Fix clearing span selector

Author: ericpre

lib/matplotlib/tests/test_widgets.py

@@ -460,6 +460,38 @@ def onselect(epress, erelease):
         assert artist.get_alpha() == 0.3
 
 
+def test_span_selector_clear():
+    ax = get_ax()
+
+    def onselect(*args):
+        pass
+
+    tool = widgets.SpanSelector(ax, onselect, 'horizontal', interactive=True)
+    do_event(tool, 'press', xdata=10, ydata=10, button=1)
+    do_event(tool, 'onmove', xdata=100, ydata=120, button=1)
+    do_event(tool, 'release', xdata=100, ydata=120, button=1)
+
+    # press-release event outside the selector to clear the selector
+    do_event(tool, 'press', xdata=130, ydata=130, button=1)
+    do_event(tool, 'release', xdata=130, ydata=130, button=1)
+    assert not tool._selection_completed
+
+    tool = widgets.SpanSelector(ax, onselect, 'horizontal', interactive=True,
+                                ignore_event_outside=True)
+    do_event(tool, 'press', xdata=10, ydata=10, button=1)
+    do_event(tool, 'onmove', xdata=100, ydata=120, button=1)
+    do_event(tool, 'release', xdata=100, ydata=120, button=1)
+
+    # press-release event outside the selector ignored
+    do_event(tool, 'press', xdata=130, ydata=130, button=1)
+    do_event(tool, 'release', xdata=130, ydata=130, button=1)
+    assert tool._selection_completed
+    assert tool.extents == (10, 100)
+
+    do_event(tool, 'on_key_press', key='escape')
+    assert not tool._selection_completed
+
+
 def test_tool_line_handle():
     ax = get_ax()
 

lib/matplotlib/widgets.py

@@ -1981,7 +1981,6 @@ def on_key_press(self, event):
                 for artist in self.artists:
                     artist.set_visible(False)
                 self.update()
-                return
             for (state, modifier) in self.state_modifier_keys.items():
                 if modifier in key:
                     self._state.add(state)
@@ -2316,6 +2315,11 @@ def direction(self, direction):
         else:
             self._direction = direction
 
+    def _on_key_press(self, event):
+        key = event.key or ''
+        if key == self.state_modifier_keys['clear']:
+            self._selection_completed = False
+
     def _release(self, event):
         """Button release event handler."""
         self._set_cursor(False)
@@ -2354,9 +2358,11 @@ def _hover(self, event):
         if self.ignore(event):
             return
 
-        if self._active_handle is not None:
+        if self._active_handle is not None or not self._selection_completed:
             # Do nothing if button is pressed and a handle is active, which may
             # occur with drag_from_anywhere=True.
+            # Do nothing if selection is not completed, which occurs when
+            # a selector has been cleared
             return
 
         _, e_dist = self._edge_handles.closest(event.x, event.y)