diff --git a/guacamole/src/main/frontend/src/app/client/controllers/clientController.js b/guacamole/src/main/frontend/src/app/client/controllers/clientController.js
index 8cacc77de..6a486fe9a 100644
--- a/guacamole/src/main/frontend/src/app/client/controllers/clientController.js
+++ b/guacamole/src/main/frontend/src/app/client/controllers/clientController.js
@@ -468,8 +468,21 @@ angular.module('client').controller('clientController', ['$scope', '$routeParams
         else if (menuShownPreviousState)
             $scope.applyParameterChanges($scope.focusedClient);
 
+        /* Broadcast changes to the menu display state */
+        $scope.$broadcast('guacMenuShown', menuShown);
+
     });
 
+    // Toggle the menu when the guacClientToggleMenu event is received
+    $scope.$on('guacToggleMenu',
+            () => $scope.menu.shown = !$scope.menu.shown);
+
+    // Show the menu when the guacClientShowMenu event is received
+    $scope.$on('guacShowMenu', () => $scope.menu.shown = true);
+
+    // Hide the menu when the guacClientHideMenu event is received
+    $scope.$on('guacHideMenu', () => $scope.menu.shown = false);
+
     // Automatically track and cache the currently-focused client
     $scope.$on('guacClientFocused', function focusedClientChanged(event, newFocusedClient) {
 
@@ -489,10 +502,9 @@ angular.module('client').controller('clientController', ['$scope', '$routeParams
 
     // Automatically update connection parameters that have been modified
     // for the current focused client
-    $scope.$on('guacClientArgumentsUpdated', function focusedClientChanged(event, focusedClient) {
+    $scope.$on('guacClientArgumentsUpdated', function argumentsChanged(event, focusedClient) {
 
-        // Update available connection parameters, if the updated arguments are
-        // for the current focused client - otherwise ignore them
+        // Ignore any updated arguments not for the current focused client
         if ($scope.focusedClient && $scope.focusedClient === focusedClient)
             $scope.menu.connectionParameters = ManagedClient.getArgumentModel(focusedClient);
 
diff --git a/guacamole/src/main/frontend/src/app/client/directives/guacTiledClients.js b/guacamole/src/main/frontend/src/app/client/directives/guacTiledClients.js
index e43c2603f..52289bcd0 100644
--- a/guacamole/src/main/frontend/src/app/client/directives/guacTiledClients.js
+++ b/guacamole/src/main/frontend/src/app/client/directives/guacTiledClients.js
@@ -62,6 +62,9 @@ angular.module('client').directive('guacTiledClients', [function guacTiledClient
     directive.controller = ['$scope', '$injector', '$element',
             function guacTiledClientsController($scope, $injector, $element) {
 
+        // Required services
+        const $rootScope = $injector.get('$rootScope');
+
         // Required types
         const ManagedClient      = $injector.get('ManagedClient');
         const ManagedClientGroup = $injector.get('ManagedClientGroup');
@@ -89,12 +92,17 @@ angular.module('client').directive('guacTiledClients', [function guacTiledClient
 
         // Notify whenever identify of currently-focused client changes
         $scope.$watch('getFocusedClient()', function focusedClientChanged(focusedClient) {
-            $scope.$emit('guacClientFocused', focusedClient);
+            $rootScope.$broadcast('guacClientFocused', focusedClient);
         });
 
         // Notify whenever arguments of currently-focused client changes
         $scope.$watch('getFocusedClient().arguments', function focusedClientParametersChanged() {
-            $scope.$emit('guacClientArgumentsUpdated', $scope.getFocusedClient());
+            $rootScope.$broadcast('guacClientArgumentsUpdated', $scope.getFocusedClient());
+        }, true);
+
+        // Notify whenever protocol of currently-focused client changes
+        $scope.$watch('getFocusedClient().protocol', function focusedClientParametersChanged() {
+            $rootScope.$broadcast('guacClientProtocolUpdated', $scope.getFocusedClient());
         }, true);
 
         /**
diff --git a/guacamole/src/main/frontend/src/app/client/templates/client.html b/guacamole/src/main/frontend/src/app/client/templates/client.html
index 829d5ef7d..66dca3a77 100644
--- a/guacamole/src/main/frontend/src/app/client/templates/client.html
+++ b/guacamole/src/main/frontend/src/app/client/templates/client.html
@@ -124,6 +124,7 @@
                     <guac-form namespace="getProtocolNamespace(focusedClient.protocol)"
                                content="focusedClient.forms"
                                model="menu.connectionParameters"
+                               client="focusedClient"
                                model-only="true"></guac-form>
                 </div>
 
diff --git a/guacamole/src/main/frontend/src/app/client/types/ManagedArgument.js b/guacamole/src/main/frontend/src/app/client/types/ManagedArgument.js
index 247d9f679..5e676bfcb 100644
--- a/guacamole/src/main/frontend/src/app/client/types/ManagedArgument.js
+++ b/guacamole/src/main/frontend/src/app/client/types/ManagedArgument.js
@@ -58,6 +58,16 @@ angular.module('client').factory('ManagedArgument', ['$q', function defineManage
          */
         this.stream = template.stream;
 
+        /**
+         * True if this argument has been modified in the webapp, but yet to
+         * be confirmed by guacd, or false in any other case. A pending
+         * argument cannot be modified again, and must be recreated before
+         * editing is enabled again.
+         *
+         * @type {boolean}
+         */
+        this.pending = false;
+
     };
 
     /**
@@ -110,9 +120,9 @@ angular.module('client').factory('ManagedArgument', ['$q', function defineManage
      * Sets the given editable argument (connection parameter) to the given
      * value, updating the behavior of the associated connection in real-time.
      * If successful, the ManagedArgument provided cannot be used for future
-     * calls to setValue() and must be replaced with a new instance. This
-     * function only has an effect if the new parameter value is different from
-     * the current value.
+     * calls to setValue() and will be read-only until replaced with a new
+     * instance. This function only has an effect if the new parameter value
+     * is different from the current value.
      *
      * @param {ManagedArgument} managedArgument
      *     The ManagedArgument instance associated with the connection
@@ -120,33 +130,24 @@ angular.module('client').factory('ManagedArgument', ['$q', function defineManage
      *
      * @param {String} value
      *     The new value to assign to the connection parameter.
-     *
-     * @returns {Boolean}
-     *     true if the connection parameter was sent and the provided
-     *     ManagedArgument instance may no longer be used for future setValue()
-     *     calls, false if the connection parameter was NOT sent as it has not
-     *     changed.
      */
     ManagedArgument.setValue = function setValue(managedArgument, value) {
 
-        // Stream new value only if value has changed
-        if (value !== managedArgument.value) {
+        // Stream new value only if value has changed and a change is not
+        // already pending
+        if (!managedArgument.pending && value !== managedArgument.value) {
 
             var writer = new Guacamole.StringWriter(managedArgument.stream);
             writer.sendText(value);
             writer.sendEnd();
 
             // ManagedArgument instance is no longer usable
-            return true;
+            managedArgument.pending = true;
 
         }
 
-        // No parameter value change was attempted and the ManagedArgument
-        // instance may be reused
-        return false;
-
     };
 
     return ManagedArgument;
 
-}]);
\ No newline at end of file
+}]);
diff --git a/guacamole/src/main/frontend/src/app/client/types/ManagedClient.js b/guacamole/src/main/frontend/src/app/client/types/ManagedClient.js
index 5dc8bce44..01769ea94 100644
--- a/guacamole/src/main/frontend/src/app/client/types/ManagedClient.js
+++ b/guacamole/src/main/frontend/src/app/client/types/ManagedClient.js
@@ -836,8 +836,7 @@ angular.module('client').factory('ManagedClient', ['$rootScope', '$injector',
      */
     ManagedClient.setArgument = function setArgument(managedClient, name, value) {
         var managedArgument = managedClient.arguments[name];
-        if (managedArgument && ManagedArgument.setValue(managedArgument, value))
-            delete managedClient.arguments[name];
+        managedArgument && ManagedArgument.setValue(managedArgument, value);
     };
 
     /**
@@ -1007,4 +1006,4 @@ angular.module('client').factory('ManagedClient', ['$rootScope', '$injector',
 
     return ManagedClient;
 
-}]);
\ No newline at end of file
+}]);
diff --git a/guacamole/src/main/frontend/src/app/form/directives/form.js b/guacamole/src/main/frontend/src/app/form/directives/form.js
index 8d35774c7..4de051bfd 100644
--- a/guacamole/src/main/frontend/src/app/form/directives/form.js
+++ b/guacamole/src/main/frontend/src/app/form/directives/form.js
@@ -17,6 +17,7 @@
  * under the License.
  */
 
+/* global _ */
 
 /**
  * A directive that allows editing of a collection of fields.
@@ -79,7 +80,19 @@ angular.module('form').directive('guacForm', [function form() {
              *
              * @type String
              */
-            focused : '='
+            focused : '=',
+
+            /**
+             * The client associated with this form, if any.
+             *
+             * NOTE: If the provided client has any managed arguments in the
+             * pending state, any fields with the same name rendered by this
+             * form will be disabled. The fields will be re-enabled when guacd
+             * sends an updated argument with a the same name.
+             *
+             * @type ManagedClient
+             */
+            client: '='
 
         },
         templateUrl: 'app/form/templates/form.html',
@@ -240,6 +253,28 @@ angular.module('form').directive('guacForm', [function form() {
 
             };
 
+
+            /**
+             * Returns whether the given field should be disabled (read-only)
+             * when presented to the current user.
+             *
+             * @param {Field} field
+             *     The field to check.
+             *
+             * @returns {Boolean}
+             *     true if the given field should be disabled, false otherwise.
+             */
+            $scope.isDisabled = function isDisabled(field) {
+
+                /*
+                 * The field is disabled if either the form as a whole is disabled,
+                 * or if a client is provided to the directive, and the field is
+                 * marked as pending.
+                 */
+                return $scope.disabled ||
+                        _.get($scope.client, ['arguments', field.name, 'pending']);
+            };
+
             /**
              * Returns whether at least one of the given fields should be
              * displayed to the current user.
diff --git a/guacamole/src/main/frontend/src/app/form/directives/formField.js b/guacamole/src/main/frontend/src/app/form/directives/formField.js
index 4fcead1d6..73ffb127e 100644
--- a/guacamole/src/main/frontend/src/app/form/directives/formField.js
+++ b/guacamole/src/main/frontend/src/app/form/directives/formField.js
@@ -68,7 +68,14 @@ angular.module('form').directive('guacFormField', [function formField() {
              *
              * @type Boolean
              */
-            focused : '='
+            focused : '=',
+
+            /**
+             * The client associated with this form field, if any.
+             *
+             * @type ManagedClient
+             */
+            client: '='
 
         },
         templateUrl: 'app/form/templates/formField.html',
diff --git a/guacamole/src/main/frontend/src/app/form/templates/form.html b/guacamole/src/main/frontend/src/app/form/templates/form.html
index 397a210c5..642c57783 100644
--- a/guacamole/src/main/frontend/src/app/form/templates/form.html
+++ b/guacamole/src/main/frontend/src/app/form/templates/form.html
@@ -10,9 +10,10 @@
         <div class="fields">
             <guac-form-field ng-repeat="field in form.fields" namespace="namespace"
                              ng-if="isVisible(field)"
-                             data-disabled="disabled"
+                             data-disabled="isDisabled(field)"
                              focused="isFocused(field)"
                              field="field"
+                             client="client"
                              model="values[field.name]"></guac-form-field>
         </div>