https://github.com/WWBN/AVideo/issues/8137

node_modules/flickity/js/lazyload.js

@@ -0,0 +1,124 @@
+// lazyload
+( function( window, factory ) {
+  // universal module definition
+  if ( typeof module == 'object' && module.exports ) {
+    // CommonJS
+    module.exports = factory(
+        require('./core'),
+        require('fizzy-ui-utils'),
+    );
+  } else {
+    // browser global
+    factory(
+        window.Flickity,
+        window.fizzyUIUtils,
+    );
+  }
+
+}( typeof window != 'undefined' ? window : this, function factory( Flickity, utils ) {
+
+const lazyAttr = 'data-flickity-lazyload';
+const lazySrcAttr = `${lazyAttr}-src`;
+const lazySrcsetAttr = `${lazyAttr}-srcset`;
+const imgSelector = `img[${lazyAttr}], img[${lazySrcAttr}], ` +
+  `img[${lazySrcsetAttr}], source[${lazySrcsetAttr}]`;
+
+Flickity.create.lazyLoad = function() {
+  this.on( 'select', this.lazyLoad );
+
+  this.handleLazyLoadComplete = this.onLazyLoadComplete.bind( this );
+};
+
+let proto = Flickity.prototype;
+
+proto.lazyLoad = function() {
+  let { lazyLoad } = this.options;
+  if ( !lazyLoad ) return;
+
+  // get adjacent cells, use lazyLoad option for adjacent count
+  let adjCount = typeof lazyLoad == 'number' ? lazyLoad : 0;
+  // lazy load images
+  this.getAdjacentCellElements( adjCount )
+    .map( getCellLazyImages )
+    .flat()
+    .forEach( ( img ) => new LazyLoader( img, this.handleLazyLoadComplete ) );
+};
+
+function getCellLazyImages( cellElem ) {
+  // check if cell element is lazy image
+  if ( cellElem.matches('img') ) {
+    let cellAttr = cellElem.getAttribute( lazyAttr );
+    let cellSrcAttr = cellElem.getAttribute( lazySrcAttr );
+    let cellSrcsetAttr = cellElem.getAttribute( lazySrcsetAttr );
+    if ( cellAttr || cellSrcAttr || cellSrcsetAttr ) {
+      return cellElem;
+    }
+  }
+  // select lazy images in cell
+  return [ ...cellElem.querySelectorAll( imgSelector ) ];
+}
+
+proto.onLazyLoadComplete = function( img, event ) {
+  let cell = this.getParentCell( img );
+  let cellElem = cell && cell.element;
+  this.cellSizeChange( cellElem );
+
+  this.dispatchEvent( 'lazyLoad', event, cellElem );
+};
+
+// -------------------------- LazyLoader -------------------------- //
+
+/**
+ * class to handle loading images
+ * @param {Image} img - Image element
+ * @param {Function} onComplete - callback function
+ */
+function LazyLoader( img, onComplete ) {
+  this.img = img;
+  this.onComplete = onComplete;
+  this.load();
+}
+
+LazyLoader.prototype.handleEvent = utils.handleEvent;
+
+LazyLoader.prototype.load = function() {
+  this.img.addEventListener( 'load', this );
+  this.img.addEventListener( 'error', this );
+  // get src & srcset
+  let src = this.img.getAttribute( lazyAttr ) ||
+    this.img.getAttribute( lazySrcAttr );
+  let srcset = this.img.getAttribute( lazySrcsetAttr );
+  // set src & serset
+  this.img.src = src;
+  if ( srcset ) this.img.setAttribute( 'srcset', srcset );
+  // remove attr
+  this.img.removeAttribute( lazyAttr );
+  this.img.removeAttribute( lazySrcAttr );
+  this.img.removeAttribute( lazySrcsetAttr );
+};
+
+LazyLoader.prototype.onload = function( event ) {
+  this.complete( event, 'flickity-lazyloaded' );
+};
+
+LazyLoader.prototype.onerror = function( event ) {
+  this.complete( event, 'flickity-lazyerror' );
+};
+
+LazyLoader.prototype.complete = function( event, className ) {
+  // unbind events
+  this.img.removeEventListener( 'load', this );
+  this.img.removeEventListener( 'error', this );
+  let mediaElem = this.img.parentNode.matches('picture') ? this.img.parentNode : this.img;
+  mediaElem.classList.add( className );
+
+  this.onComplete( this.img, event );
+};
+
+// -----  ----- //
+
+Flickity.LazyLoader = LazyLoader;
+
+return Flickity;
+
+} ) );