[gnome-control-center/sound-better-mute-icons] sound: Set audio icon based on volume

[Felipe Borges <felipeborges src gnome org>]

commit 4180e75aad7edc95d2e9162e2d4acf8670ebb94d
Author: Felipe Borges <felipeborges gnome org>
Date:   Wed Dec 18 11:32:00 2019 +0100

    sound: Set audio icon based on volume
    
    The same way that GNOME Shell does it, we set:
     * audio-volume-muted-symbolic when mute button is toggled*
     * audio-volume-low-symbolic when 0 < volume < 30%
     * audio-volume-medium-symbolic when 30% < volume < 70%
     * audio-volume-high-symbolic when 70% < volume <= 100%
    
    When "muted" we can't actually rely on volume (it can be close
    to zero but not absolute zero). Instead of requiring volume == 0,
    we track the state based on whether the mute button is active.
    
    Fixes #521

 panels/sound/cc-volume-slider.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
---
diff --git a/panels/sound/cc-volume-slider.c b/panels/sound/cc-volume-slider.c
index 98541e98a..49b5b8290 100644
--- a/panels/sound/cc-volume-slider.c
+++ b/panels/sound/cc-volume-slider.c
@@ -42,6 +42,27 @@ struct _CcVolumeSlider
 
 G_DEFINE_TYPE (CcVolumeSlider, cc_volume_slider, GTK_TYPE_BOX)
 
+static void
+update_volume_icon (CcVolumeSlider *self)
+{
+  const gchar *icon_name = NULL;
+  gdouble volume, fraction;
+
+  volume = gtk_adjustment_get_value (self->volume_adjustment);
+  fraction = (100.0 * volume) / gtk_adjustment_get_upper (self->volume_adjustment);
+
+  if (gtk_toggle_button_get_active (self->mute_button))
+    icon_name = "audio-volume-muted-symbolic";
+  else if (fraction > 0.0 && fraction < 30.0)
+    icon_name = "audio-volume-low-symbolic";
+  else if (fraction > 30.0 && fraction < 70.0)
+    icon_name = "audio-volume-medium-symbolic";
+  else
+    icon_name = "audio-volume-high-symbolic";
+
+  gtk_image_set_from_icon_name (self->stream_type_icon, icon_name, GTK_ICON_SIZE_BUTTON);
+}
+
 static void
 volume_changed_cb (CcVolumeSlider *self)
 {
@@ -57,6 +78,8 @@ volume_changed_cb (CcVolumeSlider *self)
 
   if (gvc_mixer_stream_set_volume (self->stream, (pa_volume_t) rounded))
       gvc_mixer_stream_push_volume (self->stream);
+
+  update_volume_icon (self);
 }
 
 static void
@@ -108,6 +131,8 @@ mute_button_toggled_cb (CcVolumeSlider *self)
     return;
 
   gvc_mixer_stream_change_is_muted (self->stream, gtk_toggle_button_get_active (self->mute_button));
+
+  update_volume_icon (self);
 }
 
 static void
@@ -217,6 +242,7 @@ cc_volume_slider_set_stream (CcVolumeSlider *self,
                                                                   self, G_CONNECT_SWAPPED);
       notify_volume_cb (self);
       notify_is_muted_cb (self);
+      update_volume_icon (self);
     }
 }