TreeModel

treemodel.py

from PySide6.QtCore import Qt, QAbstractItemModel, QModelIndex, QVariant

class Node:
    def __init__(self, name, parent=None, private_data=None):
        self.name = name
        self.parentNode = parent
        self.childNodes = []
        self.privateData = private_data

        if parent:
            parent.addChild(self)

    def addChild(self, child):
        self.childNodes.append(child)

    def row(self):
        if self.parentNode:
            return self.parentNode.childNodes.index(self)
        return 0

    def childCount(self):
        return len(self.childNodes)

    def child(self, row):
        return self.childNodes[row]

    def parent(self):
        return self.parentNode

    def data(self, column, role=Qt.DisplayRole):
        if role == Qt.DisplayRole:
            if column == 0:
                return self.name
        elif role == Qt.UserRole:
            return self.privateData
        return None

    def setData(self, column, value, role=Qt.EditRole):
        if role == Qt.EditRole:
            if column == 0:
                self.name = value
                return True
        elif role == Qt.UserRole:
            self.privateData = value
            return True
        return False

class TreeModel(QAbstractItemModel):
    def __init__(self, rootNode, parent=None):
        super().__init__(parent)
        self.rootNode = rootNode

    def index(self, row, column, parent=QModelIndex()):
        if not parent.isValid():
            parentNode = self.rootNode
        else:
            parentNode = parent.internalPointer()

        if row >= parentNode.childCount():
            return QModelIndex()

        childNode = parentNode.child(row)
        if childNode:
            return self.createIndex(row, column, childNode)
        else:
            return QModelIndex()

    def parent(self, index):
        if not index.isValid():
            return QModelIndex()

        childNode = index.internalPointer()
        parentNode = childNode.parent()

        if parentNode == self.rootNode:
            return QModelIndex()

        return self.createIndex(parentNode.row(), 0, parentNode)

    def rowCount(self, parent=QModelIndex()):
        if not parent.isValid():
            parentNode = self.rootNode
        else:
            parentNode = parent.internalPointer()

        return parentNode.childCount()

    def columnCount(self, parent=QModelIndex()):
        return 1

    def data(self, index, role=Qt.DisplayRole):
        if not index.isValid():
            return None

        node = index.internalPointer()

        if role == Qt.DisplayRole or role == Qt.EditRole or role == Qt.UserRole:
            return node.data(index.column(), role)

        return None

    def setData(self, index, value, role=Qt.EditRole):
        if not index.isValid():
            return False

        node = index.internalPointer()
        if node.setData(index.column(), value, role):
            self.dataChanged.emit(index, index, [role])
            return True

        return False

    def flags(self, index):
        if not index.isValid():
            return Qt.NoItemFlags

        return Qt.ItemIsEditable | Qt.ItemIsEnabled | Qt.ItemIsSelectable

if __name__ == '__main__':
    rootNode = Node('Root')
    child1Node = Node('Child 1', rootNode, {'private_key': 'private_value_1'})
    child2Node = Node('Child 2', rootNode, {'private_key': 'private_value_2'})
    grandchildNode = Node('Grandchild', child2Node, {'private_key': 'private_value_3'})

    app = QApplication(sys.argv)
    treeView