From a03f2f46ee3e0797eae85e358ddcfca9169a89c1 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 31 Dec 2011 17:52:47 -0700
Subject: [PATCH] Don't assume tokens match text nodes when measuring character
 widths

---
 src/lines-component.coffee | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/lines-component.coffee b/src/lines-component.coffee
index 9c63bdbd6..4223811bc 100644
--- a/src/lines-component.coffee
+++ b/src/lines-component.coffee
@@ -72,24 +72,33 @@ LinesComponent = React.createClass
     {editor} = @props
     rangeForMeasurement = null
     iterator = null
-    iteratorIndex = -1
+    charIndex = 0
 
     for {value, scopes}, tokenIndex in tokenizedLine.tokens
       charWidths = editor.getScopedCharWidths(scopes)
-      for char, i in value
+
+      for char in value
         unless charWidths[char]?
-          rangeForMeasurement ?= document.createRange()
-          iterator ?=  document.createNodeIterator(lineNode, NodeFilter.SHOW_TEXT, AcceptFilter)
-
-          while iteratorIndex < tokenIndex
+          unless textNode?
+            rangeForMeasurement ?= document.createRange()
+            iterator =  document.createNodeIterator(lineNode, NodeFilter.SHOW_TEXT, AcceptFilter)
             textNode = iterator.nextNode()
-            iteratorIndex++
+            textNodeIndex = 0
+            nextTextNodeIndex = textNode.textContent.length
 
+          while nextTextNodeIndex <= charIndex
+            textNode = iterator.nextNode()
+            textNodeIndex = nextTextNodeIndex
+            nextTextNodeIndex = textNodeIndex + textNode.textContent.length
+
+          i = charIndex - textNodeIndex
           rangeForMeasurement.setStart(textNode, i)
           rangeForMeasurement.setEnd(textNode, i + 1)
           charWidth = rangeForMeasurement.getBoundingClientRect().width
           editor.setScopedCharWidth(scopes, char, charWidth)
 
+        charIndex++
+
     @measuredLines.add(tokenizedLine)
 
   clearScopedCharWidths: ->