itemmodels.AbstractSortTableModel: Fix mapFromSourceRows

Author: janezd

Orange/widgets/utils/itemmodels.py

@@ -118,7 +118,7 @@ def mapToSourceRows(self, rows):
 
         Parameters
         ----------
-        rows : int or list of int or numpy.ndarray or Ellipsis
+        rows : int or list of int or numpy.ndarray of dtype=int or Ellipsis
             View (sorted) rows.
 
         Returns
@@ -127,7 +127,10 @@ def mapToSourceRows(self, rows):
             Source rows matching input rows. If they are the same,
             simply input `rows` is returned.
         """
-        if self.__sortInd is not None:
+        # self.__sortInd[rows] fails if `rows` is an empty list or array
+        if self.__sortInd is not None \
+                and (isinstance(rows, (int, type(Ellipsis)))
+                     or len(rows)):
             new_rows = self.__sortInd[rows]
             if rows is Ellipsis:
                 new_rows.setflags(write=False)
@@ -139,7 +142,7 @@ def mapFromSourceRows(self, rows):
 
         Parameters
         ----------
-        rows : int or list of int or numpy.ndarray or Ellipsis
+        rows : int or list of int or numpy.ndarray of dtype=int or Ellipsis
             Source model rows.
 
         Returns
@@ -148,7 +151,10 @@ def mapFromSourceRows(self, rows):
             ModelIndex (sorted) rows matching input source rows.
             If they are the same, simply input `rows` is returned.
         """
-        if self.__sortIndInv is not None:
+        # self.__sortInd[rows] fails if `rows` is an empty list or array
+        if self.__sortIndInv is not None \
+                and (isinstance(rows, (int, type(Ellipsis)))
+                     or len(rows)):
             new_rows = self.__sortIndInv[rows]
             if rows is Ellipsis:
                 new_rows.setflags(write=False)

Orange/widgets/utils/tests/test_itemmodels.py

@@ -3,6 +3,8 @@
 
 from unittest import TestCase
 
+import numpy as np
+
 from AnyQt.QtCore import Qt
 
 from Orange.data import Domain, ContinuousVariable, DiscreteVariable
@@ -133,6 +135,34 @@ def test_sorting(self):
         self.model.sort(1, Qt.DescendingOrder)
         self.assertSequenceEqual(self.model.mapToSourceRows(...).tolist(), [0, 1])
 
+    def test_mapToSourceRows(self):
+        # self.model is not appropriate here since it is its own inverse, so the
+        # test wouldn't check whether the method works in the right direction
+        model = PyTableModel([[1, 4],
+                              [2, 2],
+                              [3, 3]])
+        model.sort(1, Qt.AscendingOrder)
+        self.assertSequenceEqual(model.mapToSourceRows(...).tolist(), [1, 2, 0])
+        self.assertEqual(model.mapToSourceRows(1).tolist(), 2)
+        self.assertSequenceEqual(model.mapToSourceRows([1, 2]).tolist(), [2, 0])
+        self.assertSequenceEqual(model.mapToSourceRows([]), [])
+        self.assertSequenceEqual(
+            model.mapToSourceRows(np.array([], dtype=int)).tolist(), [])
+
+    def test_mapFromSourceRows(self):
+        # self.model is not appropriate here since it is its own inverse, so the
+        # test wouldn't check whether the method works in the right direction
+        model = PyTableModel([[1, 4],
+                              [2, 2],
+                              [3, 3]])
+        model.sort(1, Qt.AscendingOrder)
+        self.assertSequenceEqual(model.mapFromSourceRows(...).tolist(), [2, 0, 1])
+        self.assertEqual(model.mapFromSourceRows(1).tolist(), 0)
+        self.assertSequenceEqual(model.mapFromSourceRows([1, 2]).tolist(), [0, 1])
+        self.assertSequenceEqual(model.mapFromSourceRows([]), [])
+        self.assertSequenceEqual(
+            model.mapFromSourceRows(np.array([], dtype=int)).tolist(), [])
+
 
 class TestPyListModel(TestCase):
     @classmethod