atari-legend / legacy

jQuery(document).ready(function ($) {

    var timelineBlocks = $('.cd-timeline-block'),

        offset = 0.8;

    // hide timeline blocks which are outside the viewport

    hideBlocks(timelineBlocks, offset);

    // on scolling, show/animate timeline blocks when enter the viewport

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

        (!window.requestAnimationFrame)

            ? setTimeout(function () { showBlocks(timelineBlocks, offset); }, 100)

            : window.requestAnimationFrame(function () { showBlocks(timelineBlocks, offset); });

    });

    function hideBlocks (blocks, offset) {

        blocks.each(function () {

            ($(this).offset().top > $(window).scrollTop() + $(window).height() * offset) && $(this).find('.cd-timeline-img, .cd-timeline-content').addClass('is-hidden');

        });

    }

    function showBlocks (blocks, offset) {

        blocks.each(function () {

            ($(this).offset().top <= $(window).scrollTop() + $(window).height() * offset && $(this).find('.cd-timeline-img').hasClass('is-hidden')) && $(this).find('.cd-timeline-img, .cd-timeline-content').removeClass('is-hidden').addClass('bounce-in');

        });

    }

});