Fix categorical labels

holoviews/plotting/bokeh/element.py

@@ -4,17 +4,23 @@
 import numpy as np
 import bokeh
 import bokeh.plotting
+from holoviews.plotting.bokeh.util import bokeh_version
 from bokeh.core.properties import value
 from bokeh.models import (HoverTool, Renderer, Range1d, DataRange1d, Title,
                           FactorRange, FuncTickFormatter, Tool, Legend)
 from bokeh.models.tickers import Ticker, BasicTicker, FixedTicker, LogTicker
 from bokeh.models.widgets import Panel, Tabs
 from bokeh.models.mappers import LinearColorMapper
+from bokeh.models import CategoricalAxis
 try:
     from bokeh.models import ColorBar
     from bokeh.models.mappers import LogColorMapper, CategoricalColorMapper
 except ImportError:
     LogColorMapper, ColorBar = None, None
+if bokeh_version <= '0.13.0':
+    built_in_themes = {}
+else:
+    from bokeh.themes import built_in_themes
 from bokeh.plotting.helpers import _known_tools as known_tools
 
 from ...core import DynamicMap, CompositeOverlay, Element, Dimension
@@ -389,7 +395,12 @@ def _axis_properties(self, axis, key, plot, dimension=None,
         Returns a dictionary of axis properties depending
         on the specified axis.
         """
-        axis_props = {}
+        try:
+            axis_props = (built_in_themes[self.renderer.theme]
+                          ._json['attrs'].get('Axis', {}))
+        except KeyError:
+            axis_props = {}
+
         if ((axis == 'x' and self.xaxis in ['bottom-bare', 'top-bare']) or
             (axis == 'y' and self.yaxis in ['left-bare', 'right-bare'])):
             axis_props['axis_label_text_font_size'] = value('0pt')
@@ -434,6 +445,20 @@ def _axis_properties(self, axis, key, plot, dimension=None,
                 if jsfunc:
                     formatter = FuncTickFormatter(code=jsfunc)
                     axis_props['formatter'] = formatter
+
+        if axis == 'x':
+            xaxis = plot.xaxis[0]
+            if isinstance(xaxis, CategoricalAxis):
+                # can't just dump this with the rest of axis_props
+                # always complains about LinearAxis does not have
+                # 'group_...' attribute
+                group_label_props = {}
+                for key in list(axis_props):
+                    if key.startswith('major_label'):
+                        new_key = key.replace('major_label', 'group')
+                        group_label_props[new_key] = axis_props[key]
+                xaxis.update(**group_label_props)
+
         return axis_props
 
 
@@ -491,6 +516,7 @@ def _update_ranges(self, element, ranges):
         xfactors, yfactors = None, None
         if any(isinstance(ax_range, FactorRange) for ax_range in [x_range, y_range]):
             xfactors, yfactors = self._get_factors(element)
+
         framewise = self.framewise
         streaming = (self.streaming and any(stream._triggering for stream in self.streaming))
         xupdate = ((not self.model_changed(x_range) and (framewise or streaming))