matplotlib · iccir · Jul 31, 2026 · Jul 31, 2026 · Jul 31, 2026 · Jul 31, 2026
diff --git a/.clang-tidy b/.clang-tidy
@@ -26,6 +26,7 @@ Checks: >
   -bugprone-throwing-static-initialization,
   -clang-analyzer-optin.cplusplus.UninitializedObject,
   -clang-analyzer-optin.performance.Padding,
+  -clang-analyzer-optin.osx.cocoa.localizability.NonLocalizedStringChecker
 
 # Only report findings in matplotlib's own src/ headers, not in pybind11,
 # Python.h, agg, or other vendored includes.

diff --git a/.github/labeler.yml b/.github/labeler.yml
@@ -47,8 +47,9 @@
 "GUI: MacOSX":
   - changed-files:
       - any-glob-to-any-file:
-          - 'lib/matplotlib/backends/*_macosx.py*'
-          - 'src/_macosx.m'
+          - 'lib/matplotlib/backends/*backend_*mac*.py*'
+          - 'src/_legacymac.m'
+          - 'src/macos/**'
 "GUI: nbagg":
   - changed-files:
       - any-glob-to-any-file:

diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -1230,8 +1230,9 @@ def use(backend, *, force=True):
         backend names, which are case-insensitive:
 
         - interactive backends:
-          GTK3Agg, GTK3Cairo, GTK4Agg, GTK4Cairo, MacOSX, nbAgg, notebook, QtAgg,
-          QtCairo, TkAgg, TkCairo, WebAgg, WX, WXAgg, WXCairo, Qt5Agg, Qt5Cairo
+          GTK3Agg, GTK3Cairo, GTK4Agg, GTK4Cairo, macOS, MacOSX,
+          nbAgg, notebook, QtAgg, QtCairo, TkAgg, TkCairo, WebAgg, WX, WXAgg,
+          WXCairo, Qt5Agg, Qt5Cairo
 
         - non-interactive backends:
           agg, cairo, pdf, pgf, ps, svg, template

diff --git a/lib/matplotlib/backends/_backend_legacymac.py b/lib/matplotlib/backends/_backend_legacymac.py
@@ -0,0 +1,199 @@
+import os
+
+import matplotlib as mpl
+from matplotlib import _api, cbook
+from matplotlib._pylab_helpers import Gcf
+from . import _macosx
+from .backend_agg import FigureCanvasAgg
+from matplotlib.backend_bases import (
+    _Backend, FigureCanvasBase, FigureManagerBase, NavigationToolbar2,
+    CloseEvent, ResizeEvent, TimerBase, _allow_interrupt)
+
+
+class TimerLegacyMac(_macosx.Timer, TimerBase):
+    """Subclass of `.TimerBase` using CFRunLoop timer events."""
+    # completely implemented at the C-level (in _macosx.Timer)
+
+
+def _allow_interrupt_macos():
+    """A context manager that allows terminating a plot by sending a SIGINT."""
+    return _allow_interrupt(
+        lambda rsock: _macosx.wake_on_fd_write(rsock.fileno()), _macosx.stop)
+
+
+class FigureCanvasLegacyMac(FigureCanvasAgg, _macosx.FigureCanvas, FigureCanvasBase):
+    # docstring inherited
+
+    # Ideally this class would be `class FCMacAgg(FCAgg, FCMac)`
+    # (FC=FigureCanvas) where FCMac would be an ObjC-implemented mac-specific
+    # class also inheriting from FCBase (this is the approach with other GUI
+    # toolkits).  However, writing an extension type inheriting from a Python
+    # base class is slightly tricky (the extension type must be a heap type),
+    # and we can just as well lift the FCBase base up one level, keeping it *at
+    # the end* to have the right method resolution order.
+
+    # Events such as button presses, mouse movements, and key presses are
+    # handled in C and events (MouseEvent, etc.) are triggered from there.
+
+    required_interactive_framework = "macosx"
+    _timer_cls = TimerLegacyMac
+    manager_class = _api.classproperty(lambda cls: FigureManagerLegacyMac)
+
+    def __init__(self, figure):
+        super().__init__(figure=figure)
+        self._draw_pending = False
+        self._is_drawing = False
+        # Keep track of the timers that are alive
+        self._timers = set()
+
+    def draw(self):
+        """Render the figure and update the macosx canvas."""
+        # The renderer draw is done here; delaying causes problems with code
+        # that uses the result of the draw() to update plot elements.
+        if self._is_drawing:
+            return
+        with cbook._setattr_cm(self, _is_drawing=True):
+            super().draw()
+        self.update()
+
+    def draw_idle(self):
+        # docstring inherited
+        if not (getattr(self, '_draw_pending', False) or
+                getattr(self, '_is_drawing', False)):
+            self._draw_pending = True
+            # Add a singleshot timer to the eventloop that will call back
+            # into the Python method _draw_idle to take care of the draw
+            self._single_shot_timer(self._draw_idle)
+
+    def _single_shot_timer(self, callback):
+        """Add a single shot timer with the given callback"""
+        def callback_func(callback, timer):
+            callback()
+            self._timers.remove(timer)
+        timer = self.new_timer(interval=0)
+        timer.single_shot = True
+        timer.add_callback(callback_func, callback, timer)
+        self._timers.add(timer)
+        timer.start()
+
+    def _draw_idle(self):
+        """
+        Draw method for singleshot timer
+
+        This draw method can be added to a singleshot timer, which can
+        accumulate draws while the eventloop is spinning. This method will
+        then only draw the first time and short-circuit the others.
+        """
+        with self._idle_draw_cntx():
+            if not self._draw_pending:
+                # Short-circuit because our draw request has already been
+                # taken care of
+                return
+            self._draw_pending = False
+            self.draw()
+
+    def blit(self, bbox=None):
+        # docstring inherited
+        super().blit(bbox)
+        self.update()
+
+    def resize(self, width, height):
+        # Size from macOS is logical pixels, dpi is physical.
+        scale = self.figure.dpi / self.device_pixel_ratio
+        width /= scale
+        height /= scale
+        self.figure.set_size_inches(width, height, forward=False)
+        ResizeEvent("resize_event", self)._process()
+        self.draw_idle()
+
+    def start_event_loop(self, timeout=0):
+        # docstring inherited
+        # Set up a SIGINT handler to allow terminating a plot via CTRL-C.
+        with _allow_interrupt_macos():
+            self._start_event_loop(timeout=timeout)  # Forward to ObjC implementation.
+
+
+class NavigationToolbar2LegacyMac(_macosx.NavigationToolbar2, NavigationToolbar2):
+
+    def __init__(self, canvas):
+        data_path = cbook._get_data_path('images')
+        _, tooltips, image_names, _ = zip(*NavigationToolbar2.toolitems)
+        _macosx.NavigationToolbar2.__init__(
+            self, canvas,
+            tuple(str(data_path / image_name) + ".pdf"
+                  for image_name in image_names if image_name is not None),
+            tuple(tooltip for tooltip in tooltips if tooltip is not None))
+        NavigationToolbar2.__init__(self, canvas)
+
+    def draw_rubberband(self, event, x0, y0, x1, y1):
+        self.canvas.set_rubberband(int(x0), int(y0), int(x1), int(y1))
+
+    def remove_rubberband(self):
+        self.canvas.remove_rubberband()
+
+    def save_figure(self, *args):
+        directory = os.path.expanduser(mpl.rcParams['savefig.directory'])
+        filename = _macosx.choose_save_file('Save the figure',
+                                            directory,
+                                            self.canvas.get_default_filename())
+        if filename is None:  # Cancel
+            return
+        # Save dir for next time, unless empty str (which means use cwd).
+        if mpl.rcParams['savefig.directory']:
+            mpl.rcParams['savefig.directory'] = os.path.dirname(filename)
+        self.canvas.figure.savefig(filename)
+        return filename
+
+
+class FigureManagerLegacyMac(_macosx.FigureManager, FigureManagerBase):
+    _toolbar2_class = NavigationToolbar2LegacyMac
+
+    def __init__(self, canvas, num):
+        self._shown = False
+        _macosx.FigureManager.__init__(self, canvas)
+        icon_path = str(cbook._get_data_path('images/matplotlib.pdf'))
+        _macosx.FigureManager.set_icon(icon_path)
+        FigureManagerBase.__init__(self, canvas, num)
+        self._set_window_mode(mpl.rcParams["macosx.window_mode"])
+        if self.toolbar is not None:
+            self.toolbar.update()
+        if mpl.is_interactive():
+            self.show()
+            self.canvas.draw_idle()
+
+    def _handle_window_will_close(self):
+        CloseEvent("close_event", self.canvas)._process()
+
+    def _handle_window_should_close(self):
+        Gcf.destroy(self)
+        self.canvas.flush_events()
+
+    def destroy(self):
+        # We need to clear any pending timers that never fired, otherwise
+        # we get a memory leak from the timer callbacks holding a reference
+        while self.canvas._timers:
+            timer = self.canvas._timers.pop()
+            timer.stop()
+        super().destroy()
+
+    @classmethod
+    def start_main_loop(cls):
+        # Set up a SIGINT handler to allow terminating a plot via CTRL-C.
+        with _allow_interrupt_macos():
+            _macosx.show()
+
+    def show(self):
+        if self.canvas.figure.stale:
+            self.canvas.draw_idle()
+        if not self._shown:
+            self._show()
+            self._shown = True
+        if mpl.rcParams["figure.raise_window"]:
+            self._raise()
+
+
+@_Backend.export
+class _BackendLegacyMac(_Backend):
+    FigureCanvas = FigureCanvasLegacyMac
+    FigureManager = FigureManagerLegacyMac
+    mainloop = FigureManagerLegacyMac.start_main_loop