[javascript] contentEditable 캐럿 인덱스 위치 가져 오기

다른 답변에서 해결되지 않은 몇 가지 주름 :

1. 요소는 여러 수준의 자식 노드를 포함 할 수 있습니다 (예 : 자식 노드가있는 자식 노드가있는 자식 노드 …)
2. 선택은 다른 시작 및 끝 위치로 구성 될 수 있습니다 (예 : 여러 문자가 선택됨).
3. 캐럿 시작 / 종료를 포함하는 노드는 요소 또는 직계 자식이 아닐 수 있습니다.

다음은 요소의 textContent 값에 대한 오프셋으로 시작 및 끝 위치를 가져 오는 방법입니다.

// node_walk: walk the element tree, stop when func(node) returns false
function node_walk(node, func) {
  var result = func(node);
  for(node = node.firstChild; result !== false && node; node = node.nextSibling)
    result = node_walk(node, func);
  return result;
};

// getCaretPosition: return [start, end] as offsets to elem.textContent that
//   correspond to the selected portion of text
//   (if start == end, caret is at given position and no text is selected)
function getCaretPosition(elem) {
  var sel = window.getSelection();
  var cum_length = [0, 0];

  if(sel.anchorNode == elem)
    cum_length = [sel.anchorOffset, sel.extentOffset];
  else {
    var nodes_to_find = [sel.anchorNode, sel.extentNode];
    if(!elem.contains(sel.anchorNode) || !elem.contains(sel.extentNode))
      return undefined;
    else {
      var found = [0,0];
      var i;
      node_walk(elem, function(node) {
        for(i = 0; i < 2; i++) {
          if(node == nodes_to_find[i]) {
            found[i] = true;
            if(found[i == 0 ? 1 : 0])
              return false; // all done
          }
        }

        if(node.textContent && !node.firstChild) {
          for(i = 0; i < 2; i++) {
            if(!found[i])
              cum_length[i] += node.textContent.length;
          }
        }
      });
      cum_length[0] += sel.anchorOffset;
      cum_length[1] += sel.extentOffset;
    }
  }
  if(cum_length[0] <= cum_length[1])
    return cum_length;
  return [cum_length[1], cum_length[0]];
}

답변

$("#editable").on('keydown keyup mousedown mouseup',function(e){

       if($(window.getSelection().anchorNode).is($(this))){
    	  $('#position').html('0')
       }else{
         $('#position').html(window.getSelection().anchorOffset);
       }
 });

body{
  padding:40px;
}
#editable{
  height:50px;
  width:400px;
  border:1px solid #000;
}
#editable p{
  margin:0;
  padding:0;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.1/jquery.min.js"></script>
<div contenteditable="true" id="editable">move the cursor to see position</div>
<div>
position : <span id="position"></span>
</div>

function cursor_position() {
    var sel = document.getSelection();
    sel.modify("extend", "backward", "paragraphboundary");
    var pos = sel.toString().length;
    if(sel.anchorNode != undefined) sel.collapseToEnd();

    return pos;
}

// Demo:
var elm = document.querySelector('[contenteditable]');
elm.addEventListener('click', printCaretPosition)
elm.addEventListener('keydown', printCaretPosition)

function printCaretPosition(){
  console.log( cursor_position(), 'length:', this.textContent.trim().length )
}

<div contenteditable>some text here <i>italic text here</i> some other text here <b>bold text here</b> end of text</div>

function getCaretPosition() {
    var x = 0;
    var y = 0;
    var sel = window.getSelection();
    if(sel.rangeCount) {
        var range = sel.getRangeAt(0).cloneRange();
        if(range.getClientRects()) {
        range.collapse(true);
        var rect = range.getClientRects()[0];
        if(rect) {
            y = rect.top;
            x = rect.left;
        }
        }
    }
    return {
        x: x,
        y: y
    };
}

function getCaretCharOffset(element) {
  var caretOffset = 0;

  if (window.getSelection) {
    var range = window.getSelection().getRangeAt(0);
    var preCaretRange = range.cloneRange();
    preCaretRange.selectNodeContents(element);
    preCaretRange.setEnd(range.endContainer, range.endOffset);
    caretOffset = preCaretRange.toString().length;
  }

  else if (document.selection && document.selection.type != "Control") {
    var textRange = document.selection.createRange();
    var preCaretTextRange = document.body.createTextRange();
    preCaretTextRange.moveToElementText(element);
    preCaretTextRange.setEndPoint("EndToEnd", textRange);
    caretOffset = preCaretTextRange.text.length;
  }

  return caretOffset;
}


// Demo:
var elm = document.querySelector('[contenteditable]');
elm.addEventListener('click', printCaretPosition)
elm.addEventListener('keydown', printCaretPosition)

function printCaretPosition(){
  console.log( getCaretCharOffset(elm), 'length:', this.textContent.trim().length )
}

<div contenteditable>some text here <i>italic text here</i> some other text here <b>bold text here</b> end of text</div>

getCaretCharOffsetInDiv(e.target) + ($(window.getSelection().getRangeAt(0).startContainer.parentNode).index());

getCaretCharOffsetInDiv(e.target.parentElement) + ($(e.target).index())