loginDialog: allow timed login with disabled user list

At the moment the timed login feature is implemented in the user list.
If there's no user list, we don't show the indicator anywhere and
don't proceed with timed login.

This commit allows timed login to work when the user list is disabled.
It accomplishes this by putting the timed login indicator on the
auth prompt, in that scenario.

data/theme/gnome-shell-sass/_common.scss

@@ -1825,6 +1825,10 @@ StScrollBar {
       padding-bottom: 12px;
       spacing: 8px;
       width: 23em;
+      .login-dialog-timed-login-indicator {
+          height: 2px;
+          background-color: darken($fg_color,40%);
+      }
   }
 
   .login-dialog-prompt-label {

js/gdm/authPrompt.js

@@ -2,6 +2,7 @@
 
 const Clutter = imports.gi.Clutter;
 const Gio = imports.gi.Gio;
+const GLib = imports.gi.GLib;
 const Lang = imports.lang;
 const Pango = imports.gi.Pango;
 const Signals = imports.signals;
@@ -117,6 +118,11 @@ var AuthPrompt = new Lang.Class({
 
         this._entry.grab_key_focus();
 
+        this._timedLoginIndicator = new St.Bin({ style_class: 'login-dialog-timed-login-indicator',
+                                                 scale_x: 0 });
+
+        this.actor.add(this._timedLoginIndicator);
+
         this._message = new St.Label({ opacity: 0,
                                        styleClass: 'login-dialog-message' });
         this._message.clutter_text.line_wrap = true;
@@ -142,6 +148,40 @@ var AuthPrompt = new Lang.Class({
         this._defaultButtonWell.add_child(this._spinner.actor);
     },
 
+    showTimedLoginIndicator(time) {
+        let hold = new Batch.Hold();
+
+        this.hideTimedLoginIndicator();
+
+        let startTime = GLib.get_monotonic_time();
+
+        this._timedLoginTimeoutId = GLib.timeout_add (GLib.PRIORITY_DEFAULT, 33,
+            () => {
+                let currentTime = GLib.get_monotonic_time();
+                let elapsedTime = (currentTime - startTime) / GLib.USEC_PER_SEC;
+                this._timedLoginIndicator.scale_x = elapsedTime / time;
+                if (elapsedTime >= time) {
+                    this._timedLoginTimeoutId = 0;
+                    hold.release();
+                    return GLib.SOURCE_REMOVE;
+                }
+
+                return GLib.SOURCE_CONTINUE;
+            });
+
+        GLib.Source.set_name_by_id(this._timedLoginTimeoutId, '[gnome-shell] this._timedLoginTimeoutId');
+
+        return hold;
+    },
+
+    hideTimedLoginIndicator() {
+        if (this._timedLoginTimeoutId) {
+            GLib.source_remove(this._timedLoginTimeoutId);
+            this._timedLoginTimeoutId = 0;
+        }
+        this._timedLoginIndicator.scale_x = 0.;
+    },
+
     _onDestroy() {
         if (this._preemptiveAnswerWatchId) {
             this._idleMonitor.remove_watch(this._preemptiveAnswerWatchId);

js/gdm/loginDialog.js

@@ -738,6 +738,9 @@ var LoginDialog = new Lang.Class({
 
             if (this._authPrompt.verificationStatus == AuthPrompt.AuthPromptStatus.NOT_VERIFYING)
                 this._authPrompt.reset();
+
+            if (this._disableUserList && this._timedLoginUserListHold)
+                this._timedLoginUserListHold.release();
         }
     },
 
@@ -1019,17 +1022,33 @@ var LoginDialog = new Lang.Class({
     },
 
     _startTimedLogin(userName, delay) {
+        this._timedLoginUserName = userName;
         this._timedLoginItem = null;
         this._timedLoginDelay = delay;
         this._timedLoginAnimationTime = delay;
 
-        let tasks = [() => this._waitForItemForUser(userName),
+        let tasks = [() => {
+                         if (this._disableUserList)
+                             return;
+
+                         this._timedLoginUserListHold = this._waitForItemForUser(userName);
+
+                         return this._timedLoginUserListHold;
+                     },
 
                      () => {
+                         this._timedLoginUserListHold = null;
+
+                         if (this._disableUserList)
+                             return;
+
                          this._timedLoginItem = this._userList.getItemFromUserName(userName);
                      },
 
                      () => {
+                         if (this._disableUserList)
+                             return;
+
                          // If we're just starting out, start on the right
                          // item.
                          if (!this._userManager.is_loaded) {
@@ -1040,6 +1059,9 @@ var LoginDialog = new Lang.Class({
                      this._blockTimedLoginUntilIdle,
 
                      () => {
+                         if (this._disableUserList)
+                             return;
+
                          this._userList.scrollToItem(this._timedLoginItem);
                      },
 
@@ -1064,7 +1086,9 @@ var LoginDialog = new Lang.Class({
         if (this._timedLoginItem)
             this._timedLoginItem.hideTimedLoginIndicator();
 
-        let userName = this._timedLoginItem.user.get_user_name();
+        this._authPrompt.hideTimedLoginIndicator();
+
+        let userName = this._timedLoginUserName;
 
         if (userName)
             this._startTimedLogin(userName, this._timedLoginDelay);