fix bug in filled line plots with a black fill color, spotted by Brad…

… Buran. Also improving handling when there are no points in the filled line plot.

enthought/chaco/filled_line_plot.py

@@ -1,11 +1,10 @@
-import logging
+
 
 from enthought.traits.api import Property, Enum
 
 # Local imports
 from polygon_plot import PolygonPlot
 
-logger = logging.getLogger(__name__)
 
 def Alias(name):
     return Property(lambda obj: getattr(obj, name),
@@ -22,11 +21,9 @@ class FilledLinePlot(PolygonPlot):
     fill_direction = Enum("down", "up")
 
     def _render(self, gc, points):
-        # If there is nothing to render, render nothing
         if len(points) == 0:
-            logger.warning("No datasource for plot")
             return
-        
+
         if self.fill_direction == 'down':
             ox, oy = self.map_screen([[0,0]])[0]
         else:
@@ -38,8 +35,9 @@ def _render(self, gc, points):
             gc.clip_to_rect(self.x, self.y, self.width, self.height)
 
             # If the fill color is not transparent, then draw the fill polygon first
-            if self.face_color_[-1] != 0 and self.face_color_[:3] != (0,0,0):
-                gc.set_fill_color(self.face_color_)
+            face_col = self.face_color_
+            if not (len(face_col) == 4 and face_col[-1] == 0):
+                gc.set_fill_color(face_col)
                 gc.begin_path()
                 startx, starty = points[0]
                 if self.orientation == "h":
@@ -64,8 +62,9 @@ def _render(self, gc, points):
 
             # If the line color is not transparent, or tha same color
             # as the filled area:
-            if self.edge_color_[-1] != 0 and self.edge_color_ != self.face_color_:
-                gc.set_stroke_color(self.edge_color_)
+            edge_col = self.edge_color_
+            if (not (len(edge_col) == 4 and edge_col[-1] == 0)) and edge_col != face_col:
+                gc.set_stroke_color(edge_col)
                 gc.set_line_width(self.edge_width)
                 gc.set_line_dash(self.edge_style_)
                 gc.begin_path()