laipower/wp-content/plugins/gp-premium/page-header/functions/js/parallax.js

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JavaScript
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2020-04-07 13:03:04 +00:00
function generate_parallax_element( selector, context ) {
context = context || document;
var elements = context.querySelectorAll( selector );
return Array.prototype.slice.call( elements );
}
window.addEventListener( "scroll", function() {
var scrolledHeight= window.pageYOffset;
generate_parallax_element( ".parallax-enabled" ).forEach( function( el, index, array ) {
var limit = el.offsetTop + el.offsetHeight;
if( scrolledHeight > el.offsetTop && scrolledHeight <= limit ) {
el.style.backgroundPositionY = ( scrolledHeight - el.offsetTop ) / el.getAttribute( 'data-parallax-speed' ) + "px";
} else {
el.style.backgroundPositionY = "0";
}
});
});