Only grab key events on canvas

Give the canvas proper focus handling. This avoids messy logic that
needs to disable and enable event handling when we want to interact
with other UI elements.

It also makes sure we can properly inhibit the browser from triggering
local actions on key presses.

app/styles/base.css

@@ -870,6 +870,9 @@ select:active {
   /* IE miscalculates width without this :( */
   flex-shrink: 0;
 }
+#noVNC_canvas:focus {
+  outline: none;
+}
 
 /*Default noVNC logo.*/
 /* From: http://fonts.googleapis.com/css?family=Orbitron:700 */

app/ui.js

@@ -292,6 +292,8 @@ var UI = {
 
         document.documentElement
             .addEventListener('mousedown', UI.keepVirtualKeyboard, true);
+        document.documentElement
+            .addEventListener('touchstart', UI.keepVirtualKeyboard, true);
 
         document.getElementById("noVNC_control_bar")
             .addEventListener('touchstart', UI.activateControlbar);
@@ -356,10 +358,6 @@ var UI = {
     addClipboardHandlers: function() {
         document.getElementById("noVNC_clipboard_button")
             .addEventListener('click', UI.toggleClipboardPanel);
-        document.getElementById("noVNC_clipboard_text")
-            .addEventListener('focus', UI.displayBlur);
-        document.getElementById("noVNC_clipboard_text")
-            .addEventListener('blur', UI.displayFocus);
         document.getElementById("noVNC_clipboard_text")
             .addEventListener('change', UI.clipboardSend);
         document.getElementById("noVNC_clipboard_clear_button")
@@ -440,6 +438,7 @@ var UI = {
                     msg = _("Connected (unencrypted) to ") + UI.desktopName;
                 }
                 UI.showStatus(msg);
+                document.getElementById('noVNC_canvas').focus();
                 break;
             case 'disconnecting':
                 UI.connected = false;
@@ -1492,7 +1491,14 @@ var UI = {
             }
         }
 
-        event.preventDefault();
+        // The default action of touchstart is to generate other
+        // events, which other elements might depend on. So we can't
+        // blindly prevent that. Instead restore focus right away.
+        if (event.type === "touchstart") {
+            setTimeout(input.focus.bind(input));
+        } else {
+            event.preventDefault();
+        }
     },
 
     keyboardinputReset: function() {
@@ -1662,20 +1668,6 @@ var UI = {
         }
     },
 
-    displayBlur: function() {
-        if (UI.rfb && !UI.rfb.get_view_only()) {
-            UI.rfb.get_keyboard().set_focused(false);
-            UI.rfb.get_mouse().set_focused(false);
-        }
-    },
-
-    displayFocus: function() {
-        if (UI.rfb && !UI.rfb.get_view_only()) {
-            UI.rfb.get_keyboard().set_focused(true);
-            UI.rfb.get_mouse().set_focused(true);
-        }
-    },
-
     updateLocalCursor: function() {
         if (!UI.rfb) return;
         UI.rfb.set_local_cursor(UI.getSetting('cursor'));

core/input/keyboard.js

@@ -24,8 +24,7 @@ export default function Keyboard(defaults) {
     this._pendingKey = null;        // Key waiting for keypress
 
     set_defaults(this, defaults, {
-        'target': document,
+        'target': null,
-        'focused': true
     });
 
     // keep these here so we can refer to them later
@@ -131,8 +130,6 @@ Keyboard.prototype = {
     },
 
     _handleKeyDown: function (e) {
-        if (!this._focused) { return; }
-
         var code = this._getKeyCode(e);
         var keysym = KeyboardUtil.getKeysym(e);
 
@@ -214,8 +211,6 @@ Keyboard.prototype = {
 
     // Legacy event for browsers without code/key
     _handleKeyPress: function (e) {
-        if (!this._focused) { return; }
-
         stopEvent(e);
 
         // Are we expecting a keypress?
@@ -244,8 +239,6 @@ Keyboard.prototype = {
         this._sendKeyEvent(keysym, code, true);
     },
     _handleKeyPressTimeout: function (e) {
-        if (!this._focused) { return; }
-
         // Did someone manage to sort out the key already?
         if (this._pendingKey === null) {
             return;
@@ -282,8 +275,6 @@ Keyboard.prototype = {
     },
 
     _handleKeyUp: function (e) {
-        if (!this._focused) { return; }
-
         stopEvent(e);
 
         var code = this._getKeyCode(e);
@@ -348,7 +339,6 @@ Keyboard.prototype = {
 
 make_properties(Keyboard, [
     ['target',     'wo', 'dom'],  // DOM element that captures keyboard input
-    ['focused',    'rw', 'bool'], // Capture and send key events
 
     ['onKeyEvent', 'rw', 'func'] // Handler for key press/release
 ]);

core/input/mouse.js

@@ -31,7 +31,6 @@ export default function Mouse(defaults) {
     // Configuration attributes
     set_defaults(this, defaults, {
         'target': document,
-        'focused': true,
         'touchButton': 1
     });
 
@@ -52,8 +51,6 @@ Mouse.prototype = {
     },
 
     _handleMouseButton: function (e, down) {
-        if (!this._focused) { return; }
-
         this._updateMousePosition(e);
         var pos = this._pos;
 
@@ -156,7 +153,7 @@ Mouse.prototype = {
     },
 
     _handleMouseWheel: function (e) {
-        if (!this._focused || !this._onMouseButton) { return; }
+        if (!this._onMouseButton) { return; }
 
         this._resetWheelStepTimers();
 
@@ -201,8 +198,6 @@ Mouse.prototype = {
     },
 
     _handleMouseMove: function (e) {
-        if (! this._focused) { return; }
-
         this._updateMousePosition(e);
         if (this._onMouseMove) {
             this._onMouseMove(this._pos.x, this._pos.y);
@@ -211,8 +206,6 @@ Mouse.prototype = {
     },
 
     _handleMouseDisable: function (e) {
-        if (!this._focused) { return; }
-
         /*
          * Stop propagation if inside canvas area
          * Note: This is only needed for the 'click' event as it fails
@@ -292,7 +285,6 @@ Mouse.prototype = {
 
 make_properties(Mouse, [
     ['target',         'ro', 'dom'],   // DOM element that captures mouse input
-    ['focused',        'rw', 'bool'],  // Capture and send mouse clicks/movement
 
     ['onMouseButton',  'rw', 'func'],  // Handler for mouse button click/release
     ['onMouseMove',    'rw', 'func'],  // Handler for mouse movement

core/rfb.js

@@ -120,7 +120,6 @@ export default function RFB(defaults) {
     // set the default value on user-facing properties
     set_defaults(this, defaults, {
         'target': 'null',                       // VNC display rendering Canvas object
-        'focusContainer': document,             // DOM element that captures keyboard input
         'encrypt': false,                       // Use TLS/SSL/wss encryption
         'local_cursor': false,                  // Request locally rendered cursor
         'shared': true,                         // Request shared mode
@@ -171,7 +170,7 @@ export default function RFB(defaults) {
         throw exc;
     }
 
-    this._keyboard = new Keyboard({target: this._focusContainer,
+    this._keyboard = new Keyboard({target: this._target,
                                    onKeyEvent: this._handleKeyEvent.bind(this)});
 
     this._mouse = new Mouse({target: this._target,
@@ -385,11 +384,17 @@ RFB.prototype = {
             }
         }
 
+        // Always grab focus on some kind of click event
+        this._target.addEventListener("mousedown", this._focusCanvas);
+        this._target.addEventListener("touchstart", this._focusCanvas);
+
         Log.Debug("<< RFB.connect");
     },
 
     _disconnect: function () {
         Log.Debug(">> RFB.disconnect");
+        this._target.removeEventListener("mousedown", this._focusCanvas);
+        this._target.removeEventListener("touchstart", this._focusCanvas);
         this._cleanup();
         this._sock.close();
         this._print_stats();
@@ -448,6 +453,13 @@ RFB.prototype = {
         }
     },
 
+    // Event handler for canvas so this points to the canvas element
+    _focusCanvas: function(event) {
+        // Respect earlier handlers' request to not do side-effects
+        if (!event.defaultPrevented)
+            this.focus();
+    },
+
     /*
      * Connection states:
      *   connecting
@@ -1457,7 +1469,6 @@ RFB.prototype = {
 
 make_properties(RFB, [
     ['target', 'wo', 'dom'],                // VNC display rendering Canvas object
-    ['focusContainer', 'wo', 'dom'],        // DOM element that captures keyboard input
     ['encrypt', 'rw', 'bool'],              // Use TLS/SSL/wss encryption
     ['local_cursor', 'rw', 'bool'],         // Request locally rendered cursor
     ['shared', 'rw', 'bool'],               // Request shared mode

vnc.html

@@ -331,7 +331,7 @@
                 autocorrect="off" autocomplete="off" spellcheck="false"
                 mozactionhint="Enter"></textarea>
 
-            <canvas id="noVNC_canvas" width="0" height="0">
+            <canvas id="noVNC_canvas" width="0" height="0" tabindex="-1">
                         Canvas not supported.
             </canvas>
         </div>