FIX: check if formatters changed

jklymak · jklymak · commit 2c13f9f5d805 · 2018-11-29T14:20:57.000-08:00
diff --git a/lib/matplotlib/dates.py b/lib/matplotlib/dates.py
@@ -826,6 +826,10 @@ def __init__(self, locator, tz=None, formats=None, offset_formats=None,
         self._tz = tz
         self._oldticks = np.array([])
         self._oldlabels = None
+        self._old_formats = [''*6]
+        self._old_zero_formats = [''*6]
+        self._old_offset_formats = [''*6]
+
         self.defaultfmt = '%Y'
         # there are 6 levels with each level getting a specific format
         # 0: mostly years,  1: months,  2: days,
@@ -876,15 +880,27 @@ def __init__(self, locator, tz=None, formats=None, offset_formats=None,
         self._formatter = DateFormatter(self.defaultfmt, self._tz)
         self.show_offset = show_offset
 
+    def _anything_changed(self, ticks):
+        """ This tests if we need to reformat the ticks..."""
+        changed = False
+        if (not np.array_equal(ticks, self._oldticks) or
+                (self.formats != self._old_formats) or
+                (self.zero_formats != self._old_zero_formats) or
+                (self.offset_formats != self._old_offset_formats)):
+            changed = True
+        self._old_zero_formats = self.zero_formats.copy()
+        self._old_offset_formats = self.offset_formats.copy()
+        self._old_formats = self.formats.copy()
+        return changed
+
     def __call__(self, x, pos=None):
         if hasattr(self._locator, '_get_unit'):
             locator_unit_scale = float(self._locator._get_unit())
         else:
             locator_unit_scale = 1.0
         ticks = self._locator()
         if pos is not None:
-            if not np.array_equal(ticks, self._oldticks):
-
+            if self._anything_changed(ticks):
                 offset_fmt = ''
                 fmt = self.defaultfmt
                 self._formatter = DateFormatter(fmt, self._tz)
diff --git a/lib/matplotlib/tests/test_dates.py b/lib/matplotlib/tests/test_dates.py
@@ -547,16 +547,34 @@ def _create_auto_date_locator(date1, date2):
                [datetime.timedelta(seconds=40),
                 ['00:00', '05', '10', '15', '20', '25', '30', '35', '40']
                 ],
-               [datetime.timedelta(seconds=2),
-                ['59.5', '00:00', '00.5', '01.0', '01.5', '02.0', '02.5']
-                ],
                )
     for t_delta, expected in results:
         d2 = d1 + t_delta
         strings = _create_auto_date_locator(d1, d2)
         assert strings == expected
 
 
+def test_concise_formatter_change_format():
+    fig, ax = plt.subplots()
+
+    locator = mdates.AutoDateLocator(interval_multiples=True)
+    formatter = mdates.ConciseDateFormatter(locator)
+    d1 = datetime.datetime(1997, 1, 1)
+    d2 = d1 + datetime.timedelta(weeks=52 * 200)
+
+    ax.yaxis.set_major_locator(locator)
+    ax.yaxis.set_major_formatter(formatter)
+    ax.set_ylim(d1, d2)
+    fig.canvas.draw()
+    formatter.formats[0] = '%y'
+    ax.set_ylim(d1, d2)
+    fig.canvas.draw()
+    sts = []
+    for st in ax.get_yticklabels():
+        sts += [st.get_text()]
+    assert sts == ['80', '00', '20', '40', '60', '80',
+                   '00', '20', '40', '60', '80', '00']
+
 @image_comparison(baseline_images=['date_inverted_limit'],
                   extensions=['png'])
 def test_date_inverted_limit():
