feat(carousel): enhance circular layout handling and optimize page creation logic

src/app/shared/components/carousel/carousel.component.ts

@@ -70,6 +70,10 @@ export class CarouselComponent<T> implements AfterViewInit {
   );
   protected readonly isCircularLayout = computed(() => this.circular() && this.pageCount() > 1);
   protected readonly circularPages = computed<CarouselPage<T>[]>(() => {
+    if (!this.isCircularLayout()) {
+      return [];
+    }
+
     const pageCount = this.pageCount();
     const currentPage = this.normalizePage(this.currentPage(), pageCount);
 
@@ -270,14 +274,20 @@ export class CarouselComponent<T> implements AfterViewInit {
   }
 
   private createPage(slot: CarouselPage<T>['slot'], page: number): CarouselPage<T> {
+    const sourceItems = this.items();
+    // Layout has not necessarily been measured when a computed value is inspected.
+    const pageSize = Math.min(this.itemsPerPage(), sourceItems.length);
+    if (pageSize === 0) {
+      return { slot, items: [] };
+    }
     const pageCount = this.pageCount();
     const normalizedPage = this.normalizePage(page, pageCount);
-    const start = normalizedPage * this.itemsPerPage();
+    const start = normalizedPage * pageSize;
     const items: CarouselPageItem<T>[] = [];
 
-    for (let offset = 0; offset < this.itemsPerPage(); offset += 1) {
-      const index = (start + offset) % this.items().length;
-      items.push({ item: this.items()[index], index });
+    for (let offset = 0; offset < pageSize; offset += 1) {
+      const index = (start + offset) % sourceItems.length;
+      items.push({ item: sourceItems[index], index });
     }
 
     return { slot, items };