Add a Ken Burns effect to MetaSlider using FlexSlider

metaslider-ken-burns-effect.php

<?php 

$slideshow_id = '236';

add_filter('metaslider_css_classes', function($classes, $id) use ($slideshow_id) {
	if ($id != $slideshow_id) return $classes;
	return $classes . ' kenburns-effect';
}, 10, 2);

add_filter('metaslider_css', function($css, $settings, $id) use ($slideshow_id) {
	if ($id != $slideshow_id) return $css;
	return $css . "
	.kenburns-effect .flexslider .slides,
	.kenburns-effect .flexslider .slides > li {
		overflow: hidden;
	}
	.kenburns-effect .flexslider .slides > li .kenburns-inner {
		background-size: cover;
		background-position: center;
		position: absolute;
		width: 100%;
		height: 100%;
		left: 0;
		top: 0;
	}
	.kenburns-effect .flexslider .slides img {
		opacity: 0;
	}
	.kenburns-effect .flexslider .slides > li.flex-active-slide .kenburns-inner {
		animation: kb-zoom-out {$settings['delay']}ms;	
	}
	@-webkit-keyframes kb-zoom-out {
		0% {
			transform: scale(1.3);
		}
		100% {
			transform: scale(1);
		}
	}";
}, 10, 3);

add_filter('metaslider_flex_slider_list_item_attributes', function($attributes, $slide, $id) use ($slideshow_id) {
	if ($id != $slideshow_id) return $attributes;
	$movements = ['center left', 'center center', 'center right', 'top left', 'top center', 'top right', 'bottom left', 'bottom center', 'bottom right'];
	$attributes['data-background'] = isset($slide['src']) ? $slide['src'] : '';
	$attributes['data-movement'] = $movements[array_rand($movements)];
	return $attributes;
}, 10, 3);

add_filter('metaslider_flex_slider_javascript', function($js, $id) use ($slideshow_id) {
	if ($id != $slideshow_id) return $js;
	return $js . ";window.jQuery('.kenburns-effect .slides .ms-image').each(function() {
		var background = $(this).data('background');
		var movement = $(this).data('movement');
		$(this).prepend(\"<div class='kenburns-inner' style='background-image:url(\" + background + \");transform-origin:\" + movement + \"'></div>\");
	});";
}, 10, 2);

In case the URL goes down, see it here: https://www.youtube.com/watch?v=Rz-AB0ssFbo