lazy loading settings controller to show dialog and export e2e keys

src/settings/controllers/LazyLoadingController.js

@@ -0,0 +1,66 @@
+/*
+Copyright 2018 New Vector
+
+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 SettingsStore from "../SettingsStore";
+import SettingController from "./SettingController";
+import Modal from "../../Modal";
+import sdk from "../../index";
+import MatrixClientPeg  from "../../MatrixClientPeg";
+import dis from "../../dispatcher";
+import { _t } from "../../languageHandler";
+
+export default class LazyLoadingController extends SettingController {
+    onChange(level, roomId, newValue) {
+        dis.dispatch({action: 'flush_storage_reload'});
+    }
+
+    canChangeTo(level, roomId, newValue) {
+        return new Promise((resolve) => this._showReloadDialog(resolve));
+    }
+
+    _showReloadDialog(onFinished) {
+        const QuestionDialog = sdk.getComponent("dialogs.QuestionDialog");
+        Modal.createDialog(QuestionDialog, {
+            title: _t("Turn on/off lazy load members"),
+            description:
+                <div>
+             { _t("To enable or disable the lazy loading of members, " + 
+                "the current synced state needs to be cleared out. " + 
+                "This also includes your end-to-end encryption keys, " +
+                "so to keep being able to decrypt all your existing encrypted messages, " +
+                "you'll need to export your E2E room keys and import them again afterwards.") }
+                </div>,
+            button: _t("Clear sync state and reload"),
+            extraButtons: [
+                <button key="export" className="mx_Dialog_primary"
+                        onClick={this._onExportE2eKeysClicked}>
+                   { _t("Export E2E room keys") }
+                </button>,
+            ],
+            onFinished,
+        });
+    }
+
+    _onExportE2eKeysClicked() {
+        Modal.createTrackedDialogAsync('Export E2E Keys', '', (cb) => {
+            require.ensure(['../../async-components/views/dialogs/ExportE2eKeysDialog'], () => {
+                cb(require('../../async-components/views/dialogs/ExportE2eKeysDialog'));
+            }, "e2e-export");
+        }, {
+            matrixClient: MatrixClientPeg.get(),
+        });
+    }
+}