HTML Texeare使用向左，向右，向下，向上，向下和结束虚拟按钮进行插入符号控制

I am trying to put navigation control buttons on the HTML textarea box.So far the Tab works fine. The Backapace works fine. So do the End, Home, and Space buttons. The LEFT and RIGHT buttons keep jumping TWO characters with every click on the button.I have been banging my head for two days trying to find a solution before I decided to post the question. This is the link for the JSFiddle:[] (I am trying to put navigation control buttons o