Catch more undefined things

MuckRock · Dec 5, 2023 · 5d55de8 · 5d55de8
1 parent 7c71dac
commit 5d55de8
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Showing 2 changed files with 5 additions and 1 deletion.
diff --git a/src/util/visibility.js b/src/util/visibility.js
@@ -1,6 +1,9 @@
 // Adapted from https://svelte.dev/repl/ead0f1fcd2d4402bbbd64eca1d665341?version=3.14.1
 
 export function showIfFullyVisible(el) {
+  // for very old browsers we don't support, bail
+  if (typeof window.IntersectionObserver === "undefined") return;
+
   const setVisible = (visibility) => {
     el.style.visibility = visibility ? "visible" : "hidden";
   };

diff --git a/src/viewer/document.js b/src/viewer/document.js
@@ -227,7 +227,8 @@ class Doc extends Svue {
         if (this.scrollzoom == null) return resolve();
 
         const scrollTop =
-          (this.scrollzoom.components[pageNumber].y - this.layout.pageGap / 4) *
+          (this.scrollzoom.components[pageNumber]?.y -
+            this.layout.pageGap / 4) *
           this.scrollzoom.transform.matrix[0];
         if (this.scrollzoom.element != null) {
           this.scrollzoom.scrollTo(scrollTop);