From 173e7c8f278c2feba69526e13fdedfae8dd72341 Mon Sep 17 00:00:00 2001
From: Marcel Klehr <marcel.klehr@gmx.de>
Date: Wed, 29 Feb 2012 14:16:20 +0100
Subject: [PATCH 1/2] Extend colorutils

Add color invertion and calculation of complementary colors.
---
 static/js/colorutils.js | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/static/js/colorutils.js b/static/js/colorutils.js
index 9bba39ad..5fbefb4d 100644
--- a/static/js/colorutils.js
+++ b/static/js/colorutils.js
@@ -120,4 +120,19 @@ colorutils.blend = function(c1, c2, t)
   return [colorutils.scale(t, c1[0], c2[0]), colorutils.scale(t, c1[1], c2[1]), colorutils.scale(t, c1[2], c2[2])];
 }
 
+colorutils.invert = function(c)
+{
+  return [1 - c[0], 1 - c[1], 1- c[2]];
+}
+
+colorutils.complementary = function(c)
+{
+  var inv = colorutils.invert(c);
+  return [
+    (inv[0] >= c[0]) ? Math.min(inv[0] * 1.30, 1) : (c[0] * 0.30),
+    (inv[1] >= c[1]) ? Math.min(inv[1] * 1.59, 1) : (c[1] * 0.59),
+    (inv[2] >= c[2]) ? Math.min(inv[2] * 1.11, 1) : (c[2] * 0.11)
+  ];
+}
+
 exports.colorutils = colorutils;

From f5f82a76375bb07366f9246e15d565224e84af72 Mon Sep 17 00:00:00 2001
From: Marcel Klehr <marcel.klehr@gmx.de>
Date: Wed, 29 Feb 2012 14:21:35 +0100
Subject: [PATCH 2/2] Rework dynamic text contrast

-Remove hard coding of default text color
-add dynamic link text contrast
---
 static/js/ace2_inner.js | 30 +++++++++++++++++++++++-------
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/static/js/ace2_inner.js b/static/js/ace2_inner.js
index 71f7d20f..17d02036 100644
--- a/static/js/ace2_inner.js
+++ b/static/js/ace2_inner.js
@@ -229,18 +229,34 @@ function Ace2Inner(){
             bgcolor = fadeColor(bgcolor, info.fade);
           }
           
-          // Text color
-          var txtcolor = (colorutils.luminosity(colorutils.css2triple(bgcolor)) < 0.5) ? '#ffffff' : '#000000';
-          
           var authorStyle = dynamicCSS.selectorStyle(getAuthorColorClassSelector(
           getAuthorClassName(author)));
-          authorStyle.backgroundColor = bgcolor;
-          authorStyle.color = txtcolor;
-          
           var authorStyleTop = dynamicCSSTop.selectorStyle(getAuthorColorClassSelector(
           getAuthorClassName(author)));
+          var anchorStyle = dynamicCSS.selectorStyle(getAuthorColorClassSelector(
+          getAuthorClassName(author))+' > a')
+          
+          // author color
+          authorStyle.backgroundColor = bgcolor;
           authorStyleTop.backgroundColor = bgcolor;
-          authorStyleTop.color = txtcolor;
+          
+          // text contrast
+          if(colorutils.luminosity(colorutils.css2triple(bgcolor)) < 0.5)
+          {
+            authorStyle.color = '#ffffff';
+            authorStyleTop.color = '#ffffff';
+          }else{
+            authorStyle.color = null;
+            authorStyleTop.color = null;
+          }
+          
+          // anchor text contrast
+          if(colorutils.luminosity(colorutils.css2triple(bgcolor)) < 0.55)
+          {
+            anchorStyle.color = colorutils.triple2css(colorutils.complementary(colorutils.css2triple(bgcolor)));
+          }else{
+            anchorStyle.color = null;
+          }
         }
       }
     }