[gnome-control-center] shell: Add support for the "Back" keyboard key and Alt+Up

[Bastien Nocera <hadess src gnome org>]

commit 81385c6350557336c6c78aa7cd268c944f88a9af
Author: Bastien Nocera <hadess hadess net>
Date:   Mon Jan 14 15:24:33 2013 +0100

    shell: Add support for the "Back" keyboard key and Alt+Up
    
    https://bugzilla.gnome.org/show_bug.cgi?id=691601

 shell/gnome-control-center.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/shell/gnome-control-center.c b/shell/gnome-control-center.c
index a8f4156..827a1a4 100644
--- a/shell/gnome-control-center.c
+++ b/shell/gnome-control-center.c
@@ -1113,6 +1113,13 @@ window_key_press_event (GtkWidget          *win,
             break;
         }
     }
+  else if ((state == GDK_MOD1_MASK && event->keyval == GDK_KEY_Up) ||
+           event->keyval == GDK_KEY_Back)
+    {
+      if (notebook_get_selected_page (self->priv->notebook) != self->priv->scrolled_window)
+        shell_show_overview_page (self);
+      retval = TRUE;
+    }
   return retval;
 }