Add support for gdm greeter session

This commit adds GDM session support.

It provides a user list that talks to GDM,
handles authentication via PAM, etc.

It doesn't currently support fingerprint readers
and smartcards.

https://bugzilla.gnome.org/show_bug.cgi?id=657082

js/Makefile.am

@@ -3,6 +3,7 @@ jsdir = $(pkgdatadir)/js
 
 nobase_dist_js_DATA = 	\
 	gdm/batch.js		\
+	gdm/loginDialog.js	\
 	misc/config.js		\
 	misc/docInfo.js		\
 	misc/fileUtils.js	\

js/ui/main.js

@@ -71,6 +71,7 @@ let _errorLogStack = [];
 let _startDate;
 let _defaultCssStylesheet = null;
 let _cssStylesheet = null;
+let _gdmCssStylesheet = null;
 
 let background = null;
 
@@ -86,6 +87,17 @@ function _createUserSession() {
     networkAgent = new NetworkAgent.NetworkAgent();
 }
 
+function _createGDMSession() {
+    // We do this this here instead of at the top to prevent GDM
+    // related code from getting loaded in normal user sessions
+    const LoginDialog = imports.gdm.loginDialog;
+
+    let loginDialog = new LoginDialog.LoginDialog();
+    loginDialog.connect('loaded', function() {
+                            loginDialog.open();
+                        });
+}
+
 function _initRecorder() {
     let recorderSettings = new Gio.Settings({ schema: 'org.gnome.shell.recorder' });
 
@@ -175,6 +187,7 @@ function start() {
     global.stage.no_clear_hint = true;
 
     _defaultCssStylesheet = global.datadir + '/theme/gnome-shell.css';
+    _gdmCssStylesheet = global.datadir + '/theme/gdm.css';
     loadTheme();
 
     // Set up stage hierarchy to group all UI actors under one container.
@@ -197,7 +210,11 @@ function start() {
     keyboard = new Keyboard.Keyboard();
     notificationDaemon = new NotificationDaemon.NotificationDaemon();
     windowAttentionHandler = new WindowAttentionHandler.WindowAttentionHandler();
-    _createUserSession();
+
+    if (global.session_type == Shell.SessionType.USER)
+        _createUserSession();
+    else if (global.session_type == Shell.SessionType.GDM)
+        _createGDMSession();
 
     panel.startStatusArea();
 
@@ -434,6 +451,9 @@ function loadTheme() {
 
     let theme = new St.Theme ({ application_stylesheet: cssStylesheet });
 
+    if (global.session_type == Shell.SessionType.GDM)
+        theme.load_stylesheet(_gdmCssStylesheet);
+
     if (previousTheme) {
         let customStylesheets = previousTheme.get_custom_stylesheets();
 

js/ui/panel.js

@@ -45,6 +45,14 @@ try {
     log('NMApplet is not supported. It is possible that your NetworkManager version is too old');
 }
 
+const GDM_TRAY_ICON_ORDER = ['a11y', 'display', 'keyboard', 'volume', 'battery'];
+const GDM_TRAY_ICON_SHELL_IMPLEMENTATION = {
+    'a11y': imports.ui.status.accessibility.ATIndicator,
+    'volume': imports.ui.status.volume.Indicator,
+    'battery': imports.ui.status.power.Indicator,
+    'keyboard': imports.ui.status.keyboard.XKBIndicator
+};
+
 // To make sure the panel corners blend nicely with the panel,
 // we draw background and borders the same way, e.g. drawing
 // them as filled shapes from the outside inwards instead of
@@ -876,6 +884,14 @@ Panel.prototype = {
             this.actor.remove_style_class_name('in-overview');
         }));
 
+        if (global.session_type == Shell.SessionType.GDM) {
+            this._tray_icon_order = GDM_TRAY_ICON_ORDER;
+            this._tray_icon_shell_implementation = GDM_TRAY_ICON_SHELL_IMPLEMENTATION;
+        } else {
+            this._tray_icon_order = STANDARD_TRAY_ICON_ORDER;
+            this._tray_icon_shell_implementation = STANDARD_TRAY_ICON_SHELL_IMPLEMENTATION;
+        }
+
         this._menus = new PopupMenu.PopupMenuManager(this);
 
         this._leftBox = new St.BoxLayout({ name: 'panelLeft' });
@@ -1026,9 +1042,9 @@ Panel.prototype = {
     },
 
     startStatusArea: function() {
-        for (let i = 0; i < STANDARD_TRAY_ICON_ORDER.length; i++) {
-            let role = STANDARD_TRAY_ICON_ORDER[i];
-            let constructor = STANDARD_TRAY_ICON_SHELL_IMPLEMENTATION[role];
+        for (let i = 0; i < this._tray_icon_order.length; i++) {
+            let role = this._tray_icon_order[i];
+            let constructor = this._tray_icon_shell_implementation[role];
             if (!constructor) {
                 // This icon is not implemented (this is a bug)
                 continue;
@@ -1069,13 +1085,13 @@ Panel.prototype = {
     _onTrayIconAdded: function(o, icon, role) {
         icon.height = PANEL_ICON_SIZE;
 
-        if (STANDARD_TRAY_ICON_SHELL_IMPLEMENTATION[role]) {
+        if (this._tray_icon_shell_implementation[role]) {
             // This icon is legacy, and replaced by a Shell version
             // Hide it
             return;
         }
         // Figure out the index in our well-known order for this icon
-        let position = STANDARD_TRAY_ICON_ORDER.indexOf(role);
+        let position = this._tray_icon_order.indexOf(role);
         icon._rolePosition = position;
         let children = this._trayBox.get_children();
         let i;