[shotwell] viewer: Enable context menu

[Jens Georg <jensgeorg src gnome org>]

commit e7376bf09a8811a2380b23ccd553972d46dd4cc5
Author: Jens Georg <mail jensge org>
Date:   Thu Mar 9 22:37:03 2017 +0100

    viewer: Enable context menu
    
    Signed-off-by: Jens Georg <mail jensge org>

 src/direct/DirectPhotoPage.vala |   16 ++++++++++++++--
 1 files changed, 14 insertions(+), 2 deletions(-)
---
diff --git a/src/direct/DirectPhotoPage.vala b/src/direct/DirectPhotoPage.vala
index d6ba8ec..14b54bc 100644
--- a/src/direct/DirectPhotoPage.vala
+++ b/src/direct/DirectPhotoPage.vala
@@ -146,12 +146,24 @@ public class DirectPhotoPage : EditingHostPage {
     }
 
     protected override bool on_context_buttonpress(Gdk.EventButton event) {
-//        Gtk.Menu context_menu = (Gtk.Menu) ui.get_widget("/DirectContextMenu");
-//        popup_context_menu(context_menu, event);
+        popup_context_menu(get_context_menu(), event);
 
         return true;
     }
 
+    private Gtk.Menu context_menu;
+
+    private Gtk.Menu get_context_menu() {
+        if (context_menu == null) {
+            var model = this.builder.get_object ("DirectContextMenu")
+                as GLib.MenuModel;
+            context_menu = new Gtk.Menu.from_model (model);
+            context_menu.attach_to_widget (this, null);
+        }
+
+        return this.context_menu;
+    }
+
     private void update_zoom_menu_item_sensitivity() {
         set_action_sensitive("IncreaseSize", !get_zoom_state().is_max() && !get_photo_missing());
         set_action_sensitive("DecreaseSize", !get_zoom_state().is_default() && !get_photo_missing());