From 6b2531456ab75623a2c729b7826cac7bbe2d954a Mon Sep 17 00:00:00 2001
From: latonv <1619661+latonv@users.noreply.github.com>
Date: Wed, 8 May 2024 14:02:44 -0700
Subject: [PATCH] Prevent page number from incrementing early on very tall
 screens (#372)

---
 src/collection-browser.ts | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/collection-browser.ts b/src/collection-browser.ts
index 56a7fe81..c5a929e1 100644
--- a/src/collection-browser.ts
+++ b/src/collection-browser.ts
@@ -1461,8 +1461,13 @@ export class CollectionBrowser
     if (this.isScrollingToCell) return;
     const { visibleCellIndices } = e.detail;
     if (visibleCellIndices.length === 0) return;
-    const lastVisibleCellIndex =
-      visibleCellIndices[visibleCellIndices.length - 1];
+
+    // For page determination, do not count more than a single page of visible cells,
+    // since otherwise patrons using very tall screens will be treated as one page
+    // further than they actually are.
+    const lastIndexWithinCurrentPage =
+      Math.min(this.pageSize, visibleCellIndices.length) - 1;
+    const lastVisibleCellIndex = visibleCellIndices[lastIndexWithinCurrentPage];
     const lastVisibleCellPage =
       Math.floor(lastVisibleCellIndex / this.pageSize) + 1;
     if (this.currentPage !== lastVisibleCellPage) {