From 8c0308c88e909d1d26fbc5f6edd0ed311bdfa16e Mon Sep 17 00:00:00 2001
From: Andrea Campi <andrea.campi@zephirworks.com>
Date: Sat, 25 Aug 2012 16:27:02 +0200
Subject: [PATCH] Use element.getBoundingClient() to implement
 getOffsetWidth(); this also affects Metrics, since it uses getOffsetWidth().

element.getBoundingClient originated on IE, and is implemented by
every browser we are compatible with.
---
 src/lib/dimensions.js |  2 +-
 test/dimensions.js    | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/lib/dimensions.js b/src/lib/dimensions.js
index 3112509..d533f09 100644
--- a/src/lib/dimensions.js
+++ b/src/lib/dimensions.js
@@ -128,7 +128,7 @@ goog.scope(function() {
    * @return {!number} Value in pixels.
    */
   dimensions.getOffsetWidth = function(el) {
-    return el && el.offsetWidth || 0;
+    return el && el.getBoundingClientRect()['width'] || 0;
   };
 
   /**
diff --git a/test/dimensions.js b/test/dimensions.js
index 4560951..c78da21 100644
--- a/test/dimensions.js
+++ b/test/dimensions.js
@@ -128,6 +128,27 @@ $(function() {
     equals(d.outerH, 20);
   });
 
+  test('offsetWidth with subpixels', function() {
+    var e = $('<div></div>').addClass('testonly').appendTo('body').css({
+          fontSize: '13px',
+          lineHeight: '13px'
+        }),
+        c1 = $('<div></div>').appendTo(e).css({
+          "margin-left": '15em',
+          width: '21.5em'
+        }),
+        c2 = $('<div></div>').appendTo(e).css({
+          "margin-left": '37.5em',
+          width: '21.5em'
+        }),
+        d1 = new treesaver.dimensions.Metrics(c1[0]),
+        d2 = new treesaver.dimensions.Metrics(c2[0]);
+
+    equals(d1.outerW, d2.outerW);
+    equals(d1.outerW, treesaver.capabilities.SUPPORTS_SUBPIXELS ? 279.5 : 279);
+    equals(d2.outerW, treesaver.capabilities.SUPPORTS_SUBPIXELS ? 279.5 : 279);
+  });
+
   test('lineHeight', function() {
     var e = $('<div></div>').addClass('testonly').appendTo('body').css({
           fontSize: '14px',