[gnome-shell/gnome-3-36] unlockDialog: Set Switch User Button via _updateUserSwitchVisibility

[Florian Müllner <fmuellner src gnome org>]

commit 9ccd3437643cf2e512cd9e6021da793edbceeb80
Author: Chingkai <chuchingkai gmail com>
Date:   Sat Apr 25 08:29:16 2020 +0000

    unlockDialog: Set Switch User Button via _updateUserSwitchVisibility
    
    This commit will set the button invisible when the user's can_switch
    is false (e.g. when the session is remote) or user-switch-enabled is
    disabled.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/2687
    
    
    (cherry picked from commit d2cf13eff4f91e60fbceb7e28573d80eb5b908bb)

 js/ui/unlockDialog.js | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)
---
diff --git a/js/ui/unlockDialog.js b/js/ui/unlockDialog.js
index 29122ca515..ce71742f42 100644
--- a/js/ui/unlockDialog.js
+++ b/js/ui/unlockDialog.js
@@ -566,9 +566,17 @@ var UnlockDialog = GObject.registerClass({
         this._otherUserButton.set_pivot_point(0.5, 0.5);
         this._otherUserButton.connect('clicked', this._otherUserClicked.bind(this));
 
-        let screenSaverSettings = new Gio.Settings({ schema_id: 'org.gnome.desktop.screensaver' });
-        screenSaverSettings.bind('user-switch-enabled',
-            this._otherUserButton, 'visible', Gio.SettingsBindFlags.GET);
+        this._screenSaverSettings = new Gio.Settings({ schema_id: 'org.gnome.desktop.screensaver' });
+
+        this._userSwitchEnabledId = 0;
+        this._userSwitchEnabledId = this._screenSaverSettings.connect('changed::user-switch-enabled',
+            this._updateUserSwitchVisibility.bind(this));
+
+        this._userLoadedId = 0;
+        this._userLoadedId = this._user.connect('notify::is-loaded',
+            this._updateUserSwitchVisibility.bind(this));
+
+        this._updateUserSwitchVisibility();
 
         // Main Box
         let mainBox = new St.Widget();
@@ -828,6 +836,21 @@ var UnlockDialog = GObject.registerClass({
             this._gdmClient = null;
             delete this._gdmClient;
         }
+
+        if (this._userLoadedId) {
+            this._user.disconnect(this._userLoadedId);
+            this._userLoadedId = 0;
+        }
+
+        if (this._userSwitchEnabledId) {
+            this._screenSaverSettings.disconnect(this._userSwitchEnabledId);
+            this._userSwitchEnabledId = 0;
+        }
+    }
+
+    _updateUserSwitchVisibility() {
+        this._otherUserButton.visible = this._userManager.can_switch() &&
+            this._screenSaverSettings.get_boolean('user-switch-enabled');
     }
 
     cancel() {