Class: QgsDiagramLayerSettings

Stores the settings for rendering of all diagrams for a layer.

QgsDiagramSettings stores the settings related to rendering the individual diagrams themselves, while QgsDiagramLayerSettings stores settings which control how ALL diagrams within a layer are rendered.

class qgis.core.QgsDiagramLayerSettings

Bases: object

AboveLine = 2

AroundPoint = 0

BelowLine = 4

Curved = 3

class DiagramType

Bases: int

Free = 5

Horizontal = 4

Line = 2

class LinePlacementFlag

Bases: int

class LinePlacementFlags

class LinePlacementFlags(f: QgsDiagramLayerSettings.LinePlacementFlags | QgsDiagramLayerSettings.LinePlacementFlag)

class LinePlacementFlags(a0: QgsDiagramLayerSettings.LinePlacementFlags)

Bases: object

MapOrientation = 16

OnLine = 1

OverPoint = 1

class Placement

Bases: int

class Property(*values)

Bases: IntEnum

Data definable properties.

• BackgroundColor: Diagram background color

• StrokeColor: Stroke color

• StrokeWidth: Stroke width

• PositionX: X-coordinate data defined diagram position

• PositionY: Y-coordinate data defined diagram position

• Distance: Distance to diagram from feature

• Priority: Diagram priority (between 0 and 10)

• ZIndex: Z-index for diagram ordering

• IsObstacle: Whether diagram features act as obstacles for other diagrams/labels

• Show: Whether to show the diagram

• AlwaysShow: Whether the diagram should always be shown, even if it overlaps other diagrams/labels

• StartAngle: Angle offset for pie diagram

Single = 0

Stacked = 1

coordinateTransform(self) → QgsCoordinateTransform

Returns the coordinate transform associated with the layer, or an invalid transform if no transformation is required.

See also

setCoordinateTransform()

Return type:

QgsCoordinateTransform

dataDefinedProperties(self) → QgsPropertyCollection

Returns a reference to the diagram’s property collection, used for data defined overrides.

See also

setDataDefinedProperties()

Return type:

QgsPropertyCollection

distance(self) → float

Returns the distance between the diagram and the feature (in mm).

See also

setDistance()

Return type:

float

isObstacle(self) → bool

Returns whether the feature associated with a diagram acts as an obstacle for other labels or diagrams.

See also

setIsObstacle()

Return type:

bool

linePlacementFlags(self) → QgsDiagramLayerSettings.LinePlacementFlags

Returns the diagram placement flags. These are only used if the diagram placement is set to a line type.

See also

setLinePlacementFlags()

Return type:

QgsDiagramLayerSettings.LinePlacementFlags

placement(self) → QgsDiagramLayerSettings.Placement

Returns the diagram placement.

See also

setPlacement()

Return type:

QgsDiagramLayerSettings.Placement

prepare(self, context: QgsExpressionContext = QgsExpressionContext()) → bool

Prepares the diagrams for a specified expression context. Calling prepare before rendering multiple diagrams allows precalculation of expensive setup tasks such as parsing expressions. Returns True if preparation was successful.

Parameters:

context (QgsExpressionContext = QgsExpressionContext())

Return type:

bool

priority(self) → int

Returns the diagram priority.

Return type:

int

Returns:

diagram priority, where 0 = low and 10 = high

Note

placement priority is shared with labeling, so diagrams with a high priority may displace labels and vice-versa

See also

setPriority()

propertyDefinitions() → Dict[int, QgsPropertyDefinition]

Returns the diagram property definitions.

Return type:

Dict[int, QgsPropertyDefinition]

readXml(self, elem: QDomElement)

Reads the diagram settings from a DOM element.

See also

writeXml()

Parameters:

elem (QDomElement)

referencedFields(self, context: QgsExpressionContext = QgsExpressionContext()) → Set[str]

Returns the set of any fields referenced by the layer’s diagrams.

Parameters:

context (QgsExpressionContext = QgsExpressionContext()) – expression context the diagrams will be drawn using

Return type:

Set[str]

renderer(self) → QgsDiagramRenderer | None

Returns the diagram renderer associated with the layer.

See also

setRenderer()

Return type:

Optional[QgsDiagramRenderer]

setCoordinateTransform(self, transform: QgsCoordinateTransform)

Sets the coordinate transform associated with the layer.

Parameters:

transform (QgsCoordinateTransform) – coordinate transform. Ownership is transferred to the object.

See also

coordinateTransform()

setDataDefinedProperties(self, collection: QgsPropertyCollection)

Sets the diagram’s property collection, used for data defined overrides.

Parameters:

collection (QgsPropertyCollection) – property collection. Existing properties will be replaced.

See also

dataDefinedProperties()

See also

Property

setDistance(self, distance: float)

Sets the distance between the diagram and the feature.

Parameters:

distance (float) – distance in mm

See also

distance()

setIsObstacle(self, isObstacle: bool)

Sets whether the feature associated with a diagram acts as an obstacle for other labels or diagrams.

Parameters:

isObstacle (bool) – set to True for feature to act as obstacle

See also

isObstacle()

setLinePlacementFlags(self, flags: QgsDiagramLayerSettings.LinePlacementFlags | QgsDiagramLayerSettings.LinePlacementFlag)

Sets the the diagram placement flags. These are only used if the diagram placement is set to a line type.

Parameters:

flags (Union[QgsDiagramLayerSettings.LinePlacementFlags, QgsDiagramLayerSettings.LinePlacementFlag]) – placement value

See also

linePlacementFlags()

setPlacement(self, value: QgsDiagramLayerSettings.Placement)

Sets the diagram placement.

Parameters:

value (QgsDiagramLayerSettings.Placement) – placement value

See also

placement()

setPriority(self, value: int)

Sets the diagram priority.

Parameters:

value (int) – priority, where 0 = low and 10 = high

See also

priority()

setRenderer(self, diagramRenderer: QgsDiagramRenderer | None)

Sets the diagram renderer associated with the layer.

Parameters:

diagramRenderer (Optional[QgsDiagramRenderer]) – diagram renderer. Ownership is transferred to the object.

See also

renderer()

setShowAllDiagrams(self, showAllDiagrams: bool)

Sets whether the layer should show all diagrams, including overlapping diagrams

Parameters:

showAllDiagrams (bool) – set to True to show all diagrams

See also

showAllDiagrams()

setZIndex(self, index: float)

Sets the diagram z-index. Diagrams (or labels) with a higher z-index are drawn over diagrams with a lower z-index.

Parameters:

index (float) – diagram z-index

See also

zIndex()

showAllDiagrams(self) → bool

Returns whether the layer should show all diagrams, including overlapping diagrams

See also

setShowAllDiagrams()

Return type:

bool

writeXml(self, layerElem: QDomElement, doc: QDomDocument)

Writes the diagram settings to a DOM element.

See also

readXml()

Parameters:

• layerElem (QDomElement)

• doc (QDomDocument)

zIndex(self) → float

Returns the diagram z-index. Diagrams (or labels) with a higher z-index are drawn over diagrams with a lower z-index.

Note

z-index ordering is shared with labeling, so diagrams with a high z-index may be drawn over labels with a low z-index and vice-versa

See also

setZIndex()

Return type:

float