[gnome-shell/wip/fmuellner/es6-class-preparations: 18/18] messageTray: Chain up in NotificationPolicy constructor

[Florian Müllner <fmuellner src gnome org>]

commit a6763e7731950b5dec359218476cbb086831511e
Author: Florian Müllner <fmuellner gnome org>
Date:   Tue Dec 11 11:17:30 2018 +0100

    messageTray: Chain up in NotificationPolicy constructor
    
    We currently deliberately avoid chaining up in derived policy
    constructors to not override properties with their defaults.
    That's a neat trick that will stop working when porting to ES6
    classes, as chaining up is necessary to actually initialize the
    object there (including "this").
    
    Address this by turning all properties into (overridable) getters
    that are backed by private properties by default.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/350

 js/ui/messageTray.js | 53 ++++++++++++++++++++++++++++++----------------------
 1 file changed, 31 insertions(+), 22 deletions(-)
---
diff --git a/js/ui/messageTray.js b/js/ui/messageTray.js
index 7ce977f47..3c98b4f95 100644
--- a/js/ui/messageTray.js
+++ b/js/ui/messageTray.js
@@ -146,13 +146,40 @@ var NotificationPolicy = new Lang.Class({
                                         showInLockScreen: true,
                                         detailsInLockScreen: false
                                       });
-        Lang.copyProperties(params, this);
+        Object.getOwnPropertyNames(params).forEach(key => {
+            let desc = Object.getOwnPropertyDescriptor(params, key);
+            Object.defineProperty(this, `_${key}`, desc);
+        });
     },
 
     // Do nothing for the default policy. These methods are only useful for the
     // GSettings policy.
     store() { },
-    destroy() { }
+    destroy() { },
+
+    get enable() {
+        return this._enable;
+    },
+
+    get enableSound() {
+        return this._enableSound;
+    },
+
+    get showBanners() {
+        return this._showBanners;
+    },
+
+    get forceExpanded() {
+        return this._forceExpanded;
+    },
+
+    get showInLockScreen() {
+        return this._showInLockScreen;
+    },
+
+    get detailsInLockScreen() {
+        return this._detailsInLockScreen;
+    }
 });
 Signals.addSignalMethods(NotificationPolicy.prototype);
 
@@ -161,8 +188,7 @@ var NotificationGenericPolicy = new Lang.Class({
     Extends: NotificationPolicy,
 
     _init() {
-        // Don't chain to parent, it would try setting
-        // our properties to the defaults
+        this.parent();
 
         this.id = 'generic';
 
@@ -180,28 +206,12 @@ var NotificationGenericPolicy = new Lang.Class({
         this.emit('policy-changed', key);
     },
 
-    get enable() {
-        return true;
-    },
-
-    get enableSound() {
-        return true;
-    },
-
     get showBanners() {
         return this._masterSettings.get_boolean('show-banners');
     },
 
-    get forceExpanded() {
-        return false;
-    },
-
     get showInLockScreen() {
         return this._masterSettings.get_boolean('show-in-lock-screen');
-    },
-
-    get detailsInLockScreen() {
-        return false;
     }
 });
 
@@ -210,8 +220,7 @@ var NotificationApplicationPolicy = new Lang.Class({
     Extends: NotificationPolicy,
 
     _init(id) {
-        // Don't chain to parent, it would try setting
-        // our properties to the defaults
+        this.parent();
 
         this.id = id;
         this._canonicalId = this._canonicalizeId(id);