ScreenShield: move lock status handling to use session mode

Have distinct session modes for the lock screen and the unlock dialog,
and rework the logic in ScreenShield to have the lock-screen mode stack
onto the unlock-dialog mode (where applicable)

https://bugzilla.gnome.org/show_bug.cgi?id=682542

js/ui/messageTray.js

@@ -1513,8 +1513,7 @@ const MessageTray = new Lang.Class({
                 this._updateState();
             }));
 
-        this._isScreenLocked = false;
+        Main.sessionMode.connect('updated', Lang.bind(this, this._updateState));
-        Main.screenShield.connect('lock-status-changed', Lang.bind(this, this._onScreenLockStatusChanged));
 
         global.display.add_keybinding('toggle-message-tray',
                                       new Gio.Settings({ schema: SHELL_KEYBINDINGS_SCHEMA }),
@@ -1688,11 +1687,6 @@ const MessageTray = new Lang.Class({
             this._notificationQueue.splice(index, 1);
     },
 
-    _onScreenLockStatusChanged: function(screenShield, locked) {
-        this._isScreenLocked = locked;
-        this._updateState();
-    },
-
     _lock: function() {
         this._locked = true;
     },
@@ -1919,15 +1913,12 @@ const MessageTray = new Lang.Class({
     _updateState: function() {
         // Notifications
         let notificationQueue = this._notificationQueue.filter(Lang.bind(this, function(notification) {
-            if (this._isScreenLocked)
+            return notification.showWhenLocked || Main.sessionMode.hasNotifications;
-                return notification.showWhenLocked;
-            else
-                return true;
         }));
         let notificationUrgent = notificationQueue.length > 0 && notificationQueue[0].urgency == Urgency.CRITICAL;
         // notificationsLimited is false when the screen is locked, because they go through
         // different filtering, and we want to show non urgent messages at times
-        let notificationsLimited = (this._busy || this._inFullscreen) && !this._isScreenLocked;
+        let notificationsLimited = (this._busy || this._inFullscreen) && Main.sessionMode.hasNotifications;
         let notificationsPending = notificationQueue.length > 0 && (!notificationsLimited || notificationUrgent);
         let nextNotification = notificationQueue.length > 0 ? notificationQueue[0] : null;
         let notificationPinned = this._pointerInTray && !this._pointerInSummary && !this._notificationRemoved;
@@ -1938,7 +1929,7 @@ const MessageTray = new Lang.Class({
                                   !this._pointerInTray &&
                                   !this._locked &&
                                   !(this._pointerInKeyboard && notificationExpanded);
-        let notificationLockedOut = this._isScreenLocked && (this._notification && !this._notification.showWhenLocked);
+        let notificationLockedOut = !Main.sessionMode.hasNotifications && (this._notification && !this._notification.showWhenLocked);
         // TODO: how to deal with locked out notiifcations if want to keep showing notifications?!
         let notificationMustClose = this._notificationRemoved || notificationLockedOut || (notificationExpired && this._userActiveWhileNotificationShown) || this._notificationClosed;
         let canShowNotification = notificationsPending && this._summaryState == State.HIDDEN;
@@ -1968,7 +1959,7 @@ const MessageTray = new Lang.Class({
 
         let summaryOptionalInOverview = this._overviewVisible && !this._locked && !summaryHovered;
         let mustHideSummary = (notificationsPending && (notificationUrgent || summaryOptionalInOverview))
-                              || notificationsVisible || this._isScreenLocked;
+                              || notificationsVisible || !Main.sessionMode.hasNotifications;
 
         if (this._summaryState == State.HIDDEN && !mustHideSummary && summarySummoned)
             this._showSummary();

js/ui/screenShield.js

@@ -422,8 +422,9 @@ const ScreenShield = new Lang.Class({
         this._settings = new Gio.Settings({ schema: SCREENSAVER_SCHEMA });
 
         this._isModal = false;
-        this._isLocked = false;
         this._hasLockScreen = false;
+        this._isGreeter = false;
+        this._isActive = false;
 
         this._lightbox = new Lightbox.Lightbox(Main.uiGroup,
                                                { inhibitEvents: true,
@@ -519,7 +520,7 @@ const ScreenShield = new Lang.Class({
             // If we have a unlock dialog, cancel it
             if (this._dialog) {
                 this._dialog.cancel();
-                if (!this._keepDialog) {
+                if (!this._isGreeter) {
                     this._dialog = null;
                 }
             }
@@ -530,7 +531,7 @@ const ScreenShield = new Lang.Class({
         if (status == GnomeSession.PresenceStatus.IDLE) {
             if (this._dialog) {
                 this._dialog.cancel();
-                if (!this._keepDialog) {
+                if (!this._isGreeter) {
                     this._dialog = null;
                 }
             }
@@ -540,14 +541,14 @@ const ScreenShield = new Lang.Class({
                 this._isModal = true;
             }
 
-            if (!this._isLocked)
+            if (!this._isActive)
                 this._lightbox.show();
         } else {
             let lightboxWasShown = this._lightbox.shown;
             this._lightbox.hide();
 
             let shouldLock = lightboxWasShown && this._settings.get_boolean(LOCK_ENABLED_KEY);
-            if (shouldLock || this._isLocked) {
+            if (shouldLock || this._isActive) {
                 this.lock(false);
             } else if (this._isModal) {
                 this.unlock();
@@ -556,7 +557,13 @@ const ScreenShield = new Lang.Class({
     },
 
     showDialog: function() {
-        this.lock(true);
+        if (!this._isModal) {
+            Main.pushModal(this.actor);
+            this._isModal = true;
+        }
+
+        this.actor.show();
+        this._isGreeter = Main.sessionMode.isGreeter;
         this._ensureUnlockDialog();
         this._hideLockScreen(false);
     },
@@ -590,25 +597,24 @@ const ScreenShield = new Lang.Class({
                                time: time,
                                transition: 'linear',
                                onComplete: function() {
-                                   this._lockScreenHidden();
+                                   this._lockScreenState = MessageTray.State.HIDDEN;
+                                   this._lockScreenGroup.hide();
                                },
                                onCompleteScope: this,
                              });
         } else {
-            this._lockScreenHidden();
+            this._lockScreenState = MessageTray.State.HIDDEN;
+            this._lockScreenGroup.hide();
         }
-    },
 
-    _lockScreenHidden: function() {
+        if (Main.sessionMode.currentMode == 'lock-screen')
-        this._lockScreenState = MessageTray.State.HIDDEN;
+            Main.sessionMode.popMode('lock-screen');
-        this._lockScreenGroup.hide();
     },
 
     _ensureUnlockDialog: function() {
         if (!this._dialog) {
             let constructor = Main.sessionMode.unlockDialog;
             this._dialog = new constructor(this._lockDialogGroup);
-            this._keepDialog = Main.sessionMode.isGreeter;
             if (!this._dialog) {
                 // This session mode has no locking capabilities
                 this.unlock();
@@ -625,15 +631,6 @@ const ScreenShield = new Lang.Class({
             this._dialog.connect('failed', Lang.bind(this, this._onUnlockFailed));
             this._dialog.connect('unlocked', Lang.bind(this, this._onUnlockSucceded));
         }
-
-        if (Main.sessionMode.isGreeter) {
-            // Notify the other components that even though we are showing the
-            // screenshield, we're not in a locked state
-            // (this happens for the gdm greeter)
-
-            this._isLocked = false;
-            this.emit('lock-status-changed', false);
-        }
     },
 
     _onUnlockFailed: function() {
@@ -648,6 +645,7 @@ const ScreenShield = new Lang.Class({
     },
 
     _resetLockScreen: function(animate) {
+        this._ensureLockScreen();
         this._lockDialogGroup.scale_x = 1;
         this._lockDialogGroup.scale_y = 1;
 
@@ -679,6 +677,9 @@ const ScreenShield = new Lang.Class({
         }
 
         this._lockScreenGroup.grab_key_focus();
+
+        if (Main.sessionMode.currentMode != 'lock-screen')
+            Main.sessionMode.pushMode('lock-screen');
     },
 
     _lockScreenShown: function() {
@@ -696,7 +697,10 @@ const ScreenShield = new Lang.Class({
 
     // Some of the actors in the lock screen are heavy in
     // resources, so we only create them when needed
-    _prepareLockScreen: function() {
+    _ensureLockScreen: function() {
+        if (this._hasLockScreen)
+            return;
+
         this._lockScreenContentsBox = new St.BoxLayout({ x_align: Clutter.ActorAlign.CENTER,
                                                          y_align: Clutter.ActorAlign.CENTER,
                                                          x_expand: true,
@@ -738,7 +742,7 @@ const ScreenShield = new Lang.Class({
     },
 
     get locked() {
-        return this._isLocked;
+        return this._isActive;
     },
 
     _tweenUnlocked: function() {
@@ -760,13 +764,10 @@ const ScreenShield = new Lang.Class({
     },
 
     unlock: function() {
-        if (!this._isLocked)
-            return;
-
         if (this._hasLockScreen)
             this._clearLockScreen();
 
-        if (this._dialog && !this._keepDialog) {
+        if (this._dialog && !this._isGreeter) {
             this._dialog.destroy();
             this._dialog = null;
         }
@@ -778,30 +779,36 @@ const ScreenShield = new Lang.Class({
             this._isModal = false;
         }
 
-        this._isLocked = false;
+        this.actor.hide();
 
-        this.emit('lock-status-changed', false);
+        if (Main.sessionMode.currentMode == 'lock-screen')
-        Main.sessionMode.popMode('lock-screen');
+            Main.sessionMode.popMode('lock-screen');
+        if (Main.sessionMode.currentMode == 'unlock-dialog')
+            Main.sessionMode.popMode('unlock-dialog');
+
+        this._isActive = false;
+        this.emit('lock-status-changed');
     },
 
     lock: function(animate) {
-        if (this._isLocked)
-            return;
-
-        if (!this._hasLockScreen)
-            this._prepareLockScreen();
-
         if (!this._isModal) {
             Main.pushModal(this.actor);
             this._isModal = true;
         }
 
-        this._isLocked = true;
         this.actor.show();
+
+        if (Main.sessionMode.currentMode != 'unlock-dialog' &&
+            Main.sessionMode.currentMode != 'lock-screen') {
+            this._isGreeter = Main.sessionMode.isGreeter;
+            if (!this._isGreeter)
+                Main.sessionMode.pushMode('unlock-dialog');
+        }
+
         this._resetLockScreen(animate);
 
-        this.emit('lock-status-changed', true);
+        this._isActive = true;
-        Main.sessionMode.pushMode('lock-screen');
+        this.emit('lock-status-changed');
     },
 });
 Signals.addSignalMethods(ScreenShield.prototype);

js/ui/sessionMode.js

@@ -18,6 +18,7 @@ const _modes = {
         hasRunDialog: false,
         hasWorkspaces: false,
         hasWindows: false,
+        hasNotifications: false,
         isLocked: false,
         isGreeter: false,
         isPrimary: false,
@@ -32,6 +33,7 @@ const _modes = {
 
     'gdm': {
         allowKeybindingsWhenModal: true,
+        hasNotifications: true,
         isGreeter: true,
         isPrimary: true,
         unlockDialog: imports.gdm.loginDialog.LoginDialog,
@@ -46,7 +48,6 @@ const _modes = {
 
     'lock-screen': {
         isLocked: true,
-        isGreeter: undefined,
         unlockDialog: undefined,
         components: ['networkAgent', 'polkitAgent', 'telepathyClient'],
         panel: {
@@ -56,6 +57,17 @@ const _modes = {
         },
     },
 
+    'unlock-dialog': {
+        isLocked: true,
+        unlockDialog: undefined,
+        components: ['networkAgent', 'polkitAgent', 'telepathyClient'],
+        panel: {
+            left: ['userMenu'],
+            center: [],
+            right: ['a11y', 'keyboard', 'lockScreen']
+        },
+    },
+
     'initial-setup': {
         isPrimary: true,
         components: ['keyring'],
@@ -74,9 +86,10 @@ const _modes = {
         hasRunDialog: true,
         hasWorkspaces: true,
         hasWindows: true,
-        unlockDialog: imports.ui.unlockDialog.UnlockDialog,
+        hasNotifications: true,
         isLocked: false,
         isPrimary: true,
+        unlockDialog: imports.ui.unlockDialog.UnlockDialog,
         components: ['networkAgent', 'polkitAgent', 'telepathyClient',
                      'keyring', 'recorder', 'autorunManager', 'automountManager'],
         panel: {
@@ -118,6 +131,13 @@ const SessionMode = new Lang.Class({
         this._sync();
     },
 
+    switchMode: function(to) {
+        if (this.currentMode == to)
+            return;
+        this._modeStack[this._modeStack.length - 1] = to;
+        this._sync();
+    },
+
     get currentMode() {
         return this._modeStack[this._modeStack.length - 1];
     },

js/ui/shellDBus.js

@@ -343,8 +343,8 @@ const ScreenSaverDBus = new Lang.Class({
     _init: function() {
         this.parent();
 
-        Main.screenShield.connect('lock-status-changed', Lang.bind(this, function(shield, locked) {
+        Main.screenShield.connect('lock-status-changed', Lang.bind(this, function(shield) {
-            this._dbusImpl.emit_signal('ActiveChanged', GLib.Variant.new('(b)', [locked]));
+            this._dbusImpl.emit_signal('ActiveChanged', GLib.Variant.new('(b)', [shield.locked]));
         }));
 
         this._dbusImpl = Gio.DBusExportedObject.wrapJSObject(ScreenSaverIface, this);