matplotlib · ksunden · Jul 21, 2023 · Jun 4, 2023 · Jul 21, 2023
diff --git a/doc/users/next_whats_new/macosx_windows_tabs.rst b/doc/users/next_whats_new/macosx_windows_tabs.rst
@@ -0,0 +1,7 @@
+macosx: New figures can be opened in either windows or tabs
+-----------------------------------------------------------
+
+There is a new :rc:`macosx.window_mode`` rcParam to control how
+new figures are opened with the macosx backend. The default is
+**system** which uses the system settings, or one can specify either
+**tab** or **window** to explicitly choose the mode used to open new figures.
diff --git a/lib/matplotlib/backends/backend_macosx.py b/lib/matplotlib/backends/backend_macosx.py
@@ -145,6 +145,7 @@ def __init__(self, canvas, num):
         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.get("macosx.window_mode", "system"))
         if self.toolbar is not None:
             self.toolbar.update()
         if mpl.is_interactive():

diff --git a/lib/matplotlib/mpl-data/matplotlibrc b/lib/matplotlib/mpl-data/matplotlibrc
@@ -701,6 +701,10 @@
                                 # background by default
 #savefig.orientation: portrait  # orientation of saved figure, for PostScript output only
 
+### macosx backend params
+#macosx.window_mode : system   # How to open new figures (system, tab, window)
+                               # system uses the MacOS system preferences
+
 ### tk backend params
 #tk.window_focus:   False  # Maintain shell focus for TkAgg
 

diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
@@ -1214,6 +1214,7 @@ def _convert_validator_spec(key, conv):
     "figure.autolayout":       validate_bool,
     "figure.max_open_warning": validate_int,
     "figure.raise_window":     validate_bool,
+    "macosx.window_mode":      ["system", "tab", "window"],
 
     "figure.subplot.left":   validate_float,
     "figure.subplot.right":  validate_float,

diff --git a/src/_macosx.m b/src/_macosx.m
@@ -689,6 +689,25 @@ int mpl_check_modifier(
     return 0;
 }
 
+static PyObject*
+FigureManager__set_window_mode(FigureManager* self, PyObject* args)
+{
+    const char* window_mode;
+    if (!PyArg_ParseTuple(args, "s", &window_mode) || !self->window) {
+        return NULL;
+    }
+
+    NSString* window_mode_str = [NSString stringWithUTF8String: window_mode];
+    if ([window_mode_str isEqualToString: @"tab"]) {
+        [self->window setTabbingMode: NSWindowTabbingModePreferred];
+    } else if ([window_mode_str isEqualToString: @"window"]) {
+        [self->window setTabbingMode: NSWindowTabbingModeDisallowed];
+    } else { // system settings
+        [self->window setTabbingMode: NSWindowTabbingModeAutomatic];
+    }
+    Py_RETURN_NONE;
+}
+
 static PyObject*
 FigureManager_repr(FigureManager* self)
 {
@@ -832,6 +851,10 @@ int mpl_check_modifier(
         {"destroy",
          (PyCFunction)FigureManager_destroy,
          METH_NOARGS},
+        {"_set_window_mode",
+         (PyCFunction)FigureManager__set_window_mode,
+         METH_VARARGS,
+         "Set the window open mode (auto, tab, window)"},
         {"set_icon",
          (PyCFunction)FigureManager_set_icon,
          METH_STATIC | METH_VARARGS,