Major reworking; mapping has priority.

efiring · efiring · commit 8fe1b2a32d9d · 2020-12-23T15:10:23.000-10:00
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -6026,7 +6026,7 @@ def pcolormesh(self, *args, alpha=None, norm=None, cmap=None, vmin=None,
         if shading is None:
             shading = rcParams['pcolor.shading']
         shading = shading.lower()
-        kwargs.setdefault('edgecolors', 'None')
+        kwargs.setdefault('edgecolors', 'none')
 
         X, Y, C, shading = self._pcolorargs('pcolormesh', *args,
                                             shading=shading)
diff --git a/lib/matplotlib/collections.py b/lib/matplotlib/collections.py
@@ -171,8 +171,8 @@ def __init__(self,
         self._us_lw = [0]
         self._linewidths = [0]
         # Flags: do colors come from mapping an array?
-        self._face_is_mapped = True
-        self._edge_is_mapped = False
+        self._face_is_mapped = None
+        self._edge_is_mapped = None
         self._mapped_colors = None  # Calculated in update_scalarmappable
         self._hatch_color = mcolors.to_rgba(mpl.rcParams['hatch.color'])
         self.set_facecolor(facecolors)
@@ -803,7 +803,9 @@ def _get_default_edgecolor(self):
     def _set_edgecolor(self, c):
         set_hatch_color = True
         if c is None:
-            if mpl.rcParams['patch.force_edgecolor'] or self._edge_default:
+            if (mpl.rcParams['patch.force_edgecolor']
+                    or self._edge_default
+                    or cbook._str_equal(self._original_facecolor, 'none')):
                 c = self._get_default_edgecolor()
             else:
                 c = 'none'
@@ -874,39 +876,20 @@ def _set_mappable_flags(self):
         """
         edge0 = self._edge_is_mapped
         face0 = self._face_is_mapped
-        if self._A is None:
-            self._edge_is_mapped = False
-            self._face_is_mapped = False
-        else:
-            # Typical mapping: faces, not edges.
-            self._face_is_mapped = True
-            self._edge_is_mapped = False
-
-            # Prepare color strings to check for special cases.
-            fc = self._original_facecolor
-            if fc is None:
-                fc = self._get_default_facecolor()
-            if not isinstance(fc, str):
-                fc = 'array'
-            ec = self._original_edgecolor
-            if ec is None:
-                if mpl.rcParams['patch.force_edgecolor'] or self._edge_default:
-                    ec = self._get_default_edgecolor()
-                else:
-                    ec = 'none'
-            if not isinstance(ec, str):
-                ec = 'array'
-
-            # Handle special cases.
-            if fc == 'none':
-                self._face_is_mapped = False
-                self._edge_is_mapped = True
-            elif ec == 'face':
-                self._edge_is_mapped = True
+        self._edge_is_mapped = False
+        self._face_is_mapped = False
+        if self._A is not None:
+            if not cbook._str_equal(self._original_facecolor, 'none'):
                 self._face_is_mapped = True
+                if cbook._str_equal(self._original_edgecolor, 'face'):
+                    self._edge_is_mapped = True
+            else:
+                if self._original_edgecolor is None:
+                    self._edge_is_mapped = True
 
         mapped = self._face_is_mapped or self._edge_is_mapped
-        changed = (self._edge_is_mapped != edge0
+        changed = (edge0 is None or face0 is None
+                   or self._edge_is_mapped != edge0
                    or self._face_is_mapped != face0)
         return mapped or changed
 
@@ -1466,6 +1449,7 @@ def __init__(self, segments,  # Can be None.
                 "arguments is deprecated, and they will become keyword-only "
                 "arguments %(removal)s."
                 )
+        kwargs.setdefault('facecolors', 'none')
         super().__init__(
             zorder=zorder,
             **kwargs)
diff --git a/lib/matplotlib/tests/test_collections.py b/lib/matplotlib/tests/test_collections.py
@@ -754,49 +754,70 @@ def test_legend_inverse_size_label_relationship():
 @pytest.mark.style('default')
 @pytest.mark.parametrize('pcfunc', [plt.pcolor, plt.pcolormesh])
 def test_color_logic(pcfunc):
-    rgba_none = mcolors.to_rgba_array('none')
     z = np.arange(12).reshape(3, 4)
+    # Explicitly set an edgecolor.
     pc = pcfunc(z, edgecolors='red', facecolors='none')
+    pc.update_scalarmappable()  # This is called in draw().
+    # Define 2 reference "colors" here for multiple use.
     face_default = mcolors.to_rgba_array(pc._get_default_facecolor())
-    assert_array_equal(pc.get_edgecolor(), [[1, 0, 0, 1]])
+    mapped = pc.get_cmap()(pc.norm((z.ravel())))
+    # Github issue #1302:
+    assert mcolors.same_color(pc.get_edgecolor(), 'red')
     # Check setting attributes after initialization:
     pc = pcfunc(z)
     pc.set_facecolor('none')
     pc.set_edgecolor('red')
-    assert_array_equal(pc.get_edgecolor(), [[1, 0, 0, 1]])
+    pc.update_scalarmappable()
+    assert mcolors.same_color(pc.get_edgecolor(), [[1, 0, 0, 1]])
     pc.set_alpha(0.5)
-    assert_array_equal(pc.get_edgecolor(), [[1, 0, 0, 0.5]])
-    pc.set_edgecolor(None)  # reset to default
+    pc.update_scalarmappable()
+    assert mcolors.same_color(pc.get_edgecolor(), [[1, 0, 0, 0.5]])
     pc.set_alpha(None)  # restore default alpha
     pc.update_scalarmappable()
-    assert pc.get_edgecolor().shape == (12, 4)  # color-mapped
-    pc.set_facecolor(None)
+    assert mcolors.same_color(pc.get_edgecolor(), [[1, 0, 0, 1]])
+    # Reset edgecolor to default.
+    pc.set_edgecolor(None)
+    pc.update_scalarmappable()
+    assert mcolors.same_color(pc.get_edgecolor(), mapped)
+    pc.set_facecolor(None)  # restore default for facecolor
     pc.update_scalarmappable()
-    assert pc.get_facecolor().shape == (12, 4)  # color-mapped
-    assert_array_equal(pc.get_edgecolor(), rgba_none)  # default: 'none'
+    assert mcolors.same_color(pc.get_facecolor(), mapped)
+    assert mcolors.same_color(pc.get_edgecolor(), 'none')
     # Turn off colormapping entirely:
     pc.set_array(None)
     pc.update_scalarmappable()
-    assert_array_equal(pc.get_edgecolor(), rgba_none)
-    assert pc.get_facecolor().shape == (1, 4)  # no longer color-mapped
-    assert_array_equal(pc.get_facecolor(), face_default)
+    assert mcolors.same_color(pc.get_edgecolor(), 'none')
+    assert mcolors.same_color(pc.get_facecolor(), face_default)  # not mapped
     # Turn it back on by restoring the array (must be 1D!):
     pc.set_array(z.ravel())
     pc.update_scalarmappable()
-    assert pc.get_facecolor().shape == (12, 4)  # color-mapped
-    assert_array_equal(pc.get_edgecolor(), rgba_none)
+    assert mcolors.same_color(pc.get_facecolor(), mapped)
+    assert mcolors.same_color(pc.get_edgecolor(), 'none')
     # Give color via tuple rather than string.
     pc = pcfunc(z, edgecolors=(1, 0, 0), facecolors=(0, 1, 0))
-    assert_array_equal(pc.get_facecolor(), [[0, 1, 0, 1]])
-    assert_array_equal(pc.get_edgecolor(), [[1, 0, 0, 1]])
-    # Provide an RGB array.
+    pc.update_scalarmappable()
+    assert mcolors.same_color(pc.get_facecolor(), mapped)
+    assert mcolors.same_color(pc.get_edgecolor(), [[1, 0, 0, 1]])
+    # Provide an RGB array; mapping overrides it.
     pc = pcfunc(z, edgecolors=(1, 0, 0), facecolors=np.ones((12, 3)))
-    assert_array_equal(pc.get_facecolor(), np.ones((12, 4)))
-    assert_array_equal(pc.get_edgecolor(), [[1, 0, 0, 1]])
+    pc.update_scalarmappable()
+    assert mcolors.same_color(pc.get_facecolor(), mapped)
+    assert mcolors.same_color(pc.get_edgecolor(), [[1, 0, 0, 1]])
+    # Turn off the mapping.
+    pc.set_array(None)
+    pc.update_scalarmappable()
+    assert mcolors.same_color(pc.get_facecolor(), np.ones((12, 3)))
+    assert mcolors.same_color(pc.get_edgecolor(), [[1, 0, 0, 1]])
     # And an RGBA array.
     pc = pcfunc(z, edgecolors=(1, 0, 0), facecolors=np.ones((12, 4)))
-    assert_array_equal(pc.get_facecolor(), np.ones((12, 4)))
-    assert_array_equal(pc.get_edgecolor(), [[1, 0, 0, 1]])
+    pc.update_scalarmappable()
+    assert mcolors.same_color(pc.get_facecolor(), mapped)
+    assert mcolors.same_color(pc.get_edgecolor(), [[1, 0, 0, 1]])
+    # Turn off the mapping.
+    pc.set_array(None)
+    pc.update_scalarmappable()
+    assert mcolors.same_color(pc.get_facecolor(), np.ones((12, 4)))
+    assert mcolors.same_color(pc.get_edgecolor(), [[1, 0, 0, 1]])
 
 
 def test_LineCollection_args():
