Merge pull request #474 from kanaka/bug/throw-error-from-constructor

Throw exceptions from RFB constructor

include/display.js

@@ -86,29 +86,9 @@ var Display;
         }
 
         // Determine browser support for setting the cursor via data URI scheme
-        var curDat = [];
-        for (var i = 0; i < 8 * 8 * 4; i++) {
-            curDat.push(255);
-        }
-        try {
-            var curSave = this._target.style.cursor;
-            Display.changeCursor(this._target, curDat, curDat, 2, 2, 8, 8);
-            if (this._target.style.cursor) {
-                if (this._cursor_uri === null || this._cursor_uri === undefined) {
-                    this._cursor_uri = true;
-                }
-                Util.Info("Data URI scheme cursor supported");
-                this._target.style.cursor = curSave;
-            } else {
-                if (this._cursor_uri === null || this._cursor_uri === undefined) {
-                    this._cursor_uri = false;
-                }
-                Util.Warn("Data URI scheme cursor not supported");
-                this._target.style.cursor = "none";
-            }
-        } catch (exc) {
-            Util.Error("Data URI scheme cursor test exception: " + exc);
-            this._cursor_uri = false;
+        if (this._cursor_uri || this._cursor_uri === null ||
+                this._cursor_uri === undefined) {
+            this._cursor_uri = Util.browserSupportsCursorURIs(this._target);
         }
 
         Util.Debug("<< Display.constructor");

include/rfb.js

@@ -159,11 +159,13 @@ var RFB;
             this._encStats[this._encodings[i][1]] = [0, 0];
         }
 
+        // NB: nothing that needs explicit teardown should be done
+        // before this point, since this can throw an exception
         try {
             this._display = new Display({target: this._target});
         } catch (exc) {
             Util.Error("Display exception: " + exc);
-            this._updateState('fatal', "No working Display");
+            throw exc;
         }
 
         this._keyboard = new Keyboard({target: this._focusContainer,
@@ -217,9 +219,11 @@ var RFB;
         } else {
             Util.Warn("Using web-socket-js bridge.  Flash version: " + Util.Flash.version);
             if (!Util.Flash || Util.Flash.version < 9) {
-                this._updateState('fatal', "WebSockets or <a href='http://get.adobe.com/flashplayer'>Adobe Flash</a> is required");
+                this._cleanupSocket('fatal');
+                throw new Exception("WebSockets or <a href='http://get.adobe.com/flashplayer'>Adobe Flash</a> is required");
             } else if (document.location.href.substr(0, 7) === 'file://') {
-                this._updateState('fatal', "'file://' URL is incompatible with Adobe Flash");
+                this._cleanupSocket('fatal');
+                throw new Exception("'file://' URL is incompatible with Adobe Flash");
             } else {
                 this._updateState('loaded', 'noVNC ready: WebSockets emulation, ' + rmode);
             }
@@ -398,6 +402,32 @@ var RFB;
             }
         },
 
+        _cleanupSocket: function (state) {
+            if (this._sendTimer) {
+                clearInterval(this._sendTimer);
+                this._sendTimer = null;
+            }
+
+            if (this._msgTimer) {
+                clearInterval(this._msgTimer);
+                this._msgTimer = null;
+            }
+
+            if (this._display && this._display.get_context()) {
+                this._keyboard.ungrab();
+                this._mouse.ungrab();
+                if (state !== 'connect' && state !== 'loaded') {
+                    this._display.defaultCursor();
+                }
+                if (Util.get_logging() !== 'debug' || state === 'loaded') {
+                    // Show noVNC logo on load and when disconnected, unless in
+                    // debug mode
+                    this._display.clear();
+                }
+            }
+
+            this._sock.close();
+        },
 
         /*
          * Page states:
@@ -432,31 +462,7 @@ var RFB;
              */
             if (state in {'disconnected': 1, 'loaded': 1, 'connect': 1,
                           'disconnect': 1, 'failed': 1, 'fatal': 1}) {
-
-                if (this._sendTimer) {
-                    clearInterval(this._sendTimer);
-                    this._sendTimer = null;
-                }
-
-                if (this._msgTimer) {
-                    clearInterval(this._msgTimer);
-                    this._msgTimer = null;
-                }
-
-                if (this._display && this._display.get_context()) {
-                    this._keyboard.ungrab();
-                    this._mouse.ungrab();
-                    if (state !== 'connect' && state !== 'loaded') {
-                        this._display.defaultCursor();
-                    }
-                    if (Util.get_logging() !== 'debug' || state === 'loaded') {
-                        // Show noVNC logo on load and when disconnected, unless in
-                        // debug mode
-                        this._display.clear();
-                    }
-                }
-
-                this._sock.close();
+                this._cleanupSocket(state);
             }
 
             if (oldstate === 'fatal') {

include/ui.js

@@ -97,8 +97,6 @@ var UI;
             UI.initSetting('path', 'websockify');
             UI.initSetting('repeaterID', '');
 
-            UI.initRFB();
-
             var autoconnect = WebUtil.getQueryVar('autoconnect', false);
             if (autoconnect === 'true' || autoconnect == '1') {
                 autoconnect = true;
@@ -136,7 +134,7 @@ var UI;
             Util.addEvent(window, 'load', UI.keyboardinputReset);
 
             Util.addEvent(window, 'beforeunload', function () {
-                if (UI.rfb_state === 'normal') {
+                if (UI.rfb && UI.rfb_state === 'normal') {
                     return "You are currently connected.";
                 }
             } );
@@ -161,6 +159,7 @@ var UI;
         },
 
         initRFB: function () {
+            try {
                 UI.rfb = new RFB({'target': $D('noVNC_canvas'),
                                   'onUpdateState': UI.updateState,
                                   'onXvpInit': UI.updateXvpVisualState,
@@ -168,6 +167,11 @@ var UI;
                                   'onFBUComplete': UI.FBUComplete,
                                   'onFBResize': UI.updateViewDragButton,
                                   'onDesktopName': UI.updateDocumentTitle});
+                return true;
+            } catch (exc) {
+                UI.updateState(null, 'fatal', null, 'Unable to create RFB client -- ' + exc);
+                return false;
+            }
         },
 
         addMouseHandlers: function() {
@@ -213,12 +217,14 @@ var UI;
             $D("noVNC_connect_button").onclick = UI.connect;
 
             $D("noVNC_resize").onchange = function () {
-                var connected = UI.rfb_state === 'normal' ? true : false;
+                var connected = UI.rfb && UI.rfb_state === 'normal';
                 UI.enableDisableClip(connected);
             };
         },
 
         onresize: function (callback) {
+            if (!UI.rfb) return;
+
             var size = UI.getCanvasLimit();
 
             if (size && UI.rfb_state === 'normal' && UI.rfb.get_display()) {
@@ -480,7 +486,7 @@ var UI;
             } else {
                 UI.updateSetting('encrypt');
                 UI.updateSetting('true_color');
-                if (UI.rfb.get_display().get_cursor_uri()) {
+                if (Util.browserSupportsCursorURIs()) {
                     UI.updateSetting('cursor');
                 } else {
                     UI.updateSetting('cursor', !UI.isTouchDevice);
@@ -536,7 +542,7 @@ var UI;
             //Util.Debug(">> settingsApply");
             UI.saveSetting('encrypt');
             UI.saveSetting('true_color');
-            if (UI.rfb.get_display().get_cursor_uri()) {
+            if (Util.browserSupportsCursorURIs()) {
                 UI.saveSetting('cursor');
             }
 
@@ -558,7 +564,7 @@ var UI;
             WebUtil.selectStylesheet(UI.getSetting('stylesheet'));
             WebUtil.init_logging(UI.getSetting('logging'));
             UI.setViewClip();
-            UI.setViewDrag(UI.rfb.get_viewportDrag());
+            UI.setViewDrag(UI.rfb && UI.rfb.get_viewportDrag());
             //Util.Debug("<< settingsApply");
         },
 
@@ -642,13 +648,6 @@ var UI;
                     break;
             }
 
-            switch (state) {
-                case 'fatal':
-                case 'failed':
-                case 'disconnected':
-                    UI.initRFB();
-            }
-
             if (typeof(msg) !== 'undefined') {
                 $D('noVNC-control-bar').setAttribute("class", klass);
                 $D('noVNC_status').innerHTML = msg;
@@ -659,13 +658,12 @@ var UI;
 
         // Disable/enable controls depending on connection state
         updateVisualState: function() {
-            var connected = UI.rfb_state === 'normal' ? true : false;
+            var connected = UI.rfb && UI.rfb_state === 'normal';
 
             //Util.Debug(">> updateVisualState");
             $D('noVNC_encrypt').disabled = connected;
             $D('noVNC_true_color').disabled = connected;
-            if (UI.rfb && UI.rfb.get_display() &&
-                UI.rfb.get_display().get_cursor_uri()) {
+            if (Util.browserSupportsCursorURIs()) {
                 $D('noVNC_cursor').disabled = connected;
             } else {
                 UI.updateSetting('cursor', !UI.isTouchDevice);
@@ -780,6 +778,8 @@ var UI;
                 throw new Error("Must set host and port");
             }
 
+            if (!UI.initRFB()) return;
+
             UI.rfb.set_encrypt(UI.getSetting('encrypt'));
             UI.rfb.set_true_color(UI.getSetting('true_color'));
             UI.rfb.set_local_cursor(UI.getSetting('cursor'));
@@ -809,11 +809,15 @@ var UI;
         },
 
         displayBlur: function() {
+            if (!UI.rfb) return;
+
             UI.rfb.get_keyboard().set_focused(false);
             UI.rfb.get_mouse().set_focused(false);
         },
 
         displayFocus: function() {
+            if (!UI.rfb) return;
+
             UI.rfb.get_keyboard().set_focused(true);
             UI.rfb.get_mouse().set_focused(true);
         },
@@ -882,7 +886,7 @@ var UI;
 
         // Toggle/set/unset the viewport drag/move button
         setViewDrag: function(drag) {
-            if (!UI.rfb) { return; }
+            if (!UI.rfb) return;
 
             UI.updateViewDragButton();
 
@@ -953,7 +957,7 @@ var UI;
         // sending keyCodes in the normal keyboard events when using on screen keyboards.
         keyInput: function(event) {
 
-            if (!UI.rfb) { return; }
+            if (!UI.rfb) return;
 
             var newValue = event.target.value;
 

include/util.js

@@ -508,6 +508,29 @@ Util.stopEvent = function (e) {
     else                   { e.returnValue = false; }
 };
 
+Util._cursor_uris_supported = null;
+
+Util.browserSupportsCursorURIs = function () {
+    if (Util._cursor_uris_supported === null) {
+        try {
+            var target = document.createElement('canvas');
+            target.style.cursor = 'url("data:image/x-icon;base64,AAACAAEACAgAAAIAAgA4AQAAFgAAACgAAAAIAAAAEAAAAAEAIAAAAAAAEAAAAAAAAAAAAAAAAAAAAAAAAAD/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////AAAAAAAAAAAAAAAAAAAAAA==") 2 2, default';
+
+            if (target.style.cursor) {
+                Util.Info("Data URI scheme cursor supported");
+                Util._cursor_uris_supported = true;
+            } else {
+                Util.Warn("Data URI scheme cursor not supported");
+                Util._cursor_uris_supported = false;
+            }
+        } catch (exc) {
+            Util.Error("Data URI scheme cursor test exception: " + exc);
+            Util._cursor_uris_supported = false;
+        }
+    }
+
+    return Util._cursor_uris_supported;
+};
 
 // Set browser engine versions. Based on mootools.
 Util.Features = {xpath: !!(document.evaluate), air: !!(window.runtime), query: !!(document.querySelector)};

tests/test.display.js

@@ -28,35 +28,29 @@ describe('Display/Canvas Helper', function () {
 
     describe('checking for cursor uri support', function () {
         beforeEach(function () {
-            this._old_change_cursor = Display.changeCursor;
+            this._old_browser_supports_cursor_uris = Util.browserSupportsCursorURIs;
         });
 
         it('should disable cursor URIs if there is no support', function () {
-            Display.changeCursor = function(target) {
-                target.style.cursor = undefined;
-            };
+            Util.browserSupportsCursorURIs = function () { return false; };
             var display = new Display({ target: document.createElement('canvas'), prefer_js: true, viewport: false });
             expect(display._cursor_uri).to.be.false;
         });
 
         it('should enable cursor URIs if there is support', function () {
-            Display.changeCursor = function(target) {
-                target.style.cursor = 'pointer';
-            };
+            Util.browserSupportsCursorURIs = function () { return true; };
             var display = new Display({ target: document.createElement('canvas'), prefer_js: true, viewport: false });
             expect(display._cursor_uri).to.be.true;
         });
 
         it('respect the cursor_uri option if there is support', function () {
-            Display.changeCursor = function(target) {
-                target.style.cursor = 'pointer';
-            };
+            Util.browserSupportsCursorURIs = function () { return false; };
             var display = new Display({ target: document.createElement('canvas'), prefer_js: true, viewport: false, cursor_uri: false });
             expect(display._cursor_uri).to.be.false;
         });
 
         afterEach(function () {
-            Display.changeCursor = this._old_change_cursor;
+            Util.browserSupportsCursorURIs = this._old_browser_supports_cursor_uris;
         });
     });
 

vnc.html

@@ -46,7 +46,7 @@
 </head>
 
 <body>
-    <div id="noVNC-control-bar">
+    <div id="noVNC-control-bar" class="noVNC_status_normal">
         <!--noVNC Mobile Device only Buttons-->
         <div class="noVNC-buttons-left">
             <input type="image" alt="viewport drag" src="images/drag.png"
@@ -87,7 +87,7 @@
             </div>
         </div>
 
-        <div id="noVNC_status">Loading</div>
+        <div id="noVNC_status"></div>
 
         <!--noVNC Buttons-->
         <div class="noVNC-buttons-right">

vnc_auto.html

@@ -216,6 +216,7 @@
                 return;
             }
 
+            try {
                 rfb = new RFB({'target':       $D('noVNC_canvas'),
                                'encrypt':      WebUtil.getQueryVar('encrypt',
                                         (window.location.protocol === "https:")),
@@ -228,6 +229,11 @@
                                'onXvpInit':    xvpInit,
                                'onPasswordRequired':  passwordRequired,
                                'onFBUComplete': FBUComplete});
+            } catch (exc) {
+                UI.updateState(null, 'fatal', null, 'Unable to create RFB client -- ' + exc);
+                return; // don't continue trying to connect
+            }
+
             rfb.connect(host, port, password, path);
         };
         </script>