[gnome-control-center] sound: Fix volume sliders regression

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

commit 9d612ff1c7e2d58211e25e8584bc86c5d2598eac
Author: Robert Ancell <robert ancell canonical com>
Date:   Tue Aug 13 11:11:05 2019 +1200

    sound: Fix volume sliders regression
    
    GVC added additional checks that break where we were using a NULL value instead
    of a GvcMixerControl. Solution is to pass this object where appropriate.
    
    (gnome-control-center:833): Gvc-CRITICAL **: 11:09:33.818: gvc_mixer_control_get_vol_max_norm: assertion 
'GVC_IS_MIXER_CONTROL (control)' failed
    
    Fixes #636

 panels/sound/cc-sound-panel.c      |  3 ++
 panels/sound/cc-subwoofer-slider.c | 13 +++++++--
 panels/sound/cc-subwoofer-slider.h |  8 +++--
 panels/sound/cc-volume-slider.c    | 60 ++++++++++++++++++++++++++------------
 panels/sound/cc-volume-slider.h    | 14 +++++----
 5 files changed, 70 insertions(+), 28 deletions(-)
---
diff --git a/panels/sound/cc-sound-panel.c b/panels/sound/cc-sound-panel.c
index 672b2b1ab..b73e173c9 100644
--- a/panels/sound/cc-sound-panel.c
+++ b/panels/sound/cc-sound-panel.c
@@ -260,6 +260,9 @@ cc_sound_panel_init (CcSoundPanel *self)
   gvc_mixer_control_open (self->mixer_control);
 
   cc_stream_list_box_set_mixer_control (self->stream_list_box, self->mixer_control);
+  cc_volume_slider_set_mixer_control (self->input_volume_slider, self->mixer_control);
+  cc_volume_slider_set_mixer_control (self->output_volume_slider, self->mixer_control);
+  cc_subwoofer_slider_set_mixer_control (self->subwoofer_slider, self->mixer_control);
   cc_device_combo_box_set_mixer_control (self->input_device_combo_box, self->mixer_control, FALSE);
   cc_device_combo_box_set_mixer_control (self->output_device_combo_box, self->mixer_control, TRUE);
 }
diff --git a/panels/sound/cc-subwoofer-slider.c b/panels/sound/cc-subwoofer-slider.c
index 15884b994..ac084cd5f 100644
--- a/panels/sound/cc-subwoofer-slider.c
+++ b/panels/sound/cc-subwoofer-slider.c
@@ -91,13 +91,20 @@ cc_subwoofer_slider_class_init (CcSubwooferSliderClass *klass)
 void
 cc_subwoofer_slider_init (CcSubwooferSlider *self)
 {
-  gdouble vol_max_norm;
-
   g_resources_register (cc_sound_get_resource ());
 
   gtk_widget_init_template (GTK_WIDGET (self));
+}
+
+void
+cc_subwoofer_slider_set_mixer_control (CcSubwooferSlider *self,
+                                       GvcMixerControl   *mixer_control)
+{
+  gdouble vol_max_norm;
+
+  g_return_if_fail (CC_IS_SUBWOOFER_SLIDER (self));
 
-  vol_max_norm = gvc_mixer_control_get_vol_max_norm (NULL);
+  vol_max_norm = gvc_mixer_control_get_vol_max_norm (mixer_control);
   gtk_adjustment_set_upper (self->adjustment, vol_max_norm);
   gtk_adjustment_set_page_increment (self->adjustment, vol_max_norm / 100.0);
 }
diff --git a/panels/sound/cc-subwoofer-slider.h b/panels/sound/cc-subwoofer-slider.h
index 40e551043..8b462dcfb 100644
--- a/panels/sound/cc-subwoofer-slider.h
+++ b/panels/sound/cc-subwoofer-slider.h
@@ -21,13 +21,17 @@
 #include <gtk/gtk.h>
 #include <pulse/pulseaudio.h>
 #include <gvc-channel-map.h>
+#include <gvc-mixer-control.h>
 
 G_BEGIN_DECLS
 
 #define CC_TYPE_SUBWOOFER_SLIDER (cc_subwoofer_slider_get_type ())
 G_DECLARE_FINAL_TYPE (CcSubwooferSlider, cc_subwoofer_slider, CC, SUBWOOFER_SLIDER, GtkBox)
 
-void cc_subwoofer_slider_set_channel_map (CcSubwooferSlider *slider,
-                                          GvcChannelMap     *channel_map);
+void cc_subwoofer_slider_set_mixer_control (CcSubwooferSlider *slider,
+                                            GvcMixerControl   *mixer_control);
+
+void cc_subwoofer_slider_set_channel_map   (CcSubwooferSlider *slider,
+                                            GvcChannelMap     *channel_map);
 
 G_END_DECLS
diff --git a/panels/sound/cc-volume-slider.c b/panels/sound/cc-volume-slider.c
index ca2f70b90..7e061e540 100644
--- a/panels/sound/cc-volume-slider.c
+++ b/panels/sound/cc-volume-slider.c
@@ -34,6 +34,8 @@ struct _CcVolumeSlider
   GtkAdjustment   *volume_adjustment;
   GtkScale        *volume_scale;
 
+  gboolean         is_amplified;
+  GvcMixerControl *mixer_control;
   GvcMixerStream  *stream;
   guint            notify_volume_handler_id;
   guint            notify_is_muted_handler_id;
@@ -41,6 +43,32 @@ struct _CcVolumeSlider
 
 G_DEFINE_TYPE (CcVolumeSlider, cc_volume_slider, GTK_TYPE_BOX)
 
+static void
+update_ranges (CcVolumeSlider *self)
+{
+  gdouble vol_max_norm;
+
+  if (self->mixer_control == NULL)
+    return;
+
+  vol_max_norm = gvc_mixer_control_get_vol_max_norm (self->mixer_control);
+
+  gtk_scale_clear_marks (self->volume_scale);
+  if (self->is_amplified)
+    {
+      gtk_adjustment_set_upper (self->volume_adjustment, gvc_mixer_control_get_vol_max_amplified 
(self->mixer_control));
+      gtk_scale_add_mark (self->volume_scale,
+                          vol_max_norm,
+                          GTK_POS_BOTTOM,
+                          C_("volume", "100%"));
+    }
+  else
+    {
+      gtk_adjustment_set_upper (self->volume_adjustment, vol_max_norm);
+    }
+  gtk_adjustment_set_page_increment (self->volume_adjustment, vol_max_norm / 100.0);
+}
+
 static void
 volume_changed_cb (CcVolumeSlider *self)
 {
@@ -94,6 +122,7 @@ cc_volume_slider_dispose (GObject *object)
 {
   CcVolumeSlider *self = CC_VOLUME_SLIDER (object);
 
+  g_clear_object (&self->mixer_control);
   g_clear_object (&self->stream);
 
   G_OBJECT_CLASS (cc_volume_slider_parent_class)->dispose (object);
@@ -121,15 +150,20 @@ cc_volume_slider_class_init (CcVolumeSliderClass *klass)
 void
 cc_volume_slider_init (CcVolumeSlider *self)
 {
-  gdouble vol_max_norm;
-
   g_resources_register (cc_sound_get_resource ());
 
   gtk_widget_init_template (GTK_WIDGET (self));
+}
 
-  vol_max_norm = gvc_mixer_control_get_vol_max_norm (NULL);
-  gtk_adjustment_set_upper (self->volume_adjustment, vol_max_norm);
-  gtk_adjustment_set_page_increment (self->volume_adjustment, vol_max_norm / 100.0);
+void
+cc_volume_slider_set_mixer_control (CcVolumeSlider  *self,
+                                    GvcMixerControl *mixer_control)
+{
+  g_return_if_fail (CC_IS_VOLUME_SLIDER (self));
+
+  g_set_object (&self->mixer_control, mixer_control);
+
+  update_ranges (self);
 }
 
 void
@@ -190,17 +224,7 @@ cc_volume_slider_set_is_amplified (CcVolumeSlider *self,
 {
   g_return_if_fail (CC_IS_VOLUME_SLIDER (self));
 
-  gtk_scale_clear_marks (self->volume_scale);
-  if (is_amplified)
-    {
-      gtk_adjustment_set_upper (self->volume_adjustment, gvc_mixer_control_get_vol_max_amplified (NULL));
-      gtk_scale_add_mark (self->volume_scale,
-                          gvc_mixer_control_get_vol_max_norm (NULL),
-                          GTK_POS_BOTTOM,
-                          C_("volume", "100%"));
-    }
-  else
-    {
-      gtk_adjustment_set_upper (self->volume_adjustment, gvc_mixer_control_get_vol_max_norm (NULL));
-    }
+  self->is_amplified = is_amplified;
+
+  update_ranges (self);
 }
diff --git a/panels/sound/cc-volume-slider.h b/panels/sound/cc-volume-slider.h
index 68b5dc1d2..d0c627023 100644
--- a/panels/sound/cc-volume-slider.h
+++ b/panels/sound/cc-volume-slider.h
@@ -20,6 +20,7 @@
 
 #include <gtk/gtk.h>
 #include <pulse/pulseaudio.h>
+#include <gvc-mixer-control.h>
 #include <gvc-mixer-stream.h>
 
 #include "cc-sound-enums.h"
@@ -29,11 +30,14 @@ G_BEGIN_DECLS
 #define CC_TYPE_VOLUME_SLIDER (cc_volume_slider_get_type ())
 G_DECLARE_FINAL_TYPE (CcVolumeSlider, cc_volume_slider, CC, VOLUME_SLIDER, GtkBox)
 
-void cc_volume_slider_set_stream       (CcVolumeSlider *slider,
-                                        GvcMixerStream *stream,
-                                        CcStreamType    type);
+void cc_volume_slider_set_mixer_control (CcVolumeSlider  *slider,
+                                         GvcMixerControl *mixer_control);
 
-void cc_volume_slider_set_is_amplified (CcVolumeSlider *slider,
-                                        gboolean        is_amplified);
+void cc_volume_slider_set_stream        (CcVolumeSlider  *slider,
+                                         GvcMixerStream  *stream,
+                                         CcStreamType     type);
+
+void cc_volume_slider_set_is_amplified  (CcVolumeSlider  *slider,
+                                         gboolean         is_amplified);
 
 G_END_DECLS