Add titlecolor in rcParams (#14707)

OriolAbril · timhoffm · commit f529ceda9caa · 2019-07-19T11:47:00.000+02:00
* make ax.set_title use axes.labelcolor

* Add axes.titlecolor to rcParams

* Update docs

* Add axes title to style_sheets_reference

* Update matplotlibrc.template

* Add changes to what's new

* rename what's new file

* Add test

* Add auto behaviour in rctemplate comment
diff --git a/doc/users/next_whats_new/2019-03-29-rcparam-axes-titlelocation.rst b/doc/users/next_whats_new/2019-03-29-rcparam-axes-titlelocation.rst
diff --git a/doc/users/next_whats_new/rcparam-axes-title-location-color.rst b/doc/users/next_whats_new/rcparam-axes-title-location-color.rst
@@ -0,0 +1,9 @@
+rcParams for default axes title location and color
+--------------------------------------------------
+
+Two new rcParams have been added: ``axes.titlelocation`` denotes the default axes title
+alignment, and ``axes.titlecolor`` the default axes title color.
+
+Valid values for ``axes.titlelocation`` are: left, center, and right.
+Valid values for ``axes.titlecolor`` are: auto or a color. Setting it to auto
+will fall back to previous behaviour, which is using the color in ``text.color``.
diff --git a/examples/style_sheets/style_sheets_reference.py b/examples/style_sheets/style_sheets_reference.py
@@ -23,6 +23,7 @@ def plot_scatter(ax, prng, nb_samples=100):
         x, y = prng.normal(loc=mu, scale=sigma, size=(2, nb_samples))
         ax.plot(x, y, ls='none', marker=marker)
     ax.set_xlabel('X-label')
+    ax.set_title('Axes title')
     return ax
 
 
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -164,6 +164,7 @@ def set_title(self, label, fontdict=None, loc=None, pad=None,
 
                {'fontsize': rcParams['axes.titlesize'],
                 'fontweight' : rcParams['axes.titleweight'],
+                'color' : rcParams['axes.titlecolor'],
                 'verticalalignment': 'baseline',
                 'horizontalalignment': loc}
 
@@ -199,6 +200,9 @@ def set_title(self, label, fontdict=None, loc=None, pad=None,
             'fontweight': rcParams['axes.titleweight'],
             'verticalalignment': 'baseline',
             'horizontalalignment': loc.lower()}
+        titlecolor = rcParams['axes.titlecolor']
+        if not cbook._str_lower_equal(titlecolor, 'auto'):
+            default["color"] = titlecolor
         if pad is None:
             pad = rcParams['axes.titlepad']
         self._set_title_offset_trans(float(pad))
diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
@@ -1132,6 +1132,7 @@ def _validate_linestyle(ls):
                                                             # axes title
     'axes.titlelocation':    ['center', validate_axes_titlelocation],  # alignment of axes title
     'axes.titleweight':      ['normal', validate_string],  # font weight of axes title
+    'axes.titlecolor':       ['auto', validate_color_or_auto],  # font color of axes title
     'axes.titlepad':         [6.0, validate_float],  # pad from axes top to title in points
     'axes.grid':             [False, validate_bool],   # display grid or not
     'axes.grid.which':       ['major', validate_axis_locator],  # set whether the gid are by
diff --git a/lib/matplotlib/tests/test_rcparams.py b/lib/matplotlib/tests/test_rcparams.py
@@ -179,6 +179,13 @@ def test_mec_rcparams():
     assert ln.get_markeredgecolor() == 'r'
 
 
+def test_axes_titlecolor_rcparams():
+    mpl.rcParams['axes.titlecolor'] = 'r'
+    _, ax = plt.subplots()
+    title = ax.set_title("Title")
+    assert title.get_color() == 'r'
+
+
 def test_Issue_1713(tmpdir):
     rcpath = Path(tmpdir) / 'test_rcparams.rc'
     rcpath.write_text('timezone: UTC', encoding='UTF-32-BE')
diff --git a/matplotlibrc.template b/matplotlibrc.template
@@ -358,6 +358,8 @@
 #axes.titlelocation : center  ## alignment of the title: {left, right, center}
 #axes.titlesize     : large   ## fontsize of the axes title
 #axes.titleweight   : normal  ## font weight of title
+#axes.titlecolor    : auto    ## color of the axes title, auto falls back to text.color
+                              ## as default value
 #axes.titlepad      : 6.0     ## pad between axes and title in points
 #axes.labelsize     : medium  ## fontsize of the x any y labels
 #axes.labelpad      : 4.0     ## space between label and axis
