app/ui.js

   1 /*
   2  * noVNC: HTML5 VNC client
   3  * Copyright (C) 2018 The noVNC Authors
   4  * Licensed under MPL 2.0 (see LICENSE.txt)
   5  *
   6  * See README.md for usage and integration instructions.
   7  */
   8
   9 import * as Log from '../core/util/logging.js';
  10 import _, { l10n } from './localization.js';
  11 import { isTouchDevice, dragThreshold } from '../core/util/browser.js';
  12 import { setCapture, getPointerEvent } from '../core/util/events.js';
  13 import KeyTable from "../core/input/keysym.js";
  14 import keysyms from "../core/input/keysymdef.js";
  15 import Keyboard from "../core/input/keyboard.js";
  16 import RFB from "../core/rfb.js";
  17 import * as WebUtil from "./webutil.js";
  18
  19 const UI = {
  20
  21     connected: false,
  22     desktopName: "",
  23
  24     statusTimeout: null,
  25     hideKeyboardTimeout: null,
  26     idleControlbarTimeout: null,
  27     closeControlbarTimeout: null,
  28
  29     controlbarGrabbed: false,
  30     controlbarDrag: false,
  31     controlbarMouseDownClientY: 0,
  32     controlbarMouseDownOffsetY: 0,
  33
  34     isSafari: false,
  35     lastKeyboardinput: null,
  36     defaultKeyboardinputLen: 100,
  37
  38     inhibit_reconnect: true,
  39     reconnect_callback: null,
  40     reconnect_password: null,
  41
  42     prime(callback) {
  43         if (document.readyState === "interactive" || document.readyState === "complete") {
  44             UI.load(callback);
  45         } else {
  46             document.addEventListener('DOMContentLoaded', UI.load.bind(UI, callback));
  47         }
  48     },
  49
  50     // Setup rfb object, load settings from browser storage, then call
  51     // UI.init to setup the UI/menus
  52     load(callback) {
  53         WebUtil.initSettings(UI.start, callback);
  54     },
  55
  56     // Render default UI and initialize settings menu
  57     start(callback) {
  58
  59         // Setup global variables first
  60         UI.isSafari = (navigator.userAgent.indexOf('Safari') !== -1 &&
  61                        navigator.userAgent.indexOf('Chrome') === -1);
  62
  63         UI.initSettings();
  64
  65         // Translate the DOM
  66         l10n.translateDOM();
  67
  68         // Adapt the interface for touch screen devices
  69         if (isTouchDevice) {
  70             document.documentElement.classList.add("noVNC_touch");
  71             // Remove the address bar
  72             setTimeout(() => window.scrollTo(0, 1), 100);
  73         }
  74
  75         // Restore control bar position
  76         if (WebUtil.readSetting('controlbar_pos') === 'right') {
  77             UI.toggleControlbarSide();
  78         }
  79
  80         UI.initFullscreen();
  81
  82         // Setup event handlers
  83         UI.addControlbarHandlers();
  84         UI.addTouchSpecificHandlers();
  85         UI.addExtraKeysHandlers();
  86         UI.addMachineHandlers();
  87         UI.addConnectionControlHandlers();
  88         UI.addClipboardHandlers();
  89         UI.addSettingsHandlers();
  90         document.getElementById("noVNC_status")
  91             .addEventListener('click', UI.hideStatus);
  92
  93         // Bootstrap fallback input handler
  94         UI.keyboardinputReset();
  95
  96         UI.openControlbar();
  97
  98         UI.updateVisualState('init');
  99
 100         document.documentElement.classList.remove("noVNC_loading");
 101
 102         let autoconnect = WebUtil.getConfigVar('autoconnect', false);
 103         if (autoconnect === 'true' || autoconnect == '1') {
 104             autoconnect = true;
 105             UI.connect();
 106         } else {
 107             autoconnect = false;
 108             // Show the connect panel on first load unless autoconnecting
 109             UI.openConnectPanel();
 110         }
 111
 112         if (typeof callback === "function") {
 113             callback(UI.rfb);
 114         }
 115     },
 116
 117     initFullscreen() {
 118         // Only show the button if fullscreen is properly supported
 119         // * Safari doesn't support alphanumerical input while in fullscreen
 120         if (!UI.isSafari &&
 121             (document.documentElement.requestFullscreen ||
 122              document.documentElement.mozRequestFullScreen ||
 123              document.documentElement.webkitRequestFullscreen ||
 124              document.body.msRequestFullscreen)) {
 125             document.getElementById('noVNC_fullscreen_button')
 126                 .classList.remove("noVNC_hidden");
 127             UI.addFullscreenHandlers();
 128         }
 129     },
 130
 131     initSettings() {
 132         // Logging selection dropdown
 133         const llevels = ['error', 'warn', 'info', 'debug'];
 134         for (let i = 0; i < llevels.length; i += 1) {
 135             UI.addOption(document.getElementById('noVNC_setting_logging'), llevels[i], llevels[i]);
 136         }
 137
 138         // Settings with immediate effects
 139         UI.initSetting('logging', 'warn');
 140         UI.updateLogging();
 141
 142         // if port == 80 (or 443) then it won't be present and should be
 143         // set manually
 144         let port = window.location.port;
 145         if (!port) {
 146             if (window.location.protocol.substring(0, 5) == 'https') {
 147                 port = 443;
 148             } else if (window.location.protocol.substring(0, 4) == 'http') {
 149                 port = 80;
 150             }
 151         }
 152
 153         /* Populate the controls if defaults are provided in the URL */
 154         UI.initSetting('host', window.location.hostname);
 155         UI.initSetting('port', port);
 156         UI.initSetting('encrypt', (window.location.protocol === "https:"));
 157         UI.initSetting('view_clip', false);
 158         UI.initSetting('resize', 'off');
 159         UI.initSetting('shared', true);
 160         UI.initSetting('view_only', false);
 161         UI.initSetting('show_dot', false);
 162         UI.initSetting('path', 'websockify');
 163         UI.initSetting('repeaterID', '');
 164         UI.initSetting('reconnect', false);
 165         UI.initSetting('reconnect_delay', 5000);
 166
 167         UI.setupSettingLabels();
 168     },
 169     // Adds a link to the label elements on the corresponding input elements
 170     setupSettingLabels() {
 171         const labels = document.getElementsByTagName('LABEL');
 172         for (let i = 0; i < labels.length; i++) {
 173             const htmlFor = labels[i].htmlFor;
 174             if (htmlFor != '') {
 175                 const elem = document.getElementById(htmlFor);
 176                 if (elem) elem.label = labels[i];
 177             } else {
 178                 // If 'for' isn't set, use the first input element child
 179                 const children = labels[i].children;
 180                 for (let j = 0; j < children.length; j++) {
 181                     if (children[j].form !== undefined) {
 182                         children[j].label = labels[i];
 183                         break;
 184                     }
 185                 }
 186             }
 187         }
 188     },
 189
 190 /* ------^-------
 191 *     /INIT
 192 * ==============
 193 * EVENT HANDLERS
 194 * ------v------*/
 195
 196     addControlbarHandlers() {
 197         document.getElementById("noVNC_control_bar")
 198             .addEventListener('mousemove', UI.activateControlbar);
 199         document.getElementById("noVNC_control_bar")
 200             .addEventListener('mouseup', UI.activateControlbar);
 201         document.getElementById("noVNC_control_bar")
 202             .addEventListener('mousedown', UI.activateControlbar);
 203         document.getElementById("noVNC_control_bar")
 204             .addEventListener('keydown', UI.activateControlbar);
 205
 206         document.getElementById("noVNC_control_bar")
 207             .addEventListener('mousedown', UI.keepControlbar);
 208         document.getElementById("noVNC_control_bar")
 209             .addEventListener('keydown', UI.keepControlbar);
 210
 211         document.getElementById("noVNC_view_drag_button")
 212             .addEventListener('click', UI.toggleViewDrag);
 213
 214         document.getElementById("noVNC_control_bar_handle")
 215             .addEventListener('mousedown', UI.controlbarHandleMouseDown);
 216         document.getElementById("noVNC_control_bar_handle")
 217             .addEventListener('mouseup', UI.controlbarHandleMouseUp);
 218         document.getElementById("noVNC_control_bar_handle")
 219             .addEventListener('mousemove', UI.dragControlbarHandle);
 220         // resize events aren't available for elements
 221         window.addEventListener('resize', UI.updateControlbarHandle);
 222
 223         const exps = document.getElementsByClassName("noVNC_expander");
 224         for (let i = 0;i < exps.length;i++) {
 225             exps[i].addEventListener('click', UI.toggleExpander);
 226         }
 227     },
 228
 229     addTouchSpecificHandlers() {
 230         document.getElementById("noVNC_mouse_button0")
 231             .addEventListener('click', () => UI.setMouseButton(1));
 232         document.getElementById("noVNC_mouse_button1")
 233             .addEventListener('click', () => UI.setMouseButton(2));
 234         document.getElementById("noVNC_mouse_button2")
 235             .addEventListener('click', () => UI.setMouseButton(4));
 236         document.getElementById("noVNC_mouse_button4")
 237             .addEventListener('click', () => UI.setMouseButton(0));
 238         document.getElementById("noVNC_keyboard_button")
 239             .addEventListener('click', UI.toggleVirtualKeyboard);
 240
 241         UI.touchKeyboard = new Keyboard(document.getElementById('noVNC_keyboardinput'));
 242         UI.touchKeyboard.onkeyevent = UI.keyEvent;
 243         UI.touchKeyboard.grab();
 244         document.getElementById("noVNC_keyboardinput")
 245             .addEventListener('input', UI.keyInput);
 246         document.getElementById("noVNC_keyboardinput")
 247             .addEventListener('focus', UI.onfocusVirtualKeyboard);
 248         document.getElementById("noVNC_keyboardinput")
 249             .addEventListener('blur', UI.onblurVirtualKeyboard);
 250         document.getElementById("noVNC_keyboardinput")
 251             .addEventListener('submit', () => false);
 252
 253         document.documentElement
 254             .addEventListener('mousedown', UI.keepVirtualKeyboard, true);
 255
 256         document.getElementById("noVNC_control_bar")
 257             .addEventListener('touchstart', UI.activateControlbar);
 258         document.getElementById("noVNC_control_bar")
 259             .addEventListener('touchmove', UI.activateControlbar);
 260         document.getElementById("noVNC_control_bar")
 261             .addEventListener('touchend', UI.activateControlbar);
 262         document.getElementById("noVNC_control_bar")
 263             .addEventListener('input', UI.activateControlbar);
 264
 265         document.getElementById("noVNC_control_bar")
 266             .addEventListener('touchstart', UI.keepControlbar);
 267         document.getElementById("noVNC_control_bar")
 268             .addEventListener('input', UI.keepControlbar);
 269
 270         document.getElementById("noVNC_control_bar_handle")
 271             .addEventListener('touchstart', UI.controlbarHandleMouseDown);
 272         document.getElementById("noVNC_control_bar_handle")
 273             .addEventListener('touchend', UI.controlbarHandleMouseUp);
 274         document.getElementById("noVNC_control_bar_handle")
 275             .addEventListener('touchmove', UI.dragControlbarHandle);
 276     },
 277
 278     addExtraKeysHandlers() {
 279         document.getElementById("noVNC_toggle_extra_keys_button")
 280             .addEventListener('click', UI.toggleExtraKeys);
 281         document.getElementById("noVNC_toggle_ctrl_button")
 282             .addEventListener('click', UI.toggleCtrl);
 283         document.getElementById("noVNC_toggle_windows_button")
 284             .addEventListener('click', UI.toggleWindows);
 285         document.getElementById("noVNC_toggle_alt_button")
 286             .addEventListener('click', UI.toggleAlt);
 287         document.getElementById("noVNC_send_tab_button")
 288             .addEventListener('click', UI.sendTab);
 289         document.getElementById("noVNC_send_esc_button")
 290             .addEventListener('click', UI.sendEsc);
 291         document.getElementById("noVNC_send_ctrl_alt_del_button")
 292             .addEventListener('click', UI.sendCtrlAltDel);
 293     },
 294
 295     addMachineHandlers() {
 296         document.getElementById("noVNC_shutdown_button")
 297             .addEventListener('click', () => UI.rfb.machineShutdown());
 298         document.getElementById("noVNC_reboot_button")
 299             .addEventListener('click', () => UI.rfb.machineReboot());
 300         document.getElementById("noVNC_reset_button")
 301             .addEventListener('click', () => UI.rfb.machineReset());
 302         document.getElementById("noVNC_power_button")
 303             .addEventListener('click', UI.togglePowerPanel);
 304     },
 305
 306     addConnectionControlHandlers() {
 307         document.getElementById("noVNC_disconnect_button")
 308             .addEventListener('click', UI.disconnect);
 309         document.getElementById("noVNC_connect_button")
 310             .addEventListener('click', UI.connect);
 311         document.getElementById("noVNC_cancel_reconnect_button")
 312             .addEventListener('click', UI.cancelReconnect);
 313
 314         document.getElementById("noVNC_password_button")
 315             .addEventListener('click', UI.setPassword);
 316     },
 317
 318     addClipboardHandlers() {
 319         document.getElementById("noVNC_clipboard_button")
 320             .addEventListener('click', UI.toggleClipboardPanel);
 321         document.getElementById("noVNC_clipboard_text")
 322             .addEventListener('change', UI.clipboardSend);
 323         document.getElementById("noVNC_clipboard_clear_button")
 324             .addEventListener('click', UI.clipboardClear);
 325     },
 326
 327     // Add a call to save settings when the element changes,
 328     // unless the optional parameter changeFunc is used instead.
 329     addSettingChangeHandler(name, changeFunc) {
 330         const settingElem = document.getElementById("noVNC_setting_" + name);
 331         if (changeFunc === undefined) {
 332             changeFunc = () => UI.saveSetting(name);
 333         }
 334         settingElem.addEventListener('change', changeFunc);
 335     },
 336
 337     addSettingsHandlers() {
 338         document.getElementById("noVNC_settings_button")
 339             .addEventListener('click', UI.toggleSettingsPanel);
 340
 341         UI.addSettingChangeHandler('encrypt');
 342         UI.addSettingChangeHandler('resize');
 343         UI.addSettingChangeHandler('resize', UI.applyResizeMode);
 344         UI.addSettingChangeHandler('resize', UI.updateViewClip);
 345         UI.addSettingChangeHandler('view_clip');
 346         UI.addSettingChangeHandler('view_clip', UI.updateViewClip);
 347         UI.addSettingChangeHandler('shared');
 348         UI.addSettingChangeHandler('view_only');
 349         UI.addSettingChangeHandler('view_only', UI.updateViewOnly);
 350         UI.addSettingChangeHandler('show_dot');
 351         UI.addSettingChangeHandler('show_dot', UI.updateShowDotCursor);
 352         UI.addSettingChangeHandler('host');
 353         UI.addSettingChangeHandler('port');
 354         UI.addSettingChangeHandler('path');
 355         UI.addSettingChangeHandler('repeaterID');
 356         UI.addSettingChangeHandler('logging');
 357         UI.addSettingChangeHandler('logging', UI.updateLogging);
 358         UI.addSettingChangeHandler('reconnect');
 359         UI.addSettingChangeHandler('reconnect_delay');
 360     },
 361
 362     addFullscreenHandlers() {
 363         document.getElementById("noVNC_fullscreen_button")
 364             .addEventListener('click', UI.toggleFullscreen);
 365
 366         window.addEventListener('fullscreenchange', UI.updateFullscreenButton);
 367         window.addEventListener('mozfullscreenchange', UI.updateFullscreenButton);
 368         window.addEventListener('webkitfullscreenchange', UI.updateFullscreenButton);
 369         window.addEventListener('msfullscreenchange', UI.updateFullscreenButton);
 370     },
 371
 372 /* ------^-------
 373  * /EVENT HANDLERS
 374  * ==============
 375  *     VISUAL
 376  * ------v------*/
 377
 378     // Disable/enable controls depending on connection state
 379     updateVisualState(state) {
 380
 381         document.documentElement.classList.remove("noVNC_connecting");
 382         document.documentElement.classList.remove("noVNC_connected");
 383         document.documentElement.classList.remove("noVNC_disconnecting");
 384         document.documentElement.classList.remove("noVNC_reconnecting");
 385
 386         const transition_elem = document.getElementById("noVNC_transition_text");
 387         switch (state) {
 388             case 'init':
 389                 break;
 390             case 'connecting':
 391                 transition_elem.textContent = _("Connecting...");
 392                 document.documentElement.classList.add("noVNC_connecting");
 393                 break;
 394             case 'connected':
 395                 document.documentElement.classList.add("noVNC_connected");
 396                 break;
 397             case 'disconnecting':
 398                 transition_elem.textContent = _("Disconnecting...");
 399                 document.documentElement.classList.add("noVNC_disconnecting");
 400                 break;
 401             case 'disconnected':
 402                 break;
 403             case 'reconnecting':
 404                 transition_elem.textContent = _("Reconnecting...");
 405                 document.documentElement.classList.add("noVNC_reconnecting");
 406                 break;
 407             default:
 408                 Log.Error("Invalid visual state: " + state);
 409                 UI.showStatus(_("Internal error"), 'error');
 410                 return;
 411         }
 412
 413         if (UI.connected) {
 414             UI.updateViewClip();
 415
 416             UI.disableSetting('encrypt');
 417             UI.disableSetting('shared');
 418             UI.disableSetting('host');
 419             UI.disableSetting('port');
 420             UI.disableSetting('path');
 421             UI.disableSetting('repeaterID');
 422             UI.setMouseButton(1);
 423
 424             // Hide the controlbar after 2 seconds
 425             UI.closeControlbarTimeout = setTimeout(UI.closeControlbar, 2000);
 426         } else {
 427             UI.enableSetting('encrypt');
 428             UI.enableSetting('shared');
 429             UI.enableSetting('host');
 430             UI.enableSetting('port');
 431             UI.enableSetting('path');
 432             UI.enableSetting('repeaterID');
 433             UI.updatePowerButton();
 434             UI.keepControlbar();
 435         }
 436
 437         // State change closes the password dialog
 438         document.getElementById('noVNC_password_dlg')
 439             .classList.remove('noVNC_open');
 440     },
 441
 442     showStatus(text, status_type, time) {
 443         const statusElem = document.getElementById('noVNC_status');
 444
 445         clearTimeout(UI.statusTimeout);
 446
 447         if (typeof status_type === 'undefined') {
 448             status_type = 'normal';
 449         }
 450
 451         // Don't overwrite more severe visible statuses and never
 452         // errors. Only shows the first error.
 453         let visible_status_type = 'none';
 454         if (statusElem.classList.contains("noVNC_open")) {
 455             if (statusElem.classList.contains("noVNC_status_error")) {
 456                 visible_status_type = 'error';
 457             } else if (statusElem.classList.contains("noVNC_status_warn")) {
 458                 visible_status_type = 'warn';
 459             } else {
 460                 visible_status_type = 'normal';
 461             }
 462         }
 463         if (visible_status_type === 'error' ||
 464             (visible_status_type === 'warn' && status_type === 'normal')) {
 465             return;
 466         }
 467
 468         switch (status_type) {
 469             case 'error':
 470                 statusElem.classList.remove("noVNC_status_warn");
 471                 statusElem.classList.remove("noVNC_status_normal");
 472                 statusElem.classList.add("noVNC_status_error");
 473                 break;
 474             case 'warning':
 475             case 'warn':
 476                 statusElem.classList.remove("noVNC_status_error");
 477                 statusElem.classList.remove("noVNC_status_normal");
 478                 statusElem.classList.add("noVNC_status_warn");
 479                 break;
 480             case 'normal':
 481             case 'info':
 482             default:
 483                 statusElem.classList.remove("noVNC_status_error");
 484                 statusElem.classList.remove("noVNC_status_warn");
 485                 statusElem.classList.add("noVNC_status_normal");
 486                 break;
 487         }
 488
 489         statusElem.textContent = text;
 490         statusElem.classList.add("noVNC_open");
 491
 492         // If no time was specified, show the status for 1.5 seconds
 493         if (typeof time === 'undefined') {
 494             time = 1500;
 495         }
 496
 497         // Error messages do not timeout
 498         if (status_type !== 'error') {
 499             UI.statusTimeout = window.setTimeout(UI.hideStatus, time);
 500         }
 501     },
 502
 503     hideStatus() {
 504         clearTimeout(UI.statusTimeout);
 505         document.getElementById('noVNC_status').classList.remove("noVNC_open");
 506     },
 507
 508     activateControlbar(event) {
 509         clearTimeout(UI.idleControlbarTimeout);
 510         // We manipulate the anchor instead of the actual control
 511         // bar in order to avoid creating new a stacking group
 512         document.getElementById('noVNC_control_bar_anchor')
 513             .classList.remove("noVNC_idle");
 514         UI.idleControlbarTimeout = window.setTimeout(UI.idleControlbar, 2000);
 515     },
 516
 517     idleControlbar() {
 518         document.getElementById('noVNC_control_bar_anchor')
 519             .classList.add("noVNC_idle");
 520     },
 521
 522     keepControlbar() {
 523         clearTimeout(UI.closeControlbarTimeout);
 524     },
 525
 526     openControlbar() {
 527         document.getElementById('noVNC_control_bar')
 528             .classList.add("noVNC_open");
 529     },
 530
 531     closeControlbar() {
 532         UI.closeAllPanels();
 533         document.getElementById('noVNC_control_bar')
 534             .classList.remove("noVNC_open");
 535     },
 536
 537     toggleControlbar() {
 538         if (document.getElementById('noVNC_control_bar')
 539             .classList.contains("noVNC_open")) {
 540             UI.closeControlbar();
 541         } else {
 542             UI.openControlbar();
 543         }
 544     },
 545
 546     toggleControlbarSide() {
 547         // Temporarily disable animation, if bar is displayed, to avoid weird
 548         // movement. The transitionend-event will not fire when display=none.
 549         const bar = document.getElementById('noVNC_control_bar');
 550         const barDisplayStyle = window.getComputedStyle(bar).display;
 551         if (barDisplayStyle !== 'none') {
 552             bar.style.transitionDuration = '0s';
 553             bar.addEventListener('transitionend', () => bar.style.transitionDuration = '');
 554         }
 555
 556         const anchor = document.getElementById('noVNC_control_bar_anchor');
 557         if (anchor.classList.contains("noVNC_right")) {
 558             WebUtil.writeSetting('controlbar_pos', 'left');
 559             anchor.classList.remove("noVNC_right");
 560         } else {
 561             WebUtil.writeSetting('controlbar_pos', 'right');
 562             anchor.classList.add("noVNC_right");
 563         }
 564
 565         // Consider this a movement of the handle
 566         UI.controlbarDrag = true;
 567     },
 568
 569     showControlbarHint(show) {
 570         const hint = document.getElementById('noVNC_control_bar_hint');
 571         if (show) {
 572             hint.classList.add("noVNC_active");
 573         } else {
 574             hint.classList.remove("noVNC_active");
 575         }
 576     },
 577
 578     dragControlbarHandle(e) {
 579         if (!UI.controlbarGrabbed) return;
 580
 581         const ptr = getPointerEvent(e);
 582
 583         const anchor = document.getElementById('noVNC_control_bar_anchor');
 584         if (ptr.clientX < (window.innerWidth * 0.1)) {
 585             if (anchor.classList.contains("noVNC_right")) {
 586                 UI.toggleControlbarSide();
 587             }
 588         } else if (ptr.clientX > (window.innerWidth * 0.9)) {
 589             if (!anchor.classList.contains("noVNC_right")) {
 590                 UI.toggleControlbarSide();
 591             }
 592         }
 593
 594         if (!UI.controlbarDrag) {
 595             const dragDistance = Math.abs(ptr.clientY - UI.controlbarMouseDownClientY);
 596
 597             if (dragDistance < dragThreshold) return;
 598
 599             UI.controlbarDrag = true;
 600         }
 601
 602         const eventY = ptr.clientY - UI.controlbarMouseDownOffsetY;
 603
 604         UI.moveControlbarHandle(eventY);
 605
 606         e.preventDefault();
 607         e.stopPropagation();
 608         UI.keepControlbar();
 609         UI.activateControlbar();
 610     },
 611
 612     // Move the handle but don't allow any position outside the bounds
 613     moveControlbarHandle(viewportRelativeY) {
 614         const handle = document.getElementById("noVNC_control_bar_handle");
 615         const handleHeight = handle.getBoundingClientRect().height;
 616         const controlbarBounds = document.getElementById("noVNC_control_bar")
 617             .getBoundingClientRect();
 618         const margin = 10;
 619
 620         // These heights need to be non-zero for the below logic to work
 621         if (handleHeight === 0 || controlbarBounds.height === 0) {
 622             return;
 623         }
 624
 625         let newY = viewportRelativeY;
 626
 627         // Check if the coordinates are outside the control bar
 628         if (newY < controlbarBounds.top + margin) {
 629             // Force coordinates to be below the top of the control bar
 630             newY = controlbarBounds.top + margin;
 631
 632         } else if (newY > controlbarBounds.top +
 633                    controlbarBounds.height - handleHeight - margin) {
 634             // Force coordinates to be above the bottom of the control bar
 635             newY = controlbarBounds.top +
 636                 controlbarBounds.height - handleHeight - margin;
 637         }
 638
 639         // Corner case: control bar too small for stable position
 640         if (controlbarBounds.height < (handleHeight + margin * 2)) {
 641             newY = controlbarBounds.top +
 642                 (controlbarBounds.height - handleHeight) / 2;
 643         }
 644
 645         // The transform needs coordinates that are relative to the parent
 646         const parentRelativeY = newY - controlbarBounds.top;
 647         handle.style.transform = "translateY(" + parentRelativeY + "px)";
 648     },
 649
 650     updateControlbarHandle() {
 651         // Since the control bar is fixed on the viewport and not the page,
 652         // the move function expects coordinates relative the the viewport.
 653         const handle = document.getElementById("noVNC_control_bar_handle");
 654         const handleBounds = handle.getBoundingClientRect();
 655         UI.moveControlbarHandle(handleBounds.top);
 656     },
 657
 658     controlbarHandleMouseUp(e) {
 659         if ((e.type == "mouseup") && (e.button != 0)) return;
 660
 661         // mouseup and mousedown on the same place toggles the controlbar
 662         if (UI.controlbarGrabbed && !UI.controlbarDrag) {
 663             UI.toggleControlbar();
 664             e.preventDefault();
 665             e.stopPropagation();
 666             UI.keepControlbar();
 667             UI.activateControlbar();
 668         }
 669         UI.controlbarGrabbed = false;
 670         UI.showControlbarHint(false);
 671     },
 672
 673     controlbarHandleMouseDown(e) {
 674         if ((e.type == "mousedown") && (e.button != 0)) return;
 675
 676         const ptr = getPointerEvent(e);
 677
 678         const handle = document.getElementById("noVNC_control_bar_handle");
 679         const bounds = handle.getBoundingClientRect();
 680
 681         // Touch events have implicit capture
 682         if (e.type === "mousedown") {
 683             setCapture(handle);
 684         }
 685
 686         UI.controlbarGrabbed = true;
 687         UI.controlbarDrag = false;
 688
 689         UI.showControlbarHint(true);
 690
 691         UI.controlbarMouseDownClientY = ptr.clientY;
 692         UI.controlbarMouseDownOffsetY = ptr.clientY - bounds.top;
 693         e.preventDefault();
 694         e.stopPropagation();
 695         UI.keepControlbar();
 696         UI.activateControlbar();
 697     },
 698
 699     toggleExpander(e) {
 700         if (this.classList.contains("noVNC_open")) {
 701             this.classList.remove("noVNC_open");
 702         } else {
 703             this.classList.add("noVNC_open");
 704         }
 705     },
 706
 707 /* ------^-------
 708  *    /VISUAL
 709  * ==============
 710  *    SETTINGS
 711  * ------v------*/
 712
 713     // Initial page load read/initialization of settings
 714     initSetting(name, defVal) {
 715         // Check Query string followed by cookie
 716         let val = WebUtil.getConfigVar(name);
 717         if (val === null) {
 718             val = WebUtil.readSetting(name, defVal);
 719         }
 720         WebUtil.setSetting(name, val);
 721         UI.updateSetting(name);
 722         return val;
 723     },
 724
 725     // Set the new value, update and disable form control setting
 726     forceSetting(name, val) {
 727         WebUtil.setSetting(name, val);
 728         UI.updateSetting(name);
 729         UI.disableSetting(name);
 730     },
 731
 732     // Update cookie and form control setting. If value is not set, then
 733     // updates from control to current cookie setting.
 734     updateSetting(name) {
 735
 736         // Update the settings control
 737         let value = UI.getSetting(name);
 738
 739         const ctrl = document.getElementById('noVNC_setting_' + name);
 740         if (ctrl.type === 'checkbox') {
 741             ctrl.checked = value;
 742
 743         } else if (typeof ctrl.options !== 'undefined') {
 744             for (let i = 0; i < ctrl.options.length; i += 1) {
 745                 if (ctrl.options[i].value === value) {
 746                     ctrl.selectedIndex = i;
 747                     break;
 748                 }
 749             }
 750         } else {
 751             /*Weird IE9 error leads to 'null' appearring
 752             in textboxes instead of ''.*/
 753             if (value === null) {
 754                 value = "";
 755             }
 756             ctrl.value = value;
 757         }
 758     },
 759
 760     // Save control setting to cookie
 761     saveSetting(name) {
 762         const ctrl = document.getElementById('noVNC_setting_' + name);
 763         let val;
 764         if (ctrl.type === 'checkbox') {
 765             val = ctrl.checked;
 766         } else if (typeof ctrl.options !== 'undefined') {
 767             val = ctrl.options[ctrl.selectedIndex].value;
 768         } else {
 769             val = ctrl.value;
 770         }
 771         WebUtil.writeSetting(name, val);
 772         //Log.Debug("Setting saved '" + name + "=" + val + "'");
 773         return val;
 774     },
 775
 776     // Read form control compatible setting from cookie
 777     getSetting(name) {
 778         const ctrl = document.getElementById('noVNC_setting_' + name);
 779         let val = WebUtil.readSetting(name);
 780         if (typeof val !== 'undefined' && val !== null && ctrl.type === 'checkbox') {
 781             if (val.toString().toLowerCase() in {'0': 1, 'no': 1, 'false': 1}) {
 782                 val = false;
 783             } else {
 784                 val = true;
 785             }
 786         }
 787         return val;
 788     },
 789
 790     // These helpers compensate for the lack of parent-selectors and
 791     // previous-sibling-selectors in CSS which are needed when we want to
 792     // disable the labels that belong to disabled input elements.
 793     disableSetting(name) {
 794         const ctrl = document.getElementById('noVNC_setting_' + name);
 795         ctrl.disabled = true;
 796         ctrl.label.classList.add('noVNC_disabled');
 797     },
 798
 799     enableSetting(name) {
 800         const ctrl = document.getElementById('noVNC_setting_' + name);
 801         ctrl.disabled = false;
 802         ctrl.label.classList.remove('noVNC_disabled');
 803     },
 804
 805 /* ------^-------
 806  *   /SETTINGS
 807  * ==============
 808  *    PANELS
 809  * ------v------*/
 810
 811     closeAllPanels() {
 812         UI.closeSettingsPanel();
 813         UI.closePowerPanel();
 814         UI.closeClipboardPanel();
 815         UI.closeExtraKeys();
 816     },
 817
 818 /* ------^-------
 819  *   /PANELS
 820  * ==============
 821  * SETTINGS (panel)
 822  * ------v------*/
 823
 824     openSettingsPanel() {
 825         UI.closeAllPanels();
 826         UI.openControlbar();
 827
 828         // Refresh UI elements from saved cookies
 829         UI.updateSetting('encrypt');
 830         UI.updateSetting('view_clip');
 831         UI.updateSetting('resize');
 832         UI.updateSetting('shared');
 833         UI.updateSetting('view_only');
 834         UI.updateSetting('path');
 835         UI.updateSetting('repeaterID');
 836         UI.updateSetting('logging');
 837         UI.updateSetting('reconnect');
 838         UI.updateSetting('reconnect_delay');
 839
 840         document.getElementById('noVNC_settings')
 841             .classList.add("noVNC_open");
 842         document.getElementById('noVNC_settings_button')
 843             .classList.add("noVNC_selected");
 844     },
 845
 846     closeSettingsPanel() {
 847         document.getElementById('noVNC_settings')
 848             .classList.remove("noVNC_open");
 849         document.getElementById('noVNC_settings_button')
 850             .classList.remove("noVNC_selected");
 851     },
 852
 853     toggleSettingsPanel() {
 854         if (document.getElementById('noVNC_settings')
 855             .classList.contains("noVNC_open")) {
 856             UI.closeSettingsPanel();
 857         } else {
 858             UI.openSettingsPanel();
 859         }
 860     },
 861
 862 /* ------^-------
 863  *   /SETTINGS
 864  * ==============
 865  *     POWER
 866  * ------v------*/
 867
 868     openPowerPanel() {
 869         UI.closeAllPanels();
 870         UI.openControlbar();
 871
 872         document.getElementById('noVNC_power')
 873             .classList.add("noVNC_open");
 874         document.getElementById('noVNC_power_button')
 875             .classList.add("noVNC_selected");
 876     },
 877
 878     closePowerPanel() {
 879         document.getElementById('noVNC_power')
 880             .classList.remove("noVNC_open");
 881         document.getElementById('noVNC_power_button')
 882             .classList.remove("noVNC_selected");
 883     },
 884
 885     togglePowerPanel() {
 886         if (document.getElementById('noVNC_power')
 887             .classList.contains("noVNC_open")) {
 888             UI.closePowerPanel();
 889         } else {
 890             UI.openPowerPanel();
 891         }
 892     },
 893
 894     // Disable/enable power button
 895     updatePowerButton() {
 896         if (UI.connected &&
 897             UI.rfb.capabilities.power &&
 898             !UI.rfb.viewOnly) {
 899             document.getElementById('noVNC_power_button')
 900                 .classList.remove("noVNC_hidden");
 901         } else {
 902             document.getElementById('noVNC_power_button')
 903                 .classList.add("noVNC_hidden");
 904             // Close power panel if open
 905             UI.closePowerPanel();
 906         }
 907     },
 908
 909 /* ------^-------
 910  *    /POWER
 911  * ==============
 912  *   CLIPBOARD
 913  * ------v------*/
 914
 915     openClipboardPanel() {
 916         UI.closeAllPanels();
 917         UI.openControlbar();
 918
 919         document.getElementById('noVNC_clipboard')
 920             .classList.add("noVNC_open");
 921         document.getElementById('noVNC_clipboard_button')
 922             .classList.add("noVNC_selected");
 923     },
 924
 925     closeClipboardPanel() {
 926         document.getElementById('noVNC_clipboard')
 927             .classList.remove("noVNC_open");
 928         document.getElementById('noVNC_clipboard_button')
 929             .classList.remove("noVNC_selected");
 930     },
 931
 932     toggleClipboardPanel() {
 933         if (document.getElementById('noVNC_clipboard')
 934             .classList.contains("noVNC_open")) {
 935             UI.closeClipboardPanel();
 936         } else {
 937             UI.openClipboardPanel();
 938         }
 939     },
 940
 941     clipboardReceive(e) {
 942         Log.Debug(">> UI.clipboardReceive: " + e.detail.text.substr(0, 40) + "...");
 943         document.getElementById('noVNC_clipboard_text').value = e.detail.text;
 944         Log.Debug("<< UI.clipboardReceive");
 945     },
 946
 947     clipboardClear() {
 948         document.getElementById('noVNC_clipboard_text').value = "";
 949         UI.rfb.clipboardPasteFrom("");
 950     },
 951
 952     clipboardSend() {
 953         const text = document.getElementById('noVNC_clipboard_text').value;
 954         Log.Debug(">> UI.clipboardSend: " + text.substr(0, 40) + "...");
 955         UI.rfb.clipboardPasteFrom(text);
 956         Log.Debug("<< UI.clipboardSend");
 957     },
 958
 959 /* ------^-------
 960  *  /CLIPBOARD
 961  * ==============
 962  *  CONNECTION
 963  * ------v------*/
 964
 965     openConnectPanel() {
 966         document.getElementById('noVNC_connect_dlg')
 967             .classList.add("noVNC_open");
 968     },
 969
 970     closeConnectPanel() {
 971         document.getElementById('noVNC_connect_dlg')
 972             .classList.remove("noVNC_open");
 973     },
 974
 975     connect(event, password) {
 976
 977         // Ignore when rfb already exists
 978         if (typeof UI.rfb !== 'undefined') {
 979             return;
 980         }
 981
 982         const host = UI.getSetting('host');
 983         const port = UI.getSetting('port');
 984         const path = UI.getSetting('path');
 985
 986         if (typeof password === 'undefined') {
 987             password = WebUtil.getConfigVar('password');
 988             UI.reconnect_password = password;
 989         }
 990
 991         if (password === null) {
 992             password = undefined;
 993         }
 994
 995         UI.hideStatus();
 996
 997         if (!host) {
 998             Log.Error("Can't connect when host is: " + host);
 999             UI.showStatus(_("Must set host"), 'error');
1000             return;
1001         }
1002
1003         UI.closeAllPanels();
1004         UI.closeConnectPanel();
1005
1006         UI.updateVisualState('connecting');
1007
1008         let url;
1009
1010         url = UI.getSetting('encrypt') ? 'wss' : 'ws';
1011
1012         url += '://' + host;
1013         if (port) {
1014             url += ':' + port;
1015         }
1016         url += '/' + path;
1017
1018         UI.rfb = new RFB(document.getElementById('noVNC_container'), url,
1019                          { shared: UI.getSetting('shared'),
1020                            showDotCursor: UI.getSetting('show_dot'),
1021                            repeaterID: UI.getSetting('repeaterID'),
1022                            credentials: { password: password } });
1023         UI.rfb.addEventListener("connect", UI.connectFinished);
1024         UI.rfb.addEventListener("disconnect", UI.disconnectFinished);
1025         UI.rfb.addEventListener("credentialsrequired", UI.credentials);
1026         UI.rfb.addEventListener("securityfailure", UI.securityFailed);
1027         UI.rfb.addEventListener("capabilities", UI.updatePowerButton);
1028         UI.rfb.addEventListener("clipboard", UI.clipboardReceive);
1029         UI.rfb.addEventListener("bell", UI.bell);
1030         UI.rfb.addEventListener("desktopname", UI.updateDesktopName);
1031         UI.rfb.clipViewport = UI.getSetting('view_clip');
1032         UI.rfb.scaleViewport = UI.getSetting('resize') === 'scale';
1033         UI.rfb.resizeSession = UI.getSetting('resize') === 'remote';
1034
1035         UI.updateViewOnly(); // requires UI.rfb
1036     },
1037
1038     disconnect() {
1039         UI.closeAllPanels();
1040         UI.rfb.disconnect();
1041
1042         UI.connected = false;
1043
1044         // Disable automatic reconnecting
1045         UI.inhibit_reconnect = true;
1046
1047         UI.updateVisualState('disconnecting');
1048
1049         // Don't display the connection settings until we're actually disconnected
1050     },
1051
1052     reconnect() {
1053         UI.reconnect_callback = null;
1054
1055         // if reconnect has been disabled in the meantime, do nothing.
1056         if (UI.inhibit_reconnect) {
1057             return;
1058         }
1059
1060         UI.connect(null, UI.reconnect_password);
1061     },
1062
1063     cancelReconnect() {
1064         if (UI.reconnect_callback !== null) {
1065             clearTimeout(UI.reconnect_callback);
1066             UI.reconnect_callback = null;
1067         }
1068
1069         UI.updateVisualState('disconnected');
1070
1071         UI.openControlbar();
1072         UI.openConnectPanel();
1073     },
1074
1075     connectFinished(e) {
1076         UI.connected = true;
1077         UI.inhibit_reconnect = false;
1078
1079         let msg;
1080         if (UI.getSetting('encrypt')) {
1081             msg = _("Connected (encrypted) to ") + UI.desktopName;
1082         } else {
1083             msg = _("Connected (unencrypted) to ") + UI.desktopName;
1084         }
1085         UI.showStatus(msg);
1086         UI.updateVisualState('connected');
1087
1088         // Do this last because it can only be used on rendered elements
1089         UI.rfb.focus();
1090     },
1091
1092     disconnectFinished(e) {
1093         const wasConnected = UI.connected;
1094
1095         // This variable is ideally set when disconnection starts, but
1096         // when the disconnection isn't clean or if it is initiated by
1097         // the server, we need to do it here as well since
1098         // UI.disconnect() won't be used in those cases.
1099         UI.connected = false;
1100
1101         UI.rfb = undefined;
1102
1103         if (!e.detail.clean) {
1104             UI.updateVisualState('disconnected');
1105             if (wasConnected) {
1106                 UI.showStatus(_("Something went wrong, connection is closed"),
1107                               'error');
1108             } else {
1109                 UI.showStatus(_("Failed to connect to server"), 'error');
1110             }
1111         } else if (UI.getSetting('reconnect', false) === true && !UI.inhibit_reconnect) {
1112             UI.updateVisualState('reconnecting');
1113
1114             const delay = parseInt(UI.getSetting('reconnect_delay'));
1115             UI.reconnect_callback = setTimeout(UI.reconnect, delay);
1116             return;
1117         } else {
1118             UI.updateVisualState('disconnected');
1119             UI.showStatus(_("Disconnected"), 'normal');
1120         }
1121
1122         UI.openControlbar();
1123         UI.openConnectPanel();
1124     },
1125
1126     securityFailed(e) {
1127         let msg = "";
1128         // On security failures we might get a string with a reason
1129         // directly from the server. Note that we can't control if
1130         // this string is translated or not.
1131         if ('reason' in e.detail) {
1132             msg = _("New connection has been rejected with reason: ") +
1133                 e.detail.reason;
1134         } else {
1135             msg = _("New connection has been rejected");
1136         }
1137         UI.showStatus(msg, 'error');
1138     },
1139
1140 /* ------^-------
1141  *  /CONNECTION
1142  * ==============
1143  *   PASSWORD
1144  * ------v------*/
1145
1146     credentials(e) {
1147         // FIXME: handle more types
1148         document.getElementById('noVNC_password_dlg')
1149             .classList.add('noVNC_open');
1150
1151         setTimeout(() => document
1152             .getElementById('noVNC_password_input').focus(), 100);
1153
1154         Log.Warn("Server asked for a password");
1155         UI.showStatus(_("Password is required"), "warning");
1156     },
1157
1158     setPassword(e) {
1159         // Prevent actually submitting the form
1160         e.preventDefault();
1161
1162         const inputElem = document.getElementById('noVNC_password_input');
1163         const password = inputElem.value;
1164         // Clear the input after reading the password
1165         inputElem.value = "";
1166         UI.rfb.sendCredentials({ password: password });
1167         UI.reconnect_password = password;
1168         document.getElementById('noVNC_password_dlg')
1169             .classList.remove('noVNC_open');
1170     },
1171
1172 /* ------^-------
1173  *  /PASSWORD
1174  * ==============
1175  *   FULLSCREEN
1176  * ------v------*/
1177
1178     toggleFullscreen() {
1179         if (document.fullscreenElement || // alternative standard method
1180             document.mozFullScreenElement || // currently working methods
1181             document.webkitFullscreenElement ||
1182             document.msFullscreenElement) {
1183             if (document.exitFullscreen) {
1184                 document.exitFullscreen();
1185             } else if (document.mozCancelFullScreen) {
1186                 document.mozCancelFullScreen();
1187             } else if (document.webkitExitFullscreen) {
1188                 document.webkitExitFullscreen();
1189             } else if (document.msExitFullscreen) {
1190                 document.msExitFullscreen();
1191             }
1192         } else {
1193             if (document.documentElement.requestFullscreen) {
1194                 document.documentElement.requestFullscreen();
1195             } else if (document.documentElement.mozRequestFullScreen) {
1196                 document.documentElement.mozRequestFullScreen();
1197             } else if (document.documentElement.webkitRequestFullscreen) {
1198                 document.documentElement.webkitRequestFullscreen(Element.ALLOW_KEYBOARD_INPUT);
1199             } else if (document.body.msRequestFullscreen) {
1200                 document.body.msRequestFullscreen();
1201             }
1202         }
1203         UI.updateFullscreenButton();
1204     },
1205
1206     updateFullscreenButton() {
1207         if (document.fullscreenElement || // alternative standard method
1208             document.mozFullScreenElement || // currently working methods
1209             document.webkitFullscreenElement ||
1210             document.msFullscreenElement ) {
1211             document.getElementById('noVNC_fullscreen_button')
1212                 .classList.add("noVNC_selected");
1213         } else {
1214             document.getElementById('noVNC_fullscreen_button')
1215                 .classList.remove("noVNC_selected");
1216         }
1217     },
1218
1219 /* ------^-------
1220  *  /FULLSCREEN
1221  * ==============
1222  *     RESIZE
1223  * ------v------*/
1224
1225     // Apply remote resizing or local scaling
1226     applyResizeMode() {
1227         if (!UI.rfb) return;
1228
1229         UI.rfb.scaleViewport = UI.getSetting('resize') === 'scale';
1230         UI.rfb.resizeSession = UI.getSetting('resize') === 'remote';
1231     },
1232
1233 /* ------^-------
1234  *    /RESIZE
1235  * ==============
1236  * VIEW CLIPPING
1237  * ------v------*/
1238
1239     // Update viewport clipping property for the connection. The normal
1240     // case is to get the value from the setting. There are special cases
1241     // for when the viewport is scaled or when a touch device is used.
1242     updateViewClip() {
1243         if (!UI.rfb) return;
1244
1245         const scaling = UI.getSetting('resize') === 'scale';
1246
1247         if (scaling) {
1248             // Can't be clipping if viewport is scaled to fit
1249             UI.forceSetting('view_clip', false);
1250             UI.rfb.clipViewport  = false;
1251         } else if (isTouchDevice) {
1252             // Touch devices usually have shit scrollbars
1253             UI.forceSetting('view_clip', true);
1254             UI.rfb.clipViewport = true;
1255         } else {
1256             UI.enableSetting('view_clip');
1257             UI.rfb.clipViewport = UI.getSetting('view_clip');
1258         }
1259
1260         // Changing the viewport may change the state of
1261         // the dragging button
1262         UI.updateViewDrag();
1263     },
1264
1265 /* ------^-------
1266  * /VIEW CLIPPING
1267  * ==============
1268  *    VIEWDRAG
1269  * ------v------*/
1270
1271     toggleViewDrag() {
1272         if (!UI.rfb) return;
1273
1274         UI.rfb.dragViewport = !UI.rfb.dragViewport;
1275         UI.updateViewDrag();
1276     },
1277
1278     updateViewDrag() {
1279         if (!UI.connected) return;
1280
1281         const viewDragButton = document.getElementById('noVNC_view_drag_button');
1282
1283         if (!UI.rfb.clipViewport && UI.rfb.dragViewport) {
1284             // We are no longer clipping the viewport. Make sure
1285             // viewport drag isn't active when it can't be used.
1286             UI.rfb.dragViewport = false;
1287         }
1288
1289         if (UI.rfb.dragViewport) {
1290             viewDragButton.classList.add("noVNC_selected");
1291         } else {
1292             viewDragButton.classList.remove("noVNC_selected");
1293         }
1294
1295         // Different behaviour for touch vs non-touch
1296         // The button is disabled instead of hidden on touch devices
1297         if (isTouchDevice) {
1298             viewDragButton.classList.remove("noVNC_hidden");
1299
1300             if (UI.rfb.clipViewport) {
1301                 viewDragButton.disabled = false;
1302             } else {
1303                 viewDragButton.disabled = true;
1304             }
1305         } else {
1306             viewDragButton.disabled = false;
1307
1308             if (UI.rfb.clipViewport) {
1309                 viewDragButton.classList.remove("noVNC_hidden");
1310             } else {
1311                 viewDragButton.classList.add("noVNC_hidden");
1312             }
1313         }
1314     },
1315
1316 /* ------^-------
1317  *   /VIEWDRAG
1318  * ==============
1319  *    KEYBOARD
1320  * ------v------*/
1321
1322     showVirtualKeyboard() {
1323         if (!isTouchDevice) return;
1324
1325         const input = document.getElementById('noVNC_keyboardinput');
1326
1327         if (document.activeElement == input) return;
1328
1329         input.focus();
1330
1331         try {
1332             const l = input.value.length;
1333             // Move the caret to the end
1334             input.setSelectionRange(l, l);
1335         } catch (err) {
1336             // setSelectionRange is undefined in Google Chrome
1337         }
1338     },
1339
1340     hideVirtualKeyboard() {
1341         if (!isTouchDevice) return;
1342
1343         const input = document.getElementById('noVNC_keyboardinput');
1344
1345         if (document.activeElement != input) return;
1346
1347         input.blur();
1348     },
1349
1350     toggleVirtualKeyboard() {
1351         if (document.getElementById('noVNC_keyboard_button')
1352             .classList.contains("noVNC_selected")) {
1353             UI.hideVirtualKeyboard();
1354         } else {
1355             UI.showVirtualKeyboard();
1356         }
1357     },
1358
1359     onfocusVirtualKeyboard(event) {
1360         document.getElementById('noVNC_keyboard_button')
1361             .classList.add("noVNC_selected");
1362         if (UI.rfb) {
1363             UI.rfb.focusOnClick = false;
1364         }
1365     },
1366
1367     onblurVirtualKeyboard(event) {
1368         document.getElementById('noVNC_keyboard_button')
1369             .classList.remove("noVNC_selected");
1370         if (UI.rfb) {
1371             UI.rfb.focusOnClick = true;
1372         }
1373     },
1374
1375     keepVirtualKeyboard(event) {
1376         const input = document.getElementById('noVNC_keyboardinput');
1377
1378         // Only prevent focus change if the virtual keyboard is active
1379         if (document.activeElement != input) {
1380             return;
1381         }
1382
1383         // Only allow focus to move to other elements that need
1384         // focus to function properly
1385         if (event.target.form !== undefined) {
1386             switch (event.target.type) {
1387                 case 'text':
1388                 case 'email':
1389                 case 'search':
1390                 case 'password':
1391                 case 'tel':
1392                 case 'url':
1393                 case 'textarea':
1394                 case 'select-one':
1395                 case 'select-multiple':
1396                     return;
1397             }
1398         }
1399
1400         event.preventDefault();
1401     },
1402
1403     keyboardinputReset() {
1404         const kbi = document.getElementById('noVNC_keyboardinput');
1405         kbi.value = new Array(UI.defaultKeyboardinputLen).join("_");
1406         UI.lastKeyboardinput = kbi.value;
1407     },
1408
1409     keyEvent(keysym, code, down) {
1410         if (!UI.rfb) return;
1411
1412         UI.rfb.sendKey(keysym, code, down);
1413     },
1414
1415     // When normal keyboard events are left uncought, use the input events from
1416     // the keyboardinput element instead and generate the corresponding key events.
1417     // This code is required since some browsers on Android are inconsistent in
1418     // sending keyCodes in the normal keyboard events when using on screen keyboards.
1419     keyInput(event) {
1420
1421         if (!UI.rfb) return;
1422
1423         const newValue = event.target.value;
1424
1425         if (!UI.lastKeyboardinput) {
1426             UI.keyboardinputReset();
1427         }
1428         const oldValue = UI.lastKeyboardinput;
1429
1430         let newLen;
1431         try {
1432             // Try to check caret position since whitespace at the end
1433             // will not be considered by value.length in some browsers
1434             newLen = Math.max(event.target.selectionStart, newValue.length);
1435         } catch (err) {
1436             // selectionStart is undefined in Google Chrome
1437             newLen = newValue.length;
1438         }
1439         const oldLen = oldValue.length;
1440
1441         let inputs = newLen - oldLen;
1442         let backspaces = inputs < 0 ? -inputs : 0;
1443
1444         // Compare the old string with the new to account for
1445         // text-corrections or other input that modify existing text
1446         for (let i = 0; i < Math.min(oldLen, newLen); i++) {
1447             if (newValue.charAt(i) != oldValue.charAt(i)) {
1448                 inputs = newLen - i;
1449                 backspaces = oldLen - i;
1450                 break;
1451             }
1452         }
1453
1454         // Send the key events
1455         for (let i = 0; i < backspaces; i++) {
1456             UI.rfb.sendKey(KeyTable.XK_BackSpace, "Backspace");
1457         }
1458         for (let i = newLen - inputs; i < newLen; i++) {
1459             UI.rfb.sendKey(keysyms.lookup(newValue.charCodeAt(i)));
1460         }
1461
1462         // Control the text content length in the keyboardinput element
1463         if (newLen > 2 * UI.defaultKeyboardinputLen) {
1464             UI.keyboardinputReset();
1465         } else if (newLen < 1) {
1466             // There always have to be some text in the keyboardinput
1467             // element with which backspace can interact.
1468             UI.keyboardinputReset();
1469             // This sometimes causes the keyboard to disappear for a second
1470             // but it is required for the android keyboard to recognize that
1471             // text has been added to the field
1472             event.target.blur();
1473             // This has to be ran outside of the input handler in order to work
1474             setTimeout(event.target.focus.bind(event.target), 0);
1475         } else {
1476             UI.lastKeyboardinput = newValue;
1477         }
1478     },
1479
1480 /* ------^-------
1481  *   /KEYBOARD
1482  * ==============
1483  *   EXTRA KEYS
1484  * ------v------*/
1485
1486     openExtraKeys() {
1487         UI.closeAllPanels();
1488         UI.openControlbar();
1489
1490         document.getElementById('noVNC_modifiers')
1491             .classList.add("noVNC_open");
1492         document.getElementById('noVNC_toggle_extra_keys_button')
1493             .classList.add("noVNC_selected");
1494     },
1495
1496     closeExtraKeys() {
1497         document.getElementById('noVNC_modifiers')
1498             .classList.remove("noVNC_open");
1499         document.getElementById('noVNC_toggle_extra_keys_button')
1500             .classList.remove("noVNC_selected");
1501     },
1502
1503     toggleExtraKeys() {
1504         if (document.getElementById('noVNC_modifiers')
1505             .classList.contains("noVNC_open")) {
1506             UI.closeExtraKeys();
1507         } else  {
1508             UI.openExtraKeys();
1509         }
1510     },
1511
1512     sendEsc() {
1513         UI.rfb.sendKey(KeyTable.XK_Escape, "Escape");
1514     },
1515
1516     sendTab() {
1517         UI.rfb.sendKey(KeyTable.XK_Tab);
1518     },
1519
1520     toggleCtrl() {
1521         const btn = document.getElementById('noVNC_toggle_ctrl_button');
1522         if (btn.classList.contains("noVNC_selected")) {
1523             UI.rfb.sendKey(KeyTable.XK_Control_L, "ControlLeft", false);
1524             btn.classList.remove("noVNC_selected");
1525         } else {
1526             UI.rfb.sendKey(KeyTable.XK_Control_L, "ControlLeft", true);
1527             btn.classList.add("noVNC_selected");
1528         }
1529     },
1530
1531     toggleWindows() {
1532         const btn = document.getElementById('noVNC_toggle_windows_button');
1533         if (btn.classList.contains("noVNC_selected")) {
1534             UI.rfb.sendKey(KeyTable.XK_Super_L, "MetaLeft", false);
1535             btn.classList.remove("noVNC_selected");
1536         } else {
1537             UI.rfb.sendKey(KeyTable.XK_Super_L, "MetaLeft", true);
1538             btn.classList.add("noVNC_selected");
1539         }
1540     },
1541
1542     toggleAlt() {
1543         const btn = document.getElementById('noVNC_toggle_alt_button');
1544         if (btn.classList.contains("noVNC_selected")) {
1545             UI.rfb.sendKey(KeyTable.XK_Alt_L, "AltLeft", false);
1546             btn.classList.remove("noVNC_selected");
1547         } else {
1548             UI.rfb.sendKey(KeyTable.XK_Alt_L, "AltLeft", true);
1549             btn.classList.add("noVNC_selected");
1550         }
1551     },
1552
1553     sendCtrlAltDel() {
1554         UI.rfb.sendCtrlAltDel();
1555     },
1556
1557 /* ------^-------
1558  *   /EXTRA KEYS
1559  * ==============
1560  *     MISC
1561  * ------v------*/
1562
1563     setMouseButton(num) {
1564         const view_only = UI.rfb.viewOnly;
1565         if (UI.rfb && !view_only) {
1566             UI.rfb.touchButton = num;
1567         }
1568
1569         const blist = [0, 1, 2, 4];
1570         for (let b = 0; b < blist.length; b++) {
1571             const button = document.getElementById('noVNC_mouse_button' +
1572                                                  blist[b]);
1573             if (blist[b] === num && !view_only) {
1574                 button.classList.remove("noVNC_hidden");
1575             } else {
1576                 button.classList.add("noVNC_hidden");
1577             }
1578         }
1579     },
1580
1581     updateViewOnly() {
1582         if (!UI.rfb) return;
1583         UI.rfb.viewOnly = UI.getSetting('view_only');
1584
1585         // Hide input related buttons in view only mode
1586         if (UI.rfb.viewOnly) {
1587             document.getElementById('noVNC_keyboard_button')
1588                 .classList.add('noVNC_hidden');
1589             document.getElementById('noVNC_toggle_extra_keys_button')
1590                 .classList.add('noVNC_hidden');
1591             document.getElementById('noVNC_mouse_button' + UI.rfb.touchButton)
1592                 .classList.add('noVNC_hidden');
1593         } else {
1594             document.getElementById('noVNC_keyboard_button')
1595                 .classList.remove('noVNC_hidden');
1596             document.getElementById('noVNC_toggle_extra_keys_button')
1597                 .classList.remove('noVNC_hidden');
1598             document.getElementById('noVNC_mouse_button' + UI.rfb.touchButton)
1599                 .classList.remove('noVNC_hidden');
1600         }
1601     },
1602
1603     updateShowDotCursor() {
1604         if (!UI.rfb) return;
1605         UI.rfb.showDotCursor = UI.getSetting('show_dot');
1606     },
1607
1608     updateLogging() {
1609         WebUtil.init_logging(UI.getSetting('logging'));
1610     },
1611
1612     updateDesktopName(e) {
1613         UI.desktopName = e.detail.name;
1614         // Display the desktop name in the document title
1615         document.title = e.detail.name + " - noVNC";
1616     },
1617
1618     bell(e) {
1619         if (WebUtil.getConfigVar('bell', 'on') === 'on') {
1620             const promise = document.getElementById('noVNC_bell').play();
1621             // The standards disagree on the return value here
1622             if (promise) {
1623                 promise.catch((e) => {
1624                     if (e.name === "NotAllowedError") {
1625                         // Ignore when the browser doesn't let us play audio.
1626                         // It is common that the browsers require audio to be
1627                         // initiated from a user action.
1628                     } else {
1629                         Log.Error("Unable to play bell: " + e);
1630                     }
1631                 });
1632             }
1633         }
1634     },
1635
1636     //Helper to add options to dropdown.
1637     addOption(selectbox, text, value) {
1638         const optn = document.createElement("OPTION");
1639         optn.text = text;
1640         optn.value = value;
1641         selectbox.options.add(optn);
1642     },
1643
1644 /* ------^-------
1645  *    /MISC
1646  * ==============
1647  */
1648 };
1649
1650 // Set up translations
1651 const LINGUAS = ["cs", "de", "el", "es", "nl", "pl", "sv", "tr", "zh_CN", "zh_TW"];
1652 l10n.setup(LINGUAS);
1653 if (l10n.language !== "en" && l10n.dictionary === undefined) {
1654     WebUtil.fetchJSON('app/locale/' + l10n.language + '.json', (translations) => {
1655         l10n.dictionary = translations;
1656
1657         // wait for translations to load before loading the UI
1658         UI.prime();
1659     }, (err) => {
1660         Log.Error("Failed to load translations: " + err);
1661         UI.prime();
1662     });
1663 } else {
1664     UI.prime();
1665 }
1666
1667 export default UI;