Merge pull request #4895 from zblz/texmanager-preamble

WeatherGod · WeatherGod · commit 3f758abfa1ac · 2015-08-12T15:00:02.000-04:00
Add latex preamble to texmanager _fontconfig
diff --git a/lib/matplotlib/tests/test_texmanager.py b/lib/matplotlib/tests/test_texmanager.py
@@ -0,0 +1,21 @@
+from __future__ import (absolute_import, division, print_function,
+                        unicode_literals)
+
+import matplotlib.pyplot as plt
+from matplotlib.texmanager import TexManager
+
+
+def test_fontconfig_preamble():
+    """
+    Test that the preamble is included in _fontconfig
+    """
+    plt.rcParams['text.usetex'] = True
+
+    tm1 = TexManager()
+    font_config1 = tm1.get_font_config()
+
+    plt.rcParams['text.latex.preamble'] = [r'\usepackage{txfonts}']
+    tm2 = TexManager()
+    font_config2 = tm2.get_font_config()
+
+    assert font_config1 != font_config2
diff --git a/lib/matplotlib/texmanager.py b/lib/matplotlib/texmanager.py
@@ -203,6 +203,11 @@ def __init__(self):
                                    'default.' % ff, 'helpful')
                 setattr(self, font_family_attr, self.font_info[font_family])
             fontconfig.append(getattr(self, font_family_attr)[0])
+        # Add a hash of the latex preamble to self._fontconfig so that the
+        # correct png is selected for strings rendered with same font and dpi
+        # even if the latex preamble changes within the session
+        preamble_bytes = six.text_type(self.get_custom_preamble()).encode('utf-8')
+        fontconfig.append(md5(preamble_bytes).hexdigest())
         self._fontconfig = ''.join(fontconfig)
 
         # The following packages and commands need to be included in the latex
