jquery.firefly-0.4.js

/*
 * jQuery firefly plugin 0.4
 *
 *
 * Copyright (c) 2010 Dharmveer Motyar
 * http://motyar.blogspot.com
 *
 * $Id$
 *
 * licensed under the MIT licenses:
 *   http://www.opensource.org/licenses/mit-license.php
 *
 *
 * Creates a firefly effect.
 *
 * @example $.firefly();
 *
 * @name firefly
 * @type jQuery
 * @cat Plugins/firefly
 */
 (function($) {
  /*
   * Plugin defaults
   */
  var defaults = {
    total : 10,
    ofTop: 0,
    ofLeft: 0,
    on:'document.body',
    twinkle: 0.2,
    minPixel: 1,
    maxPixel: 2,
    color: '#fff',
    namespace: 'jqueryFireFly',

    _paused: false,
  };

  $.firefly = function(settings) {
    $.firefly.settings = $.extend({}, defaults, settings);
    $.firefly.eleHeight = $($.firefly.settings.on).height();
    $.firefly.eleWidth = $($.firefly.settings.on).width();

    if ($.firefly.settings.on!=='document.body') {
      var off = $($.firefly.settings.on).offset();
      $.firefly.offsetTop = off.top;
      $.firefly.offsetLeft = off.left;
      $.firefly.eleHeight = $($.firefly.settings.on).height();
      $.firefly.eleWidth = $($.firefly.settings.on).width();
    }  else {
      $.firefly.offsetTop = 0;
      $.firefly.offsetLeft = 0;
      $.firefly.eleHeight = $(document.body).height();
      $.firefly.eleWidth = $(document.body).width();
    }

    for (i = 0; i < $.firefly.settings.total; i++){
      var randomPixel = $.firefly.randomPixel($.firefly.settings.minPixel, $.firefly.settings.maxPixel);
      var sp = $.firefly.create(randomPixel);

      $.firefly.fly(sp);
    }

    $.firefly.sparks = $($.firefly.settings.on).children('.' + $.firefly.settings.namespace);

    this.pause = function(bool) {
      $.firefly.settings._paused = true;

      if (bool) {
        $.each($.firefly.sparks, function(iter, sp) {
          $(sp).stop(true);
        });
      }
    };

    this.resume = function() {
      $.firefly.settings._paused = false;

      $.each($.firefly.sparks, function(iter, sp) {
        $.firefly.fly(sp);
      });
    };

    return this;
  };

  $.firefly.create = function(pixelSize){
    spark = $('<div>').hide();
    spark.addClass($.firefly.settings.namespace);
    $.firefly.settings._onSparkID++;

    if ($.firefly.settings.on === 'document.body') {
      $(document.body).append(spark);
    } else {
      $($.firefly.settings.on).append(spark);
    }

    return spark.css({
      'position':'absolute',
      'width' : pixelSize,
      'height': pixelSize,
      'background-color': $.firefly.settings.color,
      'z-index': $.firefly.random(20), //under all the stuff
      top: $.firefly.offsetTop + $.firefly.random(($.firefly.eleHeight-50)),  //offsets
      left:  $.firefly.offsetLeft + $.firefly.random(($.firefly.eleWidth-50)) //offsets
    }).show();
  };

  $.firefly.fly = function(sp) {
    $(sp).animate({
      top: $.firefly.offsetTop + $.firefly.random(($.firefly.eleHeight-50)),  //offsets
      left: $.firefly.offsetLeft + $.firefly.random(($.firefly.eleWidth-50)),
      opacity: $.firefly.opacity($.firefly.settings.twinkle)
    }, {
      duration: (($.firefly.random(10) + 5) * 2000),
      done: function() {
        if (!$.firefly.settings._paused) {
          $.firefly.fly(sp);
        }
      }
    });
  };

  $.firefly.randomPixel = function(min, max) {
    return Math.floor(Math.random()*(max-min+1)+min);
  };

  $.firefly.random = function(max) {
    return Math.ceil(Math.random() * max) - 1;
  };

  $.firefly.opacity = function(min) {
    op= Math.random();
    if (op < min) {
      return 0;
    } else {
      return 1;
    }
  };
})(jQuery);