refactor alpha, but failed alpha blending in agg

matplotlib · rmorshea · Aug 6, 2015 · Jul 20, 2015 · Jul 21, 2015 · Jul 23, 2015
commit cfb0713da4f413f37f3ea69a628c7dacdd7a1b56
diff --git a/lib/matplotlib/artist.py b/lib/matplotlib/artist.py
@@ -16,7 +16,7 @@
 from .path import Path
 
 from .traitlets import (Instance, Configurable, gTransformInstance, Bool, Undefined,
-                        BaseDescriptor, getargspec, PrivateMethodMixin)
+                        BaseDescriptor, getargspec, PrivateMethodMixin, Float, TraitError)
 
 # Note, matplotlib artists use the doc strings for set and get
 # methods to enable the introspection methods of setp and getp.  Every
@@ -146,6 +146,20 @@ def _animated_changed(self, name, new):
         self.pchanged()
         self.stale = True
 
+    # Float defaults to 0.0, must have None arg
+    alpha = Float(None, allow_none=True)
+
+    def _alpha_validate(self, value, trait):
+        if 0>value>1:
+            msg = ("The '%s' trait of %s instance can only be"
+                   "transparent (0.0) through opaque (1.0)")
+            raise TraitError(msg % (trait.name, self.__class__))
+        return value
+
+    def _alpha_changed(self, name, new):
+        self.pchanged()
+        self.stale = True
+
     def __init__(self):
         # self._stale = True
         # self._axes = None
@@ -157,7 +171,7 @@ def __init__(self):
 
         # self._visible = True
         # self._animated = False
-        self._alpha = None
+        # self._alpha = None
         self.clipbox = None
         self._clippath = None
         self._clipon = True
@@ -765,12 +779,13 @@ def set_clip_path(self, path, transform=None):
         self.pchanged()
         self.stale = True
 
-    def get_alpha(self):
-        """
-        Return the alpha value used for blending - not supported on all
-        backends
-        """
-        return self._alpha
+    #!DEPRECATED
+    # def get_alpha(self):
+    #     """
+    #     Return the alpha value used for blending - not supported on all
+    #     backends
+    #     """
+    #     return self._alpha
 
     #!DEPRECATED
     # def get_visible(self):
@@ -864,16 +879,17 @@ def draw(self, renderer, *args, **kwargs):
             return
         self.stale = False
 
-    def set_alpha(self, alpha):
-        """
-        Set the alpha value used for blending - not supported on
-        all backends.
+    #!DEPRECATED
+    # def set_alpha(self, alpha):
+    #     """
+    #     Set the alpha value used for blending - not supported on
+    #     all backends.
 
-        ACCEPTS: float (0.0 transparent through 1.0 opaque)
-        """
-        self._alpha = alpha
-        self.pchanged()
-        self.stale = True
+    #     ACCEPTS: float (0.0 transparent through 1.0 opaque)
+    #     """
+    #     self._alpha = alpha
+    #     self.pchanged()
+    #     self.stale = True
 
     #!DEPRECATED
     # def set_visible(self, b):
@@ -966,7 +982,7 @@ def update_from(self, other):
         self.private('transform', other.private('transform'))
         self.transform_set = other.transform_set
         self.private('visible', other.private('visible'))
-        self._alpha = other._alpha
+        self.private('alpha',other.alpha)
         self.clipbox = other.clipbox
         self._clipon = other._clipon
         self._clippath = other._clippath

diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -4269,7 +4269,7 @@ def hexbin(self, x, y, C=None, gridsize=100, bins=None,
         collection.set_array(accum)
         collection.set_cmap(cmap)
         collection.set_norm(norm)
-        collection.set_alpha(alpha)
+        collection.alpha = alpha
         collection.update(kwargs)
 
         if vmin is not None or vmax is not None:
@@ -4330,7 +4330,7 @@ def coarse_bin(x, y, coarse):
         hbar.set_array(values)
         hbar.set_cmap(cmap)
         hbar.set_norm(norm)
-        hbar.set_alpha(alpha)
+        hbar.alpha = alpha
         hbar.update(kwargs)
         self.add_collection(hbar, autolim=False)
 
@@ -4358,7 +4358,7 @@ def coarse_bin(x, y, coarse):
         vbar.set_array(values)
         vbar.set_cmap(cmap)
         vbar.set_norm(norm)
-        vbar.set_alpha(alpha)
+        vbar.alpha = alpha
         vbar.update(kwargs)
         self.add_collection(vbar, autolim=False)
 
@@ -4940,7 +4940,7 @@ def imshow(self, X, cmap=None, norm=None, aspect=None,
                               resample=resample, **kwargs)
 
         im.set_data(X)
-        im.set_alpha(alpha)
+        im.alpha = alpha
         if im.get_clip_path() is None:
             # image does not already have clipping set, clip to axes patch
             im.set_clip_path(self.patch)
@@ -5258,7 +5258,7 @@ def pcolor(self, *args, **kwargs):
 
         collection = mcoll.PolyCollection(verts, **kwargs)
 
-        collection.set_alpha(alpha)
+        collection.alpha = alpha
         collection.set_array(C)
         if norm is not None and not isinstance(norm, mcolors.Normalize):
             msg = "'norm' must be an instance of 'mcolors.Normalize'"
@@ -5409,7 +5409,7 @@ def pcolormesh(self, *args, **kwargs):
         collection = mcoll.QuadMesh(
             Nx - 1, Ny - 1, coords,
             antialiased=antialiased, shading=shading, **kwargs)
-        collection.set_alpha(alpha)
+        collection.alpha = alpha
         collection.set_array(C)
         if norm is not None and not isinstance(norm, mcolors.Normalize):
             msg = "'norm' must be an instance of 'mcolors.Normalize'"
@@ -5593,7 +5593,7 @@ def pcolorfast(self, *args, **kwargs):
             # handle relevant superclass kwargs; the initializer
             # should do much more than it does now.
             collection = mcoll.QuadMesh(nc, nr, coords, 0, edgecolors="None")
-            collection.set_alpha(alpha)
+            collection.alpha = alpha
             collection.set_array(C)
             collection.set_cmap(cmap)
             collection.set_norm(norm)
@@ -5612,7 +5612,7 @@ def pcolorfast(self, *args, **kwargs):
                                         extent=(xl, xr, yb, yt),
                                          **kwargs)
             im.set_data(C)
-            im.set_alpha(alpha)
+            im.alpha = alpha
             self.add_image(im)
             ret = im
 

diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -2313,7 +2313,7 @@ def draw(self, renderer=None, inframe=False):
             zorder_images.sort(key=lambda x: x[0])
 
             mag = renderer.get_image_magnification()
-            ims = [(im.make_image(mag), 0, 0, im.get_alpha())
+            ims = [(im.make_image(mag), 0, 0, im.alpha)
                    for z, im in zorder_images]
 
             l, b, r, t = self.bbox.extents

diff --git a/lib/matplotlib/backends/backend_nbagg.py b/lib/matplotlib/backends/backend_nbagg.py
@@ -217,7 +217,7 @@ def closer(event):
 
     canvas = FigureCanvasNbAgg(figure)
     if rcParams['nbagg.transparent']:
-        figure.patch.set_alpha(0)
+        figure.patch.alpha = 0
     manager = FigureManagerNbAgg(canvas, num)
 
     if is_interactive():

diff --git a/lib/matplotlib/collections.py b/lib/matplotlib/collections.py
@@ -609,7 +609,7 @@ def set_facecolor(self, c):
         if c is None:
             c = mpl.rcParams['patch.facecolor']
         self._facecolors_original = c
-        self._facecolors = mcolors.colorConverter.to_rgba_array(c, self._alpha)
+        self._facecolors = mcolors.colorConverter.to_rgba_array(c, self.alpha)
         self.stale = True
 
     def set_facecolors(self, c):
@@ -657,39 +657,57 @@ def set_edgecolor(self, c):
         if c is None:
             c = mpl.rcParams['patch.edgecolor']
         self._edgecolors_original = c
-        self._edgecolors = mcolors.colorConverter.to_rgba_array(c, self._alpha)
+        self._edgecolors = mcolors.colorConverter.to_rgba_array(c, self.alpha)
         self.stale = True
 
     def set_edgecolors(self, c):
         """alias for set_edgecolor"""
         return self.set_edgecolor(c)
 
-    def set_alpha(self, alpha):
-        """
-        Set the alpha tranparencies of the collection.  *alpha* must be
-        a float or *None*.
+    def _alpha_validate(self, value, trait):
+        value = artist.Artist._alpha_validate(self, value, trait)
 
-        ACCEPTS: float or None
-        """
-        if alpha is not None:
-            try:
-                float(alpha)
-            except TypeError:
-                raise TypeError('alpha must be a float or None')
-        artist.Artist.set_alpha(self, alpha)
         try:
             self._facecolors = mcolors.colorConverter.to_rgba_array(
-                self._facecolors_original, self._alpha)
+                self._facecolors_original, value)
         except (AttributeError, TypeError, IndexError):
             pass
         try:
             if (not isinstance(self._edgecolors_original, six.string_types)
                              or self._edgecolors_original != str('face')):
                 self._edgecolors = mcolors.colorConverter.to_rgba_array(
-                    self._edgecolors_original, self._alpha)
+                    self._edgecolors_original, value)
         except (AttributeError, TypeError, IndexError):
             pass
 
+        return value
+
+    #!DEPRECATED
+    # def set_alpha(self, alpha):
+    #     """
+    #     Set the alpha tranparencies of the collection.  *alpha* must be
+    #     a float or *None*.
+
+    #     ACCEPTS: float or None
+    #     """
+    #     if alpha is not None:
+    #         try:
+    #             float(alpha)
+    #         except TypeError:
+    #             raise TypeError('alpha must be a float or None')
+    #     artist.Artist.set_alpha(self, alpha)
+    #     try:
+    #         self._facecolors = mcolors.colorConverter.to_rgba_array(
+    #             self._facecolors_original, self._alpha)
+    #     except (AttributeError, TypeError, IndexError):
+    #         pass
+    #     try:
+    #         if self._edgecolors_original != str('face'):
+    #             self._edgecolors = mcolors.colorConverter.to_rgba_array(
+    #                 self._edgecolors_original, self._alpha)
+    #     except (AttributeError, TypeError, IndexError):
+    #         pass
+
     def get_linewidths(self):
         return self._linewidths
     get_linewidth = get_linewidths
@@ -710,9 +728,9 @@ def update_scalarmappable(self):
         if not self.check_update("array"):
             return
         if self._is_filled:
-            self._facecolors = self.to_rgba(self._A, self._alpha)
+            self._facecolors = self.to_rgba(self._A, self.alpha)
         elif self._is_stroked:
-            self._edgecolors = self.to_rgba(self._A, self._alpha)
+            self._edgecolors = self.to_rgba(self._A, self.alpha)
         self.stale = True
 
     def get_fill(self):

diff --git a/lib/matplotlib/colorbar.py b/lib/matplotlib/colorbar.py
@@ -885,7 +885,7 @@ def __init__(self, ax, mappable, **kw):
 
         if isinstance(mappable, contour.ContourSet):
             CS = mappable
-            kw['alpha'] = mappable.get_alpha()
+            kw['alpha'] = mappable.alpha
             kw['boundaries'] = CS._levels
             kw['values'] = CS.cvalues
             kw['extend'] = CS.extend
@@ -900,7 +900,7 @@ def __init__(self, ax, mappable, **kw):
                 kw.setdefault('extend', cmap.colorbar_extend)
 
             if isinstance(mappable, martist.Artist):
-                kw['alpha'] = mappable.get_alpha()
+                kw['alpha'] = mappable.alpha
 
             ColorbarBase.__init__(self, ax, **kw)
 
@@ -972,7 +972,7 @@ def update_bruteforce(self, mappable):
         self.solids = None
         self.lines = list()
         self.dividers = None
-        self.set_alpha(mappable.get_alpha())
+        self.set_alpha(mappable.alpha)
         self.cmap = mappable.cmap
         self.norm = mappable.norm
         self.config_axis()

diff --git a/lib/matplotlib/contour.py b/lib/matplotlib/contour.py
@@ -1018,7 +1018,7 @@ def legend_elements(self, variable_name='x', str_format=str):
                     (0, 0), 1, 1,
                     facecolor=collection.get_facecolor()[0],
                     hatch=collection.get_hatch(),
-                    alpha=collection.get_alpha())
+                    alpha=collection.alpha)
                 artists.append(patch)
 
                 lower = str_format(lower)
@@ -1135,7 +1135,7 @@ def changed(self):
             else:
                 collection.set_color(color)
         for label, cv in zip(self.labelTexts, self.labelCValues):
-            label.set_alpha(self.alpha)
+            label.alpha = self.alpha
             label.set_color(self.labelMappable.to_rgba(cv))
         # add label colors
         cm.ScalarMappable.changed(self)

diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -660,7 +660,7 @@ def figimage(self, X,
         im.stale_callback = _stale_figure_callback
 
         im.set_array(X)
-        im.set_alpha(alpha)
+        im.alpha = alpha
         if norm is None:
             im.set_clim(vmin, vmax)
         self.images.append(im)
@@ -1229,7 +1229,7 @@ def draw(self, renderer):
             # make a composite image blending alpha
             # list of (_image.Image, ox, oy)
             mag = renderer.get_image_magnification()
-            ims = [(im.make_image(mag), im.ox, im.oy, im.get_alpha())
+            ims = [(im.make_image(mag), im.ox, im.oy, im.alpha)
                    for im in self.images]
 
             im = _image.from_images(int(self.bbox.height * mag),

diff --git a/lib/matplotlib/finance.py b/lib/matplotlib/finance.py
@@ -805,7 +805,7 @@ def _candlestick(ax, quotes, width=0.2, colorup='k', colordown='r',
             facecolor=color,
             edgecolor=color,
         )
-        rect.set_alpha(alpha)
+        rect.alpha = alpha
 
         lines.append(vline)
         patches.append(rect)