Merge pull request matplotlib#20273 from QuLogic/fix-toolmanager-gtk3

Fix cursor with toolmanager on GTK3.

Author: timhoffm

lib/matplotlib/backends/backend_gtk3.py

@@ -48,6 +48,18 @@
     cursord = {}  # deprecated in Matplotlib 3.5.
 
 
+@functools.lru_cache()
+def _mpl_to_gtk_cursor(mpl_cursor):
+    name = {
+        cursors.MOVE: "move",
+        cursors.HAND: "pointer",
+        cursors.POINTER: "default",
+        cursors.SELECT_REGION: "crosshair",
+        cursors.WAIT: "wait",
+    }[mpl_cursor]
+    return Gdk.Cursor.new_from_name(Gdk.Display.get_default(), name)
+
+
 class TimerGTK3(TimerBase):
     """Subclass of `.TimerBase` using GTK3 timer events."""
 
@@ -484,22 +496,10 @@ def set_message(self, s):
         escaped = GLib.markup_escape_text(s)
         self.message.set_markup(f'<small>{escaped}</small>')
 
-    @staticmethod
-    @functools.lru_cache()
-    def _mpl_to_gtk_cursor(mpl_cursor):
-        name = {
-            cursors.MOVE: "move",
-            cursors.HAND: "pointer",
-            cursors.POINTER: "default",
-            cursors.SELECT_REGION: "crosshair",
-            cursors.WAIT: "wait",
-        }[mpl_cursor]
-        return Gdk.Cursor.new_from_name(Gdk.Display.get_default(), name)
-
     def set_cursor(self, cursor):
         window = self.canvas.get_property("window")
         if window is not None:
-            window.set_cursor(self._mpl_to_gtk_cursor(cursor))
+            window.set_cursor(_mpl_to_gtk_cursor(cursor))
             Gtk.main_iteration()
 
     def draw_rubberband(self, event, x0, y0, x1, y1):