Index: openacs-4/packages/xowiki/www/resources/chat-common.js
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xowiki/www/resources/Attic/chat-common.js,v
diff -u -r1.10.2.6 -r1.10.2.7
--- openacs-4/packages/xowiki/www/resources/chat-common.js	2 Apr 2020 13:12:54 -0000	1.10.2.6
+++ openacs-4/packages/xowiki/www/resources/chat-common.js	2 Apr 2020 18:09:49 -0000	1.10.2.7
@@ -15,6 +15,53 @@
     notifications = 0;
 }
 
+// Add "Web notifications" of new messages
+// https://www.w3.org/TR/notifications/
+function checkNotificationPromise() {
+    try {
+        Notification.requestPermission().then();
+    } catch(e) {
+        return false;
+    }
+    return true;
+}
+function askNotificationPermission() {
+    var notificationBtn = document.getElementById('enableNotifications');
+    // function to actually ask the permissions
+    function handlePermission(permission) {
+        // Whatever the user answers, we make sure Chrome stores the information
+        if(!('permission' in Notification)) {
+            Notification.permission = permission;
+        }
+
+        // set the button to shown or hidden, depending on what the user answers
+        if(Notification.permission === 'denied' || Notification.permission === 'default') {
+            notificationBtn.style.display = 'block';
+        } else {
+            notificationBtn.style.display = 'none';
+        }
+    }
+
+    // Let's check if the browser supports notifications
+    if (!('Notification' in window)) {
+        console.log("This browser does not support notifications.");
+    } else {
+        if(checkNotificationPromise()) {
+            Notification.requestPermission()
+                .then((permission) => {
+                    handlePermission(permission);
+                })
+        } else {
+            Notification.requestPermission(function(permission) {
+                handlePermission(permission);
+            });
+        }
+    }
+}
+window.onload = function () {
+    document.getElementById('enableNotifications').addEventListener("click", askNotificationPermission);
+}
+
 // Retrieve user_id
 function chatGetMyUserId() {
     var my_user = document.getElementById('xowiki-my-user-id');
@@ -51,13 +98,21 @@
 
 // Render the data, being a user or a message
 function renderData(json) {
+    var notificationBtn = document.getElementById('enableNotifications');
+notificationBtn.addEventListener("click", askNotificationPermission);
+
     if (json.type == "message") {
         renderMessage(json);
         // Produce tab notification
         if (windowInactive) {
             notifications++;
             var newTitle = '(' + notifications + ') ' + title;
             document.title = newTitle;
+            // Web notification
+            var user_id = json.user_id;
+            var text = json.user.replace(/\\'/g, "\"") + ": " + json.message;
+            var img = "/shared/portrait-bits.tcl?user_id=" + user_id;
+            var notification = new Notification(title, { body: text, icon: img });
         }
     } else if (json.type == "users") {
         renderUsers(json);