Build out a store for the right panel state machine

This should make it easier to funnel the expected behaviour through a central block of code.

src/components/structures/RightPanel.js

@@ -1,9 +1,9 @@
 /*
 Copyright 2015, 2016 OpenMarket Ltd
 Copyright 2017 Vector Creations Ltd
-Copyright 2017 New Vector Ltd
-Copyright 2018 New Vector Ltd
+Copyright 2017, 2018 New Vector Ltd
 Copyright 2019 Michael Telatynski <7t3chguy@gmail.com>
+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.
@@ -28,6 +28,7 @@ import RateLimitedFunc from '../../ratelimitedfunc';
 import { showGroupInviteDialog, showGroupAddRoomDialog } from '../../GroupAddressPicker';
 import GroupStore from '../../stores/GroupStore';
 import SettingsStore from "../../settings/SettingsStore";
+import {RIGHT_PANEL_PHASES} from "../../stores/RightPanelStore";
 
 export default class RightPanel extends React.Component {
     static get propTypes() {
@@ -44,17 +45,7 @@ export default class RightPanel extends React.Component {
         };
     }
 
-    static Phase = Object.freeze({
-        RoomMemberList: 'RoomMemberList',
-        GroupMemberList: 'GroupMemberList',
-        GroupRoomList: 'GroupRoomList',
-        GroupRoomInfo: 'GroupRoomInfo',
-        FilePanel: 'FilePanel',
-        NotificationPanel: 'NotificationPanel',
-        RoomMemberInfo: 'RoomMemberInfo',
-        Room3pidMemberInfo: 'Room3pidMemberInfo',
-        GroupMemberInfo: 'GroupMemberInfo',
-    });
+    static Phase = RIGHT_PANEL_PHASES;
 
     constructor(props, context) {
         super(props, context);

src/settings/Settings.js

@@ -1,6 +1,7 @@
 /*
 Copyright 2017 Travis Ralston
 Copyright 2018, 2019 New Vector Ltd.
+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.
@@ -24,6 +25,8 @@ import {
 import CustomStatusController from "./controllers/CustomStatusController";
 import ThemeController from './controllers/ThemeController';
 import ReloadOnChangeController from "./controllers/ReloadOnChangeController";
+import RightPanel from "../components/structures/RightPanel";
+import {RIGHT_PANEL_PHASES} from "../stores/RightPanelStore";
 
 // These are just a bunch of helper arrays to avoid copy/pasting a bunch of times
 const LEVELS_ROOM_SETTINGS = ['device', 'room-device', 'room-account', 'account', 'config'];
@@ -463,4 +466,20 @@ export const SETTINGS = {
         displayName: _td("Show previews/thumbnails for images"),
         default: true,
     },
+    "showRightPanelInRoom": {
+        supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS,
+        default: false,
+    },
+    "showRightPanelInGroup": {
+        supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS,
+        default: false,
+    },
+    "lastRightPanelPhaseForRoom": {
+        supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS,
+        default: RIGHT_PANEL_PHASES.RoomMemberInfo,
+    },
+    "lastRightPanelPhaseForGroup": {
+        supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS,
+        default: RIGHT_PANEL_PHASES.GroupMemberList,
+    },
 };

src/settings/handlers/DeviceSettingsHandler.js

@@ -1,6 +1,7 @@
 /*
 Copyright 2017 Travis Ralston
 Copyright 2019 New Vector Ltd.
+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.
@@ -56,6 +57,17 @@ export default class DeviceSettingsHandler extends SettingsHandler {
             return null; // wrong type or otherwise not set
         }
 
+        // Special case the right panel - see `setValue` for rationale.
+        if ([
+            "showRightPanelInRoom",
+            "showRightPanelInGroup",
+            "lastRightPanelPhaseForRoom",
+            "lastRightPanelPhaseForGroup",
+        ].includes(settingName)) {
+            const val = JSON.parse(localStorage.getItem(`mx_${settingName}`) || "{}");
+            return val['value'];
+        }
+
         const settings = this._getSettings() || {};
         return settings[settingName];
     }
@@ -81,6 +93,20 @@ export default class DeviceSettingsHandler extends SettingsHandler {
             return Promise.resolve();
         }
 
+        // Special case the right panel because we want to be able to update these all
+        // concurrently without stomping on one another. We could use async/await, though
+        // that introduces just enough latency to be annoying.
+        if ([
+            "showRightPanelInRoom",
+            "showRightPanelInGroup",
+            "lastRightPanelPhaseForRoom",
+            "lastRightPanelPhaseForGroup",
+        ].includes(settingName)) {
+            localStorage.setItem(`mx_${settingName}`, JSON.stringify({value: newValue}));
+            this._watchers.notifyUpdate(settingName, null, SettingLevel.DEVICE, newValue);
+            return Promise.resolve();
+        }
+
         const settings = this._getSettings() || {};
         settings[settingName] = newValue;
         localStorage.setItem("mx_local_settings", JSON.stringify(settings));

src/stores/RightPanelStore.js

@@ -0,0 +1,126 @@
+/*
+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 dis from '../dispatcher';
+import {Store} from 'flux/utils';
+import SettingsStore, {SettingLevel} from "../settings/SettingsStore";
+
+const INITIAL_STATE = {
+    // Whether or not to show the right panel at all. We split out rooms and groups
+    // because they're different flows for the user to follow.
+    showRoomPanel: SettingsStore.getValue("showRightPanelInRoom"),
+    showGroupPanel: SettingsStore.getValue("showRightPanelInGroup"),
+
+    // The last phase (screen) the right panel was showing
+    lastRoomPhase: SettingsStore.getValue("lastRightPanelPhaseForRoom"),
+    lastGroupPhase: SettingsStore.getValue("lastRightPanelPhaseForGroup"),
+};
+
+export const RIGHT_PANEL_PHASES = Object.freeze({
+    // Room stuff
+    RoomMemberList: 'RoomMemberList',
+    FilePanel: 'FilePanel',
+    NotificationPanel: 'NotificationPanel',
+    RoomMemberInfo: 'RoomMemberInfo',
+    Room3pidMemberInfo: 'Room3pidMemberInfo',
+
+    // Group stuff
+    GroupMemberList: 'GroupMemberList',
+    GroupRoomList: 'GroupRoomList',
+    GroupRoomInfo: 'GroupRoomInfo',
+    GroupMemberInfo: 'GroupMemberInfo',
+});
+
+const GROUP_PHASES = Object.keys(RIGHT_PANEL_PHASES).filter(k => k.startsWith("Group"));
+
+/**
+ * A class for tracking the state of the right panel between layouts and
+ * sessions.
+ */
+export default class RightPanelStore extends Store {
+    static _instance;
+
+    constructor() {
+        super(dis);
+
+        // Initialise state
+        this._state = INITIAL_STATE;
+    }
+
+    get isOpenForRoom(): boolean {
+        return this._state.showRoomPanel;
+    }
+
+    get isOpenForGroup(): boolean {
+        return this._state.showGroupPanel;
+    }
+
+    get roomPanelPhase(): string {
+        return this._state.lastRoomPhase;
+    }
+
+    get groupPanelPhase(): string {
+        return this._state.lastGroupPhase;
+    }
+
+    _setState(newState) {
+        this._state = Object.assign(this._state, newState);
+        SettingsStore.setValue("showRightPanelInRoom", null, SettingLevel.DEVICE, this._state.showRoomPanel);
+        SettingsStore.setValue("showRightPanelInGroup", null, SettingLevel.DEVICE, this._state.showGroupPanel);
+        SettingsStore.setValue("lastRightPanelPhaseForRoom", null, SettingLevel.DEVICE, this._state.lastRoomPhase);
+        SettingsStore.setValue("lastRightPanelPhaseForGroup", null, SettingLevel.DEVICE, this._state.lastGroupPhase);
+        this.__emitChange();
+    }
+
+    __onDispatch(payload) {
+        if (payload.action !== 'set_right_panel_phase') return;
+
+        const targetPhase = payload.phase;
+        if (!RIGHT_PANEL_PHASES[targetPhase]) {
+            console.warn(`Tried to switch right panel to unknown phase: ${targetPhase}`);
+            return;
+        }
+
+        if (GROUP_PHASES.includes(targetPhase)) {
+            if (targetPhase === this._state.lastGroupPhase) {
+                this._setState({
+                    showGroupPanel: !this._state.showGroupPanel,
+                });
+            } else {
+                this._setState({
+                    lastGroupPhase: targetPhase,
+                });
+            }
+        } else {
+            if (targetPhase === this._state.lastRoomPhase) {
+                this._setState({
+                    showRoomPanel: !this._state.showRoomPanel,
+                });
+            } else {
+                this._setState({
+                    lastRoomPhase: targetPhase,
+                });
+            }
+        }
+    }
+
+    static getSharedInstance(): RightPanelStore {
+        if (!RightPanelStore._instance) {
+            RightPanelStore._instance = new RightPanelStore();
+        }
+        return RightPanelStore._instance;
+    }
+}