Emit xlim_changed / ylim_changed when limits expand via set_xticks / set_yticks (#31251)

Chirag3841 · web-flow · commit 02b42db27784 · 2026-03-17T11:41:53.000+01:00
* Emit xlim/ylim_changed when limits expand via set_xticks/set_yticks

* error fix

* changes done

* polar error fix

* changes fixed

* set axis name to avoid polar issue

* initial commit

* stopping reapplying limits

* error fixing

* back to basic

* set auto as none

* pushing previous implementation

* rerun CI

* remove none fallback

* use get_view_interval()

* add guard

* push commit

* callback

* callback corrected

* test file update

* test file updated

* re run ci

* tuple added

* revert changes

* trigger ci
diff --git a/lib/matplotlib/axis.py b/lib/matplotlib/axis.py
@@ -2202,9 +2202,16 @@ def _set_tick_locations(self, ticks, *, minor=False):
         ticks = self.convert_units(ticks)
         locator = mticker.FixedLocator(ticks)  # validate ticks early.
         if len(ticks):
+            old_vmin, old_vmax = self.get_view_interval()
             for axis in self._get_shared_axis():
                 # set_view_interval maintains any preexisting inversion.
                 axis.set_view_interval(min(ticks), max(ticks))
+            new_vmin, new_vmax = self.get_view_interval()
+            if old_vmin != new_vmin or old_vmax != new_vmax:
+                self.axes.callbacks.process(
+                    f"{self._get_axis_name()}lim_changed",
+                    self.axes,
+                )
         self.axes.stale = True
         if minor:
             self.set_minor_locator(locator)
diff --git a/lib/matplotlib/tests/test_axis.py b/lib/matplotlib/tests/test_axis.py
@@ -111,3 +111,20 @@ def test_grid_rcparams():
     assert ax.xaxis.get_minor_ticks()[0].gridline.get_linestyle() == def_linestyle
     assert ax.xaxis.get_major_ticks()[0].gridline.get_alpha() == def_alpha
     assert ax.xaxis.get_minor_ticks()[0].gridline.get_alpha() == 0.6
+
+
+def test_set_ticks_emits_lim_changed():
+    fig, ax1 = plt.subplots()
+    ax1.set_xlim(0.5, 1)
+    called_cartesian = []
+    ax1.callbacks.connect("xlim_changed", called_cartesian.append)
+    ax1.set_xticks([0, 100])
+    assert called_cartesian
+
+    fig = plt.figure()
+    ax2 = fig.add_subplot(projection="polar")
+    ax2.set_ylim(0.5, 1)
+    called_polar = []
+    ax2.callbacks.connect("ylim_changed", called_polar.append)
+    ax2.set_rticks([1, 2, 3])
+    assert called_polar
