MNT: simplify close handler

Author: tacaswell

mpl_gui/_promotion.py

@@ -72,22 +72,17 @@ def promote_figure(fig, *, auto_draw=True, num):
 
     # HACK: the callback in backend_bases uses GCF.destroy which misses these
     # figures by design!
-    def _destroy(event):
+    def _destroy_on_hotkey(event):
         if event.key in mpl.rcParams["keymap.quit"]:
             # grab the manager off the event
             mgr = event.canvas.manager
             if mgr is None:
-                raise RuntimeError("Should never be here, please report a bug")
-            fig = event.canvas.figure
-            # remove this callback.  Callbacks lives on the Figure so survive
-            # the canvas being replaced.
-            old_cid = getattr(mgr, "_destroy_cid", None)
-            if old_cid is not None:
-                fig.canvas.mpl_disconnect(old_cid)
-                mgr._destroy_cid = None
+                raise RuntimeError("Should never be here, please report a bug.")
             # close the window
             mgr.destroy()
 
-    manager._destroy_cid = fig.canvas.mpl_connect("key_press_event", _destroy)
+    # remove this callback.  Callbacks live on the Figure so survive the canvas
+    # being replaced.
+    fig.canvas.mpl_connect("key_press_event", _destroy_on_hotkey)
 
     return manager