/* OnloadScheduler.js - schedules functions to run when a document has loaded
 *
 * The author of this program, Safalra (Stephen Morley), irrevocably releases
 * all rights to this program, with the intention of it becoming part of the
 * public domain. Because this program is released into the public domain, it
 * comes with no warranty either expressed or implied, to the extent permitted
 * by law.
 *
 * For more public domain JavaScript code by the same author, visit:
 * http://www.safalra.com/programming/javascript/
 */
 
var OnloadScheduler =
    new function(){

      var negative = new Array();
      var positive = new Array();

      window.onload = function(){
        for (var i = negative.length - 1; i > 0; i--) execute(negative[i]);
        for (var i = 0; i < positive.length; i++)     execute(positive[i]);
        OnloadScheduler = null;
      }

      function execute(tasks){
        if (tasks){
          for (var i = 0; i < tasks.length; i++) tasks[i]();
        }
      }

      this.schedule = function(task, priority){
        if (task instanceof Function){
          if (!priority) priority = 0;
          if (priority < 0){
            if (negative[-priority]){
              negative[-priority].push(task);
            }else{
              negative[-priority] = [task];
            }
          }else{
            if (positive[priority]){
              positive[priority].push(task);
            }else{
              positive[priority] = [task];
            }
          }
        }else{
          this.schedule(function(){eval(task)}, priority);
        }
      }

    };