From 535837e0178a7365a06287e063beeeadbcdab531 Mon Sep 17 00:00:00 2001
From: Jermolene <jeremy@osmosoft.com>
Date: Mon, 24 Mar 2014 22:31:03 +0000
Subject: [PATCH] Use client bounding rect rather than offset positions for
 computing scroll positions

---
 core/modules/utils/dom/scroller.js | 27 +++++++++++----------------
 1 file changed, 11 insertions(+), 16 deletions(-)

diff --git a/core/modules/utils/dom/scroller.js b/core/modules/utils/dom/scroller.js
index 2b087e3fa..107a74449 100644
--- a/core/modules/utils/dom/scroller.js
+++ b/core/modules/utils/dom/scroller.js
@@ -55,25 +55,20 @@ Handle a scroll event hitting the page document
 */
 PageScroller.prototype.scrollIntoView = function(element) {
 	var duration = $tw.utils.getAnimationDuration();
-	// Get the offset bounds of the element
-	var bounds = {
-			left: element.offsetLeft,
-			top: element.offsetTop,
-			width: element.offsetWidth,
-			height: element.offsetHeight
-		};
-	// Walk up the tree adjusting the offset bounds by each offsetParent
-	while(element.offsetParent) {
-		element = element.offsetParent;
-		bounds.left += element.offsetLeft;
-		bounds.top += element.offsetTop;
-	}
 	// Now get ready to scroll the body
 	this.cancelScroll();
 	this.startTime = new Date();
-	var scrollPosition = $tw.utils.getScrollPosition(),
-		// We'll consider the horizontal and vertical scroll directions separately via this function
-		getEndPos = function(targetPos,targetSize,currentPos,currentSize) {
+	var scrollPosition = $tw.utils.getScrollPosition();
+	// Get the client bounds of the element and adjust by the scroll position
+	var clientBounds = element.getBoundingClientRect(),
+		bounds = {
+			left: clientBounds.left + scrollPosition.x,
+			top: clientBounds.top + scrollPosition.y,
+			width: clientBounds.width,
+			height: clientBounds.height
+		};
+	// We'll consider the horizontal and vertical scroll directions separately via this function
+	var getEndPos = function(targetPos,targetSize,currentPos,currentSize) {
 			// If the target is above/left of the current view, then scroll to it's top/left
 			if(targetPos <= currentPos) {
 				return targetPos;