added function for calculating the offset and fixed the offset of the calculation for the element

Author: borunovm

modules/mixins/utils.js

@@ -21,12 +21,15 @@ const  getHash = () => {
 
 const filterElementInContainer = (container) => (element) => container.contains ? container != element && container.contains(element) : !!(container.compareDocumentPosition(element) & 16)
 
+const calculatingOffsetParent = (c, t) =>
+  t.offsetParent.isEqualNode(c) ? t.offsetTop : t.offsetTop + calculatingOffsetParent(c, t.offsetParent);
+
 const scrollOffset = (c, t) => c === document ?
-  t.getBoundingClientRect().top + (window.scrollY || window.pageYOffset) : getComputedStyle(c).position !== "static" ? t.offsetTop : (t.getBoundingClientRect().top + c.scrollTop)
+  t.getBoundingClientRect().top + (window.scrollY || window.pageYOffset) : getComputedStyle(c).position !== 'static' ? calculatingOffsetParent(c, t) : calculatingOffsetParent(c.offsetParent, t.offsetParent) - c.offsetTop;
 
 export default {
   pushHash,
   getHash,
   filterElementInContainer,
   scrollOffset
-};
+};