nodedge.scene¶

Scene module containing Scene.

class nodedge.scene.Scene¶

Bases: nodedge.serializable.Serializable

Scene class

Instance Attributes:
	nodes - list of Nodes in this Scene edges - list of Edges in this Scene history - Instance of `SceneHistory` clipboard - Instance of `SceneClipboard` scene_width - width of this Scene in pixels scene_height - height of this Scene in pixels

isModified¶

Has this Scene been modified?

Getter:	`True` if the Scene has been modified
Setter:	set new state. Triggers Has Been Modified event
Type:	`bool`

lastSelectedItems¶

Returns last selected graphics items. This property is used to detect if selection has changed.

Returns:	Last selected items
Return type:	`list[QGraphicsItem]`

selectedItems¶

Returns currently selected Graphics Items

Returns:	list of `QGraphicsItems`
Return type:	list[QGraphicsItem]

graphicsView¶

Shortcut for returning Scene QGraphicsView

Returns:	`QGraphicsView` attached to the Scene
Return type:	`QGraphicsView`

silentSelectionEvents¶

” If this property is true, do not trigger onItemSelected when an item is selected

Returns:	True is onItemSelected is not triggered when an item is selected
Return type:	`bool`

onItemSelected(silent: bool = False)¶

Handle Item selection and trigger event Item Selected

Parameters:	silent (`bool`) – If `True` scene’s onItemSelected won’t be called and history stamp not stored.

onItemsDeselected(silent: bool = False)¶

Handle Items deselection and trigger event Items Deselected

Parameters:	silent (`bool`) – If `True` scene’s onItemsDeselected won’t be called and history stamp not stored.

doDeselectItems(silent: bool = False) → None¶

Deselects everything in scene

Parameters:	silent (`bool`) – If `True` scene’s onItemsDeselected won’t be called

addHasBeenModifiedListener(callback: Callable[None])¶

Register callback for Has Been Modified event

Parameters:	callback (`Callable[[], None]`) – callback function

addItemSelectedListener(callback: Callable[None])¶

Register callback for Item Selected event

Parameters:	callback (`Callable[[], None]`) – callback function

addItemsDeselectedListener(callback: Callable[None])¶

Register callback for Items Deselected event

Parameters:	callback – callback function

addDragEnterListener(callback: Callable[PySide2.QtGui.QDragEnterEvent, None])¶

Register callback for Drag Enter event

Parameters:	callback – callback function

addDropListener(callback: Callable[PySide2.QtGui.QDropEvent, None])¶

Register callback for Drop event

Parameters:	callback – callback function

resetLastSelectedStates() → None¶: Resets internal selected flags in all Nodes and Edges in the Scene

addNode(node: nodedge.node.Node)¶

Add Node to this Scene

Parameters:	node (`Node`) – `Node` to be added to this Scene

addEdge(edge: nodedge.edge.Edge)¶

Add Edge to this Scene

Parameters:	edge – `Edge` to be added to this Scene
Returns:	`Edge`

removeNode(nodeToRemove: nodedge.node.Node)¶: Remove Node from this Scene :param nodeToRemove: Node to be removed from this Scene :type nodeToRemove: Node

removeEdge(edgeToRemove: nodedge.edge.Edge)¶

Remove Edge from this Scene

Parameters:	edgeToRemove – `Edge` to be remove from this Scene
Returns:	`Edge`

clear() → None¶: Remove all Nodes from this Scene. This causes also to remove all Edges

saveToFile(filename)¶

Save this Scene to the file on disk.

Parameters:	filename (`str`) – where to save this scene

loadFromFile(filename: str) → None¶

Load Scene from a file on disk

Parameters:	filename (`str`) – from what file to load the Scene
Raises:	`InvalidFile` if there was an error decoding JSON file.

serialize() → collections.OrderedDict¶

Serialization method to serialize this class data into OrderedDict which can be stored in memory or file easily.

Returns:	data serialized in `OrderedDict`
Return type:	`OrderedDict`

deserialize(data: dict, hashmap: Optional[dict] = None, restoreId: bool = True, *args, **kwargs) → bool¶

Deserialization method which take data in python dict format with helping hashmap containing references to existing entities.

Parameters:	data (`dict`) – dictionary containing serialized data hashmap (`dict`) – helper dictionary containing references (by id == key) to existing objects restoreId (`bool`) – `True` if we are creating new sockets. `False` is useful when loading existing sockets which we want to keep the existing object’s id
Returns:	`True` if deserialization was successful, `False` otherwise
Return type:	`bool`

getNodeClassFromData(data)¶

Takes Node serialized data and determines which Node Class to instantiate according the description in the serialized Node.

Parameters:	data (`dict`) – serialized `Node` object data
Returns:	Instance of `Node` class to be used in this Scene
Return type:	`Node` class instance

setNodeClassSelector(classSelectingFunction)¶

Set the function which decides what Node class to instantiate during Scene deserialization. If not set, we will always instantiate Node for each Node in the Scene

Parameters:	classSelectingFunction (`function`) – function which returns `Node` class type (not instance) from `Node` serialized `dict` data
Returns:	Class Type of `Node` to be instantiated during deserialization
Return type:	`Node` class type

itemAt(pos)¶

Shortcut for retrieving item at provided Scene position

Parameters:	pos (`QPointF`) – scene position
Returns:	Qt Graphics Item at scene position
Return type:	`QGraphicsItem`

getNodeById(nodeId: int) → Optional[nodedge.node.Node]¶

Find node in the scene according to provided nodeId

Parameters:	nodeId (`int`) – ID of the node we are looking for
Returns:	Found :class:`~nodedge.node.Node` or `None`
Return type:	:class:`~nodedge.node.Node` or `None`

exception nodedge.scene.InvalidFile¶: Bases: Exception