Better validate tick direction.

- Validate rcParams["{x,y}tick.direction"].
- Move common validation and application to base Tick.apply_tickdir
  class.  Note that previously YTick.apply_tickdir failed to
  _check_in_list the tickdir value.

Author: anntzer

lib/matplotlib/axis.py

@@ -210,7 +210,14 @@ def _set_labelrotation(self, labelrotation):
         self._labelrotation = (mode, angle)
 
     def apply_tickdir(self, tickdir):
-        """Calculate ``self._pad`` and ``self._tickmarkers``."""
+        """Set tick direction.  Valid values are 'out', 'in', 'inout'."""
+        if tickdir is None:
+            tickdir = mpl.rcParams[f'{self.__name__}.direction']
+        _api.check_in_list(['in', 'out', 'inout'], tickdir=tickdir)
+        self._tickdir = tickdir
+        self._pad = self._base_pad + self.get_tick_padding()
+        self.stale = True
+        # Subclass overrides should compute _tickmarkers as appropriate here.
 
     def get_tickdir(self):
         return self._tickdir
@@ -445,19 +452,13 @@ def _get_text2_transform(self):
         return self.axes.get_xaxis_text2_transform(self._pad)
 
     def apply_tickdir(self, tickdir):
-        """Set tick direction. Valid values are 'in', 'out', 'inout'."""
-        if tickdir is None:
-            tickdir = mpl.rcParams[f'{self.__name__}.direction']
-        _api.check_in_list(['in', 'out', 'inout'], tickdir=tickdir)
-        self._tickdir = tickdir
-
-        if self._tickdir == 'in':
-            self._tickmarkers = (mlines.TICKUP, mlines.TICKDOWN)
-        elif self._tickdir == 'inout':
-            self._tickmarkers = ('|', '|')
-        else:
-            self._tickmarkers = (mlines.TICKDOWN, mlines.TICKUP)
-        self._pad = self._base_pad + self.get_tick_padding()
+        # docstring inherited
+        super().apply_tickdir(tickdir)
+        self._tickmarkers = {
+            'out': (mlines.TICKDOWN, mlines.TICKUP),
+            'in': (mlines.TICKUP, mlines.TICKDOWN),
+            'inout': ('|', '|'),
+        }[self._tickdir]
         self.stale = True
 
     def update_position(self, loc):
@@ -518,17 +519,13 @@ def _get_text2_transform(self):
         return self.axes.get_yaxis_text2_transform(self._pad)
 
     def apply_tickdir(self, tickdir):
-        if tickdir is None:
-            tickdir = mpl.rcParams[f'{self.__name__}.direction']
-        self._tickdir = tickdir
-
-        if self._tickdir == 'in':
-            self._tickmarkers = (mlines.TICKRIGHT, mlines.TICKLEFT)
-        elif self._tickdir == 'inout':
-            self._tickmarkers = ('_', '_')
-        else:
-            self._tickmarkers = (mlines.TICKLEFT, mlines.TICKRIGHT)
-        self._pad = self._base_pad + self.get_tick_padding()
+        # docstring inherited
+        super().apply_tickdir(tickdir)
+        self._tickmarkers = {
+            'out': (mlines.TICKLEFT, mlines.TICKRIGHT),
+            'in': (mlines.TICKRIGHT, mlines.TICKLEFT),
+            'inout': ('_', '_'),
+        }[self._tickdir]
         self.stale = True
 
     def update_position(self, loc):

lib/matplotlib/rcsetup.py

@@ -1280,15 +1280,14 @@ def _convert_validator_spec(key, conv):
     "xtick.major.pad":     validate_float,     # distance to label in points
     "xtick.minor.pad":     validate_float,     # distance to label in points
     "xtick.color":         validate_color,     # color of xticks
-    "xtick.labelcolor":    validate_color_or_inherit,
-    # color of xtick labels
+    "xtick.labelcolor":    validate_color_or_inherit,  # color of xtick labels
     "xtick.minor.visible": validate_bool,      # visibility of minor xticks
     "xtick.minor.top":     validate_bool,      # draw top minor xticks
     "xtick.minor.bottom":  validate_bool,      # draw bottom minor xticks
     "xtick.major.top":     validate_bool,      # draw top major xticks
     "xtick.major.bottom":  validate_bool,      # draw bottom major xticks
     "xtick.labelsize":     validate_fontsize,  # fontsize of xtick labels
-    "xtick.direction":     validate_string,    # direction of xticks
+    "xtick.direction":     ["out", "in", "inout"],  # direction of xticks
     "xtick.alignment":     ["center", "right", "left"],
 
     "ytick.left":          validate_bool,      # draw ticks on left side
@@ -1302,15 +1301,14 @@ def _convert_validator_spec(key, conv):
     "ytick.major.pad":     validate_float,     # distance to label in points
     "ytick.minor.pad":     validate_float,     # distance to label in points
     "ytick.color":         validate_color,     # color of yticks
-    "ytick.labelcolor":    validate_color_or_inherit,
-    # color of ytick labels
+    "ytick.labelcolor":    validate_color_or_inherit,  # color of ytick labels
     "ytick.minor.visible": validate_bool,      # visibility of minor yticks
     "ytick.minor.left":    validate_bool,      # draw left minor yticks
     "ytick.minor.right":   validate_bool,      # draw right minor yticks
     "ytick.major.left":    validate_bool,      # draw left major yticks
     "ytick.major.right":   validate_bool,      # draw right major yticks
     "ytick.labelsize":     validate_fontsize,  # fontsize of ytick labels
-    "ytick.direction":     validate_string,    # direction of yticks
+    "ytick.direction":     ["out", "in", "inout"],  # direction of yticks
     "ytick.alignment":     [
         "center", "top", "bottom", "baseline", "center_baseline"],