updated dockerfile and novnc files

src/jupyter_novnc_proxy/novnc/app/error-handler.js

@@ -0,0 +1,79 @@
+/*
+ * noVNC: HTML5 VNC client
+ * Copyright (C) 2019 The noVNC Authors
+ * Licensed under MPL 2.0 (see LICENSE.txt)
+ *
+ * See README.md for usage and integration instructions.
+ */
+
+// Fallback for all uncought errors
+function handleError(event, err) {
+    try {
+        const msg = document.getElementById('noVNC_fallback_errormsg');
+
+        // Work around Firefox bug:
+        // https://bugzilla.mozilla.org/show_bug.cgi?id=1685038
+        if (event.message === "ResizeObserver loop completed with undelivered notifications.") {
+            return false;
+        }
+
+        // Only show the initial error
+        if (msg.hasChildNodes()) {
+            return false;
+        }
+
+        let div = document.createElement("div");
+        div.classList.add('noVNC_message');
+        div.appendChild(document.createTextNode(event.message));
+        msg.appendChild(div);
+
+        if (event.filename) {
+            div = document.createElement("div");
+            div.className = 'noVNC_location';
+            let text = event.filename;
+            if (event.lineno !== undefined) {
+                text += ":" + event.lineno;
+                if (event.colno !== undefined) {
+                    text += ":" + event.colno;
+                }
+            }
+            div.appendChild(document.createTextNode(text));
+            msg.appendChild(div);
+        }
+
+        if (err && err.stack) {
+            div = document.createElement("div");
+            div.className = 'noVNC_stack';
+            div.appendChild(document.createTextNode(err.stack));
+            msg.appendChild(div);
+        }
+
+        document.getElementById('noVNC_fallback_error')
+            .classList.add("noVNC_open");
+
+    } catch (exc) {
+        document.write("noVNC encountered an error.");
+    }
+
+    // Try to disable keyboard interaction, best effort
+    try {
+        // Remove focus from the currently focused element in order to
+        // prevent keyboard interaction from continuing
+        if (document.activeElement) { document.activeElement.blur(); }
+
+        // Don't let any element be focusable when showing the error
+        let keyboardFocusable = 'a[href], button, input, textarea, select, details, [tabindex]';
+        document.querySelectorAll(keyboardFocusable).forEach((elem) => {
+            elem.setAttribute("tabindex", "-1");
+        });
+    } catch (exc) {
+        // Do nothing
+    }
+
+    // Don't return true since this would prevent the error
+    // from being printed to the browser console.
+    return false;
+}
+
+window.addEventListener('error', evt => handleError(evt, evt.error));
+window.addEventListener('unhandledrejection', evt => handleError(evt.reason, evt.reason));