API: convert string fontsize to points immediately

tacaswell · tacaswell · commit dbf9c627432d · 2016-08-29T23:35:59.000-04:00
This bakes into the text artist (via the FontProperties) the default
fontsize at the time of creation.
diff --git a/lib/matplotlib/font_manager.py b/lib/matplotlib/font_manager.py
@@ -909,7 +909,10 @@ def set_size(self, size):
         try:
             size = float(size)
         except ValueError:
-            if size is not None and size not in font_scalings:
+            try:
+                scale = font_scalings[size]
+                size = scale * FontManager.get_default_size()
+            except KeyError:
                 raise ValueError(
                     "Size is invalid. Valid font size are " + ", ".join(
                         str(i) for i in font_scalings.keys()))
@@ -941,7 +944,8 @@ def set_fontconfig_pattern(self, pattern):
 
     def copy(self):
         """Return a deep copy of self"""
-        return FontProperties(_init = self)
+        return FontProperties(_init=self)
+
 
 def ttfdict_to_fnames(d):
     """
diff --git a/lib/matplotlib/tests/test_text.py b/lib/matplotlib/tests/test_text.py
@@ -393,3 +393,15 @@ def test_text_stale():
     assert not ax1.stale
     assert not ax2.stale
     assert not fig.stale
+
+
+@cleanup
+def test_text_size_binding():
+    from matplotlib.font_manager import FontProperties
+
+    matplotlib.rcParams['font.size'] = 10
+    fp = FontProperties(size='large')
+    sz1 = fp.get_size_in_points()
+    matplotlib.rcParams['font.size'] = 100
+
+    assert sz1 == fp.get_size_in_points()
