image/w/core/rfb.js.orig

changeset 11
f816cf5b6bcb
parent 0
b74b0e4902c3
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/image/w/core/rfb.js.orig	Wed Oct 24 11:49:22 2018 +0200
@@ -0,0 +1,2554 @@
+/*
+ * noVNC: HTML5 VNC client
+ * Copyright (C) 2012 Joel Martin
+ * Copyright (C) 2017 Samuel Mannehed for Cendio AB
+ * Licensed under MPL 2.0 (see LICENSE.txt)
+ *
+ * See README.md for usage and integration instructions.
+ *
+ * TIGHT decoder portion:
+ * (c) 2012 Michael Tinglof, Joe Balaz, Les Piech (Mercuri.ca)
+ */
+
+import * as Log from './util/logging.js';
+import { decodeUTF8 } from './util/strings.js';
+import { supportsCursorURIs, isTouchDevice } from './util/browser.js';
+import EventTargetMixin from './util/eventtarget.js';
+import Display from "./display.js";
+import Keyboard from "./input/keyboard.js";
+import Mouse from "./input/mouse.js";
+import Websock from "./websock.js";
+import DES from "./des.js";
+import KeyTable from "./input/keysym.js";
+import XtScancode from "./input/xtscancodes.js";
+import Inflator from "./inflator.js";
+import { encodings, encodingName } from "./encodings.js";
+import "./util/polyfill.js";
+
+/*jslint white: false, browser: true */
+/*global window, Util, Display, Keyboard, Mouse, Websock, Websock_native, Base64, DES, KeyTable, Inflator, XtScancode */
+
+// How many seconds to wait for a disconnect to finish
+var DISCONNECT_TIMEOUT = 3;
+
+export default function RFB(target, url, options) {
+    if (!target) {
+        throw Error("Must specify target");
+    }
+    if (!url) {
+        throw Error("Must specify URL");
+    }
+
+    this._target = target;
+    this._url = url;
+
+    // Connection details
+    options = options || {};
+    this._rfb_credentials = options.credentials || {};
+    this._shared = 'shared' in options ? !!options.shared : true;
+    this._repeaterID = options.repeaterID || '';
+
+    // Internal state
+    this._rfb_connection_state = '';
+    this._rfb_init_state = '';
+    this._rfb_auth_scheme = '';
+    this._rfb_clean_disconnect = true;
+
+    // Server capabilities
+    this._rfb_version = 0;
+    this._rfb_max_version = 3.8;
+    this._rfb_tightvnc = false;
+    this._rfb_xvp_ver = 0;
+
+    this._fb_width = 0;
+    this._fb_height = 0;
+
+    this._fb_name = "";
+
+    this._capabilities = { power: false };
+
+    this._supportsFence = false;
+
+    this._supportsContinuousUpdates = false;
+    this._enabledContinuousUpdates = false;
+
+    this._supportsSetDesktopSize = false;
+    this._screen_id = 0;
+    this._screen_flags = 0;
+
+    this._qemuExtKeyEventSupported = false;
+
+    // Internal objects
+    this._sock = null;              // Websock object
+    this._display = null;           // Display object
+    this._flushing = false;         // Display flushing state
+    this._keyboard = null;          // Keyboard input handler object
+    this._mouse = null;             // Mouse input handler object
+
+    // Timers
+    this._disconnTimer = null;      // disconnection timer
+    this._resizeTimeout = null;     // resize rate limiting
+
+    // Decoder states and stats
+    this._encHandlers = {};
+    this._encStats = {};
+
+    this._FBU = {
+        rects: 0,
+        subrects: 0,            // RRE and HEXTILE
+        lines: 0,               // RAW
+        tiles: 0,               // HEXTILE
+        bytes: 0,
+        x: 0,
+        y: 0,
+        width: 0,
+        height: 0,
+        encoding: 0,
+        subencoding: -1,
+        background: null,
+        zlibs: []               // TIGHT zlib streams
+    };
+    for (var i = 0; i < 4; i++) {
+        this._FBU.zlibs[i] = new Inflator();
+    }
+
+    this._destBuff = null;
+    this._paletteBuff = new Uint8Array(1024);  // 256 * 4 (max palette size * max bytes-per-pixel)
+
+    this._rre_chunk_sz = 100;
+
+    this._timing = {
+        last_fbu: 0,
+        fbu_total: 0,
+        fbu_total_cnt: 0,
+        full_fbu_total: 0,
+        full_fbu_cnt: 0,
+
+        fbu_rt_start: 0,
+        fbu_rt_total: 0,
+        fbu_rt_cnt: 0,
+        pixels: 0
+    };
+
+    // Mouse state
+    this._mouse_buttonMask = 0;
+    this._mouse_arr = [];
+    this._viewportDragging = false;
+    this._viewportDragPos = {};
+    this._viewportHasMoved = false;
+
+    // Bound event handlers
+    this._eventHandlers = {
+        focusCanvas: this._focusCanvas.bind(this),
+        windowResize: this._windowResize.bind(this),
+    };
+
+    // main setup
+    Log.Debug(">> RFB.constructor");
+
+    // Create DOM elements
+    this._screen = document.createElement('div');
+    this._screen.style.display = 'flex';
+    this._screen.style.width = '100%';
+    this._screen.style.height = '100%';
+    this._screen.style.overflow = 'auto';
+    this._screen.style.backgroundColor = 'rgb(40, 40, 40)';
+    this._canvas = document.createElement('canvas');
+    this._canvas.style.margin = 'auto';
+    // Some browsers add an outline on focus
+    this._canvas.style.outline = 'none';
+    // IE miscalculates width without this :(
+    this._canvas.style.flexShrink = '0';
+    this._canvas.width = 0;
+    this._canvas.height = 0;
+    this._canvas.tabIndex = -1;
+    this._screen.appendChild(this._canvas);
+
+    // populate encHandlers with bound versions
+    this._encHandlers[encodings.encodingRaw] = RFB.encodingHandlers.RAW.bind(this);
+    this._encHandlers[encodings.encodingCopyRect] = RFB.encodingHandlers.COPYRECT.bind(this);
+    this._encHandlers[encodings.encodingRRE] = RFB.encodingHandlers.RRE.bind(this);
+    this._encHandlers[encodings.encodingHextile] = RFB.encodingHandlers.HEXTILE.bind(this);
+    this._encHandlers[encodings.encodingTight] = RFB.encodingHandlers.TIGHT.bind(this);
+
+    this._encHandlers[encodings.pseudoEncodingDesktopSize] = RFB.encodingHandlers.DesktopSize.bind(this);
+    this._encHandlers[encodings.pseudoEncodingLastRect] = RFB.encodingHandlers.last_rect.bind(this);
+    this._encHandlers[encodings.pseudoEncodingCursor] = RFB.encodingHandlers.Cursor.bind(this);
+    this._encHandlers[encodings.pseudoEncodingQEMUExtendedKeyEvent] = RFB.encodingHandlers.QEMUExtendedKeyEvent.bind(this);
+    this._encHandlers[encodings.pseudoEncodingExtendedDesktopSize] = RFB.encodingHandlers.ExtendedDesktopSize.bind(this);
+
+    // NB: nothing that needs explicit teardown should be done
+    // before this point, since this can throw an exception
+    try {
+        this._display = new Display(this._canvas);
+    } catch (exc) {
+        Log.Error("Display exception: " + exc);
+        throw exc;
+    }
+    this._display.onflush = this._onFlush.bind(this);
+    this._display.clear();
+
+    this._keyboard = new Keyboard(this._canvas);
+    this._keyboard.onkeyevent = this._handleKeyEvent.bind(this);
+
+    this._mouse = new Mouse(this._canvas);
+    this._mouse.onmousebutton = this._handleMouseButton.bind(this);
+    this._mouse.onmousemove = this._handleMouseMove.bind(this);
+
+    this._sock = new Websock();
+    this._sock.on('message', this._handle_message.bind(this));
+    this._sock.on('open', function () {
+        if ((this._rfb_connection_state === 'connecting') &&
+            (this._rfb_init_state === '')) {
+            this._rfb_init_state = 'ProtocolVersion';
+            Log.Debug("Starting VNC handshake");
+        } else {
+            this._fail("Unexpected server connection while " +
+                       this._rfb_connection_state);
+        }
+    }.bind(this));
+    this._sock.on('close', function (e) {
+        Log.Debug("WebSocket on-close event");
+        var msg = "";
+        if (e.code) {
+            msg = "(code: " + e.code;
+            if (e.reason) {
+                msg += ", reason: " + e.reason;
+            }
+            msg += ")";
+        }
+        switch (this._rfb_connection_state) {
+            case 'connecting':
+                this._fail("Connection closed " + msg);
+                break;
+            case 'connected':
+                // Handle disconnects that were initiated server-side
+                this._updateConnectionState('disconnecting');
+                this._updateConnectionState('disconnected');
+                break;
+            case 'disconnecting':
+                // Normal disconnection path
+                this._updateConnectionState('disconnected');
+                break;
+            case 'disconnected':
+                this._fail("Unexpected server disconnect " +
+                           "when already disconnected " + msg);
+                break;
+            default:
+                this._fail("Unexpected server disconnect before connecting " +
+                           msg);
+                break;
+        }
+        this._sock.off('close');
+    }.bind(this));
+    this._sock.on('error', function (e) {
+        Log.Warn("WebSocket on-error event");
+    });
+
+    // Slight delay of the actual connection so that the caller has
+    // time to set up callbacks
+    setTimeout(this._updateConnectionState.bind(this, 'connecting'));
+
+    Log.Debug("<< RFB.constructor");
+};
+
+RFB.prototype = {
+    // ===== PROPERTIES =====
+
+    dragViewport: false,
+    focusOnClick: true,
+
+    _viewOnly: false,
+    get viewOnly() { return this._viewOnly; },
+    set viewOnly(viewOnly) {
+        this._viewOnly = viewOnly;
+
+        if (this._rfb_connection_state === "connecting" ||
+            this._rfb_connection_state === "connected") {
+            if (viewOnly) {
+                this._keyboard.ungrab();
+                this._mouse.ungrab();
+            } else {
+                this._keyboard.grab();
+                this._mouse.grab();
+            }
+        }
+    },
+
+    get capabilities() { return this._capabilities; },
+
+    get touchButton() { return this._mouse.touchButton; },
+    set touchButton(button) { this._mouse.touchButton = button; },
+
+    _clipViewport: false,
+    get clipViewport() { return this._clipViewport; },
+    set clipViewport(viewport) {
+        this._clipViewport = viewport;
+        this._updateClip();
+    },
+
+    _scaleViewport: false,
+    get scaleViewport() { return this._scaleViewport; },
+    set scaleViewport(scale) {
+        this._scaleViewport = scale;
+        // Scaling trumps clipping, so we may need to adjust
+        // clipping when enabling or disabling scaling
+        if (scale && this._clipViewport) {
+            this._updateClip();
+        }
+        this._updateScale();
+        if (!scale && this._clipViewport) {
+            this._updateClip();
+        }
+    },
+
+    _resizeSession: false,
+    get resizeSession() { return this._resizeSession; },
+    set resizeSession(resize) {
+        this._resizeSession = resize;
+        if (resize) {
+            this._requestRemoteResize();
+        }
+    },
+
+    // ===== PUBLIC METHODS =====
+
+    disconnect: function () {
+        this._updateConnectionState('disconnecting');
+        this._sock.off('error');
+        this._sock.off('message');
+        this._sock.off('open');
+    },
+
+    sendCredentials: function (creds) {
+        this._rfb_credentials = creds;
+        setTimeout(this._init_msg.bind(this), 0);
+    },
+
+    sendCtrlAltDel: function () {
+        if (this._rfb_connection_state !== 'connected' || this._viewOnly) { return; }
+        Log.Info("Sending Ctrl-Alt-Del");
+
+        this.sendKey(KeyTable.XK_Control_L, "ControlLeft", true);
+        this.sendKey(KeyTable.XK_Alt_L, "AltLeft", true);
+        this.sendKey(KeyTable.XK_Delete, "Delete", true);
+        this.sendKey(KeyTable.XK_Delete, "Delete", false);
+        this.sendKey(KeyTable.XK_Alt_L, "AltLeft", false);
+        this.sendKey(KeyTable.XK_Control_L, "ControlLeft", false);
+    },
+
+    machineShutdown: function () {
+        this._xvpOp(1, 2);
+    },
+
+    machineReboot: function () {
+        this._xvpOp(1, 3);
+    },
+
+    machineReset: function () {
+        this._xvpOp(1, 4);
+    },
+
+    // Send a key press. If 'down' is not specified then send a down key
+    // followed by an up key.
+    sendKey: function (keysym, code, down) {
+        if (this._rfb_connection_state !== 'connected' || this._viewOnly) { return; }
+
+        if (down === undefined) {
+            this.sendKey(keysym, code, true);
+            this.sendKey(keysym, code, false);
+            return;
+        }
+
+        var scancode = XtScancode[code];
+
+        if (this._qemuExtKeyEventSupported && scancode) {
+            // 0 is NoSymbol
+            keysym = keysym || 0;
+
+            Log.Info("Sending key (" + (down ? "down" : "up") + "): keysym " + keysym + ", scancode " + scancode);
+
+            RFB.messages.QEMUExtendedKeyEvent(this._sock, keysym, down, scancode);
+        } else {
+            if (!keysym) {
+                return;
+            }
+            Log.Info("Sending keysym (" + (down ? "down" : "up") + "): " + keysym);
+            RFB.messages.keyEvent(this._sock, keysym, down ? 1 : 0);
+        }
+    },
+
+    focus: function () {
+        this._canvas.focus();
+    },
+
+    blur: function () {
+        this._canvas.blur();
+    },
+
+    clipboardPasteFrom: function (text) {
+        if (this._rfb_connection_state !== 'connected' || this._viewOnly) { return; }
+        RFB.messages.clientCutText(this._sock, text);
+    },
+
+    // ===== PRIVATE METHODS =====
+
+    _connect: function () {
+        Log.Debug(">> RFB.connect");
+
+        Log.Info("connecting to " + this._url);
+
+        try {
+            // WebSocket.onopen transitions to the RFB init states
+            this._sock.open(this._url, ['binary']);
+        } catch (e) {
+            if (e.name === 'SyntaxError') {
+                this._fail("Invalid host or port (" + e + ")");
+            } else {
+                this._fail("Error when opening socket (" + e + ")");
+            }
+        }
+
+        // Make our elements part of the page
+        this._target.appendChild(this._screen);
+
+        // Monitor size changes of the screen
+        // FIXME: Use ResizeObserver, or hidden overflow
+        window.addEventListener('resize', this._eventHandlers.windowResize);
+
+        // Always grab focus on some kind of click event
+        this._canvas.addEventListener("mousedown", this._eventHandlers.focusCanvas);
+        this._canvas.addEventListener("touchstart", this._eventHandlers.focusCanvas);
+
+        Log.Debug("<< RFB.connect");
+    },
+
+    _disconnect: function () {
+        Log.Debug(">> RFB.disconnect");
+        this._canvas.removeEventListener("mousedown", this._eventHandlers.focusCanvas);
+        this._canvas.removeEventListener("touchstart", this._eventHandlers.focusCanvas);
+        window.removeEventListener('resize', this._eventHandlers.windowResize);
+        this._keyboard.ungrab();
+        this._mouse.ungrab();
+        this._sock.close();
+        this._print_stats();
+        try {
+            this._target.removeChild(this._screen);
+        } catch (e) {
+            if (e.name === 'NotFoundError') {
+                // Some cases where the initial connection fails
+                // can disconnect before the _screen is created
+            } else {
+                throw e;
+            }
+        }
+        clearTimeout(this._resizeTimeout);
+        Log.Debug("<< RFB.disconnect");
+    },
+
+    _print_stats: function () {
+        var stats = this._encStats;
+
+        Log.Info("Encoding stats for this connection:");
+        Object.keys(stats).forEach(function (key) {
+            var s = stats[key];
+            if (s[0] + s[1] > 0) {
+                Log.Info("    " + encodingName(key) + ": " + s[0] + " rects");
+            }
+        });
+
+        Log.Info("Encoding stats since page load:");
+        Object.keys(stats).forEach(function (key) {
+            var s = stats[key];
+            Log.Info("    " + encodingName(key) + ": " + s[1] + " rects");
+        });
+    },
+
+    _focusCanvas: function(event) {
+        // Respect earlier handlers' request to not do side-effects
+        if (event.defaultPrevented) {
+            return;
+        }
+
+        if (!this.focusOnClick) {
+            return;
+        }
+
+        this.focus();
+    },
+
+    _windowResize: function (event) {
+        // If the window resized then our screen element might have
+        // as well. Update the viewport dimensions.
+        window.requestAnimationFrame(function () {
+            this._updateClip();
+            this._updateScale();
+        }.bind(this));
+
+        if (this._resizeSession) {
+            // Request changing the resolution of the remote display to
+            // the size of the local browser viewport.
+
+            // In order to not send multiple requests before the browser-resize
+            // is finished we wait 0.5 seconds before sending the request.
+            clearTimeout(this._resizeTimeout);
+            this._resizeTimeout = setTimeout(this._requestRemoteResize.bind(this), 500);
+        }
+    },
+
+    // Update state of clipping in Display object, and make sure the
+    // configured viewport matches the current screen size
+    _updateClip: function () {
+        var cur_clip = this._display.clipViewport;
+        var new_clip = this._clipViewport;
+
+        if (this._scaleViewport) {
+            // Disable viewport clipping if we are scaling
+            new_clip = false;
+        }
+
+        if (cur_clip !== new_clip) {
+            this._display.clipViewport = new_clip;
+        }
+
+        if (new_clip) {
+            // When clipping is enabled, the screen is limited to
+            // the size of the container.
+            let size = this._screenSize();
+            this._display.viewportChangeSize(size.w, size.h);
+            this._fixScrollbars();
+        }
+    },
+
+    _updateScale: function () {
+        if (!this._scaleViewport) {
+            this._display.scale = 1.0;
+        } else {
+            let size = this._screenSize();
+            this._display.autoscale(size.w, size.h);
+        }
+        this._fixScrollbars();
+    },
+
+    // Requests a change of remote desktop size. This message is an extension
+    // and may only be sent if we have received an ExtendedDesktopSize message
+    _requestRemoteResize: function () {
+        clearTimeout(this._resizeTimeout);
+        this._resizeTimeout = null;
+
+        if (!this._resizeSession || this._viewOnly ||
+            !this._supportsSetDesktopSize) {
+            return;
+        }
+
+        let size = this._screenSize();
+        RFB.messages.setDesktopSize(this._sock, size.w, size.h,
+                                    this._screen_id, this._screen_flags);
+
+        Log.Debug('Requested new desktop size: ' +
+                   size.w + 'x' + size.h);
+    },
+
+    // Gets the the size of the available screen
+    _screenSize: function () {
+        return { w: this._screen.offsetWidth,
+                 h: this._screen.offsetHeight };
+    },
+
+    _fixScrollbars: function () {
+        // This is a hack because Chrome screws up the calculation
+        // for when scrollbars are needed. So to fix it we temporarily
+        // toggle them off and on.
+        var orig = this._screen.style.overflow;
+        this._screen.style.overflow = 'hidden';
+        // Force Chrome to recalculate the layout by asking for
+        // an element's dimensions
+        this._screen.getBoundingClientRect();
+        this._screen.style.overflow = orig;
+    },
+
+    /*
+     * Connection states:
+     *   connecting
+     *   connected
+     *   disconnecting
+     *   disconnected - permanent state
+     */
+    _updateConnectionState: function (state) {
+        var oldstate = this._rfb_connection_state;
+
+        if (state === oldstate) {
+            Log.Debug("Already in state '" + state + "', ignoring");
+            return;
+        }
+
+        // The 'disconnected' state is permanent for each RFB object
+        if (oldstate === 'disconnected') {
+            Log.Error("Tried changing state of a disconnected RFB object");
+            return;
+        }
+
+        // Ensure proper transitions before doing anything
+        switch (state) {
+            case 'connected':
+                if (oldstate !== 'connecting') {
+                    Log.Error("Bad transition to connected state, " +
+                               "previous connection state: " + oldstate);
+                    return;
+                }
+                break;
+
+            case 'disconnected':
+                if (oldstate !== 'disconnecting') {
+                    Log.Error("Bad transition to disconnected state, " +
+                               "previous connection state: " + oldstate);
+                    return;
+                }
+                break;
+
+            case 'connecting':
+                if (oldstate !== '') {
+                    Log.Error("Bad transition to connecting state, " +
+                               "previous connection state: " + oldstate);
+                    return;
+                }
+                break;
+
+            case 'disconnecting':
+                if (oldstate !== 'connected' && oldstate !== 'connecting') {
+                    Log.Error("Bad transition to disconnecting state, " +
+                               "previous connection state: " + oldstate);
+                    return;
+                }
+                break;
+
+            default:
+                Log.Error("Unknown connection state: " + state);
+                return;
+        }
+
+        // State change actions
+
+        this._rfb_connection_state = state;
+
+        var smsg = "New state '" + state + "', was '" + oldstate + "'.";
+        Log.Debug(smsg);
+
+        if (this._disconnTimer && state !== 'disconnecting') {
+            Log.Debug("Clearing disconnect timer");
+            clearTimeout(this._disconnTimer);
+            this._disconnTimer = null;
+
+            // make sure we don't get a double event
+            this._sock.off('close');
+        }
+
+        switch (state) {
+            case 'connecting':
+                this._connect();
+                break;
+
+            case 'connected':
+                var event = new CustomEvent("connect", { detail: {} });
+                this.dispatchEvent(event);
+                break;
+
+            case 'disconnecting':
+                this._disconnect();
+
+                this._disconnTimer = setTimeout(function () {
+                    Log.Error("Disconnection timed out.");
+                    this._updateConnectionState('disconnected');
+                }.bind(this), DISCONNECT_TIMEOUT * 1000);
+                break;
+
+            case 'disconnected':
+                event = new CustomEvent(
+                    "disconnect", { detail:
+                                    { clean: this._rfb_clean_disconnect } });
+                this.dispatchEvent(event);
+                break;
+        }
+    },
+
+    /* Print errors and disconnect
+     *
+     * The parameter 'details' is used for information that
+     * should be logged but not sent to the user interface.
+     */
+    _fail: function (details) {
+        switch (this._rfb_connection_state) {
+            case 'disconnecting':
+                Log.Error("Failed when disconnecting: " + details);
+                break;
+            case 'connected':
+                Log.Error("Failed while connected: " + details);
+                break;
+            case 'connecting':
+                Log.Error("Failed when connecting: " + details);
+                break;
+            default:
+                Log.Error("RFB failure: " + details);
+                break;
+        }
+        this._rfb_clean_disconnect = false; //This is sent to the UI
+
+        // Transition to disconnected without waiting for socket to close
+        this._updateConnectionState('disconnecting');
+        this._updateConnectionState('disconnected');
+
+        return false;
+    },
+
+    _setCapability: function (cap, val) {
+        this._capabilities[cap] = val;
+        var event = new CustomEvent("capabilities",
+                                    { detail: { capabilities: this._capabilities } });
+        this.dispatchEvent(event);
+    },
+
+    _handle_message: function () {
+        if (this._sock.rQlen() === 0) {
+            Log.Warn("handle_message called on an empty receive queue");
+            return;
+        }
+
+        switch (this._rfb_connection_state) {
+            case 'disconnected':
+                Log.Error("Got data while disconnected");
+                break;
+            case 'connected':
+                while (true) {
+                    if (this._flushing) {
+                        break;
+                    }
+                    if (!this._normal_msg()) {
+                        break;
+                    }
+                    if (this._sock.rQlen() === 0) {
+                        break;
+                    }
+                }
+                break;
+            default:
+                this._init_msg();
+                break;
+        }
+    },
+
+    _handleKeyEvent: function (keysym, code, down) {
+        this.sendKey(keysym, code, down);
+    },
+
+    _handleMouseButton: function (x, y, down, bmask) {
+        if (down) {
+            this._mouse_buttonMask |= bmask;
+        } else {
+            this._mouse_buttonMask &= ~bmask;
+        }
+
+        if (this.dragViewport) {
+            if (down && !this._viewportDragging) {
+                this._viewportDragging = true;
+                this._viewportDragPos = {'x': x, 'y': y};
+                this._viewportHasMoved = false;
+
+                // Skip sending mouse events
+                return;
+            } else {
+                this._viewportDragging = false;
+
+                // If we actually performed a drag then we are done
+                // here and should not send any mouse events
+                if (this._viewportHasMoved) {
+                    return;
+                }
+
+                // Otherwise we treat this as a mouse click event.
+                // Send the button down event here, as the button up
+                // event is sent at the end of this function.
+                RFB.messages.pointerEvent(this._sock,
+                                          this._display.absX(x),
+                                          this._display.absY(y),
+                                          bmask);
+            }
+        }
+
+        if (this._viewOnly) { return; } // View only, skip mouse events
+
+        if (this._rfb_connection_state !== 'connected') { return; }
+        RFB.messages.pointerEvent(this._sock, this._display.absX(x), this._display.absY(y), this._mouse_buttonMask);
+    },
+
+    _handleMouseMove: function (x, y) {
+        if (this._viewportDragging) {
+            var deltaX = this._viewportDragPos.x - x;
+            var deltaY = this._viewportDragPos.y - y;
+
+            // The goal is to trigger on a certain physical width, the
+            // devicePixelRatio brings us a bit closer but is not optimal.
+            var dragThreshold = 10 * (window.devicePixelRatio || 1);
+
+            if (this._viewportHasMoved || (Math.abs(deltaX) > dragThreshold ||
+                                           Math.abs(deltaY) > dragThreshold)) {
+                this._viewportHasMoved = true;
+
+                this._viewportDragPos = {'x': x, 'y': y};
+                this._display.viewportChangePos(deltaX, deltaY);
+            }
+
+            // Skip sending mouse events
+            return;
+        }
+
+        if (this._viewOnly) { return; } // View only, skip mouse events
+
+        if (this._rfb_connection_state !== 'connected') { return; }
+        RFB.messages.pointerEvent(this._sock, this._display.absX(x), this._display.absY(y), this._mouse_buttonMask);
+    },
+
+    // Message Handlers
+
+    _negotiate_protocol_version: function () {
+        if (this._sock.rQlen() < 12) {
+            return this._fail("Received incomplete protocol version.");
+        }
+
+        var sversion = this._sock.rQshiftStr(12).substr(4, 7);
+        Log.Info("Server ProtocolVersion: " + sversion);
+        var is_repeater = 0;
+        switch (sversion) {
+            case "000.000":  // UltraVNC repeater
+                is_repeater = 1;
+                break;
+            case "003.003":
+            case "003.006":  // UltraVNC
+            case "003.889":  // Apple Remote Desktop
+                this._rfb_version = 3.3;
+                break;
+            case "003.007":
+                this._rfb_version = 3.7;
+                break;
+            case "003.008":
+            case "004.000":  // Intel AMT KVM
+            case "004.001":  // RealVNC 4.6
+            case "005.000":  // RealVNC 5.3
+                this._rfb_version = 3.8;
+                break;
+            default:
+                return this._fail("Invalid server version " + sversion);
+        }
+
+        if (is_repeater) {
+            var repeaterID = "ID:" + this._repeaterID;
+            while (repeaterID.length < 250) {
+                repeaterID += "\0";
+            }
+            this._sock.send_string(repeaterID);
+            return true;
+        }
+
+        if (this._rfb_version > this._rfb_max_version) {
+            this._rfb_version = this._rfb_max_version;
+        }
+
+        var cversion = "00" + parseInt(this._rfb_version, 10) +
+                       ".00" + ((this._rfb_version * 10) % 10);
+        this._sock.send_string("RFB " + cversion + "\n");
+        Log.Debug('Sent ProtocolVersion: ' + cversion);
+
+        this._rfb_init_state = 'Security';
+    },
+
+    _negotiate_security: function () {
+        // Polyfill since IE and PhantomJS doesn't have
+        // TypedArray.includes()
+        function includes(item, array) {
+            for (var i = 0; i < array.length; i++) {
+                if (array[i] === item) {
+                    return true;
+                }
+            }
+            return false;
+        }
+
+        if (this._rfb_version >= 3.7) {
+            // Server sends supported list, client decides
+            var num_types = this._sock.rQshift8();
+            if (this._sock.rQwait("security type", num_types, 1)) { return false; }
+
+            if (num_types === 0) {
+                return this._handle_security_failure("no security types");
+            }
+
+            var types = this._sock.rQshiftBytes(num_types);
+            Log.Debug("Server security types: " + types);
+
+            // Look for each auth in preferred order
+            this._rfb_auth_scheme = 0;
+            if (includes(1, types)) {
+                this._rfb_auth_scheme = 1; // None
+            } else if (includes(22, types)) {
+                this._rfb_auth_scheme = 22; // XVP
+            } else if (includes(16, types)) {
+                this._rfb_auth_scheme = 16; // Tight
+            } else if (includes(2, types)) {
+                this._rfb_auth_scheme = 2; // VNC Auth
+            } else {
+                return this._fail("Unsupported security types (types: " + types + ")");
+            }
+
+            this._sock.send([this._rfb_auth_scheme]);
+        } else {
+            // Server decides
+            if (this._sock.rQwait("security scheme", 4)) { return false; }
+            this._rfb_auth_scheme = this._sock.rQshift32();
+        }
+
+        this._rfb_init_state = 'Authentication';
+        Log.Debug('Authenticating using scheme: ' + this._rfb_auth_scheme);
+
+        return this._init_msg(); // jump to authentication
+    },
+
+    /*
+     * Get the security failure reason if sent from the server and
+     * send the 'securityfailure' event.
+     *
+     * - The optional parameter context can be used to add some extra
+     *   context to the log output.
+     *
+     * - The optional parameter security_result_status can be used to
+     *   add a custom status code to the event.
+     */
+    _handle_security_failure: function (context, security_result_status) {
+
+        if (typeof context === 'undefined') {
+            context = "";
+        } else {
+            context = " on " + context;
+        }
+
+        if (typeof security_result_status === 'undefined') {
+            security_result_status = 1; // fail
+        }
+
+        if (this._sock.rQwait("reason length", 4)) {
+            return false;
+        }
+        let strlen = this._sock.rQshift32();
+        let reason = "";
+
+        if (strlen > 0) {
+            if (this._sock.rQwait("reason", strlen, 8)) { return false; }
+            reason = this._sock.rQshiftStr(strlen);
+        }
+
+        if (reason !== "") {
+
+            let event = new CustomEvent(
+                "securityfailure",
+                { detail: { status: security_result_status, reason: reason } });
+            this.dispatchEvent(event);
+
+            return this._fail("Security negotiation failed" + context +
+                              " (reason: " + reason + ")");
+        } else {
+
+            let event = new CustomEvent(
+                "securityfailure",
+                { detail: { status: security_result_status } });
+            this.dispatchEvent(event);
+
+            return this._fail("Security negotiation failed" + context);
+        }
+    },
+
+    // authentication
+    _negotiate_xvp_auth: function () {
+        if (!this._rfb_credentials.username ||
+            !this._rfb_credentials.password ||
+            !this._rfb_credentials.target) {
+            var event = new CustomEvent("credentialsrequired",
+                                        { detail: { types: ["username", "password", "target"] } });
+            this.dispatchEvent(event);
+            return false;
+        }
+
+        var xvp_auth_str = String.fromCharCode(this._rfb_credentials.username.length) +
+                           String.fromCharCode(this._rfb_credentials.target.length) +
+                           this._rfb_credentials.username +
+                           this._rfb_credentials.target;
+        this._sock.send_string(xvp_auth_str);
+        this._rfb_auth_scheme = 2;
+        return this._negotiate_authentication();
+    },
+
+    _negotiate_std_vnc_auth: function () {
+        if (this._sock.rQwait("auth challenge", 16)) { return false; }
+
+        if (!this._rfb_credentials.password) {
+            var event = new CustomEvent("credentialsrequired",
+                                        { detail: { types: ["password"] } });
+            this.dispatchEvent(event);
+            return false;
+        }
+
+        // TODO(directxman12): make genDES not require an Array
+        var challenge = Array.prototype.slice.call(this._sock.rQshiftBytes(16));
+        var response = RFB.genDES(this._rfb_credentials.password, challenge);
+        this._sock.send(response);
+        this._rfb_init_state = "SecurityResult";
+        return true;
+    },
+
+    _negotiate_tight_tunnels: function (numTunnels) {
+        var clientSupportedTunnelTypes = {
+            0: { vendor: 'TGHT', signature: 'NOTUNNEL' }
+        };
+        var serverSupportedTunnelTypes = {};
+        // receive tunnel capabilities
+        for (var i = 0; i < numTunnels; i++) {
+            var cap_code = this._sock.rQshift32();
+            var cap_vendor = this._sock.rQshiftStr(4);
+            var cap_signature = this._sock.rQshiftStr(8);
+            serverSupportedTunnelTypes[cap_code] = { vendor: cap_vendor, signature: cap_signature };
+        }
+
+        // choose the notunnel type
+        if (serverSupportedTunnelTypes[0]) {
+            if (serverSupportedTunnelTypes[0].vendor != clientSupportedTunnelTypes[0].vendor ||
+                serverSupportedTunnelTypes[0].signature != clientSupportedTunnelTypes[0].signature) {
+                return this._fail("Client's tunnel type had the incorrect " +
+                                  "vendor or signature");
+            }
+            this._sock.send([0, 0, 0, 0]);  // use NOTUNNEL
+            return false; // wait until we receive the sub auth count to continue
+        } else {
+            return this._fail("Server wanted tunnels, but doesn't support " +
+                              "the notunnel type");
+        }
+    },
+
+    _negotiate_tight_auth: function () {
+        if (!this._rfb_tightvnc) {  // first pass, do the tunnel negotiation
+            if (this._sock.rQwait("num tunnels", 4)) { return false; }
+            var numTunnels = this._sock.rQshift32();
+            if (numTunnels > 0 && this._sock.rQwait("tunnel capabilities", 16 * numTunnels, 4)) { return false; }
+
+            this._rfb_tightvnc = true;
+
+            if (numTunnels > 0) {
+                this._negotiate_tight_tunnels(numTunnels);
+                return false;  // wait until we receive the sub auth to continue
+            }
+        }
+
+        // second pass, do the sub-auth negotiation
+        if (this._sock.rQwait("sub auth count", 4)) { return false; }
+        var subAuthCount = this._sock.rQshift32();
+        if (subAuthCount === 0) {  // empty sub-auth list received means 'no auth' subtype selected
+            this._rfb_init_state = 'SecurityResult';
+            return true;
+        }
+
+        if (this._sock.rQwait("sub auth capabilities", 16 * subAuthCount, 4)) { return false; }
+
+        var clientSupportedTypes = {
+            'STDVNOAUTH__': 1,
+            'STDVVNCAUTH_': 2
+        };
+
+        var serverSupportedTypes = [];
+
+        for (var i = 0; i < subAuthCount; i++) {
+            var capNum = this._sock.rQshift32();
+            var capabilities = this._sock.rQshiftStr(12);
+            serverSupportedTypes.push(capabilities);
+        }
+
+        for (var authType in clientSupportedTypes) {
+            if (serverSupportedTypes.indexOf(authType) != -1) {
+                this._sock.send([0, 0, 0, clientSupportedTypes[authType]]);
+
+                switch (authType) {
+                    case 'STDVNOAUTH__':  // no auth
+                        this._rfb_init_state = 'SecurityResult';
+                        return true;
+                    case 'STDVVNCAUTH_': // VNC auth
+                        this._rfb_auth_scheme = 2;
+                        return this._init_msg();
+                    default:
+                        return this._fail("Unsupported tiny auth scheme " +
+                                          "(scheme: " + authType + ")");
+                }
+            }
+        }
+
+        return this._fail("No supported sub-auth types!");
+    },
+
+    _negotiate_authentication: function () {
+        switch (this._rfb_auth_scheme) {
+            case 0:  // connection failed
+                return this._handle_security_failure("authentication scheme");
+
+            case 1:  // no auth
+                if (this._rfb_version >= 3.8) {
+                    this._rfb_init_state = 'SecurityResult';
+                    return true;
+                }
+                this._rfb_init_state = 'ClientInitialisation';
+                return this._init_msg();
+
+            case 22:  // XVP auth
+                return this._negotiate_xvp_auth();
+
+            case 2:  // VNC authentication
+                return this._negotiate_std_vnc_auth();
+
+            case 16:  // TightVNC Security Type
+                return this._negotiate_tight_auth();
+
+            default:
+                return this._fail("Unsupported auth scheme (scheme: " +
+                                  this._rfb_auth_scheme + ")");
+        }
+    },
+
+    _handle_security_result: function () {
+        if (this._sock.rQwait('VNC auth response ', 4)) { return false; }
+
+        let status = this._sock.rQshift32();
+
+        if (status === 0) { // OK
+            this._rfb_init_state = 'ClientInitialisation';
+            Log.Debug('Authentication OK');
+            return this._init_msg();
+        } else {
+            if (this._rfb_version >= 3.8) {
+                return this._handle_security_failure("security result", status);
+            } else {
+                let event = new CustomEvent("securityfailure",
+                                            { detail: { status: status } });
+                this.dispatchEvent(event);
+
+                return this._fail("Security handshake failed");
+            }
+        }
+    },
+
+    _negotiate_server_init: function () {
+        if (this._sock.rQwait("server initialization", 24)) { return false; }
+
+        /* Screen size */
+        var width = this._sock.rQshift16();
+        var height = this._sock.rQshift16();
+
+        /* PIXEL_FORMAT */
+        var bpp         = this._sock.rQshift8();
+        var depth       = this._sock.rQshift8();
+        var big_endian  = this._sock.rQshift8();
+        var true_color  = this._sock.rQshift8();
+
+        var red_max     = this._sock.rQshift16();
+        var green_max   = this._sock.rQshift16();
+        var blue_max    = this._sock.rQshift16();
+        var red_shift   = this._sock.rQshift8();
+        var green_shift = this._sock.rQshift8();
+        var blue_shift  = this._sock.rQshift8();
+        this._sock.rQskipBytes(3);  // padding
+
+        // NB(directxman12): we don't want to call any callbacks or print messages until
+        //                   *after* we're past the point where we could backtrack
+
+        /* Connection name/title */
+        var name_length = this._sock.rQshift32();
+        if (this._sock.rQwait('server init name', name_length, 24)) { return false; }
+        this._fb_name = decodeUTF8(this._sock.rQshiftStr(name_length));
+
+        if (this._rfb_tightvnc) {
+            if (this._sock.rQwait('TightVNC extended server init header', 8, 24 + name_length)) { return false; }
+            // In TightVNC mode, ServerInit message is extended
+            var numServerMessages = this._sock.rQshift16();
+            var numClientMessages = this._sock.rQshift16();
+            var numEncodings = this._sock.rQshift16();
+            this._sock.rQskipBytes(2);  // padding
+
+            var totalMessagesLength = (numServerMessages + numClientMessages + numEncodings) * 16;
+            if (this._sock.rQwait('TightVNC extended server init header', totalMessagesLength, 32 + name_length)) { return false; }
+
+            // we don't actually do anything with the capability information that TIGHT sends,
+            // so we just skip the all of this.
+
+            // TIGHT server message capabilities
+            this._sock.rQskipBytes(16 * numServerMessages);
+
+            // TIGHT client message capabilities
+            this._sock.rQskipBytes(16 * numClientMessages);
+
+            // TIGHT encoding capabilities
+            this._sock.rQskipBytes(16 * numEncodings);
+        }
+
+        // NB(directxman12): these are down here so that we don't run them multiple times
+        //                   if we backtrack
+        Log.Info("Screen: " + width + "x" + height +
+                  ", bpp: " + bpp + ", depth: " + depth +
+                  ", big_endian: " + big_endian +
+                  ", true_color: " + true_color +
+                  ", red_max: " + red_max +
+                  ", green_max: " + green_max +
+                  ", blue_max: " + blue_max +
+                  ", red_shift: " + red_shift +
+                  ", green_shift: " + green_shift +
+                  ", blue_shift: " + blue_shift);
+
+        if (big_endian !== 0) {
+            Log.Warn("Server native endian is not little endian");
+        }
+
+        if (red_shift !== 16) {
+            Log.Warn("Server native red-shift is not 16");
+        }
+
+        if (blue_shift !== 0) {
+            Log.Warn("Server native blue-shift is not 0");
+        }
+
+        // we're past the point where we could backtrack, so it's safe to call this
+        var event = new CustomEvent("desktopname",
+                                    { detail: { name: this._fb_name } });
+        this.dispatchEvent(event);
+
+        this._resize(width, height);
+
+        if (!this._viewOnly) { this._keyboard.grab(); }
+        if (!this._viewOnly) { this._mouse.grab(); }
+
+        this._fb_depth = 24;
+
+        if (this._fb_name === "Intel(r) AMT KVM") {
+            Log.Warn("Intel AMT KVM only supports 8/16 bit depths. Using low color mode.");
+            this._fb_depth = 8;
+        } else if (this._fb_name === "MBSE BrewBoard") {
+	    Log.Warn("MBSE BrewBoard only supports 8 bit depths. Using low color mode.");
+	    this._fb_depth = 8;
+	}
+
+        RFB.messages.pixelFormat(this._sock, this._fb_depth, true);
+        this._sendEncodings();
+        RFB.messages.fbUpdateRequest(this._sock, false, 0, 0, this._fb_width, this._fb_height);
+
+        this._timing.fbu_rt_start = (new Date()).getTime();
+        this._timing.pixels = 0;
+
+        // Cursor will be server side until the server decides to honor
+        // our request and send over the cursor image
+        this._display.disableLocalCursor();
+
+        this._updateConnectionState('connected');
+        return true;
+    },
+
+    _sendEncodings: function () {
+        var encs = [];
+
+        // In preference order
+        encs.push(encodings.encodingCopyRect);
+        // Only supported with full depth support
+        if (this._fb_depth == 24) {
+            encs.push(encodings.encodingTight);
+            encs.push(encodings.encodingHextile);
+            encs.push(encodings.encodingRRE);
+        }
+        encs.push(encodings.encodingRaw);
+
+        // Psuedo-encoding settings
+        encs.push(encodings.pseudoEncodingTightPNG);
+        encs.push(encodings.pseudoEncodingQualityLevel0 + 6);
+        encs.push(encodings.pseudoEncodingCompressLevel0 + 2);
+
+        encs.push(encodings.pseudoEncodingDesktopSize);
+        encs.push(encodings.pseudoEncodingLastRect);
+        encs.push(encodings.pseudoEncodingQEMUExtendedKeyEvent);
+        encs.push(encodings.pseudoEncodingExtendedDesktopSize);
+        encs.push(encodings.pseudoEncodingXvp);
+        encs.push(encodings.pseudoEncodingFence);
+        encs.push(encodings.pseudoEncodingContinuousUpdates);
+
+        if (supportsCursorURIs() &&
+            !isTouchDevice && this._fb_depth == 24) {
+            encs.push(encodings.pseudoEncodingCursor);
+        }
+
+        RFB.messages.clientEncodings(this._sock, encs);
+    },
+
+    /* RFB protocol initialization states:
+     *   ProtocolVersion
+     *   Security
+     *   Authentication
+     *   SecurityResult
+     *   ClientInitialization - not triggered by server message
+     *   ServerInitialization
+     */
+    _init_msg: function () {
+        switch (this._rfb_init_state) {
+            case 'ProtocolVersion':
+                return this._negotiate_protocol_version();
+
+            case 'Security':
+                return this._negotiate_security();
+
+            case 'Authentication':
+                return this._negotiate_authentication();
+
+            case 'SecurityResult':
+                return this._handle_security_result();
+
+            case 'ClientInitialisation':
+                this._sock.send([this._shared ? 1 : 0]); // ClientInitialisation
+                this._rfb_init_state = 'ServerInitialisation';
+                return true;
+
+            case 'ServerInitialisation':
+                return this._negotiate_server_init();
+
+            default:
+                return this._fail("Unknown init state (state: " +
+                                  this._rfb_init_state + ")");
+        }
+    },
+
+    _handle_set_colour_map_msg: function () {
+        Log.Debug("SetColorMapEntries");
+
+        return this._fail("Unexpected SetColorMapEntries message");
+    },
+
+    _handle_server_cut_text: function () {
+        Log.Debug("ServerCutText");
+
+        if (this._sock.rQwait("ServerCutText header", 7, 1)) { return false; }
+        this._sock.rQskipBytes(3);  // Padding
+        var length = this._sock.rQshift32();
+        if (this._sock.rQwait("ServerCutText", length, 8)) { return false; }
+
+        var text = this._sock.rQshiftStr(length);
+
+        if (this._viewOnly) { return true; }
+
+        var event = new CustomEvent("clipboard",
+                                    { detail: { text: text } });
+        this.dispatchEvent(event);
+
+        return true;
+    },
+
+    _handle_server_fence_msg: function() {
+        if (this._sock.rQwait("ServerFence header", 8, 1)) { return false; }
+        this._sock.rQskipBytes(3); // Padding
+        var flags = this._sock.rQshift32();
+        var length = this._sock.rQshift8();
+
+        if (this._sock.rQwait("ServerFence payload", length, 9)) { return false; }
+
+        if (length > 64) {
+            Log.Warn("Bad payload length (" + length + ") in fence response");
+            length = 64;
+        }
+
+        var payload = this._sock.rQshiftStr(length);
+
+        this._supportsFence = true;
+
+        /*
+         * Fence flags
+         *
+         *  (1<<0)  - BlockBefore
+         *  (1<<1)  - BlockAfter
+         *  (1<<2)  - SyncNext
+         *  (1<<31) - Request
+         */
+
+        if (!(flags & (1<<31))) {
+            return this._fail("Unexpected fence response");
+        }
+
+        // Filter out unsupported flags
+        // FIXME: support syncNext
+        flags &= (1<<0) | (1<<1);
+
+        // BlockBefore and BlockAfter are automatically handled by
+        // the fact that we process each incoming message
+        // synchronuosly.
+        RFB.messages.clientFence(this._sock, flags, payload);
+
+        return true;
+    },
+
+    _handle_xvp_msg: function () {
+        if (this._sock.rQwait("XVP version and message", 3, 1)) { return false; }
+        this._sock.rQskip8();  // Padding
+        var xvp_ver = this._sock.rQshift8();
+        var xvp_msg = this._sock.rQshift8();
+
+        switch (xvp_msg) {
+            case 0:  // XVP_FAIL
+                Log.Error("XVP Operation Failed");
+                break;
+            case 1:  // XVP_INIT
+                this._rfb_xvp_ver = xvp_ver;
+                Log.Info("XVP extensions enabled (version " + this._rfb_xvp_ver + ")");
+                this._setCapability("power", true);
+                break;
+            default:
+                this._fail("Illegal server XVP message (msg: " + xvp_msg + ")");
+                break;
+        }
+
+        return true;
+    },
+
+    _normal_msg: function () {
+        var msg_type;
+
+        if (this._FBU.rects > 0) {
+            msg_type = 0;
+        } else {
+            msg_type = this._sock.rQshift8();
+        }
+
+        switch (msg_type) {
+            case 0:  // FramebufferUpdate
+                var ret = this._framebufferUpdate();
+                if (ret && !this._enabledContinuousUpdates) {
+                    RFB.messages.fbUpdateRequest(this._sock, true, 0, 0,
+                                                 this._fb_width, this._fb_height);
+                }
+                return ret;
+
+            case 1:  // SetColorMapEntries
+                return this._handle_set_colour_map_msg();
+
+            case 2:  // Bell
+                Log.Debug("Bell");
+                var event = new CustomEvent("bell", { detail: {} });
+                this.dispatchEvent(event);
+                return true;
+
+            case 3:  // ServerCutText
+                return this._handle_server_cut_text();
+
+            case 150: // EndOfContinuousUpdates
+                var first = !(this._supportsContinuousUpdates);
+                this._supportsContinuousUpdates = true;
+                this._enabledContinuousUpdates = false;
+                if (first) {
+                    this._enabledContinuousUpdates = true;
+                    this._updateContinuousUpdates();
+                    Log.Info("Enabling continuous updates.");
+                } else {
+                    // FIXME: We need to send a framebufferupdaterequest here
+                    // if we add support for turning off continuous updates
+                }
+                return true;
+
+            case 248: // ServerFence
+                return this._handle_server_fence_msg();
+
+            case 250:  // XVP
+                return this._handle_xvp_msg();
+
+            default:
+                this._fail("Unexpected server message (type " + msg_type + ")");
+                Log.Debug("sock.rQslice(0, 30): " + this._sock.rQslice(0, 30));
+                return true;
+        }
+    },
+
+    _onFlush: function() {
+        this._flushing = false;
+        // Resume processing
+        if (this._sock.rQlen() > 0) {
+            this._handle_message();
+        }
+    },
+
+    _framebufferUpdate: function () {
+        var ret = true;
+        var now;
+
+        if (this._FBU.rects === 0) {
+            if (this._sock.rQwait("FBU header", 3, 1)) { return false; }
+            this._sock.rQskip8();  // Padding
+            this._FBU.rects = this._sock.rQshift16();
+            this._FBU.bytes = 0;
+            this._timing.cur_fbu = 0;
+            if (this._timing.fbu_rt_start > 0) {
+                now = (new Date()).getTime();
+                Log.Info("First FBU latency: " + (now - this._timing.fbu_rt_start));
+            }
+
+            // Make sure the previous frame is fully rendered first
+            // to avoid building up an excessive queue
+            if (this._display.pending()) {
+                this._flushing = true;
+                this._display.flush();
+                return false;
+            }
+        }
+
+        while (this._FBU.rects > 0) {
+            if (this._rfb_connection_state !== 'connected') { return false; }
+
+            if (this._sock.rQwait("FBU", this._FBU.bytes)) { return false; }
+            if (this._FBU.bytes === 0) {
+                if (this._sock.rQwait("rect header", 12)) { return false; }
+                /* New FramebufferUpdate */
+
+                var hdr = this._sock.rQshiftBytes(12);
+                this._FBU.x        = (hdr[0] << 8) + hdr[1];
+                this._FBU.y        = (hdr[2] << 8) + hdr[3];
+                this._FBU.width    = (hdr[4] << 8) + hdr[5];
+                this._FBU.height   = (hdr[6] << 8) + hdr[7];
+                this._FBU.encoding = parseInt((hdr[8] << 24) + (hdr[9] << 16) +
+                                              (hdr[10] << 8) + hdr[11], 10);
+
+                if (!this._encHandlers[this._FBU.encoding]) {
+                    this._fail("Unsupported encoding (encoding: " +
+                               this._FBU.encoding + ")");
+                    return false;
+                }
+            }
+
+            this._timing.last_fbu = (new Date()).getTime();
+
+            ret = this._encHandlers[this._FBU.encoding]();
+
+            now = (new Date()).getTime();
+            this._timing.cur_fbu += (now - this._timing.last_fbu);
+
+            if (ret) {
+                if (!(this._FBU.encoding in this._encStats)) {
+                    this._encStats[this._FBU.encoding] = [0, 0];
+                }
+                this._encStats[this._FBU.encoding][0]++;
+                this._encStats[this._FBU.encoding][1]++;
+                this._timing.pixels += this._FBU.width * this._FBU.height;
+            }
+
+            if (this._timing.pixels >= (this._fb_width * this._fb_height)) {
+                if ((this._FBU.width === this._fb_width && this._FBU.height === this._fb_height) ||
+                    this._timing.fbu_rt_start > 0) {
+                    this._timing.full_fbu_total += this._timing.cur_fbu;
+                    this._timing.full_fbu_cnt++;
+                    Log.Info("Timing of full FBU, curr: " +
+                              this._timing.cur_fbu + ", total: " +
+                              this._timing.full_fbu_total + ", cnt: " +
+                              this._timing.full_fbu_cnt + ", avg: " +
+                              (this._timing.full_fbu_total / this._timing.full_fbu_cnt));
+                }
+
+                if (this._timing.fbu_rt_start > 0) {
+                    var fbu_rt_diff = now - this._timing.fbu_rt_start;
+                    this._timing.fbu_rt_total += fbu_rt_diff;
+                    this._timing.fbu_rt_cnt++;
+                    Log.Info("full FBU round-trip, cur: " +
+                              fbu_rt_diff + ", total: " +
+                              this._timing.fbu_rt_total + ", cnt: " +
+                              this._timing.fbu_rt_cnt + ", avg: " +
+                              (this._timing.fbu_rt_total / this._timing.fbu_rt_cnt));
+                    this._timing.fbu_rt_start = 0;
+                }
+            }
+
+            if (!ret) { return ret; }  // need more data
+        }
+
+        this._display.flip();
+
+        return true;  // We finished this FBU
+    },
+
+    _updateContinuousUpdates: function() {
+        if (!this._enabledContinuousUpdates) { return; }
+
+        RFB.messages.enableContinuousUpdates(this._sock, true, 0, 0,
+                                             this._fb_width, this._fb_height);
+    },
+
+    _resize: function(width, height) {
+        this._fb_width = width;
+        this._fb_height = height;
+
+        this._destBuff = new Uint8Array(this._fb_width * this._fb_height * 4);
+
+        this._display.resize(this._fb_width, this._fb_height);
+
+        // Adjust the visible viewport based on the new dimensions
+        this._updateClip();
+        this._updateScale();
+
+        this._timing.fbu_rt_start = (new Date()).getTime();
+        this._updateContinuousUpdates();
+    },
+
+    _xvpOp: function (ver, op) {
+        if (this._rfb_xvp_ver < ver) { return; }
+        Log.Info("Sending XVP operation " + op + " (version " + ver + ")");
+        RFB.messages.xvpOp(this._sock, ver, op);
+    },
+};
+
+Object.assign(RFB.prototype, EventTargetMixin);
+
+// Class Methods
+RFB.messages = {
+    keyEvent: function (sock, keysym, down) {
+        var buff = sock._sQ;
+        var offset = sock._sQlen;
+
+        buff[offset] = 4;  // msg-type
+        buff[offset + 1] = down;
+
+        buff[offset + 2] = 0;
+        buff[offset + 3] = 0;
+
+        buff[offset + 4] = (keysym >> 24);
+        buff[offset + 5] = (keysym >> 16);
+        buff[offset + 6] = (keysym >> 8);
+        buff[offset + 7] = keysym;
+
+        sock._sQlen += 8;
+        sock.flush();
+    },
+
+    QEMUExtendedKeyEvent: function (sock, keysym, down, keycode) {
+        function getRFBkeycode(xt_scancode) {
+            var upperByte = (keycode >> 8);
+            var lowerByte = (keycode & 0x00ff);
+            if (upperByte === 0xe0 && lowerByte < 0x7f) {
+                lowerByte = lowerByte | 0x80;
+                return lowerByte;
+            }
+            return xt_scancode;
+        }
+
+        var buff = sock._sQ;
+        var offset = sock._sQlen;
+
+        buff[offset] = 255; // msg-type
+        buff[offset + 1] = 0; // sub msg-type
+
+        buff[offset + 2] = (down >> 8);
+        buff[offset + 3] = down;
+
+        buff[offset + 4] = (keysym >> 24);
+        buff[offset + 5] = (keysym >> 16);
+        buff[offset + 6] = (keysym >> 8);
+        buff[offset + 7] = keysym;
+
+        var RFBkeycode = getRFBkeycode(keycode);
+
+        buff[offset + 8] = (RFBkeycode >> 24);
+        buff[offset + 9] = (RFBkeycode >> 16);
+        buff[offset + 10] = (RFBkeycode >> 8);
+        buff[offset + 11] = RFBkeycode;
+
+        sock._sQlen += 12;
+        sock.flush();
+    },
+
+    pointerEvent: function (sock, x, y, mask) {
+        var buff = sock._sQ;
+        var offset = sock._sQlen;
+
+        buff[offset] = 5; // msg-type
+
+        buff[offset + 1] = mask;
+
+        buff[offset + 2] = x >> 8;
+        buff[offset + 3] = x;
+
+        buff[offset + 4] = y >> 8;
+        buff[offset + 5] = y;
+
+        sock._sQlen += 6;
+        sock.flush();
+    },
+
+    // TODO(directxman12): make this unicode compatible?
+    clientCutText: function (sock, text) {
+        var buff = sock._sQ;
+        var offset = sock._sQlen;
+
+        buff[offset] = 6; // msg-type
+
+        buff[offset + 1] = 0; // padding
+        buff[offset + 2] = 0; // padding
+        buff[offset + 3] = 0; // padding
+
+        var n = text.length;
+
+        buff[offset + 4] = n >> 24;
+        buff[offset + 5] = n >> 16;
+        buff[offset + 6] = n >> 8;
+        buff[offset + 7] = n;
+
+        for (var i = 0; i < n; i++) {
+            buff[offset + 8 + i] =  text.charCodeAt(i);
+        }
+
+        sock._sQlen += 8 + n;
+        sock.flush();
+    },
+
+    setDesktopSize: function (sock, width, height, id, flags) {
+        var buff = sock._sQ;
+        var offset = sock._sQlen;
+
+        buff[offset] = 251;              // msg-type
+        buff[offset + 1] = 0;            // padding
+        buff[offset + 2] = width >> 8;   // width
+        buff[offset + 3] = width;
+        buff[offset + 4] = height >> 8;  // height
+        buff[offset + 5] = height;
+
+        buff[offset + 6] = 1;            // number-of-screens
+        buff[offset + 7] = 0;            // padding
+
+        // screen array
+        buff[offset + 8] = id >> 24;     // id
+        buff[offset + 9] = id >> 16;
+        buff[offset + 10] = id >> 8;
+        buff[offset + 11] = id;
+        buff[offset + 12] = 0;           // x-position
+        buff[offset + 13] = 0;
+        buff[offset + 14] = 0;           // y-position
+        buff[offset + 15] = 0;
+        buff[offset + 16] = width >> 8;  // width
+        buff[offset + 17] = width;
+        buff[offset + 18] = height >> 8; // height
+        buff[offset + 19] = height;
+        buff[offset + 20] = flags >> 24; // flags
+        buff[offset + 21] = flags >> 16;
+        buff[offset + 22] = flags >> 8;
+        buff[offset + 23] = flags;
+
+        sock._sQlen += 24;
+        sock.flush();
+    },
+
+    clientFence: function (sock, flags, payload) {
+        var buff = sock._sQ;
+        var offset = sock._sQlen;
+
+        buff[offset] = 248; // msg-type
+
+        buff[offset + 1] = 0; // padding
+        buff[offset + 2] = 0; // padding
+        buff[offset + 3] = 0; // padding
+
+        buff[offset + 4] = flags >> 24; // flags
+        buff[offset + 5] = flags >> 16;
+        buff[offset + 6] = flags >> 8;
+        buff[offset + 7] = flags;
+
+        var n = payload.length;
+
+        buff[offset + 8] = n; // length
+
+        for (var i = 0; i < n; i++) {
+            buff[offset + 9 + i] = payload.charCodeAt(i);
+        }
+
+        sock._sQlen += 9 + n;
+        sock.flush();
+    },
+
+    enableContinuousUpdates: function (sock, enable, x, y, width, height) {
+        var buff = sock._sQ;
+        var offset = sock._sQlen;
+
+        buff[offset] = 150;             // msg-type
+        buff[offset + 1] = enable;      // enable-flag
+
+        buff[offset + 2] = x >> 8;      // x
+        buff[offset + 3] = x;
+        buff[offset + 4] = y >> 8;      // y
+        buff[offset + 5] = y;
+        buff[offset + 6] = width >> 8;  // width
+        buff[offset + 7] = width;
+        buff[offset + 8] = height >> 8; // height
+        buff[offset + 9] = height;
+
+        sock._sQlen += 10;
+        sock.flush();
+    },
+
+    pixelFormat: function (sock, depth, true_color) {
+        var buff = sock._sQ;
+        var offset = sock._sQlen;
+
+        var bpp, bits;
+
+        if (depth > 16) {
+            bpp = 32;
+        } else if (depth > 8) {
+            bpp = 16;
+        } else {
+            bpp = 8;
+        }
+
+        bits = Math.floor(depth/3);
+
+        buff[offset] = 0;  // msg-type
+
+        buff[offset + 1] = 0; // padding
+        buff[offset + 2] = 0; // padding
+        buff[offset + 3] = 0; // padding
+
+        buff[offset + 4] = bpp;                 // bits-per-pixel
+        buff[offset + 5] = depth;               // depth
+        buff[offset + 6] = 0;                   // little-endian
+        buff[offset + 7] = true_color ? 1 : 0;  // true-color
+
+        buff[offset + 8] = 0;    // red-max
+        buff[offset + 10] = 0;   // green-max
+        buff[offset + 12] = 0;   // blue-max
+
+	if (depth == 8) {
+	    buff[offset + 9] = 7;	// red-max
+	    buff[offset + 11] = 7;	// green-max
+	    buff[offset + 13] = 3;	// blue-max
+	    buff[offset + 14] = 5;	// red-shift
+	    buff[offset + 15] = 2;	// green-shift
+	    buff[offset + 16] = 0;	// blue-shift
+	} else {
+	    buff[offset + 9] = (1 << bits) - 1;  // red-max
+	    buff[offset + 11] = (1 << bits) - 1; // green-max
+	    buff[offset + 13] = (1 << bits) - 1; // blue-max
+            buff[offset + 14] = bits * 2; // red-shift
+            buff[offset + 15] = bits * 1; // green-shift
+            buff[offset + 16] = bits * 0; // blue-shift
+	}
+
+        buff[offset + 17] = 0;   // padding
+        buff[offset + 18] = 0;   // padding
+        buff[offset + 19] = 0;   // padding
+
+        sock._sQlen += 20;
+        sock.flush();
+    },
+
+    clientEncodings: function (sock, encodings) {
+        var buff = sock._sQ;
+        var offset = sock._sQlen;
+
+        buff[offset] = 2; // msg-type
+        buff[offset + 1] = 0; // padding
+
+        buff[offset + 2] = encodings.length >> 8;
+        buff[offset + 3] = encodings.length;
+
+        var i, j = offset + 4;
+        for (i = 0; i < encodings.length; i++) {
+            var enc = encodings[i];
+            buff[j] = enc >> 24;
+            buff[j + 1] = enc >> 16;
+            buff[j + 2] = enc >> 8;
+            buff[j + 3] = enc;
+
+            j += 4;
+        }
+
+        sock._sQlen += j - offset;
+        sock.flush();
+    },
+
+    fbUpdateRequest: function (sock, incremental, x, y, w, h) {
+        var buff = sock._sQ;
+        var offset = sock._sQlen;
+
+        if (typeof(x) === "undefined") { x = 0; }
+        if (typeof(y) === "undefined") { y = 0; }
+
+        buff[offset] = 3;  // msg-type
+        buff[offset + 1] = incremental ? 1 : 0;
+
+        buff[offset + 2] = (x >> 8) & 0xFF;
+        buff[offset + 3] = x & 0xFF;
+
+        buff[offset + 4] = (y >> 8) & 0xFF;
+        buff[offset + 5] = y & 0xFF;
+
+        buff[offset + 6] = (w >> 8) & 0xFF;
+        buff[offset + 7] = w & 0xFF;
+
+        buff[offset + 8] = (h >> 8) & 0xFF;
+        buff[offset + 9] = h & 0xFF;
+
+        sock._sQlen += 10;
+        sock.flush();
+    },
+
+    xvpOp: function (sock, ver, op) {
+        var buff = sock._sQ;
+        var offset = sock._sQlen;
+
+        buff[offset] = 250; // msg-type
+        buff[offset + 1] = 0; // padding
+
+        buff[offset + 2] = ver;
+        buff[offset + 3] = op;
+
+        sock._sQlen += 4;
+        sock.flush();
+    },
+};
+
+RFB.genDES = function (password, challenge) {
+    var passwd = [];
+    for (var i = 0; i < password.length; i++) {
+        passwd.push(password.charCodeAt(i));
+    }
+    return (new DES(passwd)).encrypt(challenge);
+};
+
+RFB.encodingHandlers = {
+    RAW: function () {
+        if (this._FBU.lines === 0) {
+            this._FBU.lines = this._FBU.height;
+        }
+
+        var pixelSize = this._fb_depth == 8 ? 1 : 4;
+        this._FBU.bytes = this._FBU.width * pixelSize;  // at least a line
+        if (this._sock.rQwait("RAW", this._FBU.bytes)) { return false; }
+        var cur_y = this._FBU.y + (this._FBU.height - this._FBU.lines);
+        var curr_height = Math.min(this._FBU.lines,
+                                   Math.floor(this._sock.rQlen() / (this._FBU.width * pixelSize)));
+        var data = this._sock.get_rQ();
+        var index = this._sock.get_rQi();
+        if (this._fb_depth == 8) {
+            var pixels = this._FBU.width * curr_height
+            var newdata = new Uint8Array(pixels * 4);
+            var i;
+            for (i = 0;i < pixels;i++) {
+                //newdata[i * 4 + 0] = ((data[index + i] >> 0) & 0x3) * 255 / 3;
+                //newdata[i * 4 + 1] = ((data[index + i] >> 2) & 0x3) * 255 / 3;
+                //newdata[i * 4 + 2] = ((data[index + i] >> 4) & 0x3) * 255 / 3;
+		// Convert 8 bit RGB332 color to internal RGB888.
+		newdata[i * 4 + 0] = ((data[index + i] >> 0) & 0x3) * 255 / 3;	// blue
+		newdata[i * 4 + 1] = ((data[index + i] >> 2) & 0x7) * 255 / 7;	// green
+		newdata[i * 4 + 2] = ((data[index + i] >> 5) & 0x7) * 255 / 7;	// red
+                newdata[i * 4 + 4] = 0;
+            }
+            data = newdata;
+            index = 0;
+        }
+        this._display.blitImage(this._FBU.x, cur_y, this._FBU.width,
+                                curr_height, data, index);
+        this._sock.rQskipBytes(this._FBU.width * curr_height * pixelSize);
+        this._FBU.lines -= curr_height;
+
+        if (this._FBU.lines > 0) {
+            this._FBU.bytes = this._FBU.width * pixelSize;  // At least another line
+        } else {
+            this._FBU.rects--;
+            this._FBU.bytes = 0;
+        }
+
+        return true;
+    },
+
+    COPYRECT: function () {
+        this._FBU.bytes = 4;
+        if (this._sock.rQwait("COPYRECT", 4)) { return false; }
+        this._display.copyImage(this._sock.rQshift16(), this._sock.rQshift16(),
+                                this._FBU.x, this._FBU.y, this._FBU.width,
+                                this._FBU.height);
+
+        this._FBU.rects--;
+        this._FBU.bytes = 0;
+        return true;
+    },
+
+    RRE: function () {
+        var color;
+        if (this._FBU.subrects === 0) {
+            this._FBU.bytes = 4 + 4;
+            if (this._sock.rQwait("RRE", 4 + 4)) { return false; }
+            this._FBU.subrects = this._sock.rQshift32();
+            color = this._sock.rQshiftBytes(4);  // Background
+            this._display.fillRect(this._FBU.x, this._FBU.y, this._FBU.width, this._FBU.height, color);
+        }
+
+        while (this._FBU.subrects > 0 && this._sock.rQlen() >= (4 + 8)) {
+            color = this._sock.rQshiftBytes(4);
+            var x = this._sock.rQshift16();
+            var y = this._sock.rQshift16();
+            var width = this._sock.rQshift16();
+            var height = this._sock.rQshift16();
+            this._display.fillRect(this._FBU.x + x, this._FBU.y + y, width, height, color);
+            this._FBU.subrects--;
+        }
+
+        if (this._FBU.subrects > 0) {
+            var chunk = Math.min(this._rre_chunk_sz, this._FBU.subrects);
+            this._FBU.bytes = (4 + 8) * chunk;
+        } else {
+            this._FBU.rects--;
+            this._FBU.bytes = 0;
+        }
+
+        return true;
+    },
+
+    HEXTILE: function () {
+        var rQ = this._sock.get_rQ();
+        var rQi = this._sock.get_rQi();
+
+        if (this._FBU.tiles === 0) {
+            this._FBU.tiles_x = Math.ceil(this._FBU.width / 16);
+            this._FBU.tiles_y = Math.ceil(this._FBU.height / 16);
+            this._FBU.total_tiles = this._FBU.tiles_x * this._FBU.tiles_y;
+            this._FBU.tiles = this._FBU.total_tiles;
+        }
+
+        while (this._FBU.tiles > 0) {
+            this._FBU.bytes = 1;
+            if (this._sock.rQwait("HEXTILE subencoding", this._FBU.bytes)) { return false; }
+            var subencoding = rQ[rQi];  // Peek
+            if (subencoding > 30) {  // Raw
+                this._fail("Illegal hextile subencoding (subencoding: " +
+                           subencoding + ")");
+                return false;
+            }
+
+            var subrects = 0;
+            var curr_tile = this._FBU.total_tiles - this._FBU.tiles;
+            var tile_x = curr_tile % this._FBU.tiles_x;
+            var tile_y = Math.floor(curr_tile / this._FBU.tiles_x);
+            var x = this._FBU.x + tile_x * 16;
+            var y = this._FBU.y + tile_y * 16;
+            var w = Math.min(16, (this._FBU.x + this._FBU.width) - x);
+            var h = Math.min(16, (this._FBU.y + this._FBU.height) - y);
+
+            // Figure out how much we are expecting
+            if (subencoding & 0x01) {  // Raw
+                this._FBU.bytes += w * h * 4;
+            } else {
+                if (subencoding & 0x02) {  // Background
+                    this._FBU.bytes += 4;
+                }
+                if (subencoding & 0x04) {  // Foreground
+                    this._FBU.bytes += 4;
+                }
+                if (subencoding & 0x08) {  // AnySubrects
+                    this._FBU.bytes++;  // Since we aren't shifting it off
+                    if (this._sock.rQwait("hextile subrects header", this._FBU.bytes)) { return false; }
+                    subrects = rQ[rQi + this._FBU.bytes - 1];  // Peek
+                    if (subencoding & 0x10) {  // SubrectsColoured
+                        this._FBU.bytes += subrects * (4 + 2);
+                    } else {
+                        this._FBU.bytes += subrects * 2;
+                    }
+                }
+            }
+
+            if (this._sock.rQwait("hextile", this._FBU.bytes)) { return false; }
+
+            // We know the encoding and have a whole tile
+            this._FBU.subencoding = rQ[rQi];
+            rQi++;
+            if (this._FBU.subencoding === 0) {
+                if (this._FBU.lastsubencoding & 0x01) {
+                    // Weird: ignore blanks are RAW
+                    Log.Debug("     Ignoring blank after RAW");
+                } else {
+                    this._display.fillRect(x, y, w, h, this._FBU.background);
+                }
+            } else if (this._FBU.subencoding & 0x01) {  // Raw
+                this._display.blitImage(x, y, w, h, rQ, rQi);
+                rQi += this._FBU.bytes - 1;
+            } else {
+                if (this._FBU.subencoding & 0x02) {  // Background
+                    this._FBU.background = [rQ[rQi], rQ[rQi + 1], rQ[rQi + 2], rQ[rQi + 3]];
+                    rQi += 4;
+                }
+                if (this._FBU.subencoding & 0x04) {  // Foreground
+                    this._FBU.foreground = [rQ[rQi], rQ[rQi + 1], rQ[rQi + 2], rQ[rQi + 3]];
+                    rQi += 4;
+                }
+
+                this._display.startTile(x, y, w, h, this._FBU.background);
+                if (this._FBU.subencoding & 0x08) {  // AnySubrects
+                    subrects = rQ[rQi];
+                    rQi++;
+
+                    for (var s = 0; s < subrects; s++) {
+                        var color;
+                        if (this._FBU.subencoding & 0x10) {  // SubrectsColoured
+                            color = [rQ[rQi], rQ[rQi + 1], rQ[rQi + 2], rQ[rQi + 3]];
+                            rQi += 4;
+                        } else {
+                            color = this._FBU.foreground;
+                        }
+                        var xy = rQ[rQi];
+                        rQi++;
+                        var sx = (xy >> 4);
+                        var sy = (xy & 0x0f);
+
+                        var wh = rQ[rQi];
+                        rQi++;
+                        var sw = (wh >> 4) + 1;
+                        var sh = (wh & 0x0f) + 1;
+
+                        this._display.subTile(sx, sy, sw, sh, color);
+                    }
+                }
+                this._display.finishTile();
+            }
+            this._sock.set_rQi(rQi);
+            this._FBU.lastsubencoding = this._FBU.subencoding;
+            this._FBU.bytes = 0;
+            this._FBU.tiles--;
+        }
+
+        if (this._FBU.tiles === 0) {
+            this._FBU.rects--;
+        }
+
+        return true;
+    },
+
+    TIGHT: function () {
+        this._FBU.bytes = 1;  // compression-control byte
+        if (this._sock.rQwait("TIGHT compression-control", this._FBU.bytes)) { return false; }
+
+        var checksum = function (data) {
+            var sum = 0;
+            for (var i = 0; i < data.length; i++) {
+                sum += data[i];
+                if (sum > 65536) sum -= 65536;
+            }
+            return sum;
+        };
+
+        var resetStreams = 0;
+        var streamId = -1;
+        var decompress = function (data, expected) {
+            for (var i = 0; i < 4; i++) {
+                if ((resetStreams >> i) & 1) {
+                    this._FBU.zlibs[i].reset();
+                    Log.Info("Reset zlib stream " + i);
+                }
+            }
+
+            //var uncompressed = this._FBU.zlibs[streamId].uncompress(data, 0);
+            var uncompressed = this._FBU.zlibs[streamId].inflate(data, true, expected);
+            /*if (uncompressed.status !== 0) {
+                Log.Error("Invalid data in zlib stream");
+            }*/
+
+            //return uncompressed.data;
+            return uncompressed;
+        }.bind(this);
+
+        var indexedToRGBX2Color = function (data, palette, width, height) {
+            // Convert indexed (palette based) image data to RGB
+            // TODO: reduce number of calculations inside loop
+            var dest = this._destBuff;
+            var w = Math.floor((width + 7) / 8);
+            var w1 = Math.floor(width / 8);
+
+            /*for (var y = 0; y < height; y++) {
+                var b, x, dp, sp;
+                var yoffset = y * width;
+                var ybitoffset = y * w;
+                var xoffset, targetbyte;
+                for (x = 0; x < w1; x++) {
+                    xoffset = yoffset + x * 8;
+                    targetbyte = data[ybitoffset + x];
+                    for (b = 7; b >= 0; b--) {
+                        dp = (xoffset + 7 - b) * 3;
+                        sp = (targetbyte >> b & 1) * 3;
+                        dest[dp] = palette[sp];
+                        dest[dp + 1] = palette[sp + 1];
+                        dest[dp + 2] = palette[sp + 2];
+                    }
+                }
+
+                xoffset = yoffset + x * 8;
+                targetbyte = data[ybitoffset + x];
+                for (b = 7; b >= 8 - width % 8; b--) {
+                    dp = (xoffset + 7 - b) * 3;
+                    sp = (targetbyte >> b & 1) * 3;
+                    dest[dp] = palette[sp];
+                    dest[dp + 1] = palette[sp + 1];
+                    dest[dp + 2] = palette[sp + 2];
+                }
+            }*/
+
+            for (var y = 0; y < height; y++) {
+                var b, x, dp, sp;
+                for (x = 0; x < w1; x++) {
+                    for (b = 7; b >= 0; b--) {
+                        dp = (y * width + x * 8 + 7 - b) * 4;
+                        sp = (data[y * w + x] >> b & 1) * 3;
+                        dest[dp] = palette[sp];
+                        dest[dp + 1] = palette[sp + 1];
+                        dest[dp + 2] = palette[sp + 2];
+                        dest[dp + 3] = 255;
+                    }
+                }
+
+                for (b = 7; b >= 8 - width % 8; b--) {
+                    dp = (y * width + x * 8 + 7 - b) * 4;
+                    sp = (data[y * w + x] >> b & 1) * 3;
+                    dest[dp] = palette[sp];
+                    dest[dp + 1] = palette[sp + 1];
+                    dest[dp + 2] = palette[sp + 2];
+                    dest[dp + 3] = 255;
+                }
+            }
+
+            return dest;
+        }.bind(this);
+
+        var indexedToRGBX = function (data, palette, width, height) {
+            // Convert indexed (palette based) image data to RGB
+            var dest = this._destBuff;
+            var total = width * height * 4;
+            for (var i = 0, j = 0; i < total; i += 4, j++) {
+                var sp = data[j] * 3;
+                dest[i] = palette[sp];
+                dest[i + 1] = palette[sp + 1];
+                dest[i + 2] = palette[sp + 2];
+                dest[i + 3] = 255;
+            }
+
+            return dest;
+        }.bind(this);
+
+        var rQi = this._sock.get_rQi();
+        var rQ = this._sock.rQwhole();
+        var cmode, data;
+        var cl_header, cl_data;
+
+        var handlePalette = function () {
+            var numColors = rQ[rQi + 2] + 1;
+            var paletteSize = numColors * 3;
+            this._FBU.bytes += paletteSize;
+            if (this._sock.rQwait("TIGHT palette " + cmode, this._FBU.bytes)) { return false; }
+
+            var bpp = (numColors <= 2) ? 1 : 8;
+            var rowSize = Math.floor((this._FBU.width * bpp + 7) / 8);
+            var raw = false;
+            if (rowSize * this._FBU.height < 12) {
+                raw = true;
+                cl_header = 0;
+                cl_data = rowSize * this._FBU.height;
+                //clength = [0, rowSize * this._FBU.height];
+            } else {
+                // begin inline getTightCLength (returning two-item arrays is bad for performance with GC)
+                var cl_offset = rQi + 3 + paletteSize;
+                cl_header = 1;
+                cl_data = 0;
+                cl_data += rQ[cl_offset] & 0x7f;
+                if (rQ[cl_offset] & 0x80) {
+                    cl_header++;
+                    cl_data += (rQ[cl_offset + 1] & 0x7f) << 7;
+                    if (rQ[cl_offset + 1] & 0x80) {
+                        cl_header++;
+                        cl_data += rQ[cl_offset + 2] << 14;
+                    }
+                }
+                // end inline getTightCLength
+            }
+
+            this._FBU.bytes += cl_header + cl_data;
+            if (this._sock.rQwait("TIGHT " + cmode, this._FBU.bytes)) { return false; }
+
+            // Shift ctl, filter id, num colors, palette entries, and clength off
+            this._sock.rQskipBytes(3);
+            //var palette = this._sock.rQshiftBytes(paletteSize);
+            this._sock.rQshiftTo(this._paletteBuff, paletteSize);
+            this._sock.rQskipBytes(cl_header);
+
+            if (raw) {
+                data = this._sock.rQshiftBytes(cl_data);
+            } else {
+                data = decompress(this._sock.rQshiftBytes(cl_data), rowSize * this._FBU.height);
+            }
+
+            // Convert indexed (palette based) image data to RGB
+            var rgbx;
+            if (numColors == 2) {
+                rgbx = indexedToRGBX2Color(data, this._paletteBuff, this._FBU.width, this._FBU.height);
+                this._display.blitRgbxImage(this._FBU.x, this._FBU.y, this._FBU.width, this._FBU.height, rgbx, 0, false);
+            } else {
+                rgbx = indexedToRGBX(data, this._paletteBuff, this._FBU.width, this._FBU.height);
+                this._display.blitRgbxImage(this._FBU.x, this._FBU.y, this._FBU.width, this._FBU.height, rgbx, 0, false);
+            }
+
+
+            return true;
+        }.bind(this);
+
+        var handleCopy = function () {
+            var raw = false;
+            var uncompressedSize = this._FBU.width * this._FBU.height * 3;
+            if (uncompressedSize < 12) {
+                raw = true;
+                cl_header = 0;
+                cl_data = uncompressedSize;
+            } else {
+                // begin inline getTightCLength (returning two-item arrays is for peformance with GC)
+                var cl_offset = rQi + 1;
+                cl_header = 1;
+                cl_data = 0;
+                cl_data += rQ[cl_offset] & 0x7f;
+                if (rQ[cl_offset] & 0x80) {
+                    cl_header++;
+                    cl_data += (rQ[cl_offset + 1] & 0x7f) << 7;
+                    if (rQ[cl_offset + 1] & 0x80) {
+                        cl_header++;
+                        cl_data += rQ[cl_offset + 2] << 14;
+                    }
+                }
+                // end inline getTightCLength
+            }
+            this._FBU.bytes = 1 + cl_header + cl_data;
+            if (this._sock.rQwait("TIGHT " + cmode, this._FBU.bytes)) { return false; }
+
+            // Shift ctl, clength off
+            this._sock.rQshiftBytes(1 + cl_header);
+
+            if (raw) {
+                data = this._sock.rQshiftBytes(cl_data);
+            } else {
+                data = decompress(this._sock.rQshiftBytes(cl_data), uncompressedSize);
+            }
+
+            this._display.blitRgbImage(this._FBU.x, this._FBU.y, this._FBU.width, this._FBU.height, data, 0, false);
+
+            return true;
+        }.bind(this);
+
+        var ctl = this._sock.rQpeek8();
+
+        // Keep tight reset bits
+        resetStreams = ctl & 0xF;
+
+        // Figure out filter
+        ctl = ctl >> 4;
+        streamId = ctl & 0x3;
+
+        if (ctl === 0x08)       cmode = "fill";
+        else if (ctl === 0x09)  cmode = "jpeg";
+        else if (ctl === 0x0A)  cmode = "png";
+        else if (ctl & 0x04)    cmode = "filter";
+        else if (ctl < 0x04)    cmode = "copy";
+        else return this._fail("Illegal tight compression received (ctl: " +
+                               ctl + ")");
+
+        switch (cmode) {
+            // fill use depth because TPIXELs drop the padding byte
+            case "fill":  // TPIXEL
+                this._FBU.bytes += 3;
+                break;
+            case "jpeg":  // max clength
+                this._FBU.bytes += 3;
+                break;
+            case "png":  // max clength
+                this._FBU.bytes += 3;
+                break;
+            case "filter":  // filter id + num colors if palette
+                this._FBU.bytes += 2;
+                break;
+            case "copy":
+                break;
+        }
+
+        if (this._sock.rQwait("TIGHT " + cmode, this._FBU.bytes)) { return false; }
+
+        // Determine FBU.bytes
+        switch (cmode) {
+            case "fill":
+                // skip ctl byte
+                this._display.fillRect(this._FBU.x, this._FBU.y, this._FBU.width, this._FBU.height, [rQ[rQi + 3], rQ[rQi + 2], rQ[rQi + 1]], false);
+                this._sock.rQskipBytes(4);
+                break;
+            case "png":
+            case "jpeg":
+                // begin inline getTightCLength (returning two-item arrays is for peformance with GC)
+                var cl_offset = rQi + 1;
+                cl_header = 1;
+                cl_data = 0;
+                cl_data += rQ[cl_offset] & 0x7f;
+                if (rQ[cl_offset] & 0x80) {
+                    cl_header++;
+                    cl_data += (rQ[cl_offset + 1] & 0x7f) << 7;
+                    if (rQ[cl_offset + 1] & 0x80) {
+                        cl_header++;
+                        cl_data += rQ[cl_offset + 2] << 14;
+                    }
+                }
+                // end inline getTightCLength
+                this._FBU.bytes = 1 + cl_header + cl_data;  // ctl + clength size + jpeg-data
+                if (this._sock.rQwait("TIGHT " + cmode, this._FBU.bytes)) { return false; }
+
+                // We have everything, render it
+                this._sock.rQskipBytes(1 + cl_header);  // shift off clt + compact length
+                data = this._sock.rQshiftBytes(cl_data);
+                this._display.imageRect(this._FBU.x, this._FBU.y, "image/" + cmode, data);
+                break;
+            case "filter":
+                var filterId = rQ[rQi + 1];
+                if (filterId === 1) {
+                    if (!handlePalette()) { return false; }
+                } else {
+                    // Filter 0, Copy could be valid here, but servers don't send it as an explicit filter
+                    // Filter 2, Gradient is valid but not use if jpeg is enabled
+                    this._fail("Unsupported tight subencoding received " +
+                               "(filter: " + filterId + ")");
+                }
+                break;
+            case "copy":
+                if (!handleCopy()) { return false; }
+                break;
+        }
+
+
+        this._FBU.bytes = 0;
+        this._FBU.rects--;
+
+        return true;
+    },
+
+    last_rect: function () {
+        this._FBU.rects = 0;
+        return true;
+    },
+
+    ExtendedDesktopSize: function () {
+        this._FBU.bytes = 1;
+        if (this._sock.rQwait("ExtendedDesktopSize", this._FBU.bytes)) { return false; }
+
+        var firstUpdate = !this._supportsSetDesktopSize;
+        this._supportsSetDesktopSize = true;
+
+        // Normally we only apply the current resize mode after a
+        // window resize event. However there is no such trigger on the
+        // initial connect. And we don't know if the server supports
+        // resizing until we've gotten here.
+        if (firstUpdate) {
+            this._requestRemoteResize();
+        }
+
+        var number_of_screens = this._sock.rQpeek8();
+
+        this._FBU.bytes = 4 + (number_of_screens * 16);
+        if (this._sock.rQwait("ExtendedDesktopSize", this._FBU.bytes)) { return false; }
+
+        this._sock.rQskipBytes(1);  // number-of-screens
+        this._sock.rQskipBytes(3);  // padding
+
+        for (var i = 0; i < number_of_screens; i += 1) {
+            // Save the id and flags of the first screen
+            if (i === 0) {
+                this._screen_id = this._sock.rQshiftBytes(4);    // id
+                this._sock.rQskipBytes(2);                       // x-position
+                this._sock.rQskipBytes(2);                       // y-position
+                this._sock.rQskipBytes(2);                       // width
+                this._sock.rQskipBytes(2);                       // height
+                this._screen_flags = this._sock.rQshiftBytes(4); // flags
+            } else {
+                this._sock.rQskipBytes(16);
+            }
+        }
+
+        /*
+         * The x-position indicates the reason for the change:
+         *
+         *  0 - server resized on its own
+         *  1 - this client requested the resize
+         *  2 - another client requested the resize
+         */
+
+        // We need to handle errors when we requested the resize.
+        if (this._FBU.x === 1 && this._FBU.y !== 0) {
+            var msg = "";
+            // The y-position indicates the status code from the server
+            switch (this._FBU.y) {
+            case 1:
+                msg = "Resize is administratively prohibited";
+                break;
+            case 2:
+                msg = "Out of resources";
+                break;
+            case 3:
+                msg = "Invalid screen layout";
+                break;
+            default:
+                msg = "Unknown reason";
+                break;
+            }
+            Log.Warn("Server did not accept the resize request: "
+                     + msg);
+        } else {
+            this._resize(this._FBU.width, this._FBU.height);
+        }
+
+        this._FBU.bytes = 0;
+        this._FBU.rects -= 1;
+        return true;
+    },
+
+    DesktopSize: function () {
+        this._resize(this._FBU.width, this._FBU.height);
+        this._FBU.bytes = 0;
+        this._FBU.rects -= 1;
+        return true;
+    },
+
+    Cursor: function () {
+        Log.Debug(">> set_cursor");
+        var x = this._FBU.x;  // hotspot-x
+        var y = this._FBU.y;  // hotspot-y
+        var w = this._FBU.width;
+        var h = this._FBU.height;
+
+        var pixelslength = w * h * 4;
+        var masklength = Math.floor((w + 7) / 8) * h;
+
+        this._FBU.bytes = pixelslength + masklength;
+        if (this._sock.rQwait("cursor encoding", this._FBU.bytes)) { return false; }
+
+        this._display.changeCursor(this._sock.rQshiftBytes(pixelslength),
+                                   this._sock.rQshiftBytes(masklength),
+                                   x, y, w, h);
+
+        this._FBU.bytes = 0;
+        this._FBU.rects--;
+
+        Log.Debug("<< set_cursor");
+        return true;
+    },
+
+    QEMUExtendedKeyEvent: function () {
+        this._FBU.rects--;
+
+        // Old Safari doesn't support creating keyboard events
+        try {
+            var keyboardEvent = document.createEvent("keyboardEvent");
+            if (keyboardEvent.code !== undefined) {
+                this._qemuExtKeyEventSupported = true;
+            }
+        } catch (err) {
+        }
+    },
+};

mercurial