Class: QgsCategorizedSymbolRenderer¶

class qgis.core.QgsCategorizedSymbolRenderer(attrName: str = '', categories: Iterable[QgsRendererCategory] = [])¶

Bases: QgsFeatureRenderer

Constructor for QgsCategorizedSymbolRenderer.

The attrName argument specifies the layer’s field name, or expression, which the categories will be matched against.

A list of renderer categories can optionally be specified. If no categories are specified in the constructor, they can be added later by calling addCategory().

Methods

accept

param visitor

addCategory

Adds a new category to the renderer.

capabilities

rtype

QgsFeatureRenderer.Capabilities

categories

Returns a list of all categories recognized by the renderer.

categoryIndexForLabel

Returns the index of the category with the specified label (or -1 if the label was not found, or is not unique).

categoryIndexForValue

Returns the index for the category with the specified value (or -1 if not found).

checkLegendSymbolItem

param key

classAttribute

Returns the class attribute for the renderer, which is the field name or expression string from the layer which will be matched against the renderer categories.

clone

rtype

QgsCategorizedSymbolRenderer

convertFromRenderer

Creates a new QgsCategorizedSymbolRenderer from an existing renderer.

convertSymbolRotation

convertSymbolSizeScale

copyRendererData

Clones generic renderer data to another renderer.

create

Creates a categorized renderer from an XML element.

createCategories

Create categories for a list of values.

dataDefinedSizeLegend

Returns configuration of appearance of legend when using data-defined size for marker symbols.

deleteAllCategories

Deletes all existing categories from the renderer.

deleteCategory

Deletes the category with the specified index from the renderer.

dump

rtype

str

filter

param fields

filterNeedsGeometry

rtype

bool

legendClassificationAttribute

rtype

str

legendKeysForFeature

param feature

legendSymbolItemChecked

param key

legendSymbolItems

rtype

List[QgsLegendSymbolItem]

legendSymbolItemsCheckable

rtype

bool

matchToSymbols

Replaces category symbols with the symbols from a style that have a matching name and symbol type.

moveCategory

Moves an existing category at index position from to index position to.

originalSymbolForFeature

param feature

rebuildHash

hashtable for faster access to symbols

renderFeatureWithSymbol

Render the feature with the symbol using context.

renderVertexMarker

render editing vertex marker at specified point

renderVertexMarkerPolygon

render editing vertex marker for a polygon

renderVertexMarkerPolyline

render editing vertex marker for a polyline

save

param doc

setClassAttribute

Sets the class attribute for the renderer, which is the field name or expression string from the layer which will be matched against the renderer categories.

setDataDefinedSizeLegend

Configures appearance of legend when renderer is configured to use data-defined size for marker symbols.

setLegendSymbolItem

param key

setSourceColorRamp

Sets the source color ramp.

setSourceSymbol

Sets the source symbol for the renderer, which is the base symbol used for the each categories' symbol before applying the categories' color.

skipRender

sortByLabel

Sorts the existing categories by their label.

sortByValue

Sorts the existing categories by their value.

sourceColorRamp

Returns the source color ramp, from which each categories' color is derived.

sourceSymbol

Returns the renderer's source symbol, which is the base symbol used for the each categories' symbol before applying the categories' color.

startRender

param context

stopRender

param context

symbolForFeature

param feature

symbolForValue

Returns the matching symbol corresponding to an attribute value.

symbolForValue2

Returns the matching symbol corresponding to an attribute value.

symbols

param context

toSld

param doc

updateCategoryLabel

Changes the label for the category with the specified index.

updateCategoryRenderState

Changes the render state for the category with the specified index.

updateCategorySymbol

Changes the symbol for the category with the specified index.

updateCategoryValue

Changes the value for the category with the specified index.

updateColorRamp

Update the color ramp used and all symbols colors.

updateSymbols

Update all the symbols but leave categories and colors.

usedAttributes

param context

accept(self, visitor: QgsStyleEntityVisitorInterface) → bool¶

Parameters: visitor (QgsStyleEntityVisitorInterface) –
Return type: bool

addCategory(self, category: QgsRendererCategory)¶

Adds a new category to the renderer.

See also

categories()

Parameters: category (QgsRendererCategory) –

capabilities(self) → QgsFeatureRenderer.Capabilities¶

Return type: QgsFeatureRenderer.Capabilities

categories(self) → List[QgsRendererCategory]¶

Returns a list of all categories recognized by the renderer.

Return type: List[QgsRendererCategory]

categoryIndexForLabel(self, val: str) → int¶

Returns the index of the category with the specified label (or -1 if the label was not found, or is not unique).

New in version 2.5.

Parameters: val (str) –
Return type: int

categoryIndexForValue(self, val: Any) → int¶

Returns the index for the category with the specified value (or -1 if not found).

Parameters: val (Any) –
Return type: int

checkLegendSymbolItem(self, key: str, state: bool = True)¶

Parameters

key (str) –
state (bool = True) –

classAttribute(self) → str¶

Returns the class attribute for the renderer, which is the field name or expression string from the layer which will be matched against the renderer categories.

See also

setClassAttribute()

Return type: str

clone(self) → QgsCategorizedSymbolRenderer¶

Return type: QgsCategorizedSymbolRenderer

convertFromRenderer(renderer: QgsFeatureRenderer, layer: QgsVectorLayer = None) → QgsCategorizedSymbolRenderer¶

Creates a new QgsCategorizedSymbolRenderer from an existing renderer.

Since QGIS 3.20, the optional layer parameter is required for conversions of some renderer types.

Return type: QgsCategorizedSymbolRenderer
Returns: a new renderer if the conversion was possible, otherwise None.

New in version 2.5.

Parameters

renderer (QgsFeatureRenderer) –
layer (QgsVectorLayer = None) –

convertSymbolRotation(symbol: QgsSymbol, field: str)¶: Note

this function is used to convert old rotations expressions to symbol level DataDefined angle

convertSymbolSizeScale(symbol: QgsSymbol, method: Qgis.ScaleMethod, field: str)¶: Note

this function is used to convert old sizeScale expressions to symbol level DataDefined size

copyRendererData(self, destRenderer: QgsFeatureRenderer)¶

Clones generic renderer data to another renderer. Currently clones

Order By
Paint Effect

Parameters: destRenderer – destination renderer for copied effect

create(element: QDomElement, context: QgsReadWriteContext) → QgsFeatureRenderer¶

Creates a categorized renderer from an XML element.

Parameters

element (QDomElement) –
context (QgsReadWriteContext) –

Return type

QgsFeatureRenderer

createCategories(values: Iterable[Any], symbol: QgsSymbol, layer: QgsVectorLayer = None, fieldName: str = '') → List[QgsRendererCategory]¶

Create categories for a list of values. The returned symbols in the category list will be a modification of symbol.

If layer and fieldName are specified it will try to find nicer values to represent the description for the categories based on the respective field configuration.

New in version 3.6.

Parameters

values (Iterable[Any]) –
symbol (QgsSymbol) –
layer (QgsVectorLayer = None) –
fieldName (str = '') –

Return type

List[QgsRendererCategory]

dataDefinedSizeLegend(self) → QgsDataDefinedSizeLegend¶

Returns configuration of appearance of legend when using data-defined size for marker symbols. Will return None if the functionality is disabled.

New in version 3.0.

Return type: QgsDataDefinedSizeLegend

deleteAllCategories(self)¶: Deletes all existing categories from the renderer.

See also

deleteCategory()

deleteCategory(self, catIndex: int) → bool¶

Deletes the category with the specified index from the renderer.

See also

deleteAllCategories()

Parameters: catIndex (int) –
Return type: bool

dump(self) → str¶

Return type: str

filter(self, fields: QgsFields = QgsFields()) → str¶

Parameters: fields (QgsFields = QgsFields()) –
Return type: str

filterNeedsGeometry(self) → bool¶

Return type: bool

legendClassificationAttribute(self) → str¶

Return type: str

legendKeysForFeature(self, feature: QgsFeature, context: QgsRenderContext) → Set[str]¶

Parameters

feature (QgsFeature) –
context (QgsRenderContext) –

Return type

Set[str]

legendSymbolItemChecked(self, key: str) → bool¶

Parameters: key (str) –
Return type: bool

legendSymbolItems(self) → List[QgsLegendSymbolItem]¶

Return type: List[QgsLegendSymbolItem]

legendSymbolItemsCheckable(self) → bool¶

Return type: bool

matchToSymbols(self, style: QgsStyle, type: Qgis.SymbolType, caseSensitive: bool = True, useTolerantMatch: bool = False) → Tuple[int, List[Any], List[str]]¶

Replaces category symbols with the symbols from a style that have a matching name and symbol type.

The unmatchedCategories list will be filled with all existing categories which could not be matched to a symbol in style.

The unmatchedSymbols list will be filled with all symbol names from style which were not matched to an existing category.

If caseSensitive is False, then a case-insensitive match will be performed. If useTolerantMatch is True, then non-alphanumeric characters in style and category names will be ignored during the match.

Returns the count of symbols matched.

New in version 3.4.

Parameters

style (QgsStyle) –
type (Qgis.SymbolType) –
caseSensitive (bool = True) –
useTolerantMatch (bool = False) –

Return type

Tuple[int, List[Any], List[str]]

moveCategory(self, from_: int, to: int)¶

Moves an existing category at index position from to index position to.

Parameters

from (int) –
to (int) –

originalSymbolForFeature(self, feature: QgsFeature, context: QgsRenderContext) → QgsSymbol¶

Parameters

feature (QgsFeature) –
context (QgsRenderContext) –

Return type

QgsSymbol

rebuildHash(self)¶: hashtable for faster access to symbols

renderFeatureWithSymbol(self, feature: QgsFeature, symbol: QgsSymbol, context: QgsRenderContext, layer: int, selected: bool, drawVertexMarker: bool)¶: Render the feature with the symbol using context. Use layer to specify the symbol layer, selected to specify if it should be rendered as selected and drawVertexMarker to specify if vertex markers should be rendered.

renderVertexMarker(self, pt: Union[QPointF, QPoint], context: QgsRenderContext)¶: render editing vertex marker at specified point

renderVertexMarkerPolygon(self, pts: QPolygonF, rings: Iterable[QPolygonF], context: QgsRenderContext)¶: render editing vertex marker for a polygon

renderVertexMarkerPolyline(self, pts: QPolygonF, context: QgsRenderContext)¶: render editing vertex marker for a polyline

save(self, doc: QDomDocument, context: QgsReadWriteContext) → QDomElement¶

Parameters

doc (QDomDocument) –
context (QgsReadWriteContext) –

Return type

QDomElement

setClassAttribute(self, attr: str)¶

Sets the class attribute for the renderer, which is the field name or expression string from the layer which will be matched against the renderer categories.

See also

classAttribute()

Parameters: attr (str) –

setDataDefinedSizeLegend(self, settings: QgsDataDefinedSizeLegend)¶

Configures appearance of legend when renderer is configured to use data-defined size for marker symbols. This allows configuring for which values (symbol sizes) should be shown in the legend, whether to display different symbol sizes collapsed in one legend node or separated across multiple legend nodes etc.

When renderer does not use data-defined size or does not use marker symbols, these settings will be ignored. Takes ownership of the passed settings objects. None is a valid input that disables data-defined size legend.

New in version 3.0.

Parameters: settings (QgsDataDefinedSizeLegend) –

setLegendSymbolItem(self, key: str, symbol: QgsSymbol)¶

Parameters

key (str) –
symbol (QgsSymbol) –

setSourceColorRamp(self, ramp: QgsColorRamp)¶

Sets the source color ramp.

Parameters: ramp (QgsColorRamp) – color ramp. Ownership is transferred to the renderer

See also

sourceColorRamp()

See also

setSourceSymbol()

setSourceSymbol(self, sym: QgsSymbol)¶

Sets the source symbol for the renderer, which is the base symbol used for the each categories’ symbol before applying the categories’ color.

Parameters: sym (QgsSymbol) – source symbol, ownership is transferred to the renderer

See also

sourceSymbol()

See also

setSourceColorRamp()

skipRender(self) → QgsSymbol¶

Deprecated since version No: longer used, will be removed in QGIS 4.0

Return type: QgsSymbol

sortByLabel(self, order: Qt.SortOrder = Qt.AscendingOrder)¶

Sorts the existing categories by their label.

See also

sortByValue()

Parameters: order (Qt.SortOrder = Qt.AscendingOrder) –

sortByValue(self, order: Qt.SortOrder = Qt.AscendingOrder)¶

Sorts the existing categories by their value.

See also

sortByLabel()

Parameters: order (Qt.SortOrder = Qt.AscendingOrder) –

sourceColorRamp(self) → QgsColorRamp¶

Returns the source color ramp, from which each categories’ color is derived.

See also

setSourceColorRamp()

See also

sourceSymbol()

Return type: QgsColorRamp

sourceSymbol(self) → QgsSymbol¶

Returns the renderer’s source symbol, which is the base symbol used for the each categories’ symbol before applying the categories’ color.

See also

setSourceSymbol()

See also

sourceColorRamp()

Return type: QgsSymbol

startRender(self, context: QgsRenderContext, fields: QgsFields)¶

Parameters

context (QgsRenderContext) –
fields (QgsFields) –

stopRender(self, context: QgsRenderContext)¶

Parameters: context (QgsRenderContext) –

symbolForFeature(self, feature: QgsFeature, context: QgsRenderContext) → QgsSymbol¶

Parameters

feature (QgsFeature) –
context (QgsRenderContext) –

Return type

QgsSymbol

symbolForValue(self, value: Any) → QgsSymbol¶

Returns the matching symbol corresponding to an attribute value.

Deprecated since version use: variant which takes a second bool argument instead.

Parameters: value (Any) –
Return type: QgsSymbol

symbolForValue2(self, value: Any) → Tuple[QgsSymbol, bool]¶

Returns the matching symbol corresponding to an attribute value.

Will return None if no matching symbol was found for value, or if the category corresponding to value is currently disabled (see QgsRendererCategory.renderState()).

If foundMatchingSymbol is specified then it will be set to True if a matching category was found. This can be used to differentiate between None returned as a result of no matching category vs None as a result of disabled categories.

Note

available in Python bindings as symbolForValue2

Parameters: value (Any) –
Return type: Tuple[QgsSymbol, bool]

symbols(self, context: QgsRenderContext) → List[QgsSymbol]¶

Parameters: context (QgsRenderContext) –
Return type: List[QgsSymbol]

toSld(self, doc: QDomDocument, element: QDomElement, props: Dict[str, Any] = {})¶

Parameters

doc (QDomDocument) –
element (QDomElement) –
props (Dict[str) –

updateCategoryLabel(self, catIndex: int, label: str) → bool¶

Changes the label for the category with the specified index.

A category’s label is used to represent the category within legends and the layer tree.

See also

updateCategoryValue()

See also

updateCategoryLabel()

See also

updateCategoryRenderState()

Parameters

catIndex (int) –
label (str) –

Return type

bool

updateCategoryRenderState(self, catIndex: int, render: bool) → bool¶

Changes the render state for the category with the specified index.

The render state indicates whether or not the category will be rendered, and is reflected in whether the category is checked with the project’s layer tree.

See also

updateCategoryValue()

See also

updateCategorySymbol()

See also

updateCategoryLabel()

New in version 2.5.

Parameters