Class: QgsAnnotationItem¶

Abstract base class for annotation items which are drawn with QgsAnnotationLayers.

Added in version 3.16.

Note

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

The following methods must be implemented: boundingBox(), clone(), readXml(), render(), type(), writeXml()

Class Hierarchy¶

Subclasses¶

`QgsAnnotationLineItem`	An annotation item which renders a line symbol along a line geometry.
`QgsAnnotationLineTextItem`	An annotation item which renders text along a line geometry.
`QgsAnnotationMarkerItem`	An annotation item which renders a marker symbol at a point location.
`QgsAnnotationRectItem`	Abstract base class for annotation items which render annotations in a rectangular shape.
`QgsAnnotationPointTextItem`	An annotation item which renders a text string at a point location.
`QgsAnnotationPolygonItem`	An annotation item which renders a fill symbol for a polygon geometry.

Abstract Methods

`boundingBox`	Returns the bounding box of the item's geographic location, in the parent layer's coordinate reference system.
`clone`	Returns a clone of the item.
`readXml`	Reads the item's state from the given DOM element.
`render`	Renders the item to the specified render context.
`type`	Returns a unique (untranslated) string identifying the type of item.
`writeXml`	Writes the item's state into an XML element.

Methods

`callout`	Returns the item's callout renderer, responsible for drawing item callouts.
`calloutAnchor`	Returns the callout's anchor geometry.
`enabled`	Returns `True` if the item is enabled and will be rendered in the layer.
`offsetFromCallout`	Returns the (optional) offset of the annotation item from the `calloutAnchor()`.
`offsetFromCalloutUnit`	Returns the units for the `offsetFromCallout()`.
`renderCallout`	Renders the item's callout.
`setCallout`	Sets the item's callout renderer, responsible for drawing item callouts.
`setCalloutAnchor`	Sets the callout's anchor geometry.
`setEnabled`	Sets if the item will be rendered or not in the layer.
`setOffsetFromCallout`	Sets the offset of the annotation item from the `calloutAnchor()`.
`setOffsetFromCalloutUnit`	Sets the unit for the `offsetFromCallout()`.
`setSymbologyReferenceScale`	Sets the annotation's symbology reference scale.
`setUseSymbologyReferenceScale`	Sets whether the annotation item uses a symbology reference scale.
`setZIndex`	Sets the item's z index, which controls the order in which annotation items are rendered in the layer.
`symbologyReferenceScale`	Returns the annotation's symbology reference scale.
`useSymbologyReferenceScale`	Returns `True` if the annotation item uses a symbology reference scale.
`zIndex`	Returns the item's z index, which controls the order in which annotation items are rendered in the layer.

Virtual Methods

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

`applyEdit`	Applies an edit operation to the item.
`applyEditV2`	Applies an edit operation to the item.
`copyCommonProperties`	Copies common properties from the base class from an other item.
`flags`	Returns item flags.
`nodes`	Returns the nodes for the item, used for editing the item.
`nodesV2`	Returns the nodes for the item, used for editing the item.
`readCommonProperties`	Reads common properties from the base class from the given DOM element.
`transientEditResults`	Retrieves the results of a transient (in progress) edit operation on the item.
`transientEditResultsV2`	Retrieves the results of a transient (in progress) edit operation on the item.
`writeCommonProperties`	Writes common properties from the base class into an XML element.

class qgis.core.QgsAnnotationItem[source]¶

Bases: object

virtual applyEdit(self, operation: QgsAbstractAnnotationItemEditOperation | None) → Qgis.AnnotationItemEditOperationResult[source]¶

Applies an edit operation to the item.

Deprecated since version 3.40: Use applyEditV2() instead.

Parameters:: operation (Optional[QgsAbstractAnnotationItemEditOperation])
Return type:: Qgis.AnnotationItemEditOperationResult

virtual applyEditV2(self, operation: QgsAbstractAnnotationItemEditOperation | None, context: QgsAnnotationItemEditContext) → Qgis.AnnotationItemEditOperationResult[source]¶

Applies an edit operation to the item.

Added in version 3.40.

Parameters:

operation (Optional[QgsAbstractAnnotationItemEditOperation])
context (QgsAnnotationItemEditContext)

Return type:

Qgis.AnnotationItemEditOperationResult

abstract boundingBox(self) → QgsRectangle[source]¶

Returns the bounding box of the item’s geographic location, in the parent layer’s coordinate reference system.

Return type:: QgsRectangle

abstract boundingBox(self, context: QgsRenderContext) → QgsRectangle[source]

Returns the bounding box of the item’s geographic location, in the parent layer’s coordinate reference system.

Parameters:: context (QgsRenderContext)
Return type:: QgsRectangle

callout(self) → QgsCallout | None[source]¶

Returns the item’s callout renderer, responsible for drawing item callouts.

Ownership is not transferred.

By default items do not have a callout, and it is necessary to be explicitly set a callout style (via setCallout() ) and set the callout anchor geometry (via set setCalloutAnchor() ).

Note

Callouts are only supported by items which return Qgis.AnnotationItemFlag.SupportsCallouts from flags().

See also

setCallout()

See also

calloutAnchor()

Added in version 3.40.

Return type:: Optional[QgsCallout]

calloutAnchor(self) → QgsGeometry[source]¶

Returns the callout’s anchor geometry.

The anchor dictates the geometry which the option item callout() should connect to. Depending on the callout subclass and anchor geometry type, the actual shape of the rendered callout may vary.

The callout anchor geometry is in the parent layer’s coordinate reference system.

See also

callout()

See also

setCalloutAnchor()

Added in version 3.40.

Return type:: QgsGeometry

abstract clone(self) → QgsAnnotationItem | None[source]¶

Returns a clone of the item. Ownership is transferred to the caller.

Implementations should include a call to copyCommonProperties() to copy the base class properties.

See also

copyCommonProperties()

Return type:: Optional[QgsAnnotationItem]

virtual copyCommonProperties(self, other: QgsAnnotationItem | None)[source]¶

Copies common properties from the base class from an other item.

Added in version 3.22.

Parameters:: other (Optional[QgsAnnotationItem])

enabled(self) → bool[source]¶

Returns True if the item is enabled and will be rendered in the layer.

See also

setEnabled()

Added in version 3.36.

Return type:: bool

virtual flags(self) → Qgis.AnnotationItemFlags[source]¶

Returns item flags.

Added in version 3.22.

Return type:: Qgis.AnnotationItemFlags

virtual nodes(self) → List[QgsAnnotationItemNode]¶

Returns the nodes for the item, used for editing the item.

Deprecated since version 3.40: Use nodesV2() instead.

Return type:: List[QgsAnnotationItemNode]

virtual nodesV2(self, context: QgsAnnotationItemEditContext) → List[QgsAnnotationItemNode]¶

Returns the nodes for the item, used for editing the item.

Added in version 3.40.

Parameters:: context (QgsAnnotationItemEditContext)
Return type:: List[QgsAnnotationItemNode]

offsetFromCallout(self) → QSizeF[source]¶

Returns the (optional) offset of the annotation item from the calloutAnchor().

Some annotation item subclasses support placement relative to the callout anchor. For these items, the offset from callout defines how far (in screen/page units) the item should be placed from the anchor point.

Units are defined by offsetFromCalloutUnit()

See also

setOffsetFromCallout()

Added in version 3.40.

Return type:: QSizeF

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

Returns the units for the offsetFromCallout().

See also

offsetFromCallout()

See also

setOffsetFromCalloutUnit()

Added in version 3.40.

Return type:: Qgis.RenderUnit

virtual readCommonProperties(self, element: QDomElement, context: QgsReadWriteContext) → bool[source]¶

Reads common properties from the base class from the given DOM element.

See also

readXml()

Added in version 3.22.

Parameters:

element (QDomElement)
context (QgsReadWriteContext)

Return type:

bool

abstract readXml(self, element: QDomElement, context: QgsReadWriteContext) → bool[source]¶

Reads the item’s state from the given DOM element.

Implementations should include a call to readCommonProperties() to read the base class properties.

See also

writeXml()

See also

readCommonProperties()

Parameters:

element (QDomElement)
context (QgsReadWriteContext)

Return type:

bool

abstract render(self, context: QgsRenderContext, feedback: QgsFeedback | None)[source]¶

Renders the item to the specified render context.

The feedback argument can be used to detect render cancellations during expensive render operations.

Parameters:

context (QgsRenderContext)
feedback (Optional[QgsFeedback])

renderCallout(self, context: QgsRenderContext, rect: QRectF, angle: float, calloutContext: QgsCallout.QgsCalloutContext, feedback: QgsFeedback | None)[source]¶

Renders the item’s callout.

The item must have valid callout() set.

Added in version 3.40.

Parameters:

context (QgsRenderContext)
rect (QRectF)
angle (float)
calloutContext (QgsCallout.QgsCalloutContext)
feedback (Optional[QgsFeedback])

setCallout(self, callout: QgsCallout | None)[source]¶

Sets the item’s callout renderer, responsible for drawing item callouts.

Ownership of callout is transferred to the item.

Note

Callouts are only supported by items which return Qgis.AnnotationItemFlag.SupportsCallouts from flags().

See also

callout()

See also

setCalloutAnchor()

Added in version 3.40.

Parameters:: callout (Optional[QgsCallout])

setCalloutAnchor(self, anchor: QgsGeometry)[source]¶

Sets the callout’s anchor geometry.

The anchor dictates the geometry which the option item callout() should connect to. Depending on the callout subclass and anchor geometry type, the actual shape of the rendered callout may vary.

The callout anchor geometry must be specified in the parent layer’s coordinate reference system.

See also

setCallout()

See also

calloutAnchor()

Added in version 3.40.

Parameters:: anchor (QgsGeometry)

setEnabled(self, enabled: bool)[source]¶

Sets if the item will be rendered or not in the layer.

See also

enabled()

Added in version 3.36.

Parameters:: enabled (bool)

setOffsetFromCallout(self, offset: QSizeF)[source]¶

Sets the offset of the annotation item from the calloutAnchor().

Some annotation item subclasses support placement relative to the callout anchor. For these items, the offset from callout defines how far (in screen/page units) the item should be placed from the anchor point.

Units are defined by offsetFromCalloutUnit()

See also

offsetFromCallout()

Added in version 3.40.

Parameters:: offset (QSizeF)

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

Sets the unit for the offsetFromCallout().

See also

setOffsetFromCallout()

See also

offsetFromCalloutUnit()

Added in version 3.40.

Parameters:: unit (Qgis.RenderUnit)

setSymbologyReferenceScale(self, scale: float)[source]¶

Sets the annotation’s symbology reference scale.

The reference scale will only be used if useSymbologyReferenceScale() returns True.

This represents the desired scale denominator for the rendered map, eg 1000.0 for a 1:1000 map render.

The symbology reference scale is an optional property which specifies the reference scale at which symbology in paper units (such a millimeters or points) is fixed to. For instance, if the scale is 1000 then a 2mm thick line will be rendered at exactly 2mm thick when a map is rendered at 1:1000, or 1mm thick when rendered at 1:2000, or 4mm thick at 1:500.

See also

symbologyReferenceScale()

See also

setUseSymbologyReferenceScale()

Parameters:: scale (float)

setUseSymbologyReferenceScale(self, enabled: bool)[source]¶

Sets whether the annotation item uses a symbology reference scale.

See also

useSymbologyReferenceScale()

See also

setSymbologyReferenceScale()

Parameters:: enabled (bool)

setZIndex(self, index: int)[source]¶

Sets the item’s z index, which controls the order in which annotation items are rendered in the layer.

See also

zIndex()

Parameters:: index (int)

symbologyReferenceScale(self) → float[source]¶

Returns the annotation’s symbology reference scale.

The reference scale will only be used if useSymbologyReferenceScale() returns True.

This represents the desired scale denominator for the rendered map, eg 1000.0 for a 1:1000 map render.

The symbology reference scale is an optional property which specifies the reference scale at which symbology in paper units (such a millimeters or points) is fixed to. For instance, if the scale is 1000 then a 2mm thick line will be rendered at exactly 2mm thick when a map is rendered at 1:1000, or 1mm thick when rendered at 1:2000, or 4mm thick at 1:500.

See also

setSymbologyReferenceScale()

See also

useSymbologyReferenceScale()

Return type:: float

virtual transientEditResults(self, operation: QgsAbstractAnnotationItemEditOperation | None) → QgsAnnotationItemEditOperationTransientResults | None[source]¶

Retrieves the results of a transient (in progress) edit operation on the item.

Deprecated since version 3.40: Use transientEditResultsV2() instead.

Parameters:: operation (Optional[QgsAbstractAnnotationItemEditOperation])
Return type:: Optional[QgsAnnotationItemEditOperationTransientResults]

virtual transientEditResultsV2(self, operation: QgsAbstractAnnotationItemEditOperation | None, context: QgsAnnotationItemEditContext) → QgsAnnotationItemEditOperationTransientResults | None[source]¶

Retrieves the results of a transient (in progress) edit operation on the item.

Added in version 3.40.

Parameters:

operation (Optional[QgsAbstractAnnotationItemEditOperation])
context (QgsAnnotationItemEditContext)

Return type:

Optional[QgsAnnotationItemEditOperationTransientResults]

abstract type(self) → str[source]¶

Returns a unique (untranslated) string identifying the type of item.

Return type:: str

useSymbologyReferenceScale(self) → bool[source]¶

Returns True if the annotation item uses a symbology reference scale.

See also

setUseSymbologyReferenceScale()

See also

symbologyReferenceScale()

Return type:: bool

virtual writeCommonProperties(self, element: QDomElement, document: QDomDocument, context: QgsReadWriteContext) → bool[source]¶

Writes common properties from the base class into an XML element.

See also

writeXml()

Added in version 3.22.

Parameters:

element (QDomElement)
document (QDomDocument)
context (QgsReadWriteContext)

Return type:

bool

abstract writeXml(self, element: QDomElement, document: QDomDocument, context: QgsReadWriteContext) → bool[source]¶

Writes the item’s state into an XML element.

Implementations should include a call to writeCommonProperties() to store the base class properties.

See also

readXml()

See also

writeCommonProperties()

Parameters:

element (QDomElement)
document (QDomDocument)
context (QgsReadWriteContext)

Return type:

bool

zIndex(self) → int[source]¶

Returns the item’s z index, which controls the order in which annotation items are rendered in the layer.

See also

setZIndex()

Return type:: int