fix: Alpha respected by polygon lines

plotnine/geoms/geom_boxplot.py

@@ -134,7 +134,7 @@ def flat(*args):
             'x': flat(data['x'], data['x']),
             'y': flat(data['upper'], data['lower']),
             'yend': flat(data['ymax'], data['ymin']),
-            'alpha': 1
+            'alpha': flat(data['alpha'], data['alpha'])
         })
         whiskers['xend'] = whiskers['x']
         copy_missing_columns(whiskers, data[common_columns])
@@ -199,7 +199,9 @@ def draw_legend(data, da, lyr):
         facecolor = to_rgba(data['fill'], data['alpha'])
         if facecolor is None:
             facecolor = 'none'
-
+        edgecolor = to_rgba(data['color'], data['alpha'])
+        if edgecolor is None:
+            edgecolor = 'none'
         kwargs = dict(
            linestyle=data['linetype'],
            linewidth=data['size'])
@@ -208,14 +210,15 @@ def draw_legend(data, da, lyr):
                         width=da.width*.75,
                         height=da.height*.5,
                         facecolor=facecolor,
-                        edgecolor=data['color'],
+                        edgecolor=edgecolor,
                         capstyle='projecting',
                         antialiased=False,
                         **kwargs)
         da.add_artist(box)
 
         kwargs['solid_capstyle'] = 'butt'
         kwargs['color'] = data['color']
+        kwargs['alpha'] = data['alpha']
         kwargs['linewidth'] *= SIZE_FACTOR
 
         # middle strike through

plotnine/geoms/geom_crossbar.py

@@ -73,7 +73,7 @@ def flat(*args):
                                'yend': y,
                                'group': group})
         copy_missing_columns(middle, data)
-        middle['alpha'] = 1
+        middle['alpha'] = data['alpha']
         middle['size'] *= params['fatten']
 
         has_notch = ynotchlower is not None and ynotchupper is not None

plotnine/geoms/geom_polygon.py

@@ -59,7 +59,8 @@ def draw_group(data, panel_params, coord, ax, **params):
             verts[i] = tuple(zip(df['x'], df['y']))
             fill = to_rgba(df['fill'].iloc[0], df['alpha'].iloc[0])
             facecolor[i] = 'none' if fill is None else fill
-            edgecolor[i] = df['color'].iloc[0] or 'none'
+            color = to_rgba(df['color'].iloc[0], df['alpha'].iloc[0])
+            edgecolor[i] = 'none' if color is None else color
             linestyle[i] = df['linetype'].iloc[0]
             linewidth[i] = df['size'].iloc[0]
 
@@ -96,6 +97,9 @@ def draw_legend(data, da, lyr):
                             da.width/4, da.height/4])
         if data['color'] is None:
             linewidth = 0
+            edgecolor = None
+        else:
+            edgecolor = to_rgba(data['color'], data['alpha'])
 
         facecolor = to_rgba(data['fill'], data['alpha'])
         if facecolor is None:
@@ -107,7 +111,7 @@ def draw_legend(data, da, lyr):
                          linewidth=linewidth,
                          linestyle=data['linetype'],
                          facecolor=facecolor,
-                         edgecolor=data['color'],
+                         edgecolor=edgecolor,
                          capstyle='projecting')
         da.add_artist(rect)
         return da

plotnine/geoms/geom_rect.py

@@ -53,11 +53,11 @@ def draw_group(data, panel_params, coord, ax, **params):
             verts[i] = [(l, b), (l, t), (r, t), (r, b)]
 
         fill = to_rgba(data['fill'], data['alpha'])
-        color = data['color']
 
         # prevent unnecessary borders
-        if all(color.isnull()):
+        if all(data['color'].isnull()):
             color = 'none'
+        color = to_rgba(data['color'], data['alpha'])
 
         col = PolyCollection(
             verts,

plotnine/geoms/geom_ribbon.py

@@ -45,13 +45,13 @@ def draw_group(data, panel_params, coord, ax, **params):
     def draw_unit(data, panel_params, coord, ax, **params):
         data['size'] *= SIZE_FACTOR
         fill = to_rgba(data['fill'], data['alpha'])
-        color = data['color']
-
         if fill is None:
             fill = 'none'
 
-        if all(color.isnull()):
+        if all(data['color'].isnull()):
             color = 'none'
+        else:
+            color = to_rgba(data['color'], data['alpha'])
 
         if isinstance(coord, coord_flip):
             fill_between = ax.fill_betweenx

plotnine/tests/test_geom_bar.py

@@ -0,0 +1,18 @@
+import pandas as pd
+
+from plotnine import ggplot, aes, geom_bar
+
+
+def test_bar_alpha():
+    df = pd.DataFrame(
+        {
+            "x": ["a%i" % i for i in range(10)],
+            "y": range(1, 11),
+            "alpha": [0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1],
+        }
+    )
+    p = ggplot(df, aes("x")) + geom_bar(
+        aes(y="y", alpha="alpha"),
+        stat="identity", color="blue", position="dodge"
+    )
+    assert p == "bar_alpha"

plotnine/tests/test_geom_boxplot.py

@@ -33,7 +33,7 @@ def test_aesthetics_coordflip(self):
 
 def test_params():
     p = (ggplot(df, aes('x')) +
-         geom_boxplot(df[:m], aes(y='y'), size=2, notch=True) +
+         geom_boxplot(df[:m], aes(y='y'), size=2, notch=True, alpha=0.3) +
          geom_boxplot(df[m:2*m], aes(y='y'), size=2,
                       notch=True, notchwidth=0.8) +
          # outliers