void OnDisable()
{
if (_propertyEditor != null) {
DestroyImmediate(_propertyEditor);
_propertyEditor = null;
}
_patchManager = null;
_nodeFactory = null;
_patch = null;
Undo.undoRedoPerformed -= OnUndo;
EditorApplication.hierarchyWindowChanged -= OnHierarchyWindowChanged;
}
void OnEnable()
{
_patchManager = new PatchManager();
_nodeFactory = new NodeFactory();
_mainViewSize = Vector2.one * 300; // minimum view size
_patchManager.Reset();
_patch = _patchManager.RetrieveLastSelected();
Undo.undoRedoPerformed += OnUndo;
EditorApplication.hierarchyWindowChanged += OnHierarchyWindowChanged;
}