next and previous arrow in gallery product page in prestashop 1.7.

$(document).on('click', '.product-cover .prev', function(e){
 e.preventDefault();

 var next_img = $('.js-qv-mask .product-images li img.selected').parent().parent().prev().find('img.thumb');

 $('.js-qv-mask .product-images li a').find('img').removeClass('selected');

 next_img.addClass('selected');

 $(".product-cover img").attr('src',next_img.attr('src'));

});


$(document).on('click', '.product-cover .next', function(e){

 e.preventDefault();

 var next_img = $('.js-qv-mask .product-images li img.selected').parent().parent().next().find('img.thumb');

 $('.js-qv-mask .product-images li a').find('img').removeClass('selected');

 next_img.addClass('selected');

 $(".product-cover img").attr('src',next_img.attr('src'));

});