Improves performance of annotation layer when hidden

OnedocLabs · Jul 23, 2024 · c82ea11 · c82ea11
1 parent fcb6611
commit c82ea11
Showing 1 changed file with 17 additions and 0 deletions.
diff --git a/src/lib/pdf/layers/annotation.ts b/src/lib/pdf/layers/annotation.ts
@@ -1,6 +1,8 @@
 import { AnnotationLayer } from "pdfjs-dist";
 import { useEffect, useRef } from "react";
 
+import { useVisibility } from "@/lib/viewport";
+
 import { usePDFLinkService } from "../links";
 import { usePDFPage } from "../page";
 import { cancellable } from "../utils";
@@ -20,9 +22,24 @@ export const useAnnotationLayer = (params: AnnotationLayerParams) => {
   const annotationLayerRef = useRef<HTMLDivElement>(null);
   const annotationLayerObjectRef = useRef<AnnotationLayer | null>(null);
   const linkService = usePDFLinkService();
+  const { visible } = useVisibility({
+    elementRef: annotationLayerRef,
+  });
 
   const { pdfPageProxy } = usePDFPage();
 
+  useEffect(() => {
+    if (!annotationLayerRef.current) {
+      return;
+    }
+
+    if (visible) {
+      annotationLayerRef.current.style.contentVisibility = "visible";
+    } else {
+      annotationLayerRef.current.style.contentVisibility = "hidden";
+    }
+  }, [visible]);
+
   useEffect(() => {
     if (!annotationLayerRef.current) {
       return;