js 조작 textarea 방법 집합 패키지(IE,Firefox 호 환)

<textarea id="testlujun" style="width: 300px; height: 50px;">abcdefghijklmnopqrstuvwxyz</textarea>
<br />
<input onclick="alert(TT.getCursorPosition(test))" type="button" value="    " />
<input onclick="TT.setCursorPosition(test,3)" type="button" value="     3   " />
<input onclick="TT.add(test,'  ')" type="button" value="  '  '     " />
<input onclick="TT.del(test,2)" type="button" value="     2   " />
<input onclick="TT.del(test,-2)" type="button" value="     2   " />
<input onclick="TT.sel(test,0,2)" type="button" value="    0-2   " />
<input onclick="TT.selString(test,'mno')" type="button" value="    'mno'   " />
<script type="text/javascript">// <![CDATA[
var test = document.getElementById('testlujun');
var TT = {

 /*
  *       
  * @Method getCursorPosition
  * @param t element
  * @return number
  */
 getCursorPosition: function(t){
  if (document.selection) {
   t.focus();
   var ds = document.selection;
   var range = ds.createRange();
   var stored_range = range.duplicate();
   stored_range.moveToElementText(t);
   stored_range.setEndPoint("EndToEnd", range);
   t.selectionStart = stored_range.text.length - range.text.length;
   t.selectionEnd = t.selectionStart + range.text.length;
   return t.selectionStart;
  } else return t.selectionStart
 },

 
 /*
  *       
  * @Method setCursorPosition
  * @param t element
  * @param p number
  * @return
  */
 setCursorPosition:function(t, p){
  this.sel(t,p,p);
 },

 /*
  *        
  * @Method add
  * @param t element
  * @param txt String
  * @return
  */
 add:function (t, txt){
  var val = t.value;
  if(document.selection){
   t.focus()
   document.selection.createRange().text = txt;  
  } else {
   var cp = t.selectionStart;
   var ubbLength = t.value.length;
   var s = t.scrollTop;
  // document.getElementById('aaa').innerHTML += s + '<br />';
   t.value = t.value.slice(0,t.selectionStart) + txt + t.value.slice(t.selectionStart, ubbLength);
   this.setCursorPosition(t, cp + txt.length);
  // document.getElementById('aaa').innerHTML += t.scrollTop + '<br />';
   firefox=navigator.userAgent.toLowerCase().match(/firefox\/([\d\.]+)/) && setTimeout(function(){
    if(t.scrollTop != s) t.scrollTop=s;
   },0)
  };
 },

 
 /*
  *              n    
  * @Method del
  * @param t element
  * @param n number  n>0    n<0   
  * @return
  *      value     scrollTop      0
  */
 del:function(t, n){
  var p = this.getCursorPosition(t);
  var s = t.scrollTop;
  var val = t.value;
  t.value = n > 0 ? val.slice(0, p - n) + val.slice(p):
      val.slice(0, p) + val.slice(p - n);
  this.setCursorPosition(t ,p - (n < 0 ? 0 : n));
  firefox=navigator.userAgent.toLowerCase().match(/firefox\/([\d\.]+)/) && setTimeout(function(){
   if(t.scrollTop != s) t.scrollTop=s;
  },10)
 },

 /*
  *    s   z      
  * @Method sel
  * @param t element
  * @param s number
  * @param z number
  * @return
  */
 sel:function(t, s, z){
  if(document.selection){
   var range = t.createTextRange();
   range.moveEnd('character', -t.value.length);         
   range.moveEnd('character', z);
   range.moveStart('character', s);
   range.select();
  }else{
   t.setSelectionRange(s,z);
   t.focus();
  }
 },

 
 /*
  *        
  * @Method sel
  * @param t element
  * @param s String
  * @return
  */
 selString:function(t, s){
  var index = t.value.indexOf(s);
  index != -1 ? this.sel(t, index, index + s.length) : false;
 }
}
// ]]></script>