[gnome-shell] environment: Add convenience method for adjustment transitions

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 8ac2086ed1b2284666f59c2c26f15fd620ce1ac5
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Jul 25 16:21:46 2019 +0200

    environment: Add convenience method for adjustment transitions
    
    By now, Tweener is used exclusively to animate changes to the
    StAdjustment:value property. But not for long, as now that we
    implement the same transition API as Clutter.Actor, we can
    re-use the existing convenience method for property transitions
    for adjustment changes as well.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/669

 js/ui/environment.js | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/js/ui/environment.js b/js/ui/environment.js
index f2944a5c1..60d73d9cc 100644
--- a/js/ui/environment.js
+++ b/js/ui/environment.js
@@ -220,6 +220,11 @@ function init() {
     Clutter.Actor.prototype.ease_property = function(propName, target, params) {
         _easeActorProperty(this, propName, target, params);
     };
+    St.Adjustment.prototype.ease = function(target, params) {
+        // we're not an actor of course, but we implement the same
+        // transition API as Clutter.Actor, so this works anyway
+        _easeActorProperty(this, 'value', target, params);
+    };
 
     Clutter.Actor.prototype.toString = function() {
         return St.describe_actor(this);