Ruler setup enhanced

- Issue: on an entirely fresh installation the "Ruler"
  entry was not visible. Now, a new standard template
  called "Ruler" is present.
- Ruler templates with categories cannot be deleted
  any more and are shown with italic font. If they
  were deleted, they would show up again after restart.

src/ant/ant/antConfigPage.cc

@@ -29,6 +29,7 @@
 #include "antConfig.h"
 #include "layConverters.h"
 #include "layQtTools.h"
+#include "tlExceptions.h"
 
 #include <QInputDialog>
 
@@ -254,6 +255,7 @@ ConfigPage4::add_clicked ()
   } else {
     new_one = m_ruler_templates [m_current_template];
   }
+  new_one.category (std::string ());
   m_ruler_templates.insert (m_ruler_templates.begin () + m_current_template, new_one);
   m_ruler_templates [m_current_template].title (tl::to_string (QObject::tr ("New Ruler")));
   update_list ();
@@ -264,7 +266,12 @@ ConfigPage4::add_clicked ()
 void  
 ConfigPage4::del_clicked ()
 {
+BEGIN_PROTECTED
+
   if (m_current_template >= 0 && m_current_template < int (m_ruler_templates.size ())) {
+    if (! m_ruler_templates [m_current_template].category ().empty ()) {
+      throw tl::Exception (tl::to_string (tr ("This ruler is a built-in template and cannot be deleted")));
+    }
     m_ruler_templates.erase (m_ruler_templates.begin () + m_current_template);
     if (m_current_template > 0) {
       --m_current_template;
@@ -276,6 +283,8 @@ ConfigPage4::del_clicked ()
     update_list ();
     show ();
   }
+
+END_PROTECTED
 }
 
 void  
@@ -309,6 +318,12 @@ ConfigPage4::update_list ()
   mp_ui->template_list->clear ();
   for (std::vector <ant::Template>::const_iterator t = m_ruler_templates.begin (); t != m_ruler_templates.end (); ++t) {
     mp_ui->template_list->addItem (tl::to_qstring (t->title ()));
+    if (! t->category ().empty ()) {
+      QListWidgetItem *item = mp_ui->template_list->item (int (t - m_ruler_templates.begin ()));
+      QFont font = item->font ();
+      font.setItalic (true);
+      item->setFont (font);
+    }
   }
   mp_ui->template_list->setCurrentRow (m_current_template);
   m_current_changed_enabled = true;

src/ant/ant/antPlugin.cc

@@ -171,6 +171,9 @@ PluginDeclaration::config_finalize ()
 void 
 PluginDeclaration::initialized (lay::PluginRoot *)
 {
+  ant::Template ruler_template (tl::to_string (QObject::tr ("Ruler")), "$X", "$Y", "$D", ant::Object::STY_ruler, ant::Object::OL_diag, true, lay::AC_Global, "_ruler");
+  register_annotation_template (ruler_template);
+
   ant::Template pos_template (tl::to_string (QObject::tr ("Cross")), "", "", "$U,$V", ant::Object::STY_cross_both, ant::Object::OL_diag, true, lay::AC_Global, "_cross");
   pos_template.set_mode (ant::Template::RulerSingleClick);
   register_annotation_template (pos_template);
@@ -178,6 +181,8 @@ PluginDeclaration::initialized (lay::PluginRoot *)
   ant::Template auto_template (tl::to_string (QObject::tr ("Measure")), "$X", "$Y", "$D", ant::Object::STY_ruler, ant::Object::OL_diag, true, lay::AC_Global, "_measure");
   auto_template.set_mode (ant::Template::RulerAutoMetric);
   register_annotation_template (auto_template);
+
+  update_menu ();
 }
 
 void 
@@ -217,18 +222,16 @@ PluginDeclaration::update_menu ()
 {
   lay::AbstractMenuProvider *mp = lay::AbstractMenuProvider::instance ();
 
-  if (m_templates.empty ()) {
-    m_templates.push_back (Template ());
-  }
-
   if (m_current_template < 0 || m_current_template >= int (m_templates.size ())) {
     m_current_template = 0;
   }
     
-  std::vector<std::string> menu_entries = mp->menu ()->group ("ruler_mode_group");
+  if (m_current_template >= 0 && m_current_template < int (m_templates.size ())) {
-  for (std::vector<std::string>::const_iterator m = menu_entries.begin (); m != menu_entries.end (); ++m) {
+    std::vector<std::string> menu_entries = mp->menu ()->group ("ruler_mode_group");
-    lay::Action action = mp->menu ()->action (*m);
+    for (std::vector<std::string>::const_iterator m = menu_entries.begin (); m != menu_entries.end (); ++m) {
-    action.set_title (m_templates [m_current_template].title ());
+      lay::Action action = mp->menu ()->action (*m);
+      action.set_title (m_templates [m_current_template].title ());
+    }
   }
   
   std::vector<std::string> tmpl_group = mp->menu ()->group ("ruler_templates_group");