Fix antialiasing with old pycairo/cairocffi.

QuLogic · QuLogic · commit ed2880ce53ae · 2021-03-29T20:28:19.000-04:00
The `cairo.Antialias` Enum was added in pycairo 1.13, but we support
1.11. It also appears to not exist in cairocffi.
diff --git a/lib/matplotlib/backends/backend_cairo.py b/lib/matplotlib/backends/backend_cairo.py
@@ -250,8 +250,8 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
             ctx.set_font_size(prop.get_size_in_points() * self.dpi / 72)
             opts = cairo.FontOptions()
             opts.set_antialias(
-                cairo.Antialias.DEFAULT if mpl.rcParams["text.antialiased"]
-                else cairo.Antialias.NONE)
+                cairo.ANTIALIAS_DEFAULT if mpl.rcParams["text.antialiased"]
+                else cairo.ANTIALIAS_NONE)
             ctx.set_font_options(opts)
             if angle:
                 ctx.rotate(np.deg2rad(-angle))
@@ -357,7 +357,7 @@ def set_alpha(self, alpha):
 
     def set_antialiased(self, b):
         self.ctx.set_antialias(
-            cairo.Antialias.DEFAULT if b else cairo.Antialias.NONE)
+            cairo.ANTIALIAS_DEFAULT if b else cairo.ANTIALIAS_NONE)
 
     def set_capstyle(self, cs):
         self.ctx.set_line_cap(_api.check_getitem(self._capd, capstyle=cs))
