Close #1255.

CHANGELOG.md

@@ -1,3 +1,5 @@
+- **New feature**: `Color user IDs`, enabled by default
+
 ## 3.10.0 - *2013-08-22*
 
 - **New feature**: `Linkify` and `Clean Links`, enabled by default

css/style.css

@@ -959,3 +959,12 @@ a.hide-announcement {
 .entry input {
   margin: 0;
 }
+
+/* colored uid */
+
+.posteruid.painted  {
+  padding: 0 5px;
+  border-radius: 1em;
+  font-size: 0.8em;
+  cursor: pointer;
+}

src/General/Config.coffee

@@ -50,6 +50,7 @@ Config =
       'Thread Excerpt':               [true,  'Show an excerpt of the thread in the tab title.']
       'Thread Stats':                 [true,  'Display reply, image, and page count.']
       'Thread Watcher':               [true,  'Bookmark threads.']
+      'Color user IDs':               [true,  'Assign unique colors to user IDs on boards that use them.']
     'Posting':
       'Quick Reply':                  [true,  'All-in-one form to reply, create threads, automate dumping and more.']
       'Persistent QR':                [false, 'The Quick reply won\'t disappear after posting.']

src/General/Main.coffee

@@ -107,6 +107,7 @@ Main =
     initFeature 'Mark OP Quotes',           QuoteOP
     initFeature 'Mark Cross-thread Quotes', QuoteCT
     initFeature 'Anonymize',                Anonymize
+    initFeature 'Color user IDs',           IDColor
     initFeature 'Time Formatting',          Time
     initFeature 'Relative Post Dates',      RelativeDates
     initFeature 'File Info Formatting',     FileInfo

src/Miscellaneous/IDColor.coffee

@@ -0,0 +1,40 @@
+IDColor =
+  init: ->
+    return if g.VIEW is 'catalog' or !Conf['Color user IDs']
+    @ids = {}
+
+    Post::callbacks.push
+      name: 'Color user IDs'
+      cb:   @node
+
+  node: ->
+    return if @isClone or !(uid = @info.uniqueID)
+    rgb = IDColor.compute uid
+    span = @nodes.uniqueID
+    {style} = span
+    style.color = rgb[3]
+    style.backgroundColor = "rgb(#{rgb[0]},#{rgb[1]},#{rgb[2]})"
+    $.addClass span, 'painted'
+    span.textContent = uid
+    span.title = 'Highlight posts by this ID'
+
+  compute: (uniqueID) ->
+    if uniqueID of IDColor.ids
+      return IDColor.ids[uniqueID]
+    hash = @hash uniqueID
+    rgb = [
+      (hash >> 24) & 0xFF
+      (hash >> 16) & 0xFF
+      (hash >> 8)  & 0xFF
+    ]
+    rgb.push if (rgb[0] * 0.299 + rgb[1] * 0.587 + rgb[2] * 0.114) > 125
+      'black'
+    else
+      'white'
+    @ids[uniqueID] = rgb
+
+  hash: (uniqueID) ->
+    msg = 0
+    for i in [0...uniqueID.length]
+      msg = (msg << 5) - msg + uniqueID.charCodeAt i
+    msg