ocarina: Hide queue when empty

This was something that I did in 4.x, and I like the feature.  Who wants
to see an empty notebook page?

include/ocarina/body.h

@@ -2,8 +2,11 @@
 #define OCARINA_BODY_H
 
 #include <ocarina/gtk.h>
+#include <ocarina/page.h>
 
 GtkWidget *get_tabs();
-void add_page(GtkWidget *, GtkWidget *, bool);
+unsigned int add_page(GtkWidget *, GtkWidget *, bool);
+void hide_page(unsigned int);
+void show_page(unsigned int);
 
 #endif /* OCARINA_BODY_H */

include/ocarina/page.h

@@ -18,6 +18,9 @@ class Page
 		void add_footer(GtkWidget *);
 		void remove_header(GtkWidget *);
 		void remove_footer(GtkWidget *);
+
+		void hide();
+		void show();
 };
 
 #endif /* OCARINA_PAGE_H */

ocarina/body/page.cpp

@@ -49,3 +49,13 @@ GtkWidget *Page::get_page()
 {
 	return table;
 }
+
+void Page::hide()
+{
+	gtk_widget_hide(table);
+}
+
+void Page::show()
+{
+	gtk_widget_show(table);
+}

ocarina/body/tabs.cpp

@@ -52,8 +52,9 @@ GtkWidget *get_tabs()
 	return tabs;
 }
 
-void add_page(GtkWidget *label, GtkWidget *content, bool fill)
+unsigned int add_page(GtkWidget *label, GtkWidget *content, bool fill)
 {
+	unsigned int index = pages.size();
 	Page page(content);
 	pages.push_back(page);
 
@@ -65,4 +66,16 @@ void add_page(GtkWidget *label, GtkWidget *content, bool fill)
 						   TRUE,
 						   GTK_PACK_START);
 	}
+
+	return index;
 };
+
+void hide_page(unsigned int index)
+{
+	pages[index].hide();
+}
+
+void show_page(unsigned int index)
+{
+	pages[index].show();
+}

ocarina/queue.cpp

@@ -12,6 +12,7 @@ using namespace std;
 static SongList queue_list;
 static struct SongListFuncs queue_funcs;
 static list <MenuItem> queue_menu;
+unsigned int queue_index;;
 
 namespace ocarina
 {
@@ -19,7 +20,11 @@ namespace ocarina
 	void queue::refresh()
 	{
 		queue_list.clear();
-		queue_list.fill();
+		if (libsaria::queue::size() > 0) {
+			queue_list.fill();
+			show_page(queue_index);
+		} else
+			hide_page(queue_index);
 	}
 
 	void queue::init()
@@ -28,7 +33,8 @@ namespace ocarina
 		queue_funcs.size = libsaria::queue::size;
 
 		queue_list.init("Queue", &queue_funcs, &queue_menu);
-		add_page(queue_list.get_label(), queue_list.get_window(), true);
+		queue_index = add_page(queue_list.get_label(),
+				       queue_list.get_window(), true);
 		ocarina::queue::refresh();
 	}