Extract Scroll Storage controller

assets/controllers/scroll_storage_controller.js

@@ -0,0 +1,19 @@
+import { Controller } from '@hotwired/stimulus';
+
+export default class extends Controller {
+  static values = { entryId: Number };
+
+  connect() {
+    window.scrollTo({
+      top: window.innerHeight * localStorage[`wallabag.article.${this.entryIdValue}.percent`],
+      behavior: 'smooth',
+    });
+  }
+
+  saveScroll() {
+    const scrollPercent = window.scrollY / window.innerHeight;
+    const scrollPercentRounded = Math.round(scrollPercent * 100) / 100;
+
+    localStorage[`wallabag.article.${this.entryIdValue}.percent`] = scrollPercentRounded;
+  }
+}