[glom] Print Layout: Do not show the formatting context menu items when it is useless.

[Murray Cumming <murrayc src gnome org>]

commit 44681fc6c0462fc394a4a3fc0a75f4519336a312
Author: Murray Cumming <murrayc murrayc com>
Date:   Thu Sep 8 15:51:14 2011 +0200

    Print Layout: Do not show the formatting context menu items when it is useless.
    
    * glom/print_layout/canvas_print_layout.cc: on_item_show_context_menu():
    Disable the formatting context menu item when appropriate.

 ChangeLog                                |    7 +++++++
 glom/print_layout/canvas_print_layout.cc |   12 +++++++++++-
 2 files changed, 18 insertions(+), 1 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 1e2eb2e..793f566 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2011-09-08  Murray Cumming  <murrayc murrayc com>
 
+	Print Layout: Do not show the formatting context menu items when it is useless.
+
+	* glom/print_layout/canvas_print_layout.cc: on_item_show_context_menu():
+	Disable the formatting context menu item when appropriate.
+
+2011-09-08  Murray Cumming  <murrayc murrayc com>
+
 	Use pygobject-3.0
 
 	* configure.ac: Instead of pygobject-2.0. Because everything else (such as 
diff --git a/glom/print_layout/canvas_print_layout.cc b/glom/print_layout/canvas_print_layout.cc
index 7c69021..ded230b 100644
--- a/glom/print_layout/canvas_print_layout.cc
+++ b/glom/print_layout/canvas_print_layout.cc
@@ -308,10 +308,20 @@ void Canvas_PrintLayout::setup_context_menu()
 
 void Canvas_PrintLayout::on_item_show_context_menu(guint button, guint32 activate_time, Glib::RefPtr<CanvasLayoutItem> item)
 {
-  if(!m_context_menu)
+  if(!m_context_menu || !item)
     return;
 
   m_context_item = item;
+  
+  //Do not enable the Formatting menu item for all types of items:
+  sharedptr<LayoutItem> layout_item = m_context_item->get_layout_item();
+  bool enable_formatting = false;
+  if(sharedptr<LayoutItem_WithFormatting>::cast_dynamic(layout_item))
+  {
+    enable_formatting = true;
+  }
+
+  m_action_formatting->set_sensitive(enable_formatting);
 
   m_context_menu->popup(button, activate_time);
 }