sessionMode: Allow changing the session mode at runtime

Since we eventually want to add a system for changing the top panel
contents depending on the current state of the shell, let's use the
"session mode" feature for this, and add a mechanism for updating the
session mode at runtime. Add support for every key besides the two
functional keys, and make all the components update automatically when the
session mode is changed. Add a new lock-screen mode, and make the lock
screen change to this when locked.

https://bugzilla.gnome.org/show_bug.cgi?id=683156

js/ui/calendar.js

@@ -339,22 +339,10 @@ const DBusEventSource = new Lang.Class({
 });
 Signals.addSignalMethods(DBusEventSource.prototype);
 
-// Calendar:
-// @eventSource: is an object implementing the EventSource API, e.g. the
-// requestRange(), getEvents(), hasEvents() methods and the ::changed signal.
 const Calendar = new Lang.Class({
     Name: 'Calendar',
 
-    _init: function(eventSource) {
+    _init: function() {
-        if (eventSource) {
-            this._eventSource = eventSource;
-
-            this._eventSource.connect('changed', Lang.bind(this,
-                                                           function() {
-                                                               this._update(false);
-                                                           }));
-        }
-
         this._weekStart = Shell.util_get_week_start();
         this._weekdate = NaN;
         this._digitWidth = NaN;
@@ -391,6 +379,24 @@ const Calendar = new Lang.Class({
         this._buildHeader ();
     },
 
+    // @eventSource: is an object implementing the EventSource API, e.g. the
+    // requestRange(), getEvents(), hasEvents() methods and the ::changed signal.
+    setEventSource: function(eventSource) {
+        if (this._eventSource) {
+            this._eventSource.disconnect(this._eventSourceChangedId);
+            this._eventSource = null;
+        }
+
+        this._eventSource = eventSource;
+
+        if (this._eventSource) {
+            this._eventSourceChangedId = this._eventSource.connect('changed', Lang.bind(this, function() {
+                this._update(false);
+            }));
+            this._update(true);
+        }
+    },
+
     // Sets the calendar to show a specific date
     setDate: function(date, forceReload) {
         if (!_sameDay(date, this._selectedDate)) {
@@ -621,16 +627,25 @@ Signals.addSignalMethods(Calendar.prototype);
 const EventsList = new Lang.Class({
     Name: 'EventsList',
 
-    _init: function(eventSource) {
+    _init: function() {
         this.actor = new St.BoxLayout({ vertical: true, style_class: 'events-header-vbox'});
         this._date = new Date();
-        this._eventSource = eventSource;
-        this._eventSource.connect('changed', Lang.bind(this, this._update));
         this._desktopSettings = new Gio.Settings({ schema: 'org.gnome.desktop.interface' });
         this._desktopSettings.connect('changed', Lang.bind(this, this._update));
         this._weekStart = Shell.util_get_week_start();
+    },
 
-        this._update();
+    setEventSource: function(eventSource) {
+        if (this._eventSource) {
+            this._eventSource.disconnect(this._eventSourceChangedId);
+            this._eventSource = null;
+        }
+
+        this._eventSource = eventSource;
+
+        if (this._eventSource) {
+            this._eventSourceChangedId = this._eventSource.connect('changed', Lang.bind(this, this._update));
+        }
     },
 
     _addEvent: function(dayNameBox, timeBox, eventTitleBox, includeDayName, day, time, desc) {

js/ui/dateMenu.js

@@ -70,16 +70,8 @@ const DateMenuButton = new Lang.Class({
         this._date.style_class = 'datemenu-date-label';
         vbox.add(this._date);
 
-        if (Main.sessionMode.showCalendarEvents) {
+        this._eventList = new Calendar.EventsList();
-            this._eventSource = new Calendar.DBusEventSource();
+        this._calendar = new Calendar.Calendar();
-            this._eventList = new Calendar.EventsList(this._eventSource);
-        } else {
-            this._eventSource = null;
-            this._eventList = null;
-        }
-
-        // Calendar
-        this._calendar = new Calendar.Calendar(this._eventSource);
 
         this._calendar.connect('selected-date-changed',
                                Lang.bind(this, function(calendar, date) {
@@ -101,13 +93,10 @@ const DateMenuButton = new Lang.Class({
             item.actor.reparent(vbox);
         }
 
-        if (Main.sessionMode.showCalendarEvents) {
+        this._separator = new St.DrawingArea({ style_class: 'calendar-vertical-separator',
-            // Add vertical separator
-
-            item = new St.DrawingArea({ style_class: 'calendar-vertical-separator',
                                                pseudo_class: 'highlighted' });
-            item.connect('repaint', Lang.bind(this, _onVertSepRepaint));
+        this._separator.connect('repaint', Lang.bind(this, _onVertSepRepaint));
-            hbox.add(item);
+        hbox.add(this._separator);
 
         // Fill up the second column
         vbox = new St.BoxLayout({ name: 'calendarEventsArea',
@@ -117,11 +106,10 @@ const DateMenuButton = new Lang.Class({
         // Event list
         vbox.add(this._eventList.actor, { expand: true });
 
-            item = new PopupMenu.PopupMenuItem(_("Open Calendar"));
+        this._openCalendarItem = new PopupMenu.PopupMenuItem(_("Open Calendar"));
-            item.connect('activate', Lang.bind(this, this._onOpenCalendarActivate));
+        this._openCalendarItem.connect('activate', Lang.bind(this, this._onOpenCalendarActivate));
-            item.actor.can_focus = false;
+        this._openCalendarItem.actor.can_focus = false;
-            vbox.add(item.actor, {y_align: St.Align.END, expand: true, y_fill: false});
+        vbox.add(this._openCalendarItem.actor, {y_align: St.Align.END, expand: true, y_fill: false});
-        }
 
         // Whenever the menu is opened, select today
         this.menu.connect('open-state-changed', Lang.bind(this, function(menu, isOpen) {
@@ -151,6 +139,32 @@ const DateMenuButton = new Lang.Class({
         this._clock = new GnomeDesktop.WallClock();
         this._clock.connect('notify::clock', Lang.bind(this, this._updateClockAndDate));
         this._updateClockAndDate();
+
+        Main.sessionMode.connect('updated', Lang.bind(this, this._sessionUpdated));
+        this._sessionUpdated();
+    },
+
+    _setEventsVisibility: function(visible) {
+        this._separator.visible = visible;
+        this._eventList.visible = visible;
+        this._openCalendarItem.visible = visible;
+    },
+
+    _setEventSource: function(eventSource) {
+        this._calendar.setEventSource(eventSource);
+        this._eventList.setEventSource(eventSource);
+    },
+
+    _sessionUpdated: function() {
+        let eventSource;
+        let showEvents = Main.sessionMode.showCalendarEvents;
+        if (showEvents) {
+            eventSource = new Calendar.DBusEventSource();
+        } else {
+            eventSource = null;
+        }
+        this._setEventSource(eventSource);
+        this._setEventsVisibility(showEvents);
     },
 
     _updateClockAndDate: function() {

js/ui/extensionSystem.js

@@ -8,6 +8,7 @@ const Gio = imports.gi.Gio;
 const St = imports.gi.St;
 
 const ExtensionUtils = imports.misc.extensionUtils;
+const Main = imports.ui.main;
 
 const ExtensionState = {
     ENABLED: 1,
@@ -38,6 +39,9 @@ const disconnect = Lang.bind(_signals, _signals.disconnect);
 
 const ENABLED_EXTENSIONS_KEY = 'enabled-extensions';
 
+var initted = false;
+var enabled;
+
 function disableExtension(uuid) {
     let extension = ExtensionUtils.extensions[uuid];
     if (!extension)
@@ -216,6 +220,9 @@ function initExtension(uuid) {
 function onEnabledExtensionsChanged() {
     let newEnabledExtensions = global.settings.get_strv(ENABLED_EXTENSIONS_KEY);
 
+    if (!enabled)
+        return;
+
     // Find and enable all the newly enabled extensions: UUIDs found in the
     // new setting, but not in the old one.
     newEnabledExtensions.filter(function(uuid) {
@@ -243,7 +250,7 @@ function onEnabledExtensionsChanged() {
     enabledExtensions = newEnabledExtensions;
 }
 
-function loadExtensions() {
+function _loadExtensions() {
     global.settings.connect('changed::' + ENABLED_EXTENSIONS_KEY, onEnabledExtensionsChanged);
     enabledExtensions = global.settings.get_strv(ENABLED_EXTENSIONS_KEY);
 
@@ -257,3 +264,43 @@ function loadExtensions() {
     });
     finder.scanExtensions();
 }
+
+function enableAllExtensions() {
+    if (enabled)
+        return;
+
+    if (!initted) {
+        _loadExtensions();
+        initted = true;
+    } else {
+        enabledExtensions.forEach(function(uuid) {
+            enableExtension(uuid);
+        });
+    }
+    enabled = true;
+}
+
+function disableAllExtensions() {
+    if (!enabled)
+        return;
+
+    if (initted) {
+        enabledExtensions.forEach(function(uuid) {
+            disableExtension(uuid);
+        });
+    }
+
+    enabled = false;
+}
+
+function _sessionUpdated() {
+    if (Main.sessionMode.allowExtensions)
+        enableAllExtensions();
+    else
+        disableAllExtensions();
+}
+
+function init() {
+    Main.sessionMode.connect('updated', _sessionUpdated);
+    _sessionUpdated();
+}

js/ui/layout.js

@@ -639,7 +639,6 @@ const Chrome = new Lang.Class({
 
         this._monitors = [];
         this._inOverview = false;
-        this._isLocked = false;
         this._updateRegionIdle = 0;
         this._freezeUpdateCount = 0;
 
@@ -658,12 +657,9 @@ const Chrome = new Lang.Class({
     },
 
     init: function() {
-        Main.overview.connect('showing',
+        Main.overview.connect('showing', Lang.bind(this, this._overviewShowing));
-                             Lang.bind(this, this._overviewShowing));
+        Main.overview.connect('hidden', Lang.bind(this, this._overviewHidden));
-        Main.overview.connect('hidden',
+        Main.sessionMode.connect('updated', Lang.bind(this, this._sessionUpdated));
-                             Lang.bind(this, this._overviewHidden));
-        Main.screenShield.connect('lock-status-changed',
-                                  Lang.bind(this, this._lockStatusChanged));
     },
 
     addActor: function(actor, params) {
@@ -763,7 +759,7 @@ const Chrome = new Lang.Class({
             if (!actorData.isToplevel)
                 continue;
 
-            if (this._inOverview || this._isLocked)
+            if (this._inOverview || Main.sessionMode.hasWindows)
                 visible = true;
             else if (this.findMonitorForActor(actorData.actor).inFullscreen)
                 visible = false;
@@ -785,8 +781,7 @@ const Chrome = new Lang.Class({
         this._queueUpdateRegions();
     },
 
-    _lockStatusChanged: function(shield, locked) {
+    _sessionUpdated: function() {
-        this._isLocked = locked;
         this._updateVisibility();
         this._queueUpdateRegions();
     },

js/ui/main.js

@@ -143,6 +143,11 @@ function _initRecorder() {
     });
 }
 
+function _sessionUpdated() {
+    Meta.keybindings_set_custom_handler('panel-run-dialog', sessionMode.hasRunDialog ? openRunDialog : null);
+    loadTheme();
+}
+
 function start() {
     // These are here so we don't break compatibility.
     global.logError = window.log;
@@ -217,29 +222,17 @@ function start() {
 
     sessionMode.createSession();
 
-    panel.init();
     layoutManager.init();
     keyboard.init();
     overview.init();
 
-    if (sessionMode.hasWorkspaces)
     global.screen.override_workspace_layout(Meta.ScreenCorner.TOPLEFT,
                                             false, -1, 1);
+    Meta.keybindings_set_custom_handler('panel-main-menu', Lang.bind(overview, overview.toggle));
+    global.display.connect('overlay-key', Lang.bind(overview, overview.toggle));
 
-    if (sessionMode.hasRunDialog) {
+    sessionMode.connect('update', _sessionUpdated);
-        Meta.keybindings_set_custom_handler('panel-run-dialog', function() {
+    _sessionUpdated();
-           getRunDialog().open();
-        });
-    }
-
-    if (sessionMode.hasOverview) {
-        Meta.keybindings_set_custom_handler('panel-main-menu', function () {
-            overview.toggle();
-        });
-
-        global.display.connect('overlay-key',
-                               Lang.bind(overview, overview.toggle));
-    }
 
     // Provide the bus object for gnome-session to
     // initiate logouts.
@@ -275,10 +268,8 @@ function start() {
 
     _nWorkspacesChanged();
 
-    if (sessionMode.allowExtensions) {
     ExtensionDownloader.init();
-        ExtensionSystem.loadExtensions();
+    ExtensionSystem.init();
-    }
 }
 
 let _workspaces = [];
@@ -617,7 +608,7 @@ function _globalKeyPressHandler(actor, event) {
             if (!sessionMode.hasRunDialog)
                 return false;
 
-            getRunDialog().open();
+            openRunDialog();
             return true;
         case Meta.KeyBindingAction.PANEL_MAIN_MENU:
         case Meta.KeyBindingAction.OVERLAY_KEY:
@@ -763,11 +754,11 @@ function createLookingGlass() {
     return lookingGlass;
 }
 
-function getRunDialog() {
+function openRunDialog() {
     if (runDialog == null) {
         runDialog = new RunDialog.RunDialog();
     }
-    return runDialog;
+    runDialog.open();
 }
 
 /**

js/ui/overview.js

@@ -93,15 +93,20 @@ const Overview = new Lang.Class({
     Name: 'Overview',
 
     _init: function() {
-        this.isDummy = !Main.sessionMode.hasOverview;
+        this._overviewCreated = false;
 
-        // We only have an overview in user sessions, so
+        Main.sessionMode.connect('updated', Lang.bind(this, this._sessionUpdated));
-        // create a dummy overview in other cases
+        this._sessionUpdated();
-        if (this.isDummy) {
+    },
-            this.animationInProgress = false;
+
-            this.visible = false;
+    _createOverview: function() {
+        if (this._overviewCreated)
             return;
-        }
+
+        if (this.isDummy)
+            return;
+
+        this._overviewCreated = true;
 
         // The main BackgroundActor is inside global.window_group which is
         // hidden when displaying the overview, so we create a new
@@ -174,6 +179,11 @@ const Overview = new Lang.Class({
         this._needsFakePointerEvent = false;
     },
 
+    _sessionUpdated: function() {
+        this.isDummy = !Main.sessionMode.hasOverview;
+        this._createOverview();
+    },
+
     // The members we construct that are implemented in JS might
     // want to access the overview as Main.overview to connect
     // signal handlers and so forth. So we create them after

js/ui/panel.js

@@ -468,15 +468,6 @@ const AppMenuButton = new Lang.Class({
         this._sync();
     },
 
-    setLockedState: function(locked) {
-        if (locked) {
-            this.hide();
-        } else {
-            this.show();
-            this._sync();
-        }
-    },
-
     _sync: function() {
         let tracker = Shell.WindowTracker.get_default();
         let focusedApp = tracker.focus_app;
@@ -943,8 +934,6 @@ const Panel = new Lang.Class({
             this.actor.remove_style_class_name('in-overview');
         }));
 
-        Main.screenShield.connect('lock-status-changed', Lang.bind(this, this._onLockStateChanged));
-
         this.menuManager = new PopupMenu.PopupMenuManager(this);
 
         this._leftBox = new St.BoxLayout({ name: 'panelLeft' });
@@ -975,6 +964,9 @@ const Panel = new Lang.Class({
         Main.layoutManager.panelBox.add(this.actor);
         Main.ctrlAltTabManager.addGroup(this.actor, _("Top Bar"), 'start-here-symbolic',
                                         { sortGroup: CtrlAltTab.SortGroup.TOP });
+
+        Main.sessionMode.connect('updated', Lang.bind(this, this._sessionUpdated));
+        this._updatePanel();
     },
 
     _getPreferredWidth: function(actor, forHeight, alloc) {
@@ -1103,11 +1095,27 @@ const Panel = new Lang.Class({
         menu.actor.navigate_focus(null, Gtk.DirectionType.TAB_FORWARD, false);
     },
 
-    init: function() {
+    set boxOpacity(value) {
+        let isReactive = value > 0;
+
+        this._leftBox.opacity = value;
+        this._leftBox.reactive = isReactive;
+        this._centerBox.opacity = value;
+        this._centerBox.reactive = isReactive;
+        this._rightBox.opacity = value;
+        this._rightBox.reactive = isReactive;
+    },
+
+    get boxOpacity() {
+        return this._leftBox.opacity;
+    },
+
+    _updatePanel: function() {
         let panel = Main.sessionMode.panel;
-        this._initBox(panel.left, this._leftBox);
+        this._hideIndicators();
-        this._initBox(panel.center, this._centerBox);
+        this._updateBox(panel.left, this._leftBox);
-        this._initBox(panel.right, this._rightBox);
+        this._updateBox(panel.center, this._centerBox);
+        this._updateBox(panel.right, this._rightBox);
     },
 
     _initBox: function(elements, box) {
@@ -1119,20 +1127,97 @@ const Panel = new Lang.Class({
                 // bluetooth or network)
                 continue;
             }
+        }
+    },
 
-            let indicator = new constructor(this);
+    _tweenAndUpdatePanel: function() {
-            this._addToPanelBox(role, indicator, i, box);
+        this._closeIndicatorMenus();
+
+        Tweener.addTween(this, {
+            boxOpacity: 0,
+            time: Overview.ANIMATION_TIME / 2,
+            transition: 'easeOutQuad',
+            onCompleteScope: this,
+            onComplete: function() {
+                this._updatePanel();
+                Tweener.addTween(this, {
+                    boxOpacity: 255,
+                    time: Overview.ANIMATION_TIME / 2,
+                    transition: 'easeOutQuad'
+                });
+            }
+        });
+    },
+
+    _sessionUpdated: function() {
+        this._tweenAndUpdatePanel();
+    },
+
+    _closeIndicatorMenus: function() {
+        for (let role in this.statusArea) {
+            let indicator = this.statusArea[role];
+            indicator.menu.close();
+        }
+    },
+
+    _hideIndicators: function() {
+        for (let role in PANEL_ITEM_IMPLEMENTATIONS) {
+            let indicator = this.statusArea[role];
+            if (!indicator)
+                continue;
+            indicator._panelContainer.hide();
+        }
+    },
+
+    _ensureIndicator: function(role) {
+        let indicator = this.statusArea[role];
+        if (!indicator) {
+            let constructor = PANEL_ITEM_IMPLEMENTATIONS[role];
+            if (!constructor) {
+                // This icon is not implemented (this is a bug)
+                return null;
+            }
+            indicator = new constructor(this);
+            this.statusArea[role] = indicator;
+        }
+        return indicator;
+    },
+
+    _updateBox: function(elements, box) {
+        let nChildren = box.get_n_children();
+
+        for (let i = 0; i < elements.length; i++) {
+            let role = elements[i];
+            let indicator = this._ensureIndicator(role);
+            if (indicator == null)
+                continue;
+
+            this._addToPanelBox(role, indicator, i + nChildren, box);
         }
     },
 
     _addToPanelBox: function(role, indicator, position, box) {
-        box.insert_child_at_index(indicator.actor, position);
+        let container = indicator._panelContainer;
+        if (!container) {
+            container = new St.Bin({ y_fill: true,
+                                     child: indicator.actor });
+            indicator._panelContainer = container;
+        }
+        container.show();
+
+        let parent = container.get_parent();
+        if (parent) {
+            parent.remove_actor(container);
+        }
+
+        box.insert_child_at_index(container, position);
         if (indicator.menu)
             this.menuManager.addMenu(indicator.menu);
         this.statusArea[role] = indicator;
         let destroyId = indicator.connect('destroy', Lang.bind(this, function(emitter) {
             delete this.statusArea[role];
             emitter.disconnect(destroyId);
+            container.destroy();
         }));
     },
 
@@ -1150,12 +1235,8 @@ const Panel = new Lang.Class({
             right: this._rightBox
         };
         let boxContainer = boxes[box] || this._rightBox;
+        this.statusArea[role] = indicator;
         this._addToPanelBox(role, indicator, position, boxContainer);
         return indicator;
-    },
+    }
-
-    _onLockStateChanged: function(shield, locked) {
-        for (let id in this.statusArea)
-            this.statusArea[id].setLockedState(locked);
-    },
 });

js/ui/panelMenu.js

@@ -146,13 +146,6 @@ const Button = new Lang.Class({
         }
     },
 
-    setLockedState: function(locked) {
-        // default behaviour is to hide completely
-        if (locked)
-            this.menu.close();
-        this.actor.visible = !locked;
-    },
-
     _onButtonPress: function(actor, event) {
         if (!this.menu)
             return;

js/ui/popupMenu.js

@@ -870,6 +870,12 @@ const PopupMenuBase = new Lang.Class({
         this._activeMenuItem = null;
         this._childMenus = [];
         this._settingsActions = { };
+
+        this._sessionUpdatedId = Main.sessionMode.connect('updated', Lang.bind(this, this._sessionUpdated));
+    },
+
+    _sessionUpdated: function() {
+        this._setSettingsVisibility(Main.sessionMode.allowSettings);
     },
 
     addAction: function(title, callback) {
@@ -883,9 +889,6 @@ const PopupMenuBase = new Lang.Class({
     },
 
     addSettingsAction: function(title, desktopFile) {
-        if (!Main.sessionMode.allowSettings)
-            return null;
-
         let menuItem = this.addAction(title, function() {
                            let app = Shell.AppSystem.get_default().lookup_setting(desktopFile);
 
@@ -903,7 +906,7 @@ const PopupMenuBase = new Lang.Class({
         return menuItem;
     },
 
-    setSettingsVisibility: function(visible) {
+    _setSettingsVisibility: function(visible) {
         for (let id in this._settingsActions) {
             let item = this._settingsActions[id];
             item.actor.visible = visible;
@@ -1172,6 +1175,9 @@ const PopupMenuBase = new Lang.Class({
         this.actor.destroy();
 
         this.emit('destroy');
+
+        Main.sessionMode.disconnect(this._sessionUpdatedId);
+        this._sessionUpdatedId = 0;
     }
 });
 Signals.addSignalMethods(PopupMenuBase.prototype);
@@ -2041,6 +2047,9 @@ const PopupMenuManager = new Lang.Class({
     },
 
     addMenu: function(menu, position) {
+        if (this._findMenu(menu) > -1)
+            return;
+
         let menudata = {
             menu:              menu,
             openStateChangeId: menu.connect('open-state-changed', Lang.bind(this, this._onMenuOpenState)),

js/ui/screenShield.js

@@ -735,6 +735,9 @@ const ScreenShield = new Lang.Class({
     },
 
     unlock: function() {
+        if (!this._isLocked)
+            return;
+
         if (this._hasLockScreen)
             this._clearLockScreen();
 
@@ -762,9 +765,13 @@ const ScreenShield = new Lang.Class({
         this.actor.hide();
 
         this.emit('lock-status-changed', false);
+        Main.sessionMode.popMode('lock-screen');
     },
 
     lock: function(animate) {
+        if (this._isLocked)
+            return;
+
         if (!this._hasLockScreen)
             this._prepareLockScreen();
 
@@ -778,6 +785,7 @@ const ScreenShield = new Lang.Class({
         this._resetLockScreen(animate);
 
         this.emit('lock-status-changed', true);
+        Main.sessionMode.pushMode('lock-screen');
     },
 });
 Signals.addSignalMethods(ScreenShield.prototype);

js/ui/sessionMode.js

@@ -1,6 +1,7 @@
 // -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
 
 const Lang = imports.lang;
+const Signals = imports.signals;
 
 const Main = imports.ui.main;
 const Params = imports.misc.params;
@@ -15,16 +16,33 @@ const _modes = {
              allowKeybindingsWhenModal: true,
              hasRunDialog: false,
              hasWorkspaces: false,
+             hasWindows: false,
              createSession: Main.createGDMSession,
              createUnlockDialog: Main.createGDMLoginDialog,
              panel: {
                  left: [],
                  center: ['dateMenu'],
                  right: ['a11y', 'display', 'keyboard',
-                         'volume', 'battery', 'lockScreen', 'powerMenu']
+                         'volume', 'battery', 'powerMenu']
              }
            },
 
+    'lock-screen': {
+        hasOverview: false,
+        showCalendarEvents: false,
+        allowSettings: false,
+        allowExtensions: false,
+        allowKeybindingsWhenModal: false,
+        hasRunDialog: false,
+        hasWorkspaces: false,
+        hasWindows: false,
+        panel: {
+            left: ['userMenu'],
+            center: [],
+            right: ['lockScreen']
+        },
+    },
+
     'initial-setup': { hasOverview: false,
                        showCalendarEvents: false,
                        allowSettings: false,
@@ -36,7 +54,7 @@ const _modes = {
                        panel: {
                            left: [],
                            center: ['dateMenu'],
-                           right: ['a11y', 'keyboard', 'volume', 'lockScreen']
+                           right: ['a11y', 'keyboard', 'volume']
                        }
                      },
 
@@ -47,13 +65,14 @@ const _modes = {
               allowKeybindingsWhenModal: false,
               hasRunDialog: true,
               hasWorkspaces: true,
+              hasWindows: true,
               createSession: Main.createUserSession,
               createUnlockDialog: Main.createSessionUnlockDialog,
               panel: {
                   left: ['activities', 'appMenu'],
                   center: ['dateMenu'],
                   right: ['a11y', 'keyboard', 'volume', 'bluetooth',
-                          'network', 'battery', 'lockScreen', 'userMenu']
+                          'network', 'battery', 'userMenu']
               }
             }
 };
@@ -68,8 +87,29 @@ const SessionMode = new Lang.Class({
     Name: 'SessionMode',
 
     _init: function() {
-        let params = _modes[global.session_mode];
+        global.connect('notify::session-mode', Lang.bind(this, this._sync));
+        this._modeStack = [global.session_mode];
+        this._sync();
+    },
 
+    pushMode: function(mode) {
+        this._modeStack.push(mode);
+        this._sync();
+    },
+
+    popMode: function(mode) {
+        if (this.currentMode != mode || this._modeStack.length === 1)
+            throw new Error("Invalid SessionMode.popMode");
+        this._modeStack.pop();
+        this._sync();
+    },
+
+    get currentMode() {
+        return this._modeStack[this._modeStack.length - 1];
+    },
+
+    _sync: function() {
+        let params = _modes[this.currentMode];
         params = Params.parse(params, _modes[DEFAULT_MODE]);
 
         this._createSession = params.createSession;
@@ -78,6 +118,7 @@ const SessionMode = new Lang.Class({
         delete params.createUnlockDialog;
 
         Lang.copyProperties(params, this);
+        this.emit('updated');
     },
 
     createSession: function() {
@@ -92,3 +133,4 @@ const SessionMode = new Lang.Class({
             return null;
     },
 });
+Signals.addSignalMethods(SessionMode.prototype);

js/ui/status/accessibility.js

@@ -75,10 +75,6 @@ const ATIndicator = new Lang.Class({
         this.menu.addSettingsAction(_("Universal Access Settings"), 'gnome-universal-access-panel.desktop');
     },
 
-    setLockedState: function(locked) {
-        this.actor.visible = !locked;
-    },
-
     _buildItemExtended: function(string, initial_value, writable, on_set) {
         let widget = new PopupMenu.PopupSwitchMenuItem(string, initial_value);
         if (!writable)

js/ui/status/bluetooth.js

@@ -88,11 +88,6 @@ const Indicator = new Lang.Class({
         this._applet.connect('cancel-request', Lang.bind(this, this._cancelRequest));
     },
 
-    setLockedState: function(locked) {
-        this._isLocked = locked;
-        this._updateKillswitch();
-    },
-
     _updateKillswitch: function() {
         let current_state = this._applet.killswitch_state;
         let on = current_state == GnomeBluetooth.KillswitchState.UNBLOCKED;
@@ -107,7 +102,7 @@ const Indicator = new Lang.Class({
             /* TRANSLATORS: this means that bluetooth was disabled by hardware rfkill */
             this._killswitch.setStatus(_("hardware disabled"));
 
-        this.actor.visible = !this._isLocked && has_adapter;
+        this.actor.visible = has_adapter;
 
         if (on) {
             this._discoverable.actor.show();

js/ui/status/keyboard.js

@@ -166,22 +166,21 @@ const InputSourceIndicator = new Lang.Class({
 
         this._inputSourcesChanged();
 
+        this.menu.addMenuItem(new PopupMenu.PopupSeparatorMenuItem());
+        this._showLayoutItem = this.menu.addAction(_("Show Keyboard Layout"), Lang.bind(this, this._showLayout));
+
+        Main.sessionMode.connect('updated', Lang.bind(this, this._sessionUpdated));
+        this._sessionUpdated();
+
+        this.menu.addSettingsAction(_("Region and Language Settings"), 'gnome-region-panel.desktop');
+    },
+
+    _sessionUpdated: function() {
         // re-using "allowSettings" for the keyboard layout is a bit shady,
         // but at least for now it is used as "allow popping up windows
         // from shell menus"; we can always add a separate sessionMode
         // option if need arises.
-        if (Main.sessionMode.allowSettings) {
+        this._showLayoutItem.visible = Main.sessionMode.allowSettings;
-            this.menu.addMenuItem(new PopupMenu.PopupSeparatorMenuItem());
-            this._showLayoutItem = this.menu.addAction(_("Show Keyboard Layout"), Lang.bind(this, this._showLayout));
-        }
-        this.menu.addSettingsAction(_("Region and Language Settings"), 'gnome-region-panel.desktop');
-    },
-
-    setLockedState: function(locked) {
-        if (Main.sessionMode.allowSettings) {
-            this._showLayoutItem.actor.visible = !locked;
-        }
-        this.menu.setSettingsVisibility(!locked);
     },
 
     _currentInputSourceChanged: function() {

js/ui/status/lockScreenMenu.js

@@ -16,7 +16,6 @@ const Indicator = new Lang.Class({
 
     _init: function() {
         this.parent(null, _("Volume, network, battery"));
-        this.actor.hide();
 
         this._volume = Main.panel.statusArea.volume;
         if (this._volume) {
@@ -54,9 +53,5 @@ const Indicator = new Lang.Class({
             this._battery.mainIcon.bind_property('visible', this._batteryIcon, 'visible',
                                                  GObject.BindingFlags.SYNC_CREATE);
         }
-    },
-
-    setLockedState: function(locked) {
-        this.actor.visible = locked;
     }
 });

js/ui/status/network.js

@@ -1567,7 +1567,6 @@ const NMApplet = new Lang.Class({
         this.secondaryIcon = this.addIcon(new Gio.ThemedIcon({ name: 'network-vpn-symbolic' }));
         this.secondaryIcon.hide();
 
-        this._isLocked = false;
         this._client = NMClient.Client.new();
 
         this._statusSection = new PopupMenu.PopupMenuSection();
@@ -1675,11 +1674,6 @@ const NMApplet = new Lang.Class({
         }));
     },
 
-    setLockedState: function(locked) {
-        this._isLocked = locked;
-        this._syncNMState();
-    },
-
     _ensureSource: function() {
         if (!this._source) {
             this._source = new MessageTray.Source(_("Network Manager"),
@@ -2063,7 +2057,7 @@ const NMApplet = new Lang.Class({
 
     _syncNMState: function() {
         this.mainIcon.visible = this._client.manager_running;
-        this.actor.visible = this.mainIcon.visible && !this._isLocked;
+        this.actor.visible = this.mainIcon.visible;
 
         if (!this._client.networking_enabled) {
             this.setIcon('network-offline-symbolic');

js/ui/status/power.js

@@ -56,7 +56,6 @@ const Indicator = new Lang.Class({
 
         this._proxy = new PowerManagerProxy(Gio.DBus.session, BUS_NAME, OBJECT_PATH);
 
-        this._isLocked = false;
         this._deviceItems = [ ];
         this._hasPrimary = false;
         this._primaryDeviceId = null;
@@ -77,11 +76,6 @@ const Indicator = new Lang.Class({
         this._devicesChanged();
     },
 
-    setLockedState: function(locked) {
-        this._isLocked = locked;
-        this._syncIcon();
-    },
-
     _readPrimaryDevice: function() {
         this._proxy.GetPrimaryDeviceRemote(Lang.bind(this, function(result, error) {
             if (error) {
@@ -160,7 +154,7 @@ const Indicator = new Lang.Class({
             hasIcon = true;
         }
         this.mainIcon.visible = hasIcon;
-        this.actor.visible = hasIcon && !this._isLocked;
+        this.actor.visible = hasIcon;
     },
 
     _devicesChanged: function() {

js/ui/status/volume.js

@@ -217,8 +217,6 @@ const Indicator = new Lang.Class({
     _init: function() {
         this.parent('audio-volume-muted-symbolic', _("Volume"));
 
-        this._isLocked = false;
-
         this._control = getMixerControl();
         this._volumeMenu = new VolumeMenu(this._control);
         this._volumeMenu.connect('icon-changed', Lang.bind(this, function(menu, icon) {
@@ -235,13 +233,8 @@ const Indicator = new Lang.Class({
         this.actor.connect('scroll-event', Lang.bind(this, this._onScrollEvent));
     },
 
-    setLockedState: function(locked) {
-        this._isLocked = locked;
-        this._syncVisibility();
-    },
-
     _syncVisibility: function() {
-        this.actor.visible = this._hasPulseAudio && !this._isLocked;
+        this.actor.visible = this._hasPulseAudio;
         this.mainIcon.visible = this._hasPulseAudio;
     },
 

js/ui/userMenu.js

@@ -58,6 +58,11 @@ const UserAvatarWidget = new Lang.Class({
                                   reactive: params.reactive });
     },
 
+    setSensitive: function(sensitive) {
+        this.actor.can_focus = sensitive;
+        this.actor.reactive = sensitive;
+    },
+
     update: function() {
         let iconFile = this._user.get_icon_file();
         if (!GLib.file_test(iconFile, GLib.FileTest.EXISTS))
@@ -236,6 +241,10 @@ const IMStatusChooserItem = new Lang.Class({
             if (this.actor.mapped)
                 this._updateUser();
         }));
+
+        this.connect('sensitive-changed', function(sensitive) {
+            this._avatar.setSensitive(sensitive);
+        });
     },
 
     _restorePresence: function() {
@@ -560,10 +569,15 @@ const UserMenuButton = new Lang.Class({
                                        Lang.bind(this, this._updateHaveShutdown));
 
         this._upClient.connect('notify::can-suspend', Lang.bind(this, this._updateSuspendOrPowerOff));
+
+        Main.sessionMode.connect('updated', Lang.bind(this, this._sessionUpdated));
+        this._sessionUpdated();
     },
 
-    setLockedState: function(locked) {
+    _sessionUpdated: function() {
-        this.actor.visible = !locked;
+        let allowSettings = Main.sessionMode.allowSettings;
+        this._statusChooser.setSensitive(allowSettings);
+        this._systemSettings.visible = allowSettings;
     },
 
     _onDestroy: function() {
@@ -707,7 +721,6 @@ const UserMenuButton = new Lang.Class({
         let item;
 
         item = new IMStatusChooserItem();
-        if (Main.sessionMode.allowSettings)
         item.connect('activate', Lang.bind(this, this._onMyAccountActivate));
         this.menu.addMenuItem(item);
         this._statusChooser = item;
@@ -720,11 +733,10 @@ const UserMenuButton = new Lang.Class({
         item = new PopupMenu.PopupSeparatorMenuItem();
         this.menu.addMenuItem(item);
 
-        if (Main.sessionMode.allowSettings) {
         item = new PopupMenu.PopupMenuItem(_("System Settings"));
         item.connect('activate', Lang.bind(this, this._onPreferencesActivate));
         this.menu.addMenuItem(item);
-        }
+        this._systemSettings = item;
 
         item = new PopupMenu.PopupSeparatorMenuItem();
         this.menu.addMenuItem(item);