输入tab

HTML

<div id="editor" contenteditable>
</div>
<textarea id="textarea"></textarea>
<br>
<button>测试Tab</button>

CSS

#editor,
textarea {
  width: 300px;
  height: 60px;
  background: #fff;
  border: 1px solid #ddd;
}

JavaScript

$('#editor, textarea').keydown(function(e){
    if(e.keyCode === 9) {
        /* this.innerHTML = this.innerHTML += '&nbsp;&nbsp;&nbsp;&nbsp;' */;
        document.execCommand('insertText', false, '    ')
        e.preventDefault();
    }
})