node_scene_history Module

A module containing all code for working with History (Undo/Redo)

Events

History Modified

after History Stamp has been stored or restored

History Stored

after History Stamp has been stored

History Restored

after History Stamp has been restored

SceneHistory Class

class nodeeditor.node_scene_history.SceneHistory(scene: Scene)

Bases: object

Class contains all the code for undo/redo operations

Parameters

scene (Scene) – Reference to the Scene

Instance Attributes

  • scene - reference to the Scene

  • history_limit - number of history steps that can be stored

clear()

Reset the history stack

storeInitialHistoryStamp()

Helper function usually used when new or open file requested

addHistoryModifiedListener(callback: function)

Register callback for HistoryModified event

Parameters

callback – callback function

addHistoryStoredListener(callback: function)

Register callback for HistoryStored event

Parameters

callback – callback function

addHistoryRestoredListener(callback: function)

Register callback for HistoryRestored event

Parameters

callback – callback function

canUndo() → bool

Return True if Undo is available for current History Stack

Return type

bool

canRedo() → bool

Return True if Redo is available for current History Stack

Return type

bool

undo()

Undo operation

redo()

Redo operation

restoreHistory()

Restore History Stamp from History stack.

Triggers:

  • History Modified event

  • History Restored event

storeHistory(desc: str, setModified: bool = False)

Store History Stamp into History Stack

Parameters

  • desc (str) – Description of current History Stamp

  • setModified (bool) – if True marks Scene with has_been_modified

Triggers:

  • History Modified

  • History Stored

captureCurrentSelection() → dict

Create dictionary with a list of selected nodes and a list of selected edges :return: dict ‘nodes’ - list of selected nodes, ‘edges’ - list of selected edges :rtype: dict

createHistoryStamp(desc: str) → dict

Create History Stamp. Internally serialize whole scene and the current selection

Parameters

desc – Descriptive label for the History Stamp

Returns

History stamp serializing state of Scene and current selection

Return type

dict

restoreHistoryStamp(history_stamp: dict)

Restore History Stamp to current Scene with selection of items included

Parameters

history_stamp (dict) – History Stamp to restore