[gnome-shell] system: Track buttonGroup visibility using a group of actors

[Florian Müllner <fmuellner src gnome org>]

commit a497afe695a9966c66efb40d1da4f255df632dfa
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Sat Aug 31 23:09:04 2019 +0200

    system: Track buttonGroup visibility using a group of actors
    
    Cleanup the visibility check on actions by using an array of actors to
    track, so that we don't repeat the same variables multiple times.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/700

 js/ui/status/system.js | 30 ++++++++++++------------------
 1 file changed, 12 insertions(+), 18 deletions(-)
---
diff --git a/js/ui/status/system.js b/js/ui/status/system.js
index 2b2d991842..f18a8e270e 100644
--- a/js/ui/status/system.js
+++ b/js/ui/status/system.js
@@ -137,15 +137,6 @@ var Indicator = class extends PanelMenu.SystemIndicator {
         this._sessionUpdated();
     }
 
-    _updateActionsVisibility() {
-        let visible = (this._settingsAction.visible ||
-                       this._orientationLockAction.visible ||
-                       this._lockScreenAction.visible ||
-                       this._altSwitcher.actor.visible);
-
-        this.buttonGroup.visible = visible;
-    }
-
     _sessionUpdated() {
         this._settingsAction.visible = Main.sessionMode.allowSettings;
     }
@@ -302,15 +293,18 @@ var Indicator = class extends PanelMenu.SystemIndicator {
 
         this.menu.addMenuItem(item);
 
-
-        this._settingsAction.connect('notify::visible',
-                                     () => this._updateActionsVisibility());
-        this._orientationLockAction.connect('notify::visible',
-                                            () => this._updateActionsVisibility());
-        this._lockScreenAction.connect('notify::visible',
-                                       () => this._updateActionsVisibility());
-        this._altSwitcher.actor.connect('notify::visible',
-                                        () => this._updateActionsVisibility());
+        let visibilityGroup = [
+            this._settingsAction,
+            this._orientationLockAction,
+            this._lockScreenAction,
+            this._altSwitcher.actor,
+        ];
+
+        for (let actor of visibilityGroup) {
+            actor.connect('notify::visible', () => {
+                this.buttonGroup.visible = visibilityGroup.some(a => a.visible);
+            });
+        }
     }
 
     _onSettingsClicked() {