[gnome-shell] locatePointer: Bind ripples creation to settings

[Florian Müllner <fmuellner src gnome org>]

commit a53b48de4c773f4513584b5fb3bb96074ad0d7e0
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Sat Aug 31 01:57:12 2019 +0200

    locatePointer: Bind ripples creation to settings
    
    Don't create ripples if locate pointer is not enabled, and bind
    creation to the relative desktop interface settings key.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/700

 js/ui/locatePointer.js | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)
---
diff --git a/js/ui/locatePointer.js b/js/ui/locatePointer.js
index 10caa656d0..6ae29419a3 100644
--- a/js/ui/locatePointer.js
+++ b/js/ui/locatePointer.js
@@ -11,12 +11,26 @@ const LOCATE_POINTER_SCHEMA = "org.gnome.desktop.interface";
 var LocatePointer = class {
     constructor() {
         this._settings = new Gio.Settings({ schema_id: LOCATE_POINTER_SCHEMA });
-        this._ripples = new Ripples.Ripples(0.5, 0.5, 'ripple-pointer-location');
-        this._ripples.addTo(Main.uiGroup);
+        this._settings.connect(`changed::${LOCATE_POINTER_KEY}`, () => this._syncEnabled());
+        this._syncEnabled();
+    }
+
+    _syncEnabled() {
+        let enabled = this._settings.get_boolean(LOCATE_POINTER_KEY);
+        if (enabled == !!this._ripples)
+            return;
+
+        if (enabled) {
+            this._ripples = new Ripples.Ripples(0.5, 0.5, 'ripple-pointer-location');
+            this._ripples.addTo(Main.uiGroup);
+        } else {
+            this._ripples.destroy();
+            this._ripples = null;
+        }
     }
 
     show() {
-        if (!this._settings.get_boolean(LOCATE_POINTER_KEY))
+        if (!this._ripples)
             return;
 
         let [x, y] = global.get_pointer();