QR code preloading

output/main.js

@@ -69,6 +69,7 @@ function onLoad() {
 	markSortableColumns();
 	addQRModalHandlers();
 	addServerIconInteractions();
+	preloadQRCodes();
 }
 
 function displayQRModal(communityID) {
@@ -170,6 +171,16 @@ function addQRModalHandlers() {
 
 }
 
+function preloadQRCodes() {
+	const rows = dom.tbl_communities_content_rows();
+	const identifiers = rows.map(
+		rowElement => rowElement.getAttribute(ATTRIBUTES.ROW.IDENTIFIER)
+	);
+	for (const identifier of identifiers) {
+		(new Image()).src = communityQRCodeURL(identifier);
+	}
+}
+
 function createJoinLinkButtons() {
 	const join_URLs = dom.join_urls();
 	Array.from(join_URLs).forEach((td_url) => {

sites/+components/qr_modals.php

@@ -55,7 +55,7 @@
 		</div>
 		<div id="details-modal-end">
 			<img
-				src="qr-codes/android+118d.png"
+				src=""
 				id="details-modal-qr-code"
 				title="Community join link encoded as QR code"
 			>