/** jquery.blank ver. 1.1 - JQuery Plugin
 * Implements default text for text fields when disappear when the user focuses the element.
 *
 * Options:
 *	defaultCSS:       CSS styling when the textbox is displaying its default text. This can
 *	                  be either an object hash or a function that returns a object hash. This
 *	                  value is directly passed to jquery's css method.
 *	                  Defaults to {color: '#999'}.
 *	defaultFocusCSS:  Identical to defaultCSS, but this is used when the user focuses the
 *	                  text input but has not typed anything yet. This is only used when
 *	                  defaultUntilType is set to true.
 *	                  Defaults to {color: '#bbb'}.
 *	normalCSS:        Identical for defaultCSS except it applies to the CSS styling for when
 *	                  the user enters text into the input box.
 *	                  Defaults to a function which looks into a merged hash of both
 *	                  defaultCSS and defaultFocusCSS for css properties that were set and
 *	                  gets the computated style when this jquery.blank is called.
 *	defaultUntilType: Sets the default text to display when the user focuses on the text
 *	                  input but does not highlight anything. Refer to Apple's me.com for a
 *	                  similar kind of effect with the login textboxes.
 *	                  Defaults to false.
 * =============
 * Copyright (c) 2009 Jeff Hui <contrib@jeffhui.net>
 * 
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 */
(function($){
$.fn.blank = function(text, options){
  // when we use $(el).blank() # returns a true/false if the input is actually blank
  if(text == undefined){
    var d = this.data('blank');
	if(d != undefined)
		return true;
	else
		return false;
  }
  // setting an element to have a default-value behavior
  var opt = {
	defaultCSS: {color: '#999'},
	normalCSS: function(el, defCSS, defFocusCSS){
	  // here we just try to get default css styles from the element
	  // for all key values of defCSS
	  var css = $.extend({}, defCSS, defFocusCSS);
	  var e = $(this);
	  $.each(defCSS, function(i, v){
		css[i] = $.curCSS(e.get(0), i);
	  });
	  return css;
	},
	defaultFocusCSS: {color: '#bbb'},
	defaultUntilType: false
  };
  $.extend(opt, options);

  // it's outside the each call since less function defs inside the each call
  // makes things faster. Plus we're calling this multiple times
  function call(func, el, param){
	if($.isFunction(func))
	  return (param != undefined) ? func.call(el, el, param) : func.call(el, el);
	else
	  return func;
  }

  return this.each(function(){
	var d = call(opt.defaultCSS, this);
	var df = call(opt.defaultFocusCSS, this, d);
	var n = call(opt.normalCSS, this, d, df);
	var el = $(this);
    if(!el.is('input[type=text], textarea'))
      return true; // continue

	if(!opt.defaultUntilType){
      el.blur(function(){
        if($.trim(el.val()) === '')
          el.val(text).css(d).data('blank', 1);
        else
		  el.removeData('blank');
      }).focus(function(){
  	    if(el.blank())
  		  el.val('').css(n);
      }).blur();

	} else { // if !opt.defaultUntilType

	  el.data('blank', 1);
	  el.blur(function(){
	    if(el.data('blank'))
		  el.css(d).val(text);
	  }).mouseup(function(){
		if(!el.blank()) return true;
		var e = el.get(0);
	    if(e.selectionStart !== undefined){ // W3C compliant browsers
		  e.selectionStart = 0;
		  e.selectionEnd = 0;
		} else if(e.createTextRange){ // IE-browsers
		  var tr = e.createTextRange();
		  tr.collapse(true);
		  tr.moveStart('character', 0);
		  tr.moveEnd('character', 0);
		  tr.select();
		}
	  }).focus(function(){
	    if(el.blank()){
	      el.css(df);
	    }
      }).keydown(function(evt){
		var ignoreList = [
			8,  // backspace
			9,  // tab
			16, // shift
			17, // alt
			18, // pause/break
			20, // capslock
			27, // esc
			33, // pgup
			34, // pgdown
			35, // end
			36, // home
			91, // left winkey
			92, // right winkey
			144,// numlock
			145 // scroll lock
		]
		if(ignoreList.indexOf(evt.keyCode) !== -1)
		  return true;
		var v = el.val();
	    if(el.blank())
		  el.removeData('blank').css(n).val(v.substring(0, v.length-text.length));
	  }).keyup(function(){
		var v = el.val();
		if(!el.blank() && v === '')
		  el.data('blank', 1).css(df);
	  }).blur();
    }
  });
};
})(jQuery);