Merge pull request matplotlib#27218 from tacaswell/api/remove_lastevent

API: finish LocationEvent.lastevent removal

Author: QuLogic

doc/api/next_api_changes/removals/27218-TAC.rst

@@ -0,0 +1,7 @@
+Remove hard reference to ``lastevent`` in ``LocationEvent``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+
+This was previously used to detect exiting from axes, however the hard
+reference would keep closed `.Figure` objects and their children alive longer
+than expected.

lib/matplotlib/backend_bases.py

@@ -1271,10 +1271,6 @@ class LocationEvent(Event):
         The keyboard modifiers currently being pressed (except for KeyEvent).
     """
 
-    # Fully delete all occurrences of lastevent after deprecation elapses.
-    _lastevent = None
-    lastevent = _api.deprecated("3.8")(
-        _api.classproperty(lambda cls: cls._lastevent))
     _last_axes_ref = None
 
     def __init__(self, name, canvas, x, y, guiEvent=None, *, modifiers=None):
@@ -1527,8 +1523,6 @@ def _mouse_handler(event):
                 event.canvas.callbacks.process("axes_enter_event", event)
         LocationEvent._last_axes_ref = (
             weakref.ref(event.inaxes) if event.inaxes else None)
-        LocationEvent._lastevent = (
-            None if event.name == "figure_leave_event" else event)
 
 
 def _get_renderer(figure, print_method=None):

lib/matplotlib/backend_bases.pyi

@@ -220,7 +220,6 @@ class ResizeEvent(Event):
 class CloseEvent(Event): ...
 
 class LocationEvent(Event):
-    lastevent: Event | None
     x: int
     y: int
     inaxes: Axes | None