jquery ReverseResize Extension

jquery.ui.extension.js

$.ui.plugin.add("resizable", "alsoResizeReverse", {

  start: function(event, ui) {

    var self = $(this).data("ui-resizable"), o = self.options;

    var _store = function(exp) {
      $(exp).each(function() {
        $(this).data("resizable-alsoresize-reverse", {
          width: parseInt($(this).width(), 10), height: parseInt($(this).height(), 10),
          left: parseInt($(this).css('left'), 10), top: parseInt($(this).css('top'), 10)
        });
      });
    };

    if (typeof(o.alsoResizeReverse) == 'object' && !o.alsoResizeReverse.parentNode) {
      if (o.alsoResizeReverse.length) { o.alsoResize = o.alsoResizeReverse[0];    _store(o.alsoResizeReverse); }
      else { $.each(o.alsoResizeReverse, function(exp, c) { _store(exp); }); }
    }else{
      _store(o.alsoResizeReverse);
    }
  },

  resize: function(event, ui){
    var self = $(this).data("ui-resizable"), o = self.options, os = self.originalSize, op = self.originalPosition;

    var delta = {
        height: (self.size.height - os.height) || 0, width: (self.size.width - os.width) || 0,
        top: (self.position.top - op.top) || 0, left: (self.position.left - op.left) || 0
      },

      _alsoResizeReverse = function(exp, c) {
        $(exp).each(function() {
          var el = $(this), start = $(this).data("resizable-alsoresize-reverse"), style = {}, css = c && c.length ? c : ['width', 'height', 'top', 'left'];

          $.each(css || ['width', 'height', 'top', 'left'], function(i, prop) {
            var sum = (start[prop]||0) - (delta[prop]||0); // subtracting instead of adding
            if (sum && sum >= 0)
              style[prop] = sum || null;
          });

          //Opera fixing relative position
          if (/relative/.test(el.css('position')) && $.browser &&  $.browser.opera) {
            self._revertToRelativePosition = true;
            el.css({ position: 'absolute', top: 'auto', left: 'auto' });
          }

          el.css(style);
        });
      };

    if (typeof(o.alsoResizeReverse) == 'object' && !o.alsoResizeReverse.nodeType) {
      $.each(o.alsoResizeReverse, function(exp, c) { _alsoResizeReverse(exp, c); });
    }else{
      _alsoResizeReverse(o.alsoResizeReverse);
    }
  },

  stop: function(event, ui){
    var self = $(this).data("ui-resizable");

    //Opera fixing relative position
    if (self._revertToRelativePosition && $.browser.opera) {
      self._revertToRelativePosition = false;
      el.css({ position: 'relative' });
    }

    $(this).removeData("resizable-alsoresize-reverse");
  }
});