view hierarchy:
```
    BrawlView
        SwitchView
            SessionView
                SyncStatusBar
                ListView(left-panel)
                SwitchView
                    RoomPlaceholderView
                    RoomView
                        MiddlePanel
                            ListView(timeline)
                            ComposerView
                        RightPanel
            SessionStartView
                SessionPickView
                LoginView
```