Add an option to invite users to upgraded private rooms

The option doesn't show up on public room upgrades.

src/components/views/dialogs/RoomUpgradeWarningDialog.js

@@ -0,0 +1,136 @@
+/*
+Copyright 2019 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React from 'react';
+import PropTypes from 'prop-types';
+import {_t} from "../../../languageHandler";
+import sdk from "../../../index";
+import LabelledToggleSwitch from "../elements/LabelledToggleSwitch";
+import MatrixClientPeg from "../../../MatrixClientPeg";
+
+export default class RoomUpgradeWarningDialog extends React.Component {
+    static propTypes = {
+        onFinished: PropTypes.func.isRequired,
+        roomId: PropTypes.string.isRequired,
+        targetVersion: PropTypes.string.isRequired,
+    };
+
+    constructor(props) {
+        super(props);
+
+        const room = MatrixClientPeg.get().getRoom(this.props.roomId);
+        const joinRules = room ? room.currentState.getStateEvents("m.room.join_rules", "") : null;
+        const isPrivate = joinRules ? joinRules.getContent()['join_rule'] !== 'public' : true;
+        this.state = {
+            currentVersion: room ? room.getVersion() : "1",
+            isPrivate,
+            inviteUsersToNewRoom: true,
+        };
+    }
+
+    _onContinue = () => {
+        this.props.onFinished({continue: true, invite: this.state.isPrivate && this.state.inviteUsersToNewRoom});
+    };
+
+    _onCancel = () => {
+        this.props.onFinished({continue: false, invite: false});
+    };
+
+    _onInviteUsersToggle = (newVal) => {
+        this.setState({inviteUsersToNewRoom: newVal});
+    };
+
+    render() {
+        const BaseDialog = sdk.getComponent('views.dialogs.BaseDialog');
+        const DialogButtons = sdk.getComponent('views.elements.DialogButtons');
+
+        let inviteToggle = null;
+        if (this.state.isPrivate) {
+            inviteToggle = (
+                <LabelledToggleSwitch
+                    value={this.state.inviteUsersToNewRoom} toggleInFront={true}
+                    onChange={this._onInviteUsersToggle}
+                    label={_t("Invite joined members to the new room automatically")} />
+            );
+        }
+
+        return (
+            <BaseDialog className='mx_RoomUpgradeWarningDialog' hasCancel={true}
+                        onFinished={this.props.onFinished}
+                        title={_t("Room upgrade confirmation")}>
+                <div>
+                    <p>{_t("Upgrading a room can be destructive and isn't always necessary.")}</p>
+                    <p>
+                        {_t(
+                            "Room upgrades are usually recommended when a room version is considered " +
+                            "<i>unstable</i>. Unstable room versions might have bugs, missing features, or " +
+                            "security vulnerabilities.",
+                            {}, {
+                                "i": (sub) => <i>{sub}</i>,
+                            },
+                        )}
+                    </p>
+                    <p>
+                        {_t(
+                            "Room upgrades usually only affect <i>server-side</i> processing of the " +
+                            "room. If you're having problems with your Riot client, please file an issue " +
+                            "with <issueLink />.",
+                            {}, {
+                                "i": (sub) => <i>{sub}</i>,
+                                "issueLink": () => {
+                                    return <a href="https://github.com/vector-im/riot-web/issues/new/choose"
+                                              target="_blank" rel="noopener">
+                                        https://github.com/vector-im/riot-web/issues/new/choose
+                                    </a>;
+                                },
+                            },
+                        )}
+                    </p>
+                    <p>
+                        {_t(
+                            "<b>Warning</b>: Upgrading a room will <i>not automatically migrate room " +
+                            "members to the new version of the room.</i> We'll post a link to the new room " +
+                            "in the old version of the room - room members will have to click this link to " +
+                            "join the new room.",
+                            {}, {
+                                "b": (sub) => <b>{sub}</b>,
+                                "i": (sub) => <i>{sub}</i>,
+                            },
+                        )}
+                    </p>
+                    <p>
+                        {_t(
+                            "Please confirm that you'd like to go forward with upgrading this room " +
+                            "from <oldVersion /> to <newVersion />.",
+                            {},
+                            {
+                                oldVersion: () => <code>{this.state.currentVersion}</code>,
+                                newVersion: () => <code>{this.props.targetVersion}</code>,
+                            },
+                        )}
+                    </p>
+                    {inviteToggle}
+                </div>
+                <DialogButtons
+                    primaryButton={_t("Continue")}
+                    onPrimaryButtonClick={this._onContinue}
+                    cancelButton={_t("Cancel")}
+                    onCancel={this._onCancel}
+                />
+            </BaseDialog>
+        );
+    }
+}