Emit xlim_changed on shared axes.

anntzer · anntzer · commit 231c502d1e37 · 2023-06-01T16:23:18.000+02:00
diff --git a/lib/matplotlib/axis.py b/lib/matplotlib/axis.py
@@ -32,6 +32,8 @@
 _gridline_param_names = ['grid_' + name
                          for name in _line_param_names + _line_param_aliases]
 
+_NoRecursionMarker = object()
+
 
 class Tick(martist.Artist):
     """
@@ -1225,15 +1227,19 @@ def _set_lim(self, v0, v1, *, emit=True, auto):
         if auto is not None:
             self._set_autoscale_on(bool(auto))
 
+        # Undocumented internal feature: setting emit to _NoRecursionMarker causes
+        # signal emission but doesn't propagate to shared axed (thus preventing
+        # infinite recursion).
         if emit:
             self.axes.callbacks.process(f"{name}lim_changed", self.axes)
-            # Call all of the other axes that are shared with this one
-            for other in self._get_shared_axes():
-                if other is not self.axes:
-                    other._axis_map[name]._set_lim(
-                        v0, v1, emit=False, auto=auto)
-                    if other.figure != self.figure:
-                        other.figure.canvas.draw_idle()
+            if emit != _NoRecursionMarker:
+                # Call all of the other axes that are shared with this one
+                for other in self._get_shared_axes():
+                    if other is not self.axes:
+                        other._axis_map[name]._set_lim(
+                            v0, v1, emit=_NoRecursionMarker, auto=auto)
+                        if other.figure != self.figure:
+                            other.figure.canvas.draw_idle()
 
         self.stale = True
         return v0, v1
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -8704,3 +8704,12 @@ def test_tick_param_labelfont():
     plt.title('Title in sans-serif')
     for text in ax.get_xticklabels():
         assert text.get_fontfamily()[0] == 'monospace'
+
+
+def test_xylim_changed_shared():
+    fig, axs = plt.subplots(2, sharex=True, sharey=True)
+    events = []
+    axs[1].callbacks.connect("xlim_changed", events.append)
+    axs[1].callbacks.connect("ylim_changed", events.append)
+    axs[0].set(xlim=[1, 3], ylim=[2, 4])
+    assert events == [axs[1], axs[1]]
