Detect direction of user selection with javascript

Question

I am emulating text editor in my project with custom caret, but native selection. Is there any way how to detect in which direction did user select the text? Lets say, that user has selected text "hello world". There are two possibilities, he could start with clicking his mouse on letter 'd' and ends on letter 'h', or he could start on letter 'h' and end on letter 'd'. Is there any easy way how to distinguish between these two situations? Thank you.

Answer 1

Old question, but I thought I'd add an easier solution:

var sel = getSelection(),
position = sel.anchorNode.compareDocumentPosition(sel.focusNode),
backward = false;
// position == 0 if nodes are the same
if (!position && sel.anchorOffset > sel.focusOffset || 
  position === Node.DOCUMENT_POSITION_PRECEDING)
  backward = true; 

Node.compareDocumentPosition (MDN)