JavaScript - 为写在 contenteditable div 中的每个字母添加跨度

Question

我想创建添加 <span> 的脚本contenteditable div 的每个字母。例如:
如果您在 contenteditable div 中写了一些东西，在 HTML 代码中，您将看到:

<div contenteditable="true">
    SomeText
</div>

我必须做些什么才能看到这样的东西:

<div contenteditable="true">
    <span>S</span>
    <span>o</span>
    <span>m</span>
    <span>e</span>
    <span>T</span>
    <span>e</span>
    <span>x</span>
    <span>t</span>
</div>  

我写了一些代码(使用 Rangy )，但它不起作用。您可以在下面看到该代码，但我不推荐它，因为它太长了，而且正如我所说，它不起作用。

$('#Box').keypress(function() {
  setTimeout(function() {
    var selLenght = getCaretCharacterOffsetWithin(document.getElementById('Box'));

    var precedingChar = "",
      sel, range, precedingRange;
    sel = rangy.getSelection();
    range = sel.getRangeAt(0).cloneRange();
    range.setStart(document.getElementById('Box'), 0);
    sel.setSingleRange(range);
    sel.removeAllRanges();
    range.setStart(document.getElementById('Box'), selLenght - 21);
    sel.setSingleRange(range);
/*
    var newElem = document.createElement('span');
    newElem.className = 'test';
    $(newElem).html(range.extractContents());
    range.insertNode(newElem);
    $('#MainBox > span:empty').remove();
*/
    rangy.getSelection().move('character', 0);
  });
});

function getCaretCharacterOffsetWithin(element) {
    var caretOffset = 0;
    if (typeof window.getSelection != "undefined") {
        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 (typeof document.selection != "undefined" && 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;
}

div{
  width: 400px;
  height: 200px;
  border: 1px solid black;
}

<script src="https://github.com/timdown/rangy/blob/master/lib/rangy-core.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<div contenteditable="true" id="Box"></div>

我怎样才能在 JavaScript 和/或 JQuery 和/或免费用于商业用途的外部库中做类似的事情？
感谢您的帮助。

Answer 1

使用 jQuery 你可以做类似下面的事情，还要注意我们需要一些辅助函数来管理光标位置。

var box = $('#Box');
var button = $('button');

box.on('input', function(e) {
  restoreCaret = saveCaretPosition(this);
  box.html(wrapLetters(box.text()));
  restoreCaret();
});

var textContent = '';
button.on('mousedown', function() {
  button.text('Hide HTML');
  textContent = box.text();
  box.text(box.html());
});
button.on('mouseup', function() {
  button.text('Show HTML');
  box.text(textContent);
  box.html(wrapLetters(textContent));
});


/* HELPERS */
function wrapLetters(textContent) {
  return textContent.split('').map(function(letter) {
    return '<span>' + letter + '</span>';
  }).join('');
}

function saveCaretPosition(context) {
  var selection = window.getSelection();
  var range = selection.getRangeAt(0);
  range.setStart(context, 0);
  var len = range.toString().length;

  return function restore() {
    var pos = getTextNodeAtPosition(context, len);
    selection.removeAllRanges();
    var range = new Range();
    range.setStart(pos.node, pos.position);
    selection.addRange(range);

  }
}

function getTextNodeAtPosition(root, index) {
  var lastNode = null;

  var treeWalker = document.createTreeWalker(root, NodeFilter.SHOW_TEXT, function next(elem) {
    if (index > elem.textContent.length) {
      index -= elem.textContent.length;
      lastNode = elem;
      return NodeFilter.FILTER_REJECT
    }
    return NodeFilter.FILTER_ACCEPT;
  });
  var c = treeWalker.nextNode();
  return {
    node: c ? c : root,
    position: c ? index : 0
  };
}

#Box {
  width: 400px;
  height: 100px;
  border: 1px solid black;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<div contenteditable="true" id="Box"></div>

<button>Show HTML</button>