[gnome-shell] volume: Add smooth scrolling to adjust output volume

[Jasper St. Pierre <jstpierre src gnome org>]

commit 8d4855f1008b9d0d9e579c0ac81fd2ce076c3faa
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Sun Nov 4 10:53:23 2012 -0500

    volume: Add smooth scrolling to adjust output volume
    
    Allow users to smoothly scroll on the volume indicator icon
    to adjust the volume. Do this by simply passing the scroll
    event to the slider inside the menu.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=687573

 js/ui/popupMenu.js     |    7 ++++++-
 js/ui/status/volume.js |   24 +++---------------------
 2 files changed, 9 insertions(+), 22 deletions(-)
---
diff --git a/js/ui/popupMenu.js b/js/ui/popupMenu.js
index fd4b928..6bcc994 100644
--- a/js/ui/popupMenu.js
+++ b/js/ui/popupMenu.js
@@ -636,7 +636,7 @@ const PopupSliderMenuItem = new Lang.Class({
         return true;
     },
 
-    _onScrollEvent: function (actor, event) {
+    scroll: function(event) {
         let direction = event.get_scroll_direction();
         let delta;
 
@@ -655,10 +655,15 @@ const PopupSliderMenuItem = new Lang.Class({
         }
 
         this._value = Math.min(Math.max(0, this._value + delta), 1);
+
         this._slider.queue_repaint();
         this.emit('value-changed', this._value);
     },
 
+    _onScrollEvent: function(actor, event) {
+        this.scroll(event);
+    },
+
     _motionEvent: function(actor, event) {
         let absX, absY;
         [absX, absY] = event.get_coords();
diff --git a/js/ui/status/volume.js b/js/ui/status/volume.js
index 99b003b..faccf84 100644
--- a/js/ui/status/volume.js
+++ b/js/ui/status/volume.js
@@ -69,26 +69,8 @@ const VolumeMenu = new Lang.Class({
         this._onControlStateChanged();
     },
 
-    scroll: function(direction) {
-        let currentVolume = this._output.volume;
-
-        if (direction == Clutter.ScrollDirection.DOWN) {
-            let prev_muted = this._output.is_muted;
-            this._output.volume = Math.max(0, currentVolume - this._volumeMax * VOLUME_ADJUSTMENT_STEP);
-            if (this._output.volume < 1) {
-                this._output.volume = 0;
-                if (!prev_muted)
-                    this._output.change_is_muted(true);
-            }
-            this._output.push_volume();
-        }
-        else if (direction == Clutter.ScrollDirection.UP) {
-            this._output.volume = Math.min(this._volumeMax, currentVolume + this._volumeMax * VOLUME_ADJUSTMENT_STEP);
-            this._output.change_is_muted(false);
-            this._output.push_volume();
-        }
-
-        this._notifyVolumeChange();
+    scroll: function(event) {
+        this._outputSlider.scroll(event);
     },
 
     _onControlStateChanged: function() {
@@ -279,6 +261,6 @@ const Indicator = new Lang.Class({
     },
 
     _onScrollEvent: function(actor, event) {
-        this._volumeMenu.scroll(event.get_scroll_direction());
+        this._volumeMenu.scroll(event);
     }
 });