the fontcolor is unfortunately lost in plain files. if the fillcolor is very

dark, switch to white as the fontcolor instead of black

2 files changed, 20 insertions, 3 deletions

diff --git a/dotviewer/drawgraph.py b/dotviewer/drawgraph.py
index 1cc74e60a0..51cd7bc034 100644
--- a/dotviewer/drawgraph.py
+++ b/dotviewer/drawgraph.py
@@ -7,6 +7,7 @@ from __future__ import generators
 import re, os, math
 import pygame
 from pygame.locals import *
+
 from strunicode import forceunicode
 
 
@@ -702,6 +703,15 @@ def getcolor(name, default):
     else:
         return default
 
+def ensure_readable(fgcolor, bgcolor):
+    if bgcolor is None:
+        return fgcolor
+    r, g, b = bgcolor
+
+    l = 0.2627 * r + 0.6780 * g + 0.0593 * b
+    if l < 70:
+        return (255, 255, 255)
+    return fgcolor
 
 class GraphLayout:
     fixedfont = False
@@ -1285,6 +1295,7 @@ class GraphRenderer:
 class TextSnippet:
     
     def __init__(self, renderer, text, fgcolor, bgcolor=None, font=None):
+        fgcolor = ensure_readable(fgcolor, bgcolor)
         self.renderer = renderer
         self.imgs = []
         self.parts = []
diff --git a/dotviewer/test/test_interactive.py b/dotviewer/test/test_interactive.py
index 0f116856b3..4db0fbf53b 100644
--- a/dotviewer/test/test_interactive.py
+++ b/dotviewer/test/test_interactive.py
@@ -48,9 +48,6 @@ SOURCE2=r'''digraph f {
 }'''
 
 
-
-
-
 def setup_module(mod):
     if not option.pygame:
         py.test.skip("--pygame not enabled")
@@ -185,3 +182,12 @@ def test_linewidth():
     dotfile = udir.join('graph2.dot')
     page = graphpage.DotFileGraphPage(str(dotfile))
     graphclient.display_page(page)
+
+def test_ensure_readable():
+    from dotviewer import graphpage, graphclient
+    tmpname = udir.join("graph5.dot")
+    tmpname.write('''digraph f {
+        node1 [shape="box", label="readable???", color="black", fillcolor="black", style="filled"];
+    }''')
+    page = graphpage.DotFileGraphPage(str(tmpname))
+    graphclient.display_page(page)