Update handles when canvas is resized

dstansby · dstansby · commit baea5726e1ce · 2022-01-18T11:26:48.000Z
diff --git a/lib/matplotlib/widgets.py b/lib/matplotlib/widgets.py
@@ -2952,6 +2952,9 @@ def __init__(self, ax, onselect, drawtype='box',
             # so the selector is defined in display coordinates, which makes
             # it much easier to handle rotation and scaling
             to_draw.set_transform(None)
+            # Becasue the transform in display coords, need to manually
+            # add a resize callback for when the axes are reszied
+            self.ax.figure.canvas.mpl_connect('resize_event', self._on_resize)
 
         if drawtype == 'line':
             _api.warn_deprecated(
@@ -3018,6 +3021,10 @@ def __init__(self, ax, onselect, drawtype='box',
         property(lambda self: self.grab_range,
                  lambda self, value: setattr(self, "grab_range", value)))
 
+    def _on_resize(self, event):
+        # Callback for an Axes resize
+        self._update_handles()
+
     @property
     def _position_state(self):
         """Return a named tuple containing all position state attributes."""
@@ -3437,13 +3444,15 @@ def _update_selection_artist(self):
             self._selection_artist.set_data([xy0[0], xy1[0]], [xy0[1], xy1[1]])
 
         if self._interactive:
-            # Update displayed handles
-            self._corner_handles.set_data(*self.corners)
-            self._edge_handles.set_data(*self.edge_centers)
-            self._center_handle.set_data(*self.center)
+            self._update_handles()
 
         self.update()
 
+    def _update_handles(self):
+        self._corner_handles.set_data(*self.corners)
+        self._edge_handles.set_data(*self.edge_centers)
+        self._center_handle.set_data(*self.center)
+
     def _set_active_handle(self, event):
         """Set active handle based on the location of the mouse event."""
         # Note: event.xdata/ydata in data coordinates, event.x/y in pixels
