[gnome-shell/wip/fmuellner/volume-change-feedback: 14/17] volume: Add back sound feedback on scroll

[Florian Müllner <fmuellner src gnome org>]

commit 036f38613fa0ee6987d4d025e1d7bc4d5649fea8
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Feb 23 23:58:22 2018 +0100

    volume: Add back sound feedback on scroll
    
    Commit 8d4855f1008 accidentally removed the volume change feedback
    for scroll events. Add it back to be consistent again with moving
    the slider via arrow keys, slider drags/clicks and gsd's media keys
    handling.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/issues/53

 js/ui/status/volume.js | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)
---
diff --git a/js/ui/status/volume.js b/js/ui/status/volume.js
index 0f46118983..9a2dad8944 100644
--- a/js/ui/status/volume.js
+++ b/js/ui/status/volume.js
@@ -1,7 +1,7 @@
 // -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
 /* exported Indicator */
 
-const { Clutter, Gio, GObject, Gvc, St } = imports.gi;
+const { Clutter, Gio, GLib, GObject, Gvc, St } = imports.gi;
 const Signals = imports.signals;
 
 const Main = imports.ui.main;
@@ -30,6 +30,9 @@ var StreamSlider = class {
 
         this.item = new PopupMenu.PopupBaseMenuItem({ activate: false });
 
+        this._inDrag = false;
+        this._notifyVolumeChangeId = 0;
+
         this._slider = new Slider.Slider(0);
 
         this._soundSettings = new Gio.Settings({ schema_id: 'org.gnome.desktop.sound' });
@@ -38,7 +41,11 @@ var StreamSlider = class {
 
         this._sliderChangedId = this._slider.connect('notify::value',
                                                      this._sliderChanged.bind(this));
-        this._slider.connect('drag-end', this._notifyVolumeChange.bind(this));
+        this._slider.connect('drag-begin', () => (this._inDrag = true));
+        this._slider.connect('drag-end', () => {
+            this._inDrag = false;
+            this._notifyVolumeChange();
+        });
 
         this._icon = new St.Icon({ style_class: 'popup-menu-icon' });
         this.item.add(this._icon);
@@ -116,6 +123,14 @@ var StreamSlider = class {
                 this._stream.change_is_muted(false);
         }
         this._stream.push_volume();
+
+        if (!this._notifyVolumeChangeId && !this._inDrag) {
+            this._notifyVolumeChangeId = GLib.timeout_add(GLib.PRIORITY_DEFAULT, 30, () => {
+                this._notifyVolumeChange();
+                this._notifyVolumeChangeId = 0;
+                return GLib.SOURCE_REMOVE;
+            });
+        }
     }
 
     _notifyVolumeChange() {