Tweak sidebar ui

origin commit:
https://gitlab.gnome.org/GNOME/eog/commit/fff55c6

Author: trinhanhngoc

data/metadata-sidebar.ui

@@ -18,6 +18,9 @@
             <property name="orientation">vertical</property>
             <property name="row_spacing">3</property>
             <property name="column_spacing">6</property>
+            <property name="margin-start">6</property>
+            <property name="margin-end">6</property>
+            <property name="margin-bottom">6</property>
             <child>
               <object class="GtkLabel" id="label1">
                 <property name="visible">True</property>

src/eom-metadata-sidebar.c

@@ -534,7 +534,6 @@ eom_metadata_sidebar_new (EomWindow *window)
 			       "vadjustment", NULL,
 			       "hscrollbar-policy", GTK_POLICY_NEVER,
 			       "vscrollbar-policy", GTK_POLICY_AUTOMATIC,
-			       "border-width", 6,
 			       "parent-window", window,
 			       NULL);
 }

src/eom-sidebar.c

@@ -358,6 +358,10 @@ eom_sidebar_init (EomSidebar *eom_sidebar)
 
 	eom_sidebar->priv = eom_sidebar_get_instance_private (eom_sidebar);
 
+	gtk_style_context_add_class (
+	        gtk_widget_get_style_context (GTK_WIDGET (eom_sidebar)),
+	                                      GTK_STYLE_CLASS_SIDEBAR);
+
 	/* data model */
 	eom_sidebar->priv->page_model = (GtkTreeModel *)
 			gtk_list_store_new (PAGE_COLUMN_NUM_COLS,
@@ -368,6 +372,7 @@ eom_sidebar_init (EomSidebar *eom_sidebar)
 
 	/* top option menu */
 	hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
+	g_object_set (hbox, "border-width", 6, NULL);
 	eom_sidebar->priv->hbox = hbox;
 	gtk_box_pack_start (GTK_BOX (eom_sidebar), hbox, FALSE, FALSE, 0);
 	gtk_widget_show (hbox);
@@ -438,8 +443,6 @@ eom_sidebar_init (EomSidebar *eom_sidebar)
 
 	gtk_notebook_set_show_border (GTK_NOTEBOOK (eom_sidebar->priv->notebook), FALSE);
 	gtk_notebook_set_show_tabs (GTK_NOTEBOOK (eom_sidebar->priv->notebook), FALSE);
-	gtk_widget_set_margin_start (eom_sidebar->priv->notebook, 6);
-	gtk_widget_set_margin_end (eom_sidebar->priv->notebook, 6);
 
 	gtk_box_pack_start (GTK_BOX (eom_sidebar), eom_sidebar->priv->notebook,
 			    TRUE, TRUE, 0);