Class: QgsMarkerSymbolLayer¶

Abstract base class for marker symbol layers.

Note

This is an abstract class, with methods which must be implemented by a subclass.

The following methods must be implemented: bounds(), QgsSymbolLayer.clone(), QgsSymbolLayer.layerType(), QgsSymbolLayer.properties(), renderPoint()

Class Hierarchy¶

Base classes¶

QgsSymbolLayer

Abstract base class for symbol layers.

Subclasses¶

`QgsRasterMarkerSymbolLayer`	Raster marker symbol layer class.
`QgsEllipseSymbolLayer`	A symbol layer for rendering objects with major and minor axis (e.g. ellipse, rectangle, etc).
`QgsSimpleMarkerSymbolLayerBase`	Abstract base class for simple marker symbol layers.
`QgsFontMarkerSymbolLayer`	A marker symbol layer which displays characters rendered using a font.
`QgsMaskMarkerSymbolLayer`	Special symbol layer that uses its sub symbol as a selective mask.
`QgsSvgMarkerSymbolLayer`	A marker symbol layer which renders an SVG graphic.
`QgsVectorFieldSymbolLayer`	A symbol layer class for displaying displacement arrows based on point layer attributes.

Enums

`HorizontalAnchorPoint`	Marker symbol horizontal anchor points.
`VerticalAnchorPoint`	Marker symbol vertical anchor points.

Abstract Methods

`bounds`	Returns the approximate bounding box of the marker symbol layer, taking into account any data defined overrides and offsets which are set for the marker layer.
`renderPoint`	Renders a marker at the specified point.

Methods

`angle`	Returns the rotation angle for the marker, in degrees clockwise from north.
`horizontalAnchorPoint`	Returns the horizontal anchor point for positioning the symbol.
`markerOffset`	Calculates the required marker offset, including both the symbol offset and any displacement required to align with the marker's anchor point.
`markerOffset2`	Calculates the required marker offset, including both the symbol offset and any displacement required to align with the marker's anchor point.
`markerOffsetWithWidthAndHeight`	Calculates the required marker offset, including both the symbol offset and any displacement required to align with the marker's anchor point.
`offset`	Returns the marker's offset, which is the horizontal and vertical displacement which the rendered marker will have from the original feature's geometry.
`offsetMapUnitScale`	Returns the map unit scale for the symbol's offset.
`offsetUnit`	Returns the units for the symbol's offset.
`scaleMethod`	Returns the method to use for scaling the marker's size.
`setAngle`	Sets the rotation angle for the marker.
`setHorizontalAnchorPoint`	Sets the horizontal anchor point for positioning the symbol.
`setLineAngle`	Sets the line angle modification for the symbol's angle.
`setOffset`	Sets the marker's offset, which is the horizontal and vertical displacement which the rendered marker should have from the original feature's geometry.
`setOffsetMapUnitScale`	Sets the map unit scale for the symbol's offset.
`setOffsetUnit`	Sets the units for the symbol's offset.
`setScaleMethod`	Sets the method to use for scaling the marker's size.
`setSizeMapUnitScale`	Sets the map unit scale for the symbol's size.
`setSizeUnit`	Sets the units for the symbol's size.
`setVerticalAnchorPoint`	Sets the vertical anchor point for positioning the symbol.
`size`	Returns the symbol size.
`sizeMapUnitScale`	Returns the map unit scale for the symbol's size.
`sizeUnit`	Returns the units for the symbol's size.
`verticalAnchorPoint`	Returns the vertical anchor point for positioning the symbol.

Virtual Methods

In PyQGIS, only methods marked as virtual can be safely overridden in a Python subclass of QgsMarkerSymbolLayer. See the FAQ for more details.

`setSize`	Sets the symbol size.
`writeSldMarker`	Writes the symbol layer definition as a SLD XML element.

class qgis.core.QgsMarkerSymbolLayer[source]¶

Bases: QgsSymbolLayer

__init__(locked: bool = False)

Constructor for QgsMarkerSymbolLayer.

Parameters:: locked (bool = False) – set to True to lock symbol color

class HorizontalAnchorPoint(*values)¶

Bases: IntEnum

Marker symbol horizontal anchor points.

Note

Prior to QGIS 3.44 this was available as QgsMarkerSymbolLayer.HorizontalAnchorPoint

Added in version 3.44.

Left: Align to left side of symbol
Center: Align to horizontal center of symbol

Available as QgsMarkerSymbolLayer.HCenter in older QGIS releases.
Right: Align to right side of symbol

class VerticalAnchorPoint(*values)¶

Bases: IntEnum

Marker symbol vertical anchor points.

Note

Prior to QGIS 3.44 this was available as QgsMarkerSymbolLayer.VerticalAnchorPoint

Added in version 3.44.

Top: Align to top of symbol
Center: Align to vertical center of symbol

Available as QgsMarkerSymbolLayer.VCenter in older QGIS releases.
Bottom: Align to bottom of symbol
Baseline: Align to baseline of symbol, e.g. font baseline for font marker symbol layers. Treated as Bottom if no baseline is available for the symbol layer type.

Added in version 3.44.

angle(self) → float[source]¶

Returns the rotation angle for the marker, in degrees clockwise from north.

See also

setAngle()

Return type:: float

abstract bounds(self, point: QPointF | QPoint, context: QgsSymbolRenderContext) → QRectF[source]¶

Returns the approximate bounding box of the marker symbol layer, taking into account any data defined overrides and offsets which are set for the marker layer.

Return type:

QRectF

Returns:

approximate symbol bounds, in painter units

Parameters:

point (Union[QPointF, QPoint])
context (QgsSymbolRenderContext)

horizontalAnchorPoint(self) → Qgis.HorizontalAnchorPoint[source]¶

Returns the horizontal anchor point for positioning the symbol. The symbol will be drawn so that the horizontal anchor point is aligned with the marker’s desired location.

See also

setHorizontalAnchorPoint()

See also

verticalAnchorPoint()

Return type:: Qgis.HorizontalAnchorPoint

markerOffset(self, context: QgsSymbolRenderContext)[source]¶

Calculates the required marker offset, including both the symbol offset and any displacement required to align with the marker’s anchor point.

Parameters:

context (QgsSymbolRenderContext) -> (float) – symbol render context
offsetX – will be set to required horizontal offset (in painter units)
offsetY – will be set to required vertical offset (in painter units)

markerOffset2(self, context: QgsSymbolRenderContext, width: float, height: float, widthUnit: Qgis.RenderUnit, heightUnit: Qgis.RenderUnit, widthMapUnitScale: QgsMapUnitScale, heightMapUnitScale: QgsMapUnitScale)¶

Calculates the required marker offset, including both the symbol offset and any displacement required to align with the marker’s anchor point.

Parameters:

context (QgsSymbolRenderContext) – symbol render context
width (float) – marker width
height (float) – marker height
widthUnit (Qgis.RenderUnit) – unit for marker width
heightUnit (Qgis.RenderUnit) – unit for marker height
offsetX – will be set to required horizontal offset (in painter units)
offsetY – will be set to required vertical offset (in painter units)
widthMapUnitScale (QgsMapUnitScale) – map unit scale for marker width
heightMapUnitScale (QgsMapUnitScale) -> (float) – map unit scale for marker height

markerOffsetWithWidthAndHeight(self, context: QgsSymbolRenderContext, width: float, height: float)¶

Calculates the required marker offset, including both the symbol offset and any displacement required to align with the marker’s anchor point.

Parameters:

context (QgsSymbolRenderContext) – symbol render context
width (float) – marker width
height (float) -> (float) – marker height
offsetX – will be set to required horizontal offset (in painter units)
offsetY – will be set to required vertical offset (in painter units)

offset(self) → QPointF[source]¶

Returns the marker’s offset, which is the horizontal and vertical displacement which the rendered marker will have from the original feature’s geometry. Units are specified by offsetUnit().

See also

setOffset()

See also

offsetUnit()

See also

offsetMapUnitScale()

Return type:: QPointF

offsetMapUnitScale(self) → QgsMapUnitScale¶

Returns the map unit scale for the symbol’s offset.

See also

setOffsetMapUnitScale()

See also

offset()

See also

offsetUnit()

Return type:: QgsMapUnitScale

offsetUnit(self) → Qgis.RenderUnit[source]¶

Returns the units for the symbol’s offset.

See also

setOffsetUnit()

See also

offset()

See also

offsetMapUnitScale()

Return type:: Qgis.RenderUnit

abstract renderPoint(self, point: QPointF | QPoint, context: QgsSymbolRenderContext)[source]¶

Renders a marker at the specified point. Derived classes must implement this to handle drawing the point.

Parameters:

point (Union[QPointF, QPoint]) – position at which to render point, in painter units
context (QgsSymbolRenderContext) – symbol render context

scaleMethod(self) → Qgis.ScaleMethod[source]¶

Returns the method to use for scaling the marker’s size.

See also

setScaleMethod()

Return type:: Qgis.ScaleMethod

setAngle(self, angle: float)[source]¶

Sets the rotation angle for the marker.

Parameters:: angle (float) – angle in degrees clockwise from north.

See also

angle()

See also

setLineAngle()

setHorizontalAnchorPoint(self, h: Qgis.HorizontalAnchorPoint)[source]¶

Sets the horizontal anchor point for positioning the symbol.

Parameters:: h (Qgis.HorizontalAnchorPoint) – anchor point. Symbol will be drawn so that the horizontal anchor point is aligned with the marker’s desired location.

See also

horizontalAnchorPoint()

See also

setVerticalAnchorPoint()

setLineAngle(self, lineAngle: float)[source]¶

Sets the line angle modification for the symbol’s angle. This angle is added to the marker’s rotation and data defined rotation before rendering the symbol, and is usually used for orienting symbols to match a line’s angle.

Parameters:: lineAngle (float) – Angle in degrees clockwise from north, valid values are between 0 and 360

See also

setAngle()

See also

angle()

setOffset(self, offset: QPointF | QPoint)[source]¶

Sets the marker’s offset, which is the horizontal and vertical displacement which the rendered marker should have from the original feature’s geometry.

Parameters:: offset (Union[QPointF, QPoint]) – marker offset. Units are specified by offsetUnit()

See also

offset()

See also

setOffsetUnit()

See also

setOffsetMapUnitScale()

setOffsetMapUnitScale(self, scale: QgsMapUnitScale)[source]¶

Sets the map unit scale for the symbol’s offset.

Parameters:: scale (QgsMapUnitScale) – offset map unit scale

See also

offsetMapUnitScale()

See also

setOffset()

See also

setOffsetUnit()

setOffsetUnit(self, unit: Qgis.RenderUnit)[source]¶

Sets the units for the symbol’s offset.

Parameters:: unit (Qgis.RenderUnit) – offset units

See also

offsetUnit()

See also

setOffset()

See also

setOffsetMapUnitScale()

setScaleMethod(self, scaleMethod: Qgis.ScaleMethod)[source]¶

Sets the method to use for scaling the marker’s size.

Parameters:: scaleMethod (Qgis.ScaleMethod) – scale method

See also

scaleMethod()

virtual setSize(self, size: float)[source]¶

Sets the symbol size.

Parameters:: size (float) – symbol size. Units are specified by sizeUnit().

See also

size()

See also

setSizeUnit()

See also

setSizeMapUnitScale()

setSizeMapUnitScale(self, scale: QgsMapUnitScale)[source]¶

Sets the map unit scale for the symbol’s size.

Parameters:: scale (QgsMapUnitScale) – size map unit scale

See also

sizeMapUnitScale()

See also

setSize()

See also

setSizeUnit()

setSizeUnit(self, unit: Qgis.RenderUnit)[source]¶

Sets the units for the symbol’s size.

Parameters:: unit (Qgis.RenderUnit) – size units

See also

sizeUnit()

See also

setSize()

See also

setSizeMapUnitScale()

setVerticalAnchorPoint(self, v: Qgis.VerticalAnchorPoint)[source]¶

Sets the vertical anchor point for positioning the symbol.

Parameters:: v (Qgis.VerticalAnchorPoint) – anchor point. Symbol will be drawn so that the vertical anchor point is aligned with the marker’s desired location.

See also

verticalAnchorPoint()

See also

setHorizontalAnchorPoint()

size(self) → float[source]¶

Returns the symbol size. Units are specified by sizeUnit().

See also

setSize()

See also

sizeUnit()

See also

sizeMapUnitScale()

Return type:: float

sizeMapUnitScale(self) → QgsMapUnitScale¶

Returns the map unit scale for the symbol’s size.

See also

setSizeMapUnitScale()

See also

size()

See also

sizeUnit()

Return type:: QgsMapUnitScale

sizeUnit(self) → Qgis.RenderUnit[source]¶

Returns the units for the symbol’s size.

See also

setSizeUnit()

See also

size()

See also

sizeMapUnitScale()

Return type:: Qgis.RenderUnit

verticalAnchorPoint(self) → Qgis.VerticalAnchorPoint[source]¶

Returns the vertical anchor point for positioning the symbol. The symbol will be drawn so that the vertical anchor point is aligned with the marker’s desired location.

See also

setVerticalAnchorPoint()

See also

horizontalAnchorPoint()

Return type:: Qgis.VerticalAnchorPoint

virtual writeSldMarker(self, doc: QDomDocument, element: QDomElement, props: Dict[str, Any])[source]¶

Writes the symbol layer definition as a SLD XML element.

Parameters:

doc (QDomDocument) – XML document
element (QDomElement) – parent XML element
props (Dict[str, Any]) – symbol layer definition (see properties())

Deprecated since version 3.44: Use the version with QgsSldExportContext instead.

virtual writeSldMarker(self, doc: QDomDocument, element: QDomElement, context: QgsSldExportContext) → bool[source]

Writes the symbol layer definition as a SLD XML element.

Parameters:

doc (QDomDocument) – XML document
element (QDomElement) – parent XML element
context (QgsSldExportContext) – export context

Added in version 3.44.

Return type:: bool