[glom] Choices combo widgets: Improve the API.

[Murray Cumming <murrayc src gnome org>]

commit 7f9c004e98d37bdde9bc0338fa04cd6d08a8cf02
Author: Murray Cumming <murrayc murrayc com>
Date:   Sat Sep 11 13:43:54 2010 +0200

    Choices combo widgets: Improve the API.
    
    * glom/mode_data/datawidget/combochoiceswithtreemodel.[h|cc]:
    Make create_model() non virtual, instead adding a pure virtual use_model().
    * glom/mode_data/datawidget/combo.[h|cc]:
    * glom/mode_data/datawidget/comboentry.[h|cc]:
    * glom/mode_data/db_adddel/cellrenderer_dblist.[h|cc]: Change the
    create_model() overrides to use_model() overrides.

 ChangeLog                                          |   11 +++++++++++
 glom/mode_data/datawidget/combo.cc                 |    8 ++++----
 glom/mode_data/datawidget/combo.h                  |    2 +-
 .../datawidget/combochoiceswithtreemodel.cc        |    3 +++
 .../datawidget/combochoiceswithtreemodel.h         |    7 ++++++-
 glom/mode_data/datawidget/comboentry.cc            |    9 ++++-----
 glom/mode_data/datawidget/comboentry.h             |    2 +-
 glom/mode_data/db_adddel/cellrenderer_dblist.cc    |    7 +++----
 glom/mode_data/db_adddel/cellrenderer_dblist.h     |    2 +-
 9 files changed, 34 insertions(+), 17 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 98d1f0e..b206a94 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,16 @@
 2010-09-11  Murray Cumming  <murrayc murrayc com>
 
+	Choices combo widgets: Improve the API.
+
+	* glom/mode_data/datawidget/combochoiceswithtreemodel.[h|cc]: 
+	Make create_model() non virtual, instead adding a pure virtual use_model().
+	* glom/mode_data/datawidget/combo.[h|cc]: 
+	* glom/mode_data/datawidget/comboentry.[h|cc]: 
+	* glom/mode_data/db_adddel/cellrenderer_dblist.[h|cc]: Change the 
+	create_model() overrides to use_model() overrides.
+
+2010-09-11  Murray Cumming  <murrayc murrayc com>
+
 	Choices combo widgets: Initial work to make the model generic.
 
 	* glom/mode_data/datawidget/combochoiceswithtreemodel.[h|cc]: Change 
diff --git a/glom/mode_data/datawidget/combo.cc b/glom/mode_data/datawidget/combo.cc
index 7e5de3a..c19f110 100644
--- a/glom/mode_data/datawidget/combo.cc
+++ b/glom/mode_data/datawidget/combo.cc
@@ -69,16 +69,16 @@ ComboGlom::~ComboGlom()
 {
 }
 
-void ComboGlom::create_model(guint columns_count)
+void ComboGlom::use_model()
 {
-  //Create the model itself:
-  ComboChoicesWithTreeModel::create_model(columns_count);
+  Glib::RefPtr<Gtk::TreeModel> model = get_choices_model();
 
   //Show the model in the view:
-  set_model(get_choices_model());
+  set_model(model);
   
   clear();
 
+  const guint columns_count = model->get_n_columns();
   for(guint i = 0; i < columns_count; ++i)
   {
     Gtk::CellRendererText* cell = Gtk::manage(new Gtk::CellRendererText);
diff --git a/glom/mode_data/datawidget/combo.h b/glom/mode_data/datawidget/combo.h
index 17afac0..f6cb62d 100644
--- a/glom/mode_data/datawidget/combo.h
+++ b/glom/mode_data/datawidget/combo.h
@@ -74,7 +74,7 @@ public:
 
 private:
   void init();
-  virtual void create_model(guint columns_count);
+  virtual void use_model();
 
   #ifndef GLOM_ENABLE_MAEMO
   // Note that this is a normal signal handler when glibmm was complied
diff --git a/glom/mode_data/datawidget/combochoiceswithtreemodel.cc b/glom/mode_data/datawidget/combochoiceswithtreemodel.cc
index b48a556..4aba921 100644
--- a/glom/mode_data/datawidget/combochoiceswithtreemodel.cc
+++ b/glom/mode_data/datawidget/combochoiceswithtreemodel.cc
@@ -69,6 +69,9 @@ void ComboChoicesWithTreeModel::create_model(guint columns_count)
 
   //Create the model:
   m_refModel = Gtk::ListStore::create(record);
+  
+  //Call the derived class's (virtual) implementation of this:
+  use_model();
 }
 
 void ComboChoicesWithTreeModel::delete_model()
diff --git a/glom/mode_data/datawidget/combochoiceswithtreemodel.h b/glom/mode_data/datawidget/combochoiceswithtreemodel.h
index edbb38a..219893e 100644
--- a/glom/mode_data/datawidget/combochoiceswithtreemodel.h
+++ b/glom/mode_data/datawidget/combochoiceswithtreemodel.h
@@ -44,7 +44,12 @@ public:
   
 protected:
   void init();
-  virtual void create_model(guint columns_count);
+  void create_model(guint columns_count);
+  
+  /** Derived classes should implement this to present the model in their view,
+   * for instance by adding Gtk::CellRenderers.
+   */
+  virtual void use_model() = 0;
 
   virtual void set_choices_with_second(const type_list_values_with_second& list_values);
 
diff --git a/glom/mode_data/datawidget/comboentry.cc b/glom/mode_data/datawidget/comboentry.cc
index 8cb793f..fc68d07 100644
--- a/glom/mode_data/datawidget/comboentry.cc
+++ b/glom/mode_data/datawidget/comboentry.cc
@@ -108,15 +108,14 @@ ComboEntry::~ComboEntry()
 {
 }
 
-void ComboEntry::create_model(guint columns_count)
+void ComboEntry::use_model()
 {
-  //Create the model itself:
-  ComboChoicesWithTreeModel::create_model(columns_count);
-
   //Show model in the view:
-  set_model(get_choices_model());
+  Glib::RefPtr<Gtk::TreeModel> model = get_choices_model();
+  set_model(model);
   set_text_column(0);
 
+  const guint columns_count = model->get_n_columns();
   for(guint i = 0; i < columns_count; ++i)
   {
     Gtk::CellRendererText* cell = 0;
diff --git a/glom/mode_data/datawidget/comboentry.h b/glom/mode_data/datawidget/comboentry.h
index df8fe21..b151c12 100644
--- a/glom/mode_data/datawidget/comboentry.h
+++ b/glom/mode_data/datawidget/comboentry.h
@@ -73,7 +73,7 @@ public:
 
 private:
   void init();
-  virtual void create_model(guint columns_count);
+  virtual void use_model();
 
 
   //Overrides of default signal handlers:
diff --git a/glom/mode_data/db_adddel/cellrenderer_dblist.cc b/glom/mode_data/db_adddel/cellrenderer_dblist.cc
index d2c790b..7e6a64a 100644
--- a/glom/mode_data/db_adddel/cellrenderer_dblist.cc
+++ b/glom/mode_data/db_adddel/cellrenderer_dblist.cc
@@ -36,13 +36,12 @@ CellRendererDbList::~CellRendererDbList()
 }
 
 
-void CellRendererDbList::create_model(guint columns_count)
+void CellRendererDbList::use_model()
 {
-  //Create the model itself:
-  DataWidgetChildren::ComboChoicesWithTreeModel::create_model(columns_count);
+  Glib::RefPtr<Gtk::TreeModel> model = get_choices_model();
 
   //Show model in the view:
-  property_model() = get_choices_model();
+  property_model() = model;
   property_text_column() = 0; //This must be a text column, in m_refModel.
   property_editable() = true; //It would be useless if we couldn't edit it.
 
diff --git a/glom/mode_data/db_adddel/cellrenderer_dblist.h b/glom/mode_data/db_adddel/cellrenderer_dblist.h
index 6828f19..f48c0cb 100644
--- a/glom/mode_data/db_adddel/cellrenderer_dblist.h
+++ b/glom/mode_data/db_adddel/cellrenderer_dblist.h
@@ -47,7 +47,7 @@ public:
 
 private:
 
-  virtual void create_model(guint columns_count);
+  virtual void use_model();
   virtual void on_editing_started(Gtk::CellEditable* cell_editable, const Glib::ustring& path);
 
   virtual void set_value(const Gnome::Gda::Value& value);