fix(AddPeopleDialog): Improve contact invite form

- Disables the invite buttons while invites are ongoing
- Adds a keyboard shortcut (Enter) to send out invites
- Closes AddPeopleDialog upon successful invites sent
- Fixes the SecurityDialog closing when trying to set E2EE key via Enter shortcut
- Removes superfluous separator from SecurityDialog

css/modals/invite/_invite_more.scss

                 padding: 8px 16px;
                 background: #0376DA;
             }
+
+            &.disabled {
+                & > a {
+                    pointer-events: none;
+                }
+            }
         }
 
         &.stream {

css/modals/security/_security.scss

                         font-size: 14px;
                         color: #6FB1EA;
                     }
-
-                    &>a+a {
-                        margin-left: 24px;
-                    }
                 }
             }
         }
 
-        &> :first-child:not(:last-child) {
+        & > :first-child:not(:last-child) {
             margin-right: 24px;
         }
 

react/features/e2ee/components/E2EESection.js

                         disabled = { !editing }
                         name = 'e2eeKey'
                         onChange = { this._onKeyChange }
+                        onKeyDown = { this._onKeyDown }
                         placeholder = { t('dialog.e2eeNoKey') }
                         ref = { this.fieldRef }
                         type = 'password'
         this.setState({ key: event.target.value.trim() });
     }
 
+    _onKeyDown: (Object) => void;
+
+    /**
+     * Handler for the keydown event on the form, preventing the closing of the dialog.
+     *
+     * @param {Object} event - The DOM event triggered by keydown events.
+     * @returns {void}
+     */
+    _onKeyDown(event) {
+        if (event.key === 'Enter') {
+            event.preventDefault();
+        }
+    }
+
     _onSet: () => void;
 
     /**

react/features/invite/actionTypes.js

  */
 export const SET_CALLEE_INFO_VISIBLE = 'SET_CALLEE_INFO_VISIBLE';
 
+/**
+ * The type of redux action to signal that the {@code AddPeopleDialog} should close.
+ */
+export const HIDE_ADD_PEOPLE_DIALOG = 'HIDE_ADD_PEOPLE_DIALOG';
+
 /**
  * The type of the action which signals an error occurred while requesting dial-
  * in numbers.

react/features/invite/actions.any.js

 import {
     ADD_PENDING_INVITE_REQUEST,
     BEGIN_ADD_PEOPLE,
+    HIDE_ADD_PEOPLE_DIALOG,
     REMOVE_PENDING_INVITE_REQUESTS,
     SET_CALLEE_INFO_VISIBLE,
     UPDATE_DIAL_IN_NUMBERS_FAILED,
     };
 }
 
+/**
+ * Creates a (redux) action to signal that the {@code AddPeopleDialog}
+ * should close.
+ *
+ * @returns {{
+ *     type: HIDE_ADD_PEOPLE_DIALOG
+ * }}
+ */
+export function hideAddPeopleDialog() {
+    return {
+        type: HIDE_ADD_PEOPLE_DIALOG
+    };
+}
+
 
 /**
  * Invites (i.e. Sends invites to) an array of invitees (which may be a

react/features/invite/components/add-people-dialog/web/InviteContactsForm.js

 import { getLocalParticipant } from '../../../../base/participants';
 import { MultiSelectAutocomplete } from '../../../../base/react';
 import { connect } from '../../../../base/redux';
+import { hideAddPeopleDialog } from '../../../actions';
 import AbstractAddPeopleDialog, {
     type Props as AbstractProps,
     type State,
         this._parseQueryResults = this._parseQueryResults.bind(this);
         this._setMultiSelectElement = this._setMultiSelectElement.bind(this);
         this._renderFooterText = this._renderFooterText.bind(this);
+        this._onKeyDown = this._onKeyDown.bind(this);
 
         this._resourceClient = {
             makeQuery: this._query,
         }
 
         return (
-            <div className = 'add-people-form-wrap'>
+            <div
+                className = 'add-people-form-wrap'
+                onKeyDown = { this._onKeyDown }>
                 { this._renderErrorMessage() }
                 <MultiSelectAutocomplete
                     footer = { footerText }
                         this._multiselect.setSelectedItems(itemsToSelect);
                     }
                 } else {
-                    // Do nothing.
+                    this.props.dispatch(hideAddPeopleDialog());
                 }
             });
     }
 
+    _onKeyDown: (Object) => void;
+
+    /**
+     * Handles 'Enter' key in the form to trigger the invite.
+     *
+     * @param {Object} event - The key event.
+     * @returns {void}
+     */
+    _onKeyDown(event) {
+        const { inviteItems } = this.state;
+
+        if (event.key === 'Enter') {
+            event.preventDefault();
+            if (!this._isAddDisabled() && inviteItems.length) {
+                this._onSubmit();
+            }
+        }
+    }
+
     _parseQueryResults: (?Array<Object>) => Array<Object>;
 
     /**
         }
 
         return (
-            <div className = 'invite-more-dialog invite-buttons'>
+            <div className = { `invite-more-dialog invite-buttons${this._isAddDisabled() ? ' disabled' : ''}` }>
                 <a
                     className = 'invite-more-dialog invite-buttons-cancel'
                     onClick = { this._onClearItems }>

react/features/invite/middleware.web.js

 // @flow
 
-import { openDialog } from '../base/dialog';
+import { hideDialog, openDialog } from '../base/dialog';
 import { MiddlewareRegistry } from '../base/redux';
 
-import { BEGIN_ADD_PEOPLE } from './actionTypes';
+import { BEGIN_ADD_PEOPLE, HIDE_ADD_PEOPLE_DIALOG } from './actionTypes';
 import { AddPeopleDialog } from './components';
 import './middleware.any';
 
     switch (action.type) {
     case BEGIN_ADD_PEOPLE:
         return _beginAddPeople(store, next, action);
+    case HIDE_ADD_PEOPLE_DIALOG:
+        return _hideAddPeopleDialog(store, next, action);
     }
 
     return next(action);
 
     return result;
 }
+
+/**
+ * Notifies the feature invite that the action {@link HIDE_ADD_PEOPLE_DIALOG} is being
+ * dispatched within a specific redux {@code store}.
+ *
+ * @param {Store} store - The redux store in which the specified {@code action}
+ * is being dispatched.
+ * @param {Dispatch} next - The redux {@code dispatch} function to dispatch the
+ * specified {@code action} to the specified {@code store}.
+ * @param {Action} action - The redux action {@code HIDE_ADD_PEOPLE_DIALOG} which is
+ * being dispatched in the specified {@code store}.
+ * @private
+ * @returns {*} The value returned by {@code next(action)}.
+ */
+function _hideAddPeopleDialog({ dispatch }, next, action) {
+    dispatch(hideDialog(AddPeopleDialog));
+
+    return next(action);
+}

react/features/lobby/components/web/LobbySection.js

         }
 
         return (
-            <div id = 'lobby-section'>
-                { t('lobby.enableDialogText') }
-                <div className = 'control-row'>
-                    <label>
-                        { t('lobby.toggleLabel') }
-                    </label>
-                    <Switch
-                        onValueChange = { this._onToggleLobby }
-                        value = { this.state.lobbyEnabled } />
+            <>
+                <div id = 'lobby-section'>
+                    { t('lobby.enableDialogText') }
+                    <div className = 'control-row'>
+                        <label>
+                            { t('lobby.toggleLabel') }
+                        </label>
+                        <Switch
+                            onValueChange = { this._onToggleLobby }
+                            value = { this.state.lobbyEnabled } />
+                    </div>
                 </div>
-            </div>
+                <div className = 'separator-line' />
+            </>
         );
     }
 

react/features/security/components/security-dialog/SecurityDialog.js

             width = { 'small' }>
             <div className = 'security-dialog'>
                 <LobbySection />
-                <div className = 'separator-line' />
                 <PasswordSection
                     canEditPassword = { _canEditPassword }
                     conference = { _conference }