From 99d4c955567235eecea43d179ef27aa654cdc561 Mon Sep 17 00:00:00 2001
From: Wolfgang Sourdeau <wsourdeau@inverse.ca>
Date: Tue, 22 Apr 2008 17:16:37 +0000
Subject: [PATCH] Monotone-Parent: 4da2e2aa68da3f6c69bddae3167041872607c9d2
 Monotone-Revision: 589cbe87a5260166298c57c4fa50494edb7b9fbd

Monotone-Author: wsourdeau@inverse.ca
Monotone-Date: 2008-04-22T17:16:37
Monotone-Branch: ca.inverse.sogo
---
 ChangeLog                                     |  5 ++
 UI/Scheduler/UIxCalendarSelector.m            | 48 ++++++++++++++++++-
 .../SchedulerUI/UIxCalendarSelector.wox       |  2 +-
 UI/WebServerResources/SchedulerUI.js          | 35 ++------------
 UI/WebServerResources/generic.js              | 17 +++++++
 5 files changed, 74 insertions(+), 33 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index ef99e9b12..327220f8f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2008-04-22  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
 
+	* UI/Scheduler/UIxCalendarSelector.m ([UIxCalendarSelector
+	-contrastingTextColor]): new method (code taken from Lightning)
+	that returns a foreground color easily readible based on the
+	brightness of the background color.
+
 	* SoObjects/SOGo/SOGoGCSFolder.m ([SOGoGCSFolder
 	-setDavDisplayName:newName]): deny the renaming of the folder if
 	not owner.
diff --git a/UI/Scheduler/UIxCalendarSelector.m b/UI/Scheduler/UIxCalendarSelector.m
index 820865478..a4ec65ef3 100644
--- a/UI/Scheduler/UIxCalendarSelector.m
+++ b/UI/Scheduler/UIxCalendarSelector.m
@@ -36,6 +36,35 @@
 
 #import "UIxCalendarSelector.h"
 
+static inline unsigned int
+_intValueFromHexChar (unichar hexChar)
+{
+  unichar base;
+
+  if (hexChar >= '0' && hexChar <= '9')
+    base = '0';
+  else if (hexChar >= 'A' && hexChar <= 'F')
+    base = 'A' - 10;
+  else
+    base = 'a' - 10;
+
+  return (hexChar - base);
+}
+
+static inline unsigned int
+_intValueFromHex (NSString *hexString)
+{
+  unsigned int value, count, max;
+
+  value = 0;
+  max = [hexString length];
+  for (count = 0; count < max; count++)
+    value = (value * 16
+	     + _intValueFromHexChar([hexString characterAtIndex: count]));
+
+  return value;
+}
+
 @implementation UIxCalendarSelector
 
 - (id) init
@@ -87,8 +116,7 @@
 		    forKey: @"id"];
 	  [calendar setObject: fDisplayName forKey: @"displayName"];
 	  [calendar setObject: folderName forKey: @"folder"];
-	  [calendar setObject: [folder calendarColor]
-		    forKey: @"color"];
+	  [calendar setObject: [folder calendarColor] forKey: @"color"];
 	  isActive = [NSNumber numberWithBool: [folder isActive]];
 	  [calendar setObject: isActive forKey: @"active"];
 	  [calendar setObject: [folder ownerInContext: context]
@@ -124,6 +152,22 @@
 	   keysWithFormat: @"color: %{color}; background-color: %{color};"];
 }
 
+/* code taken from Lightning 0.7 */
+- (NSString *) contrastingTextColor
+{
+  NSString *bgColor;
+  unsigned int red, green, blue;
+  float brightness;
+
+  bgColor = [[currentCalendar objectForKey: @"color"] substringFromIndex: 1];
+  red = _intValueFromHex ([bgColor substringFromRange: NSMakeRange (0, 2)]);
+  green = _intValueFromHex ([bgColor substringFromRange: NSMakeRange (2, 2)]);
+  blue = _intValueFromHex ([bgColor substringFromRange: NSMakeRange (4, 2)]);
+  brightness = (0.299 * red) + (0.587 * green) + (0.114 * blue);
+
+  return ((brightness < 144) ? @"white" : @"black");
+}
+
 - (WOResponse *) calendarsListAction
 {
   WOResponse *response;
diff --git a/UI/Templates/SchedulerUI/UIxCalendarSelector.wox b/UI/Templates/SchedulerUI/UIxCalendarSelector.wox
index a02893ffa..245f7a8f3 100644
--- a/UI/Templates/SchedulerUI/UIxCalendarSelector.wox
+++ b/UI/Templates/SchedulerUI/UIxCalendarSelector.wox
@@ -9,7 +9,7 @@
   <style type="text/css">
     <var:foreach list="calendars" item="currentCalendar">
 .calendarFolder<var:string value="currentCalendar.folder" />
-{ background-color: <var:string value="currentCalendar.color" /> !important; }
+{ background-color: <var:string value="currentCalendar.color" /> !important; color: <var:string value="contrastingTextColor" /> !important; }
 div.colorBox.calendarFolder<var:string value="currentCalendar.folder" />
 { color: <var:string value="currentCalendar.color" /> !important; }
     </var:foreach>
diff --git a/UI/WebServerResources/SchedulerUI.js b/UI/WebServerResources/SchedulerUI.js
index 903ac7e85..d14608d19 100644
--- a/UI/WebServerResources/SchedulerUI.js
+++ b/UI/WebServerResources/SchedulerUI.js
@@ -4,7 +4,6 @@ var listFilter = 'view_today';
 
 var listOfSelection = null;
 var selectedCalendarCell;
-var calendarColorIndex = null;
 
 var showCompletedTasks = 0;
 
@@ -1689,32 +1688,6 @@ function appendCalendar(folderName, folderPath) {
     li.setAttribute("id", folderPath);
     li.setAttribute("owner", owner);
 
-    // Generate new color
-    if (calendarColorIndex == null)
-      calendarColorIndex = items.length;
-    calendarColorIndex++;
-    var colorTable = [1, 1, 1];
-    var color;
-    var currentValue = calendarColorIndex;
-    var index = 0;
-    while (currentValue) {
-      if (currentValue & 1)
-	colorTable[index]++;
-      if (index == 3)
-	index = 0;
-      currentValue >>= 1;
-      index++;
-    }
-    colorTable[0] = parseInt(255 / colorTable[0]) - 1;
-    colorTable[1] = parseInt(255 / colorTable[1]) - 1;
-    colorTable[2] = parseInt(255 / colorTable[2]) - 1;
-
-    color = "#"
-      + colorTable[2].toString(16)
-      + colorTable[1].toString(16)
-      + colorTable[0].toString(16);
-    //log ("color = " + color);
-    
     var checkBox = document.createElement("input");
     checkBox.setAttribute("type", "checkbox");
     li.appendChild(checkBox);
@@ -1738,12 +1711,13 @@ function appendCalendar(folderName, folderPath) {
     triggerAjaxRequest(url, calendarEntryCallback, folderPath);
     
     // Update CSS for events color
-    appendStyleElement(folderPath, color);
+    appendStyleElement(folderPath, "#AAAAAA");
   }
 }
 
 function appendStyleElement(folderPath, color) {
-  if (document.styleSheets) {    
+  if (document.styleSheets) {
+    var fgColor = getContrastingTextColor(color);
     var styleElement = document.createElement("style");
     styleElement.type = "text/css";
     var selectors = [
@@ -1751,7 +1725,8 @@ function appendStyleElement(folderPath, color) {
 		     'div.colorBox.calendarFolder' + folderPath.substr(1)
 		     ];
     var rules = [
-		 ' { background-color: ' + color + ' !important; }',
+		 ' { background-color: ' + color + ' !important;'
+		 + ' color: ' + fgColor + ' !important; }',
 		 ' { color: ' + color + ' !important; }'
 		 ];
     for (var i = 0; i < rules.length; i++)
diff --git a/UI/WebServerResources/generic.js b/UI/WebServerResources/generic.js
index c21d70318..bee042053 100644
--- a/UI/WebServerResources/generic.js
+++ b/UI/WebServerResources/generic.js
@@ -307,6 +307,23 @@ function onAjaxRequestStateChange(http) {
   }
 }
 
+/* taken from Lightning */
+function getContrastingTextColor(bgColor) {
+  var calcColor = bgColor.substring(1);
+  var red = parseInt(calcColor.substring(0, 2), 16);
+  var green = parseInt(calcColor.substring(2, 4), 16);
+  var blue = parseInt(calcColor.substring(4, 6), 16);
+
+  // Calculate the brightness (Y) value using the YUV color system.
+  var brightness = (0.299 * red) + (0.587 * green) + (0.114 * blue);
+  
+  // Consider all colors with less than 56% brightness as dark colors and
+  // use white as the foreground color, otherwise use black.
+  return ((brightness < 144)
+	  ? "white"
+	  : "black");
+}
+
 function triggerAjaxRequest(url, callback, userdata, content, headers) {
   var http = createHTTPClient();