[3.12] gh-103820: IDLE: Do not interpret buttons 4/5 as scrolling on non-X11 (GH-103821) (GH-114901)

Also fix test_mousewheel: do not skip a check which was broken due to incorrect
delta on Aqua and XQuartz, and probably not because of `.update_idletasks()`.
(cherry picked from commit d25d4ee60c)

Co-authored-by: Christopher Chavez <chrischavez@gmx.us>

Lib/idlelib/editor.py

@@ -166,6 +166,7 @@ class EditorWindow:
             text.bind("<3>",self.right_menu_event)
 
         text.bind('<MouseWheel>', wheel_event)
+        if text._windowingsystem == 'x11':
             text.bind('<Button-4>', wheel_event)
             text.bind('<Button-5>', wheel_event)
         text.bind('<Configure>', self.handle_winconfig)

Lib/idlelib/idle_test/test_sidebar.py

@@ -690,16 +690,22 @@ class ShellSidebarTest(unittest.TestCase):
         last_lineno = get_end_linenumber(text)
         self.assertIsNotNone(text.dlineinfo(text.index(f'{last_lineno}.0')))
 
-        # Scroll up using the <MouseWheel> event.
+        # Delta for <MouseWheel>, whose meaning is platform-dependent.
-        # The meaning of delta is platform-dependent.
+        delta = 1 if sidebar.canvas._windowingsystem == 'aqua' else 120
-        delta = -1 if sys.platform == 'darwin' else 120
+
+        # Scroll up.
+        if sidebar.canvas._windowingsystem == 'x11':
+            sidebar.canvas.event_generate('<Button-4>', x=0, y=0)
+        else:
             sidebar.canvas.event_generate('<MouseWheel>', x=0, y=0, delta=delta)
         yield
-        if sys.platform != 'darwin':  # .update_idletasks() does not work.
         self.assertIsNone(text.dlineinfo(text.index(f'{last_lineno}.0')))
 
-        # Scroll back down using the <Button-5> event.
+        # Scroll back down.
+        if sidebar.canvas._windowingsystem == 'x11':
             sidebar.canvas.event_generate('<Button-5>', x=0, y=0)
+        else:
+            sidebar.canvas.event_generate('<MouseWheel>', x=0, y=0, delta=-delta)
         yield
         self.assertIsNotNone(text.dlineinfo(text.index(f'{last_lineno}.0')))
 

Lib/idlelib/tree.py

@@ -285,6 +285,7 @@ class TreeNode:
         self.label.bind("<1>", self.select_or_edit)
         self.label.bind("<Double-1>", self.flip)
         self.label.bind("<MouseWheel>", lambda e: wheel_event(e, self.canvas))
+        if self.label._windowingsystem == 'x11':
             self.label.bind("<Button-4>", lambda e: wheel_event(e, self.canvas))
             self.label.bind("<Button-5>", lambda e: wheel_event(e, self.canvas))
         self.text_id = id
@@ -460,6 +461,7 @@ class ScrolledCanvas:
         self.canvas.bind("<Key-Up>", self.unit_up)
         self.canvas.bind("<Key-Down>", self.unit_down)
         self.canvas.bind("<MouseWheel>", wheel_event)
+        if self.canvas._windowingsystem == 'x11':
             self.canvas.bind("<Button-4>", wheel_event)
             self.canvas.bind("<Button-5>", wheel_event)
         #if isinstance(master, Toplevel) or isinstance(master, Tk):

Misc/NEWS.d/next/IDLE/2023-04-25-03-01-23.gh-issue-103820.LCSpza.rst

@@ -0,0 +1,2 @@
+Revise IDLE bindings so that events from mouse button 4/5 on non-X11
+windowing systems (i.e. Win32 and Aqua) are not mistaken for scrolling.