Class: QgsAnnotationLayer

class qgis.core.QgsAnnotationLayer(name: str, options: QgsAnnotationLayer.LayerOptions)

Bases: QgsMapLayer

Constructor for a new QgsAnnotationLayer with the specified layer name.

The options argument specifies load-time layer options.

Represents a map layer containing a set of georeferenced annotations, e.g. markers, lines, polygons or text items.

Annotation layers store a set of QgsAnnotationItem items, which are rendered according to the item’s z-order.

New in version 3.16:

Methods

addItem

Adds an item to the layer.

appendError

Add error message

childEvent

clear

Removes all items from the layer.

clone

rtype

QgsAnnotationLayer

connectNotify

createMapRenderer

param rendererContext

customEvent

decodedSource

Called by readLayerXML(), used by derived classes to decode provider's specific data source from project files.

disconnectNotify

encodedSource

Called by writeLayerXML(), used by derived classes to encode provider's specific data source to project files.

extent

rtype

QgsRectangle

hasDependencyCycle

Checks whether a new set of dependencies will introduce a cycle this method is now deprecated and always return False, because circular dependencies are now correctly managed.

isEmpty

Returns True if the annotation layer is empty and contains no annotations.

isSignalConnected

items

Returns a map of items contained in the layer, by unique item ID.

opacity

Returns the opacity for the annotation layer, where opacity is a value between 0 (totally transparent) and 1.0 (fully opaque).

readCommonStyle

Read style data common to all layer types

readCustomProperties

Read custom properties from project file.

readStyleManager

Read style manager's configuration (if any).

readSymbology

param node

readXml

param layerNode

receivers

removeItem

Removes (and deletes) the item with matching id.

reset

Resets the annotation layer to a default state, and clears all items from it.

sender

senderSignalIndex

setError

Sets error message

setExtent

Sets the extent

setOpacity

Sets the opacity for the annotation layer, where opacity is a value between 0 (totally transparent) and 1.0 (fully opaque).

setProviderType

Sets the providerType (provider key)

setTransformContext

param context

setValid

Sets whether layer is valid or not

timerEvent

writeCommonStyle

Write style data common to all layer types

writeCustomProperties

Write custom properties to project file.

writeStyleManager

Write style manager's configuration (if exists).

writeSymbology

param node

writeXml

param layer_node

class LayerOptions(transformContext: QgsCoordinateTransformContext)

Bases: sip.wrapper

Constructor for LayerOptions.

QgsAnnotationLayer.LayerOptions(QgsAnnotationLayer.LayerOptions)

transformContext
addItem(self, item: QgsAnnotationItem) str

Adds an item to the layer.

Ownership of item is transferred to the layer.

Returns the unique ID assigned to the item.

Parameters

item (QgsAnnotationItem) –

Return type

str

appendError(self, error: QgsErrorMessage)

Add error message

childEvent(self, QChildEvent)
clear(self)

Removes all items from the layer.

clone(self) QgsAnnotationLayer
Return type

QgsAnnotationLayer

connectNotify(self, QMetaMethod)
createMapRenderer(self, rendererContext: QgsRenderContext) QgsMapLayerRenderer
Parameters

rendererContext (QgsRenderContext) –

Return type

QgsMapLayerRenderer

customEvent(self, QEvent)
decodedSource(self, source: str, dataProvider: str, context: QgsReadWriteContext) str

Called by readLayerXML(), used by derived classes to decode provider’s specific data source from project files. Typically resolving absolute or relative paths, usernames and passwords or drivers prefixes (“HDF5:”)

Parameters
  • source – data source to decode, typically read from layer’s DOM element “datasource”

  • dataProvider – string identification of data provider (e.g. “ogr”), typically read from layer’s DOM element

  • context – reading context (e.g. for conversion between relative and absolute paths)

Returns

decoded source, typically to be used as the layer’s datasource

New in version 3.2.

disconnectNotify(self, QMetaMethod)
encodedSource(self, source: str, context: QgsReadWriteContext) str

Called by writeLayerXML(), used by derived classes to encode provider’s specific data source to project files. Typically resolving absolute or relative paths, usernames and passwords or drivers prefixes (“HDF5:”)

Parameters
  • source – data source to encode, typically QgsMapLayer.source()

  • context – writing context (e.g. for conversion between relative and absolute paths)

Returns

encoded source, typically to be written in the DOM element “datasource”

New in version 3.2.

extent(self) QgsRectangle
Return type

QgsRectangle

hasDependencyCycle(self, Iterable[QgsMapLayerDependency]) bool

Checks whether a new set of dependencies will introduce a cycle this method is now deprecated and always return False, because circular dependencies are now correctly managed.

Deprecated since version QGIS: 3.10

isEmpty(self) bool

Returns True if the annotation layer is empty and contains no annotations.

Return type

bool

isSignalConnected(self, QMetaMethod) bool
items(self) object

Returns a map of items contained in the layer, by unique item ID.

This map contains references to items owned by the layer, and ownership of these remains with the layer.

Return type

object

opacity(self) float

Returns the opacity for the annotation layer, where opacity is a value between 0 (totally transparent) and 1.0 (fully opaque).

See also

setOpacity()

Return type

float

readCommonStyle(self, layerElement: QDomElement, context: QgsReadWriteContext, categories: Union[QgsMapLayer.StyleCategories, QgsMapLayer.StyleCategory] = QgsMapLayer.AllStyleCategories)

Read style data common to all layer types

New in version 3.0.

readCustomProperties(self, layerNode: QDomNode, keyStartsWith: str = '')

Read custom properties from project file.

Parameters
  • layerNode – note to read from

  • keyStartsWith – reads only properties starting with the specified string (or all if the string is empty)

readStyleManager(self, layerNode: QDomNode)

Read style manager’s configuration (if any). To be called by subclasses.

readSymbology(self, node: QDomNode, errorMessage: str, context: QgsReadWriteContext, categories: Union[QgsMapLayer.StyleCategories, QgsMapLayer.StyleCategory] = QgsMapLayer.AllStyleCategories) bool
Parameters
Return type

bool

readXml(self, layerNode: QDomNode, context: QgsReadWriteContext) bool
Parameters
Return type

bool

receivers(self, PYQT_SIGNAL) int
removeItem(self, id: str) bool

Removes (and deletes) the item with matching id.

Parameters

id (str) –

Return type

bool

reset(self)

Resets the annotation layer to a default state, and clears all items from it.

sender(self) QObject
senderSignalIndex(self) int
setError(self, error: QgsError)

Sets error message

setExtent(self, rect: QgsRectangle)

Sets the extent

setOpacity(self, opacity: float)

Sets the opacity for the annotation layer, where opacity is a value between 0 (totally transparent) and 1.0 (fully opaque).

See also

opacity()

Parameters

opacity (float) –

setProviderType(self, providerType: str)

Sets the providerType (provider key)

setTransformContext(self, context: QgsCoordinateTransformContext)
Parameters

context (QgsCoordinateTransformContext) –

setValid(self, valid: bool)

Sets whether layer is valid or not

timerEvent(self, QTimerEvent)
writeCommonStyle(self, layerElement: QDomElement, document: QDomDocument, context: QgsReadWriteContext, categories: Union[QgsMapLayer.StyleCategories, QgsMapLayer.StyleCategory] = QgsMapLayer.AllStyleCategories)

Write style data common to all layer types

New in version 3.0.

writeCustomProperties(self, layerNode: QDomNode, doc: QDomDocument)

Write custom properties to project file.

writeStyleManager(self, layerNode: QDomNode, doc: QDomDocument)

Write style manager’s configuration (if exists). To be called by subclasses.

writeSymbology(self, node: QDomNode, doc: QDomDocument, errorMessage: str, a3: QgsReadWriteContext, categories: Union[QgsMapLayer.StyleCategories, QgsMapLayer.StyleCategory] = QgsMapLayer.AllStyleCategories) bool
Parameters
Return type

bool

writeXml(self, layer_node: QDomNode, doc: QDomDocument, context: QgsReadWriteContext) bool
Parameters
Return type

bool