp.

width() [1/2]

double QgsLineSymbol::width

(

)

const

Returns the estimated width for the whole symbol, which is the maximum width of all marker symbol layers in the symbol.

Warning

This returned value is inaccurate if the symbol consists of multiple symbol layers with different width units. Use the overload accepting a QgsRenderContext argument instead for accurate sizes in this case.

See also

setWidth()

Definition at line 1758 of file qgssymbol.cpp.

width() [2/2]

double QgsLineSymbol::width

(

const QgsRenderContext &

context

)

const

Returns the symbol width, in painter units.

This is the maximum width of all marker symbol layers in the symbol.

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

See also

setWidth()

Since

QGIS 3.4.5

Definition at line 1778 of file qgssymbol.cpp.

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

• /build/qgis-3.10.0+15buster/src/core/symbology/qgssymbol.h
• /build/qgis-3.10.0+15buster/src/core/symbology/qgssymbol.cpp