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

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
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:
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:
Return type:

bool