def parent(self, index):
if not index.isValid():
return QModelIndex()
parent = index.internalPointer()
if parent == Root:
return QModelIndex()
grandparent, row = self.model.index_manager.get_parent_and_row(parent)
return self.createIndex(row, 0, grandparent)
def rowCount(self, index=QModelIndex()):
row_index = self._to_row_index(index)
try:
if self.model.can_have_children(row_index):
return self.model.get_row_count(row_index)
except Exception:
logger.exception("Error in rowCount")
return 0
def columnCount(self, index=QModelIndex()):
row_index = self._to_row_index(index)
try:
# the number of columns is constant; leaf rows return 0
if self.model.can_have_children(row_index):
return self.model.get_column_count() + 1
except Exception:
logger.exception("Error in columnCount")
return 0
def _to_model_index(self, row_index, column_index):
if len(row_index) == 0:
return QModelIndex()
index = self.model.index_manager.from_sequence(row_index[:-1])
row = row_index[-1]
if len(column_index) == 0:
column = 0
else:
column = column_index[0] + 1
return self.createIndex(row, column, index)