Improve noVNC integration

aleksis/apps/rwasupport/static/rwasupport/viewers/vnc/error-handler.js

-/*
- * 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.
- */
-
-// NB: this should *not* be included as a module until we have
-// native support in the browsers, so that our error handler
-// can catch script-loading errors.
-
-// No ES6 can be used in this file since it's used for the translation
-/* eslint-disable prefer-arrow-callback */
-
-(function _scope() {
-    "use strict";
-
-    // Fallback for all uncought errors
-    function handleError(event, err) {
-        try {
-            const msg = document.getElementById('noVNC_fallback_errormsg');
-
-            // 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.");
-        }
-        // Don't return true since this would prevent the error
-        // from being printed to the browser console.
-        return false;
-    }
-    window.addEventListener('error', function onerror(evt) { handleError(evt, evt.error); });
-    window.addEventListener('unhandledrejection', function onreject(evt) { handleError(evt.reason, evt.reason); });
-})();