[gnome-usage] window: Add a HdyViewSwitcherBar

[Adrien Plazas <aplazas src gnome org>]

commit a875690439c129393a858a48bcbdbd4c523c47da
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Tue Sep 10 19:19:52 2019 +0200

    window: Add a HdyViewSwitcherBar
    
    This will be used to present the main pages when the view switcher
    doesn't fit in the header bar.

 src/window.vala | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)
---
diff --git a/src/window.vala b/src/window.vala
index d36b012..338eb29 100644
--- a/src/window.vala
+++ b/src/window.vala
@@ -29,6 +29,7 @@ namespace Usage
     public class Window : Gtk.ApplicationWindow
     {
         private Usage.HeaderBar header_bar;
+        private Hdy.ViewSwitcherBar viewswitcher_bar;
         private View[] views;
 
                public Window(Gtk.Application application)
@@ -52,8 +53,12 @@ namespace Usage
 
                        var stack = new Gtk.Stack();
             stack.visible = true;
+            stack.vexpand = true;
                        header_bar = new Usage.HeaderBar(stack);
                        set_titlebar(header_bar);
+            viewswitcher_bar = new Hdy.ViewSwitcherBar();
+            viewswitcher_bar.visible = true;
+            viewswitcher_bar.stack = stack;
 
             views = new View[]
             {
@@ -75,7 +80,11 @@ namespace Usage
                 }
             });
 
-            this.add(stack);
+            var box = new Gtk.Box(Gtk.Orientation.VERTICAL, 0);
+            box.visible = true;
+            box.add(stack);
+            box.add(viewswitcher_bar);
+            this.add(box);
         }
 
         public Usage.HeaderBar get_header_bar()