QAIM - Can't select indexes from different model or with different parents

[demberto]

@dataclass
class EventPath:
    parent: AnyEvent | EventPath
    row: int

    def __post_init__(self) -> None:
        self.parents: list[EventPath] = []
        ancestor = self.parent
        while isinstance(ancestor, EventPath):
            self.parents.insert(0, ancestor)
            ancestor = ancestor.parent
        self.event = ancestor
        self.depth = len(self.parents)
        self.has_children = self.event.id > DATA

    def __len__(self) -> int:
        if self.has_children and isinstance(self.value, (list, dict)):
            return len(self.value)  # type: ignore
        return 0

    @cached_property
    def children(self) -> list[EventPath]:
        return [EventPath(self, i) for i in range(len(self))]


class EventItemModel(QAbstractItemModel):
    def __init__(self, events: Sequence[AnyEvent]) -> None:
        super().__init__()
        self.events = events
        self.paths = [EventPath(event, i) for i, event in enumerate(events)]

    def index(self, row: int, column: int, parent: QModelIndex = QModelIndex()) -> QModelIndex:
        if not parent.isValid():
            return self.createIndex(row, column, self.paths[row])

        path: EventPath = parent.internalPointer()
        return self.createIndex(row, column, path.children[row])

    def parent(self, child: QModelIndex):
        path: EventPath = child.internalPointer()
        if child.column() > 0 or isinstance(path.parent, EventBase):
            return QModelIndex()

        return self.createIndex(path.parent.row, 0, path.parent)

    def rowCount(self, parent: QModelIndex = QModelIndex()) -> int:
        if not parent.isValid():
            return len(self.events)

        path: EventPath = parent.internalPointer()
        return len(path)

    def columnCount(self, parent: QModelIndex = ...) -> int:
        return 2

For child level items, it always says Can't select indexes from different model or with different parents, when I clearly return the correct parent index.

Weird things happen when I try double clicking the children apart from the message above:

• Jumps to some random parent index much above it.
• Highlights some random index not at the same level.

Is it because of cached_property?

I have done debugging in the call to parent to verify if parent.parent indeed points to the same memory location and it does. The parent.parent.row is same for all children too.