Update formatter with Locator in dates.py

ImportanceOfBeingErnest · ImportanceOfBeingErnest · commit c62ea1327c20 · 2018-10-15T17:58:07.000+02:00
diff --git a/lib/matplotlib/axis.py b/lib/matplotlib/axis.py
@@ -1567,6 +1567,8 @@ def set_minor_formatter(self, formatter):
                             "matplotlib.ticker.Formatter")
         self.isDefault_minfmt = False
         self.minor.formatter = formatter
+        if hasattr(self.minor.formatter, "_ismajor"):
+            self.minor.formatter._ismajor = False
         formatter.set_axis(self)
         self.stale = True
 
@@ -1583,9 +1585,6 @@ def set_major_locator(self, locator):
                             "matplotlib.ticker.Locator")
         self.isDefault_majloc = False
         self.major.locator = locator
-        if (hasattr(self.get_major_formatter(), "_locator") and
-            hasattr(self.get_major_formatter(), "_tz")):
-            self.get_major_formatter()._locator = locator
         locator.set_axis(self)
         self.stale = True
 
@@ -1602,9 +1601,6 @@ def set_minor_locator(self, locator):
                             "matplotlib.ticker.Locator")
         self.isDefault_minloc = False
         self.minor.locator = locator
-        if (hasattr(self.get_minor_formatter(), "_locator") and
-            hasattr(self.get_minor_formatter(), "_tz")):
-            self.get_minor_formatter()._locator = locator
         locator.set_axis(self)
         self.stale = True
 
diff --git a/lib/matplotlib/dates.py b/lib/matplotlib/dates.py
@@ -806,6 +806,7 @@ def __init__(self, locator, tz=None, defaultfmt='%Y-%m-%d'):
         returned by ``locator._get_unit()``.
         """
         self._locator = locator
+        self._ismajor = True
         self._tz = tz
         self.defaultfmt = defaultfmt
         self._formatter = DateFormatter(self.defaultfmt, tz)
@@ -821,7 +822,16 @@ def __init__(self, locator, tz=None, defaultfmt='%Y-%m-%d'):
                            rcParams['date.autoformatter.microsecond']}
 
     def __call__(self, x, pos=None):
-        locator_unit_scale = float(self._locator._get_unit())
+        # Check if locator is still the one from the axis to format
+        if hasattr(self.axis, "get_major_locator"):
+            pot_locator = self.axis.get_major_locator() if self._ismajor \
+                          else self.axis.get_minor_locator()
+            if self._locator is not pot_locator:
+                self._locator = pot_locator
+        try:
+            locator_unit_scale = float(self._locator._get_unit())
+        except AttributeError:
+            locator_unit_scale = 1
         # Pick the first scale which is greater than the locator unit.
         fmt = next((fmt for scale, fmt in sorted(self.scaled.items())
                     if scale >= locator_unit_scale),
diff --git a/lib/matplotlib/tests/test_dates.py b/lib/matplotlib/tests/test_dates.py
@@ -11,6 +11,7 @@
 import matplotlib.pyplot as plt
 from matplotlib.cbook import MatplotlibDeprecationWarning
 import matplotlib.dates as mdates
+import matplotlib.ticker as mticker
 
 
 def __has_pytz():
@@ -222,7 +223,7 @@ def test_DateFormatter():
 
 def test_locator_set_formatter():
     """
-    Test if setting the locator only will update the formatter to use
+    Test if setting the locator only will update the AutoDateFormatter to use
     the new locator.
     """
     plt.rcParams["date.autoformatter.minute"] = "%d %H:%M"
@@ -240,6 +241,17 @@ def test_locator_set_formatter():
                 '30 09:30', '30 10:00', '30 10:30']
     assert ticklabels == expected
 
+    ax.xaxis.set_major_locator(mticker.NullLocator())
+    ax.xaxis.set_minor_locator(mdates.MinuteLocator((5, 55)))
+    decoy_loc = mdates.MinuteLocator((12, 27))
+    ax.xaxis.set_minor_formatter(mdates.AutoDateFormatter(decoy_loc))
+
+    ax.xaxis.set_minor_locator(mdates.MinuteLocator((15, 45)))
+    fig.canvas.draw()
+    ticklabels = [tl.get_text() for tl in ax.get_xticklabels(which="minor")]
+    expected = ['30 08:15', '30 08:45', '30 09:15', '30 09:45', '30 10:15']
+    assert ticklabels == expected
+
 
 def test_date_formatter_strftime():
     """
