/*! Copyright (c) 2009 Brandon Aaron (http://brandonaaron.net)
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 *
 * Version: 1.1.0-pre
 * Requires jQuery 1.3+
 * Docs: http://docs.jquery.com/Plugins/livequery
 */
 
(function($) {
 
$.extend($.fn, {
  livequery: function(type, fn, fn2) {
    var self = this, q;
 
    // Handle different call patterns
    if ($.isFunction(type))
      fn2 = fn, fn = type, type = undefined;
 
    // See if Live Query already exists
    $.each( $.livequery.queries, function(i, query) {
      if ( self.selector == query.selector && self.context == query.context &&
        type == query.type && (!fn || fn.$lqguid == query.fn.$lqguid) && (!fn2 || fn2.$lqguid == query.fn2.$lqguid) )
          // Found the query, exit the each loop
          return (q = query) && false;
    });
 
    // Create new Live Query if it wasn't found
    q = q || new $.livequery(this.selector, this.context, type, fn, fn2);
 
    // Make sure it is running
    q.stopped = false;
 
    // Run it immediately for the first time
    q.run();
 
    // Contnue the chain
    return this;
  },
 
  expire: function(type, fn, fn2) {
    var self = this;
 
    // Handle different call patterns
    if ($.isFunction(type))
      fn2 = fn, fn = type, type = undefined;
 
    // Find the Live Query based on arguments and stop it
    $.each( $.livequery.queries, function(i, query) {
      if ( self.selector == query.selector && self.context == query.context &&
        (!type || type == query.type) && (!fn || fn.$lqguid == query.fn.$lqguid) && (!fn2 || fn2.$lqguid == query.fn2.$lqguid) && !this.stopped )
          $.livequery.stop(query.id);
    });
 
    // Continue the chain
    return this;
  }
});
 
$.livequery = function(selector, context, type, fn, fn2) {
  this.selector = selector;
  this.context  = context;
  this.type     = type;
  this.fn       = fn;
  this.fn2      = fn2;
  this.elements = [];
  this.stopped  = false;
 
  // The id is the index of the Live Query in $.livequery.queries
  this.id = $.livequery.queries.push(this)-1;
 
  // Mark the functions for matching later on
  fn.$lqguid = fn.$lqguid || $.livequery.guid++;
  if (fn2) fn2.$lqguid = fn2.$lqguid || $.livequery.guid++;
 
  // Return the Live Query
  return this;
};
 
$.livequery.prototype = {
  stop: function() {
    var query = this;
 
    if ( this.type )
      // Unbind all bound events
      this.elements.unbind(this.type, this.fn);
    else if (this.fn2)
      // Call the second function for all matched elements
      this.elements.each(function(i, el) {
        query.fn2.apply(el);
      });
 
    // Clear out matched elements
    this.elements = [];
 
    // Stop the Live Query from running until restarted
    this.stopped = true;
  },
 
  run: function() {
    // Short-circuit if stopped
    if ( this.stopped ) return;
    var query = this;
 
    var oEls = this.elements,
      els  = $(this.selector, this.context),
      nEls = els.not(oEls);
 
    // Set elements to the latest set of matched elements
    this.elements = els;
 
    if (this.type) {
      // Bind events to newly matched elements
      nEls.bind(this.type, this.fn);
 
      // Unbind events to elements no longer matched
      if (oEls.length > 0)
        $.each(oEls, function(i, el) {
          if ( $.inArray(el, els) < 0 )
            $.event.remove(el, query.type, query.fn);
        });
    }
    else {
      // Call the first function for newly matched elements
      nEls.each(function() {
        query.fn.apply(this);
      });
 
      // Call the second function for elements no longer matched
      if ( this.fn2 && oEls.length > 0 )
        $.each(oEls, function(i, el) {
          if ( $.inArray(el, els) < 0 )
            query.fn2.apply(el);
        });
    }
  }
};
 
$.extend($.livequery, {
  guid: 0,
  queries: [],
  queue: [],
  running: false,
  timeout: null,
 
  checkQueue: function() {
    if ( $.livequery.running && $.livequery.queue.length ) {
      var length = $.livequery.queue.length;
      // Run each Live Query currently in the queue
      while ( length-- )
        $.livequery.queries[ $.livequery.queue.shift() ].run();
    }
  },
 
  pause: function() {
    // Don't run anymore Live Queries until restarted
    $.livequery.running = false;
  },
 
  play: function() {
    // Restart Live Queries
    $.livequery.running = true;
    // Request a run of the Live Queries
    $.livequery.run();
  },
 
  registerPlugin: function() {
    $.each( arguments, function(i,n) {
      // Short-circuit if the method doesn't exist
      if (!$.fn[n]) return;
 
      // Save a reference to the original method
      var old = $.fn[n];
 
      // Create a new method
      $.fn[n] = function() {
        // Call the original method
        var r = old.apply(this, arguments);
 
        // Request a run of the Live Queries
        $.livequery.run();
 
        // Return the original methods result
        return r;
      }
    });
  },
 
  run: function(id) {
    if (id != undefined) {
      // Put the particular Live Query in the queue if it doesn't already exist
      if ( $.inArray(id, $.livequery.queue) < 0 )
        $.livequery.queue.push( id );
    }
    else
      // Put each Live Query in the queue if it doesn't already exist
      $.each( $.livequery.queries, function(id) {
        if ( $.inArray(id, $.livequery.queue) < 0 )
          $.livequery.queue.push( id );
      });
 
    // Clear timeout if it already exists
    if ($.livequery.timeout) clearTimeout($.livequery.timeout);
    // Create a timeout to check the queue and actually run the Live Queries
    $.livequery.timeout = setTimeout($.livequery.checkQueue, 20);
  },
 
  stop: function(id) {
    if (id != undefined)
      // Stop are particular Live Query
      $.livequery.queries[ id ].stop();
    else
      // Stop all Live Queries
      $.each( $.livequery.queries, function(id) {
        $.livequery.queries[ id ].stop();
      });
  }
});
 
// Register core DOM manipulation methods
$.livequery.registerPlugin('append', 'prepend', 'after', 'before', 'wrap', 'attr', 'removeAttr', 'addClass', 'removeClass', 'toggleClass', 'empty', 'remove');
 
// Run Live Queries when the Document is ready
$(function() { $.livequery.play(); });
 
})(jQuery);