From 17f89e9bd352f866a60e32dadbd7d60085310adf Mon Sep 17 00:00:00 2001
From: Wu Cheng-Han <jacky_cute0808@hotmail.com>
Date: Thu, 2 Jul 2015 20:30:43 +0800
Subject: [PATCH] Optimized syncscroll.js buildMap, make it faster

---
 public/js/syncscroll.js | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/public/js/syncscroll.js b/public/js/syncscroll.js
index 2ed3ff03..a9eafe48 100644
--- a/public/js/syncscroll.js
+++ b/public/js/syncscroll.js
@@ -199,6 +199,8 @@ function buildMapInner(syncBack) {
 
     acc = 0;
     var lines = editor.getValue().split('\n');
+    var lineHeight = parseFloat(sourceLikeDiv.css('line-height'));
+    var div = sourceLikeDiv[0];
     for (i = 0; i < lines.length; i++) {
         var str = lines[i];
         var h, lh;
@@ -211,9 +213,8 @@ function buildMapInner(syncBack) {
         }
 
         sourceLikeDiv.text(str);
-        h = parseFloat(sourceLikeDiv.css('height'));
-        lh = parseFloat(sourceLikeDiv.css('line-height'));
-        acc += Math.round(h / lh);
+        h = parseFloat(div.clientHeight);
+        acc += Math.round(h / lineHeight);
     }
     sourceLikeDiv.remove();
     _lineHeightMap.push(acc);
@@ -260,7 +261,7 @@ function buildMapInner(syncBack) {
     scrollMap = _scrollMap;
     lineHeightMap = _lineHeightMap;
 
-    if(loaded && syncBack)
+    if (loaded && syncBack)
         syncScrollToView();
 }