Added handle position checks to test_widgets.py

Author: andrew-fennell

lib/matplotlib/tests/test_widgets.py

@@ -1105,19 +1105,30 @@ def test_range_slider(orientation):
     # Check initial value is set correctly
     assert_allclose(slider.val, (0.1, 0.34))
 
+    def handle_positions(slider):
+        if orientation == "vertical":
+            return [h.get_ydata()[0] for h in slider._handles]
+        else:
+            return [h.get_xdata()[0] for h in slider._handles]
+
     slider.set_val((0.2, 0.6))
     assert_allclose(slider.val, (0.2, 0.6))
+    assert_allclose(handle_positions(slider), (0.2, 0.6))
+
     box = slider.poly.get_extents().transformed(ax.transAxes.inverted())
     assert_allclose(box.get_points().flatten()[idx], [0.2, .25, 0.6, .75])
 
     slider.set_val((0.2, 0.1))
     assert_allclose(slider.val, (0.1, 0.2))
+    assert_allclose(handle_positions(slider), (0.1, 0.2))
 
     slider.set_val((-1, 10))
     assert_allclose(slider.val, (0, 1))
+    assert_allclose(handle_positions(slider), (0, 1))
 
     slider.reset()
-    assert_allclose(slider.val, [0.1, 0.34])
+    assert_allclose(slider.val, (0.1, 0.34))
+    assert_allclose(handle_positions(slider), (0.1, 0.34))
 
 
 def check_polygon_selector(event_sequence, expected_result, selections_count,

lib/matplotlib/widgets.py

@@ -838,18 +838,16 @@ def _update(self, event):
             self._active_handle = None
             return
 
+        # determine which handle was grabbed
         if self.orientation == "vertical":
-            # determine which handle was grabbed
-            event_handle = np.argmin(
+            handle_index = np.argmin(
                 np.abs([h.get_ydata()[0] - event.ydata for h in self._handles])
             )
-            handle = self._handles[event_handle]
         else:
-            # determine which handle was grabbed
-            event_handle = np.argmin(
+            handle_index = np.argmin(
                 np.abs([h.get_xdata()[0] - event.xdata for h in self._handles])
             )
-            handle = self._handles[event_handle]
+        handle = self._handles[handle_index]
 
         # these checks ensure smooth behavior if the handles swap which one
         # has a higher value. i.e. if one is dragged over and past the other.