jquery - Javascript Contenteditable - set Cursor / Caret to index

Question

How would I go a about modifying this(How to set caret(cursor) position in contenteditable element (div)?) so it accepts a number index and element and sets the cursor position to that index?

For example: If I had the paragraph:

<p contenteditable="true">This is a paragraph.</p>

And I called:

setCaret($(this).get(0), 3)

The cursor would move to index 3 like so:

Thi|s is a paragraph.

---

I have this but with no luck:

function setCaret(contentEditableElement, index)
{
    var range,selection;
    if(document.createRange)//Firefox, Chrome, Opera, Safari, IE 9+
    {
        range = document.createRange();//Create a range (a range is a like the selection but invisible)
        range.setStart(contentEditableElement,index);
        range.collapse(true);
        selection = window.getSelection();//get the selection object (allows you to change selection)
        selection.removeAllRanges();//remove any selections already made
        selection.addRange(range);//make the range you have just created the visible selection
    }
    else if(document.selection)//IE 8 and lower
    { 
        range = document.body.createTextRange();//Create a range (a range is a like the selection but invisible)
        range.moveToElementText(contentEditableElement);//Select the entire contents of the element with the range
        range.collapse(false);//collapse the range to the end point. false means collapse to end rather than the start
        range.select();//Select the range (make it the visible selection
    }
}

http://jsfiddle.net/BanQU/4/

Answer 1

Here's an answer adapted from Persisting the changes of range objects after selection in HTML. Bear in mind that this is less than perfect in several ways (as is MaxArt's, which uses the same approach): firstly, only text nodes are taken into account, meaning that line breaks implied by <br> and block elements are not included in the index; secondly, all text nodes are considered, even those inside elements that are hidden by CSS or inside <script> elements; thirdly, consecutive white space characters that are collapsed on the page are all included in the index; finally, IE <= 8's rules are different again because it uses a different mechanism.

var setSelectionByCharacterOffsets = null;

if (window.getSelection && document.createRange) {
    setSelectionByCharacterOffsets = function(containerEl, start, end) {
        var charIndex = 0, range = document.createRange();
        range.setStart(containerEl, 0);
        range.collapse(true);
        var nodeStack = [containerEl], node, foundStart = false, stop = false;

        while (!stop && (node = nodeStack.pop())) {
            if (node.nodeType == 3) {
                var nextCharIndex = charIndex + node.length;
                if (!foundStart && start >= charIndex && start <= nextCharIndex) {
                    range.setStart(node, start - charIndex);
                    foundStart = true;
                }
                if (foundStart && end >= charIndex && end <= nextCharIndex) {
                    range.setEnd(node, end - charIndex);
                    stop = true;
                }
                charIndex = nextCharIndex;
            } else {
                var i = node.childNodes.length;
                while (i--) {
                    nodeStack.push(node.childNodes[i]);
                }
            }
        }

        var sel = window.getSelection();
        sel.removeAllRanges();
        sel.addRange(range);
    }
} else if (document.selection) {
    setSelectionByCharacterOffsets = function(containerEl, start, end) {
        var textRange = document.body.createTextRange();
        textRange.moveToElementText(containerEl);
        textRange.collapse(true);
        textRange.moveEnd("character", end);
        textRange.moveStart("character", start);
        textRange.select();
    };
}