Class: QgsLayoutNodesItem

class qgis.core.QgsLayoutNodesItem

Bases: QgsLayoutItem

An abstract layout item that provides generic methods for node based shapes such as polygon or polylines.

New in version 3.0.

QgsLayoutNodesItem(layout: QgsLayout) Constructor for QgsLayoutNodesItem, attached to the specified layout.

QgsLayoutNodesItem(polygon: QPolygonF, layout: QgsLayout) Constructor for a QgsLayoutNodesItem with the given polygon nodes, attached to the specified layout.

Methods

addNode	Add a node in current shape.
adjustPointForReferencePosition	Adjusts the specified point at which a reference position of the item sits and returns the top left corner of the item, if reference point were placed at the specified position.
applyDataDefinedSize	Applies any present data defined size overrides to the specified layout size.
applyItemSizeConstraint	Applies any item-specific size constraint handling to a given targetSize in layout units.
boundingRect	rtype: QRectF
childEvent
computeDistance	Compute an euclidean distance between 2 nodes.
connectNotify
contextMenuEvent
customEvent
deselectNode	Deselects any selected nodes.
disconnectNotify
dragEnterEvent
dragLeaveEvent
dragMoveEvent
draw	param context:
drawBackground	Draws the background for the item.
drawDebugRect	Draws a debugging rectangle of the item's current bounds within the specified painter.
drawFrame	Draws the frame around the item.
drawRefreshingOverlay	Draws a "refreshing" overlay icon on the item.
dropEvent
estimatedFrameBleed	rtype: float
focusInEvent
focusOutEvent
framePath	Returns the path to use when drawing the item's frame or background.
hoverEnterEvent
hoverLeaveEvent
hoverMoveEvent
inputMethodEvent
inputMethodQuery
isSignalConnected
itemChange
itemFlags	rtype: QgsLayoutItem.Flags
keyPressEvent
keyReleaseEvent
mouseDoubleClickEvent
mouseMoveEvent
mousePressEvent
mouseReleaseEvent
moveNode	Moves a node to a new position.
nodeAtPosition	Search for the nearest node in the shape within a maximal area.
nodePosition	Gets the position of a node in scene coordinates.
nodes	Returns the nodes the shape consists of.
nodesSize	Returns the number of nodes in the shape.
positionAtReferencePoint	Returns the current position (in layout units) of a reference point for the item.
prepareGeometryChange
readObjectPropertiesFromElement	Sets object properties from a DOM element
readPropertiesFromElement	param element:
receivers
refreshBackgroundColor	Refresh item's background color, considering data defined colors.
refreshBlendMode	Refresh item's blend mode, considering data defined blend mode.
refreshFrame	Refresh item's frame, considering data defined colors and frame size.
refreshItemPosition	Refreshes an item's position by rechecking it against any possible overrides such as data defined positioning.
refreshItemRotation	Refreshes an item's rotation by rechecking it against any possible overrides such as data defined rotation.
refreshItemSize	Refreshes an item's size by rechecking it against any possible item fixed or minimum sizes.
refreshOpacity	Refresh item's opacity, considering data defined opacity.
removeNode	Remove a node with specified index from the shape.
rescaleToFitBoundingBox	Rescale the current shape according to the item's bounding box.
sceneEvent
sceneEventFilter
selectedNode	Returns the currently selected node, or -1 if no node is selected.
sender
senderSignalIndex
setDisplayNodes	Set whether the item's nodes should be displayed.
setFixedSize	Sets a fixed size for the layout item, which prevents it from being freely resized.
setMinimumSize	Sets the minimum allowed size for the layout item.
setNodes	Sets the nodes the shape consists of.
setSelectedNode	Selects a node by index.
timerEvent
topLeftToReferencePoint	Returns the position for the reference point of the item, if the top-left of the item was placed at the specified point.
updateBoundingRect	Called when the bounding rect of the item should recalculated.
updateMicroFocus
updateSceneRect	Update the current scene rectangle for this item.
wheelEvent
writeObjectPropertiesToElement	Stores object properties within an XML DOM element.
writePropertiesToElement	param element:

addNode(self, point: QPointF | QPoint, checkArea: bool = True, radius: float = 10) → bool

Add a node in current shape.

Parameters:

• point (Union[QPointF) – is the location of the new node (in scene coordinates)

• checkArea (bool = True) – is a flag to indicate if there’s a space constraint.

• radius (float = 10) – is the space contraint and is used only if checkArea is True. Typically, if this flag is True, the new node has to be nearer than radius to the shape to be added.

Return type:

bool

adjustPointForReferencePosition(self, point: QPointF | QPoint, size: QSizeF, reference: QgsLayoutItem.ReferencePoint) → QPointF

Adjusts the specified point at which a reference position of the item sits and returns the top left corner of the item, if reference point were placed at the specified position.

applyDataDefinedSize(self, size: QgsLayoutSize) → QgsLayoutSize

Applies any present data defined size overrides to the specified layout size.

applyItemSizeConstraint(self, targetSize: QSizeF) → QSizeF

Applies any item-specific size constraint handling to a given targetSize in layout units. Subclasses can override this method if they need to apply advanced logic regarding item sizes, which cannot be covered by setFixedSize() or setMinimumSize(). Item size constraints are applied after fixed, minimum and data defined size constraints.

See also

setFixedSize()

See also

setMinimumSize()

boundingRect(self) → QRectF

Return type:

QRectF

childEvent(self, QChildEvent)

computeDistance(self, pt1: QPointF | QPoint, pt2: QPointF | QPoint) → float

Compute an euclidean distance between 2 nodes.

Parameters:

• pt1 (Union[QPointF) –

• pt2 (Union[QPointF) –

Return type:

float

connectNotify(self, QMetaMethod)

contextMenuEvent(self, QGraphicsSceneContextMenuEvent)

customEvent(self, QEvent)

deselectNode(self)

Deselects any selected nodes.

disconnectNotify(self, QMetaMethod)

dragEnterEvent(self, QGraphicsSceneDragDropEvent)

dragLeaveEvent(self, QGraphicsSceneDragDropEvent)

dragMoveEvent(self, QGraphicsSceneDragDropEvent)

draw(self, context: QgsLayoutItemRenderContext)

Parameters:

context (QgsLayoutItemRenderContext) –

drawBackground(self, context: QgsRenderContext)

Draws the background for the item.

See also

framePath()

drawDebugRect(self, painter: QPainter)

Draws a debugging rectangle of the item’s current bounds within the specified painter.

Parameters:

painter – destination QPainter

drawFrame(self, context: QgsRenderContext)

Draws the frame around the item.

See also

framePath()

drawRefreshingOverlay(self, painter: QPainter, itemStyle: QStyleOptionGraphicsItem)

Draws a “refreshing” overlay icon on the item.

New in version 3.32.

dropEvent(self, QGraphicsSceneDragDropEvent)

estimatedFrameBleed(self) → float

Return type:

float

focusInEvent(self, QFocusEvent)

focusOutEvent(self, QFocusEvent)

framePath(self) → QPainterPath

Returns the path to use when drawing the item’s frame or background.

See also

drawFrame()

See also

drawBackground()

New in version 3.16.

hoverEnterEvent(self, QGraphicsSceneHoverEvent)

hoverLeaveEvent(self, QGraphicsSceneHoverEvent)

hoverMoveEvent(self, QGraphicsSceneHoverEvent)

inputMethodEvent(self, QInputMethodEvent)

inputMethodQuery(self, Qt.InputMethodQuery) → Any

isSignalConnected(self, QMetaMethod) → bool

itemChange(self, QGraphicsItem.GraphicsItemChange, Any) → Any

itemFlags(self) → QgsLayoutItem.Flags

Return type:

QgsLayoutItem.Flags

keyPressEvent(self, QKeyEvent)

keyReleaseEvent(self, QKeyEvent)

mouseDoubleClickEvent(self, QGraphicsSceneMouseEvent)

mouseMoveEvent(self, QGraphicsSceneMouseEvent)

mousePressEvent(self, QGraphicsSceneMouseEvent)

mouseReleaseEvent(self, QGraphicsSceneMouseEvent)

moveNode(self, index: int, node: QPointF | QPoint) → bool

Moves a node to a new position.

Parameters:

• index (int) – the index of the node to move

• node (Union[QPointF) – is the new position in scene coordinate

Return type:

bool

nodeAtPosition(self, point: QPointF | QPoint, searchInRadius: bool = True, radius: float = 10) → int

Search for the nearest node in the shape within a maximal area. Returns the index of the nearest node or -1 if no node was found.

Parameters:

• point (Union[QPointF) – is the location to search for nodes from (in scene coordinates)

• searchInRadius (bool = True) – is a flag to indicate if the area of research is limited in space.

• radius (float = 10) – is only used if searchInRadius is True

Return type:

int

nodePosition(self, index: int, position: QPointF | QPoint) → bool

Gets the position of a node in scene coordinates.

Parameters:

• index (int) – of the node

• position (Union[QPointF) – the position of the node

Return type:

bool

Returns:

True if the index is valid and the position is set, False otherwise

nodes(self) → QPolygonF

Returns the nodes the shape consists of.

See also

setNodes()

Return type:

QPolygonF

nodesSize(self) → int

Returns the number of nodes in the shape.

Return type:

int

positionAtReferencePoint(self, reference: QgsLayoutItem.ReferencePoint) → QPointF

Returns the current position (in layout units) of a reference point for the item.

prepareGeometryChange(self)

readObjectPropertiesFromElement(self, parentElement: QDomElement, document: QDomDocument, context: QgsReadWriteContext) → bool

Sets object properties from a DOM element

Parameters:

• parentElement – is the parent DOM element for the object

• document – DOM document

• context – read write context

Returns:

True if read was successful

See also

writeObjectPropertiesToElement()

readPropertiesFromElement(self, element: QDomElement, document: QDomDocument, context: QgsReadWriteContext) → bool

Parameters:

• element (QDomElement) –

• document (QDomDocument) –

• context (QgsReadWriteContext) –

Return type:

bool

receivers(self, PYQT_SIGNAL) → int

refreshBackgroundColor(self, updateItem: bool = True)

Refresh item’s background color, considering data defined colors. If updateItem is set to False, the item will not be automatically updated after the frame color is set and a later call to update() must be made.

refreshBlendMode(self)

Refresh item’s blend mode, considering data defined blend mode.

refreshFrame(self, updateItem: bool = True)

Refresh item’s frame, considering data defined colors and frame size. If updateItem is set to False, the item will not be automatically updated after the frame is set and a later call to update() must be made.

refreshItemPosition(self)

Refreshes an item’s position by rechecking it against any possible overrides such as data defined positioning.

See also

refreshItemSize()

refreshItemRotation(self, origin: QPointF | QPoint = None)

Refreshes an item’s rotation by rechecking it against any possible overrides such as data defined rotation.

The optional origin point specifies the origin (in item coordinates) around which the rotation should be applied.

See also

refreshItemSize()

See also

refreshItemPosition()

refreshItemSize(self)

Refreshes an item’s size by rechecking it against any possible item fixed or minimum sizes.

See also

setFixedSize()

See also

setMinimumSize()

See also

refreshItemPosition()

refreshOpacity(self, updateItem: bool = True)

Refresh item’s opacity, considering data defined opacity. If updateItem is set to False the item will not be automatically updated after the opacity is set and a later call to update() must be made.

removeNode(self, index: int) → bool

Remove a node with specified index from the shape.

Parameters:

index (int) –

Return type:

bool

rescaleToFitBoundingBox(self)

Rescale the current shape according to the item’s bounding box. Useful when the shape is resized thanks to the rubber band.

sceneEvent(self, QEvent) → bool

sceneEventFilter(self, QGraphicsItem, QEvent) → bool

selectedNode(self) → int

Returns the currently selected node, or -1 if no node is selected.

Return type:

int

sender(self) → QObject

senderSignalIndex(self) → int

setDisplayNodes(self, display: bool = True)

Set whether the item’s nodes should be displayed.

Parameters:

display (bool = True) –

setFixedSize(self, size: QgsLayoutSize)

Sets a fixed size for the layout item, which prevents it from being freely resized. Set an empty size if item can be freely resized.

See also

fixedSize()

See also

setMinimumSize()

setMinimumSize(self, size: QgsLayoutSize)

Sets the minimum allowed size for the layout item. Set an empty size if item can be freely resized.

See also

minimumSize()

See also

setFixedSize()

setNodes(self, nodes: QPolygonF)

Sets the nodes the shape consists of.

See also

nodes()

Parameters:

nodes (QPolygonF) –

setSelectedNode(self, index: int) → bool

Selects a node by index.

Parameters:

index (int) –

Return type:

bool

timerEvent(self, QTimerEvent)

topLeftToReferencePoint(self, point: QgsLayoutPoint) → QgsLayoutPoint

Returns the position for the reference point of the item, if the top-left of the item was placed at the specified point.

updateBoundingRect(self)

Called when the bounding rect of the item should recalculated. Subclasses should update currentRectangle in their implementations.

updateMicroFocus(self)

updateSceneRect(self)

Update the current scene rectangle for this item.

wheelEvent(self, QGraphicsSceneWheelEvent)

writeObjectPropertiesToElement(self, parentElement: QDomElement, document: QDomDocument, context: QgsReadWriteContext) → bool

Stores object properties within an XML DOM element.

Parameters:

• parentElement – is the parent DOM element to store the object’s properties in

• document – DOM document

• context – read write context

Returns:

True if write was successful

See also

readObjectPropertiesFromElement()

writePropertiesToElement(self, element: QDomElement, document: QDomDocument, context: QgsReadWriteContext) → bool

Parameters:

• element (QDomElement) –

• document (QDomDocument) –

• context (QgsReadWriteContext) –

Return type:

bool