nexxT.services.gui.GraphEditor module

This module provides the graph editor GUI service of the nexxT service.

class nexxT.services.gui.GraphEditor.BaseGraphScene(parent)

Bases: QGraphicsScene

Basic graph display and manipulation scene. Generic base class intended to be overwritten.

class ConnectionItem(portFrom, portTo)

Bases: QGraphicsPathItem

This item corresponds with a connection between an output and an input port.

__init__(self, path: PySide6.QtGui.QPainterPath, /, parent: PySide6.QtWidgets.QGraphicsItem | None = None) → None

__init__(self, /, parent: PySide6.QtWidgets.QGraphicsItem | None = None) → None

Initialize self. See help(type(self)) for accurate signature.

hoverEnterEvent(event)

override for hover enter events

Parameters:

event – the QT event

Returns:

hoverLeaveEvent(event)

override for hover leave events

Parameters:

event – the QT event

Returns:

static itemTypeName()

Returns an identificytion string.

Returns:

shape()

Unsure if this is needed, but it may give better hover positions

Returns:

sync()

Synchronizes the view with the model.

Returns:

KEY_ITEM = 0

class NodeItem(name)

Bases: QGraphicsItemGroup

An item which represents a node in the graph. The item group is also used for grouping the port items.

__init__(self, /, parent: PySide6.QtWidgets.QGraphicsItem | None = None) → None

Initialize self. See help(type(self)) for accurate signature.

addInPortItem(name)

Adds a new input port to the node

Parameters:

name – the port name

Returns:

addOutPortItem(name)

Adds a new output port to the node

Parameters:

name – the port name

Returns:

getInPortItem(name)

Searches for the input port named by name

Parameters:

name – a string instance

Returns:

a PortItem instance

getOutPortItem(name)

Searches for the output port named by name

Parameters:

name – a string instance

Returns:

a PortItem instance

hoverEnter()

Slot called on hover enter

Returns:

hoverLeave()

Slot called on hover leave.

Returns:

itemChange(change, value)

overwritten from QGraphicsItem

Parameters:

• change – the thing that has changed

• value – the new value

Returns:

static itemTypeName()

return a class identification name.

Returns:

nodeHeight()

Returns:

the node height in pixels including spacing.

nodeWidth()

Returns:

the node width in pixels including spacing.

paint(painter, option, widget)

Overwritten from base class to prevent drawing the selection rectangle

Parameters:

• painter – a QPainter instance

• option – a QStyleOptionGraphicsItem instance

• widget – a QWidget instance or None

Returns:

sync()

synchronize the item with the model (also the ports)

Returns:

class PortItem(name, nodeItem)

Bases: object

This class represents a port in a node.

__init__(name, nodeItem)

hoverEnter()

Slot called on hover enter

Returns:

hoverLeave()

Slot called on hover leave.

Returns:

static itemTypeName()

Returns a class identification string.

Returns:

remove()

Removes this port from its item group.

Returns:

scenePosChanged(value)

Slot called on scene position changes, need to synchronize connections.

Parameters:

value

Returns:

setPos(x, y, isOutput)

Sets the position of this item to the given coordinates, assigns output / input property.

Parameters:

• x – the x coordinate

• y – the y coordinate

• isOutput – a boolean

Returns:

sync()

Synchronizes the item to the model.

Returns:

STYLE_ROLE_BRUSH = 2

STYLE_ROLE_HSPACING = 5

STYLE_ROLE_PEN = 1

STYLE_ROLE_RRRADIUS = 3

STYLE_ROLE_SIZE = 0

STYLE_ROLE_TEXT_BRUSH = 6

STYLE_ROLE_VSPACING = 4

__init__(self, sceneRect: PySide6.QtCore.QRectF, /, parent: PySide6.QtCore.QObject | None = None, *, backgroundBrush: PySide6.QtGui.QBrush | None = None, foregroundBrush: PySide6.QtGui.QBrush | None = None, itemIndexMethod: PySide6.QtWidgets.QGraphicsScene.ItemIndexMethod | None = None, bspTreeDepth: int | None = None, palette: PySide6.QtGui.QPalette | None = None, font: PySide6.QtGui.QFont | None = None, stickyFocus: bool | None = None, minimumRenderSize: float | None = None, focusOnTouch: bool | None = None) → None

__init__(self, /, parent: PySide6.QtCore.QObject | None = None, *, backgroundBrush: PySide6.QtGui.QBrush | None = None, foregroundBrush: PySide6.QtGui.QBrush | None = None, itemIndexMethod: PySide6.QtWidgets.QGraphicsScene.ItemIndexMethod | None = None, sceneRect: PySide6.QtCore.QRectF | None = None, bspTreeDepth: int | None = None, palette: PySide6.QtGui.QPalette | None = None, font: PySide6.QtGui.QFont | None = None, stickyFocus: bool | None = None, minimumRenderSize: float | None = None, focusOnTouch: bool | None = None) → None

__init__(self, x: float, y: float, width: float, height: float, /, parent: PySide6.QtCore.QObject | None = None, *, backgroundBrush: PySide6.QtGui.QBrush | None = None, foregroundBrush: PySide6.QtGui.QBrush | None = None, itemIndexMethod: PySide6.QtWidgets.QGraphicsScene.ItemIndexMethod | None = None, sceneRect: PySide6.QtCore.QRectF | None = None, bspTreeDepth: int | None = None, palette: PySide6.QtGui.QPalette | None = None, font: PySide6.QtGui.QFont | None = None, stickyFocus: bool | None = None, minimumRenderSize: float | None = None, focusOnTouch: bool | None = None) → None

Initialize self. See help(type(self)) for accurate signature.

addConnection(nodeFrom, portFrom, nodeTo, portTo)

Add a connection to the graph

Parameters:

• nodeFrom – the start node’s name

• portFrom – the start node’s port

• nodeTo – the end node’s name

• portTo – the end node’s port

Returns:

addInPort(node, name)

add an input port to a node

Parameters:

• node – the node name

• name – the port name

Returns:

addNode(name)

Add a named node to the graph

Parameters:

name – a string instance

Returns:

addOutPort(node, name)

Adds an output port to a node

Parameters:

• node – the node name

• name – the port name

Returns:

autoLayout()

Automatic layout of nodes using a heuristic layering algorithm.

Returns:

connectionAddRequest

static getData(item, role)

returns render-relevant information about the specified item can be overriden in concrete editor instances

Parameters:

• item – an instance of BaseGraphScene.NodeItem, BaseGraphScene.PortItem or BaseGraphScene.ConnectionItem

• role – one of STYLE_ROLE_SIZE, STYLE_ROLE_PEN, STYLE_ROLE_BRUSH, STYLE_ROLE_RRRADIUS, STYLE_ROLE_VSPACING, STYLE_ROLE_HSPACING

Returns:

the expected item related to the role

graphItemAt(scenePos)

Returns the graph item at the specified scene position

Parameters:

scenePos – a QPoint instance

Returns:

a NodeItem, PortItem or ConnectionItem instance

mouseMoveEvent(event)

Override from QGraphicsScene (used for dragging connections)

Parameters:

event – the QT event

Returns:

mousePressEvent(event)

Override from QGraphicsScene (used for dragging connections)

Parameters:

event – the QT event

Returns:

mouseReleaseEvent(event)

Override from QGraphicsScene (used for dragging connections)

Parameters:

event – the QT event

Returns:

removeConnection(nodeFrom, portFrom, nodeTo, portTo)

Removes a connection from the graph

Parameters:

• nodeFrom – the start node’s name

• portFrom – the start node’s port

• nodeTo – the end node’s name

• portTo – the end node’s port

Returns:

removeInPort(node, name)

Remove an input port from a node

Parameters:

• node – the node name

• name – the port name

Returns:

removeNode(name)

Remove a node from the graph

Parameters:

name – the node name

Returns:

removeOutPort(node, name)

Remove an output port from a node

Parameters:

• node – the node name

• name – the port name

Returns:

renameInPort(node, oldName, newName)

Rename an input port from a node

Parameters:

• node – the node name

• oldName – the old port name

• newName – the new port name

Returns:

renameNode(oldName, newName)

Rename a node in the graph

Parameters:

• oldName – the old name

• newName – the new name

Returns:

renameOutPort(node, oldName, newName)

Rename an output port from a node

Parameters:

• node – the node name

• oldName – the old port name

• newName – the new port name

Returns:

staticMetaObject = PySide6.QtCore.QMetaObject("BaseGraphScene" inherits "QGraphicsScene": Methods:   #21 type=Signal, signature=connectionAddRequest(QString,QString,QString,QString), parameters=QString, QString, QString, QString )

class nexxT.services.gui.GraphEditor.GraphScene(graph, parent)

Bases: BaseGraphScene

Concrete class interacting with a BaseGraph or FilterGraph instance

__init__(self, sceneRect: PySide6.QtCore.QRectF, /, parent: PySide6.QtCore.QObject | None = None, *, backgroundBrush: PySide6.QtGui.QBrush | None = None, foregroundBrush: PySide6.QtGui.QBrush | None = None, itemIndexMethod: PySide6.QtWidgets.QGraphicsScene.ItemIndexMethod | None = None, bspTreeDepth: int | None = None, palette: PySide6.QtGui.QPalette | None = None, font: PySide6.QtGui.QFont | None = None, stickyFocus: bool | None = None, minimumRenderSize: float | None = None, focusOnTouch: bool | None = None) → None

__init__(self, /, parent: PySide6.QtCore.QObject | None = None, *, backgroundBrush: PySide6.QtGui.QBrush | None = None, foregroundBrush: PySide6.QtGui.QBrush | None = None, itemIndexMethod: PySide6.QtWidgets.QGraphicsScene.ItemIndexMethod | None = None, sceneRect: PySide6.QtCore.QRectF | None = None, bspTreeDepth: int | None = None, palette: PySide6.QtGui.QPalette | None = None, font: PySide6.QtGui.QFont | None = None, stickyFocus: bool | None = None, minimumRenderSize: float | None = None, focusOnTouch: bool | None = None) → None

__init__(self, x: float, y: float, width: float, height: float, /, parent: PySide6.QtCore.QObject | None = None, *, backgroundBrush: PySide6.QtGui.QBrush | None = None, foregroundBrush: PySide6.QtGui.QBrush | None = None, itemIndexMethod: PySide6.QtWidgets.QGraphicsScene.ItemIndexMethod | None = None, sceneRect: PySide6.QtCore.QRectF | None = None, bspTreeDepth: int | None = None, palette: PySide6.QtGui.QPalette | None = None, font: PySide6.QtGui.QFont | None = None, stickyFocus: bool | None = None, minimumRenderSize: float | None = None, focusOnTouch: bool | None = None) → None

Initialize self. See help(type(self)) for accurate signature.

addFilterFromEntryPoint()

Add a filter from its corresponding entry point (the entry point is deduced from the sender action’s data()).

Returns:

addInputPort()

Adds an input port to a node

Returns:

addOutputPort()

Adds an output port to a node

Returns:

compositeFilters()

Get a list of names of composite filters.

Returns:

a list of strings

contextMenuEvent(event)

Overwritten from QGraphicsScene.

getData(item, role)

returns render-relevant information about the specified item can be overriden in concrete editor instances

Parameters:

• item – an instance of BaseGraphScene.NodeItem, BaseGraphScene.PortItem or BaseGraphScene.ConnectionItem

• role – one of STYLE_ROLE_SIZE, STYLE_ROLE_PEN, STYLE_ROLE_BRUSH, STYLE_ROLE_RRRADIUS, STYLE_ROLE_VSPACING, STYLE_ROLE_HSPACING

Returns:

the expected item related to the role

onAddComposite()

Called when the user wants to add a new composite filter to this graph.

Returns:

onAddFilterFromFile()

Called when the user wants to add a new filter from a file (FilterGraph variant). Opens a dialog to select the file.

Returns:

onAddFilterFromMod()

Called when the user wants to add a new filter from a python module.

Returns:

onAddNode()

Called when the user wants to add a new node. (Generic variant)

Returns:

onConnSetBlocking()

Sets the conmnection to blocking mode.

Returns:

onConnSetCustom()

Sets the connection to a custom width.

Returns:

onConnSetNonBlocking()

Sets the conmnection to non blocking mode.

Returns:

onConnectionRemove()

Removes a connection

Returns:

onSuggestDynamicPorts()

Called when the user wants to add dynamic ports based on the filter’s suggestions.

Returns:

removeDialog()

Opens a dialog for removing an item (Node or Port)

Returns:

renameDialog()

Opens a dialog for renamign an item (node or port)

Returns:

setThread()

Opens a dialog to enter the new thread of the node.

Returns:

staticMetaObject = PySide6.QtCore.QMetaObject("GraphScene" inherits "BaseGraphScene": )

class nexxT.services.gui.GraphEditor.MyGraphicsPathItem(*args, **kw)

Bases: QGraphicsPathItem, QObject

Little subclass for receiving hover events and scene position changes outside the items

__init__(self, path: PySide6.QtGui.QPainterPath, /, parent: PySide6.QtWidgets.QGraphicsItem | None = None) → None

__init__(self, /, parent: PySide6.QtWidgets.QGraphicsItem | None = None) → None

Initialize self. See help(type(self)) for accurate signature.

hoverEnter

hoverEnterEvent(event)

emit corresponding singal

Parameters:

event – the qt event

Returns:

hoverLeave

hoverLeaveEvent(event)

emit corresponding signal

Parameters:

event – the qt event

Returns:

itemChange(change, value)

in case of scene position changes, emit the corresponding signal

Parameters:

• change – what has changed

• value – the new value

Returns:

scenePosChanged

staticMetaObject = PySide6.QtCore.QMetaObject("MyGraphicsPathItem" inherits "QObject": Methods:   #4 type=Signal, signature=hoverEnter()   #5 type=Signal, signature=hoverLeave()   #6 type=Signal, signature=scenePosChanged(QPointF), parameters=QPointF )

class nexxT.services.gui.GraphEditor.MySimpleTextItem(*args, **kw)

Bases: QGraphicsSimpleTextItem

QGraphicsSimpleTextItem with a background brush

__init__(self, text: str, /, parent: PySide6.QtWidgets.QGraphicsItem | None = None) → None

__init__(self, /, parent: PySide6.QtWidgets.QGraphicsItem | None = None) → None

Initialize self. See help(type(self)) for accurate signature.

paint(painter, option, widget)

first paint the background and afterwards use standard paint method

Parameters:

• painter – a QPainter instance

• option – unused

• widget – unused

Returns:

setBackgroundBrush(brush)

set the background brush

Parameters:

brush – a QBrush instance

Returns:

class nexxT.services.gui.GraphEditor.PortSelectorDialog(parent, inputPorts, outputPorts, graph, nodeName)

Bases: QDialog

Dialog for selecting the ports which shall be created.

__init__(parent, inputPorts, outputPorts, graph, nodeName)

Constructor

Parameters:

• parent – this dialog’s parent widget

• inputPorts – the list of input port names

• outputPorts – the list of output port names

• graph – the corresponding BaseGraph instance

• nodeName – the name of the corresponding node

accept()

Accepts user selection.

static getSelectedPorts(parent, inputPorts, outputPorts, graph, nodeName)

Convenience function for executing the dialog.

Parameters:

• parent – this dialog’s parent widget

• inputPorts – the list of input port names

• outputPorts – the list of output port names

• graph – the corresponding BaseGraph instance

• nodeName – the name of the corresponding node

reject()

Rejects user selection.

staticMetaObject = PySide6.QtCore.QMetaObject("PortSelectorDialog" inherits "QDialog": )