Fix lazy loading on the genre pages (#6799)

* Fix genre tab from sorting shows randomly

* Fix loading elements that have already been loaded

* Fix lazyLoader for show and movie genre tabs

* Reduce time window in which callback may be executed again

src/components/lazyLoader/lazyLoaderIntersectionObserver.js

@@ -7,10 +7,10 @@ export class LazyLoader {
     createObserver() {
         const callback = this.options.callback;
 
-        const observer = new IntersectionObserver(
-            (entries) => {
+        const newObserver = new IntersectionObserver(
+            (entries, observer) => {
                 entries.forEach(entry => {
-                    callback(entry);
+                    callback(entry, observer);
                 });
             },
             {
@@ -18,7 +18,7 @@ export class LazyLoader {
                 threshold: 0
             });
 
-        this.observer = observer;
+        this.observer = newObserver;
     }
 
     addElements(elements) {

src/controllers/movies/moviegenres.js

@@ -52,8 +52,14 @@ export default function (view, params, tabContent) {
         return !layoutManager.desktop;
     }
 
-    const fillItemsContainer = (entry) => {
+    const fillItemsContainer = (entry, observer) => {
+        if (!entry.isIntersecting) {
+            return;
+        }
+
         const elem = entry.target;
+        observer.unobserve(elem);
+
         const id = elem.getAttribute('data-id');
         const viewStyle = this.getCurrentViewStyle();
         let limit = viewStyle == 'Thumb' || viewStyle == 'ThumbCard' ? 5 : 9;

src/controllers/shows/tvgenres.js

@@ -52,8 +52,14 @@ export default function (view, params, tabContent) {
         return !layoutManager.desktop;
     }
 
-    function fillItemsContainer(entry) {
+    function fillItemsContainer(entry, observer) {
+        if (!entry.isIntersecting) {
+            return;
+        }
+
         const elem = entry.target;
+        observer.unobserve(elem);
+
         const id = elem.getAttribute('data-id');
         const viewStyle = self.getCurrentViewStyle();
         let limit = viewStyle == 'Thumb' || viewStyle == 'ThumbCard' ? 5 : 9;