[gnome-2048] Don't allow opening scores dialog if no scores exist

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 34134f17268e3ab7b53b350c715941c15005d59e
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Sun Feb 22 12:26:57 2015 -0600

    Don't allow opening scores dialog if no scores exist
    
    The scores dialog seems to be pretty broken right now, but pretty sure
    the code in GNOME 2048 is correct.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=744975

 src/application.vala |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/src/application.vala b/src/application.vala
index 5a958eb..5e8b26b 100644
--- a/src/application.vala
+++ b/src/application.vala
@@ -143,6 +143,7 @@ public class Application : Gtk.Application
         try {
           Scores.Category cat = (_settings.get_int ("rows") == 4) ? _grid4_cat : _grid5_cat;
           _scores_ctx.add_score (_game.score, cat);
+          ((SimpleAction) lookup_action ("scores")).set_enabled (true);
         } catch (GLib.Error e) {
           stderr.printf ("%s\n", e.message);
         }
@@ -310,6 +311,9 @@ public class Application : Gtk.Application
     _scores_ctx = new Scores.Context ("gnome-2048", "", _window, Scores.Style.PLAIN_DESCENDING);
     _grid4_cat = new Scores.Category ("grid4", "Grid 4 x 4");
     _grid5_cat = new Scores.Category ("grid5", "Grid 5 x 5");
+
+    if (!_scores_ctx.has_scores ())
+      ((SimpleAction) lookup_action ("scores")).set_enabled (false);
   }
 
   private void new_game_cb ()