[gnome-control-center] background: Replace GtkStack child names with widget references

[Robert Ancell <rancell src gnome org>]

commit e9ca51789c3a54a6effc246fab42f41ff180b248
Author: Robert Ancell <robert ancell canonical com>
Date:   Wed Nov 20 14:48:59 2019 +1300

    background: Replace GtkStack child names with widget references
    
    The child names are easier to break if widgets are changed - this can't be
    detected by the compiler.

 panels/background/cc-background-preview.c  |  8 ++++++--
 panels/background/cc-background-preview.ui | 10 ++--------
 2 files changed, 8 insertions(+), 10 deletions(-)
---
diff --git a/panels/background/cc-background-preview.c b/panels/background/cc-background-preview.c
index 17b47d6e4..9fef9be40 100644
--- a/panels/background/cc-background-preview.c
+++ b/panels/background/cc-background-preview.c
@@ -28,7 +28,9 @@ struct _CcBackgroundPreview
 
   GtkImage         *animated_background_icon;
   GtkLabel         *desktop_clock_label;
+  GtkFrame         *desktop_frame;
   GtkDrawingArea   *drawing_area;
+  GtkFrame         *lock_frame;
   GtkLabel         *lock_screen_label;
   GtkStack         *stack;
 
@@ -231,8 +233,8 @@ cc_background_preview_set_property (GObject      *object,
     {
     case PROP_IS_LOCK_SCREEN:
       self->is_lock_screen = g_value_get_boolean (value);
-      gtk_stack_set_visible_child_name (self->stack,
-                                        self->is_lock_screen ? "lock" : "desktop");
+      gtk_stack_set_visible_child (self->stack,
+                                   self->is_lock_screen ? GTK_WIDGET (self->lock_frame) : GTK_WIDGET 
(self->desktop_frame));
       break;
 
     case PROP_ITEM:
@@ -325,7 +327,9 @@ cc_background_preview_class_init (CcBackgroundPreviewClass *klass)
 
   gtk_widget_class_bind_template_child (widget_class, CcBackgroundPreview, animated_background_icon);
   gtk_widget_class_bind_template_child (widget_class, CcBackgroundPreview, desktop_clock_label);
+  gtk_widget_class_bind_template_child (widget_class, CcBackgroundPreview, desktop_frame);
   gtk_widget_class_bind_template_child (widget_class, CcBackgroundPreview, drawing_area);
+  gtk_widget_class_bind_template_child (widget_class, CcBackgroundPreview, lock_frame);
   gtk_widget_class_bind_template_child (widget_class, CcBackgroundPreview, lock_screen_label);
   gtk_widget_class_bind_template_child (widget_class, CcBackgroundPreview, stack);
 
diff --git a/panels/background/cc-background-preview.ui b/panels/background/cc-background-preview.ui
index 0906847e1..30f7902ca 100644
--- a/panels/background/cc-background-preview.ui
+++ b/panels/background/cc-background-preview.ui
@@ -34,7 +34,7 @@
             <property name="expand">True</property>
 
             <child>
-              <object class="GtkFrame">
+              <object class="GtkFrame" id="desktop_frame">
                 <property name="visible">True</property>
                 <property name="can-focus">False</property>
                 <property name="shadow-type">none</property>
@@ -104,14 +104,11 @@
                 </child>
 
               </object>
-              <packing>
-                <property name="name">desktop</property>
-              </packing>
             </child>
 
 
             <child>
-              <object class="GtkFrame">
+              <object class="GtkFrame" id="lock_frame">
                 <property name="visible">True</property>
                 <property name="can-focus">False</property>
                 <property name="shadow-type">none</property>
@@ -128,9 +125,6 @@
                   <class name="lock-screen-preview" />
                 </style>
               </object>
-              <packing>
-                <property name="name">lock</property>
-              </packing>
             </child>
           </object>
         </child>