;

(function ($, window, document, undefined) {

var pluginName = "scrollAnimations",

/**

* This SearchHintOptions object can be overridden during initialization

* @type {

{offset: number}}

*/

defaults = {

offset: 0.8

};

var timer;

/**

* ScrollAnimations - applies an animate class to elements when scrolled into the viewport

*

* @author Westley Mon <wmarchment@mindgruve.com>

* @version 1.0.1

*

* @param {jQuery} element jQuery instance of selected elements

* @param {ScrollAnimationsOptions} options Custom options will be merged with the defaults

* @constructor

*/

function ScrollAnimations(element, options) {

if (element) {

this.element = element;

this.animationElements = [];

this.triggerPoint = null;

this.lastScrollPos = -1;

// jQuery has an extend method which merges the contents of two or

// more objects, storing the result in the first object. The first object

// is generally empty as we don't want to alter the default options for

// future instances of the plugin

this.options = $.extend( {}, defaults, options );

this._defaults = defaults;

this._name = pluginName;

window.onload = this.init();

}

}

ScrollAnimations.prototype = {

init: function() {

var _this = this;

var $els = $(this.element);

//setup all items

_this.setup($els);

// start an interval to update the page rather than onscroll

var scrollIntervalID = setInterval(function () {

_this.updatePage(_this);

}, 10);

$(window).on('resize', function () {

_this.resize();

});

},

resize: function () {

var _this = this;

clearTimeout(timer);

timer = setTimeout(function () {

_this.setTriggerpoint();

}, 50);

},

setTriggerpoint: function() {

this.triggerPoint = window.innerHeight * this.options.offset;

},

setup: function(items) {

this.setTriggerpoint();

var $this = $(items),

$children = $this.find('[data-animation-child]');

if ($children.length) {

// setup children

$children.each(function() {

var $child = $(this);

var $delay = $child.attr('data-animation-delay');

$child.css({

'-webkit-animation-delay': $delay,

'-moz-animation-delay': $delay,

'-ms-animation-delay': $delay,

'-o-animation-delay': $delay,

'animation-delay': $delay

});

});

} else {

var $delay = $this.attr('data-animation-delay');

// setup single item

$this.css({

'-webkit-animation-delay': $delay,

'-moz-animation-delay': $delay,

'-ms-animation-delay': $delay,

'-o-animation-delay': $delay,

'animation-delay': $delay

});

}

this.animationElements.push($this);

},

updatePage: function (plugin) {

var _this = plugin;

window.requestAnimationFrame(function () {

_this.animateElements();

});

},

animateElements: function() {

var _this = this;

var scrollPos = window.pageYOffset;

// have we scrolled since the last rAF? if not, return.

if (scrollPos === this.lastScrollPos) return;

this.lastScrollPos = scrollPos;

$(_this.animationElements).each(function() {

var $this = $(this),

$children = $this.find('[data-animation-child]');

if ($this.hasClass('animated') || (scrollPos < $this.offset().top - _this.triggerPoint))

return; // don't continue if its already been animated or scroll position hasn't hit the trigger point yet

if ($children.length) {

$this.addClass('animated');

// animate the children

$children.each(function() {

$(this).addClass('animated').addClass( $(this).attr('data-animation') )

});

} else {

// animate the single item

$this.addClass('animated').addClass( $this.attr('data-animation') );

}

});

}

};

$.fn[ pluginName ] = function (options) {

return this.each(function() {

if (!$.data(this, "plugin_" + pluginName)) {

$.data(this, "plugin_" + pluginName,

new ScrollAnimations(this, options));

}

});

};

//add support for amd

if (typeof define === "function" && define.amd) {

define(function () {

return ScrollAnimations;

});

}

})(jQuery, window, document);