node_graphics_view Module

A module containing Graphics View for NodeEditor

Constants

nodeeditor.node_graphics_view.MODE_NOOP = 1

Mode representing ready state

nodeeditor.node_graphics_view.MODE_EDGE_DRAG = 2

Mode representing when we drag edge state

nodeeditor.node_graphics_view.MODE_EDGE_CUT = 3

Mode representing when we draw a cutting edge

nodeeditor.node_graphics_view.MODE_EDGES_REROUTING = 4

Mode representing when we re-route existing edges

nodeeditor.node_graphics_view.EDGE_DRAG_START_THRESHOLD = 50

Distance when click on socket to enable Drag Edge

QDMGraphicsView class

class nodeeditor.node_graphics_view.QDMGraphicsView(grScene: QDMGraphicsScene, parent: QWidget = None)

Bases: PyQt5.QtWidgets.QGraphicsView

Class representing NodeEditor’s Graphics View

Parameters
Instance Attributes

  • grScene - reference to the QDMGraphicsScene

  • mode - state of the Graphics View

  • zoomInFactor- float - zoom step scaling, default 1.25

  • zoomClamp - bool - do we clamp zooming or is it infinite?

  • zoom - current zoom step

  • zoomStep - int - the relative zoom step when zooming in/out

  • zoomRange - [min, max]

scenePosChanged

pyqtSignal emitted when cursor position on the Scene has changed

initUI()

Set up this QGraphicsView

isSnappingEnabled(event: Optional[PyQt5.QtGui.QInputEvent] = None) → bool

Returns True if snapping is currently enabled

resetMode()

Helper function to re-set the grView’s State Machine state to the default

dragEnterEvent(event: PyQt5.QtGui.QDragEnterEvent)

Trigger our registered Drag Enter events

dropEvent(event: PyQt5.QtGui.QDropEvent)

Trigger our registered Drop events

addDragEnterListener(callback: function)

Register callback for Drag Enter event

Parameters

callback – callback function

addDropListener(callback: function)

Register callback for Drop event

Parameters

callback – callback function

mousePressEvent(event: PyQt5.QtGui.QMouseEvent)

Dispatch Qt’s mousePress event to corresponding function below

mouseReleaseEvent(event: PyQt5.QtGui.QMouseEvent)

Dispatch Qt’s mouseRelease event to corresponding function below

middleMouseButtonPress(event: PyQt5.QtGui.QMouseEvent)

When Middle mouse button was pressed

middleMouseButtonRelease(event: PyQt5.QtGui.QMouseEvent)

When Middle mouse button was released

leftMouseButtonPress(event: PyQt5.QtGui.QMouseEvent)

When Left mouse button was pressed

leftMouseButtonRelease(event: PyQt5.QtGui.QMouseEvent)

When Left mouse button was released

rightMouseButtonPress(event: PyQt5.QtGui.QMouseEvent)

When Right mouse button was pressed

rightMouseButtonRelease(event: PyQt5.QtGui.QMouseEvent)

When Right mouse button was release

mouseMoveEvent(event: PyQt5.QtGui.QMouseEvent)

Overriden Qt’s mouseMoveEvent handling Scene/View logic

keyPressEvent(event: PyQt5.QtGui.QKeyEvent)

Note

This overridden Qt’s method was used for handling key shortcuts, before we implemented proper QWindow with Actions and Menu. Still the commented code serves as an example on how to handle key presses without Qt’s framework for Actions and shortcuts. There is also an example on how to solve the problem when a Node contains Text/LineEdit and we press the Delete key (also serving to delete Node)

Parameters

event (QKeyEvent) – Qt’s Key event

Returns

cutIntersectingEdges()

Compare which Edges intersect with current Cut line and delete them safely

setSocketHighlights(scenepos: PyQt5.QtCore.QPointF, highlighted: bool = True, radius: float = 50)

Set/disable socket highlights in Scene area defined by scenepos and radius

deleteSelected()

Shortcut for safe deleting every object selected in the Scene.

debug_modifiers(event)

Helper function get string if we hold Ctrl, Shift or Alt modifier keys

getItemAtClick(event: PyQt5.QtCore.QEvent) → QGraphicsItem

Return the object on which we’ve clicked/release mouse button

Parameters

event (QEvent) – Qt’s mouse or key event

Returns

QGraphicsItem which the mouse event happened or None

distanceBetweenClickAndReleaseIsOff(event: PyQt5.QtGui.QMouseEvent) → bool

Measures if we are too far from the last Mouse button click scene position. This is used for detection if we release too far after we clicked on a Socket

Parameters

event (QMouseEvent) – Qt’s mouse event

Returns

True if we released too far from where we clicked before

wheelEvent(event: PyQt5.QtGui.QWheelEvent)

overridden Qt’s wheelEvent. This handles zooming