/* $Id: builder.hg,v 1.19 2006/05/10 20:59:27 murrayc Exp $ */

/* Copyright (C) 2007 The gtkmm Development Team
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <gtkmm/widget.h>

_DEFS(gtkmm,gtk)
_PINCLUDE(glibmm/private/object_p.h)


namespace Gtk
{

/** Exception class for Gdk::Builder errors.
 */
_WRAP_GERROR(BuilderError,GtkBuilderError,GTK_BUILDER_ERROR)

/** Build an interface from a UI definition description.
 *
 * This object represents an `instantiation' of an UI definition description.
 * When one of these objects is created, the XML file is read, and the interface 
 * is created. The Gtk::Builder object then provides an interface for accessing the 
 * widgets in the interface by the names assigned to them inside the UI description.
 *
 * @newin2p12
 */
class Builder : public Glib::Object
{
  _CLASS_GOBJECT(Builder, GtkBuilder, GTK_BUILDER, Glib::Object, GObject)
 
protected:
 _CTOR_DEFAULT
 _IGNORE(gtk_builder_new)

public:
  _WRAP_CREATE()
  //TODO: Documentation:

  /** Parses a file containing a GtkBuilder UI definition.
   *
   * @param filename the name of the file to parse.
   * @result A new Builder object, or a null pointer if an error occurred.
   * @throws Glib::FileError, Glib::MarkupError
   *
   * @newin2p12
   **/
  static Glib::RefPtr<Builder> create_from_file(const std::string& filename);


  /** Parses a string containing a GtkBuilder UI definition.
   *
   * @buffer: the string to parse
   * @result A new Builder object, or a null pointer if an error occurred.
   * @throws Glib::MarkupError
   *
   * @newin2p12
   **/
  static Glib::RefPtr<Builder> create_from_string(const Glib::ustring& buffer);

  _WRAP_METHOD(bool add_from_file(const std::string& filename), gtk_builder_add_from_file, errthrow)

  /** Parses a string containing a GtkBuilder UI definition 
   * and merges it with the current contents of the builder.
   *
   * @buffer: the string to parse
   * @result true on success or false if an error occurred.
   * @throws Glib::MarkupError
   *
   * @newin2p12
   **/
  #ifdef GLIBMM_EXCEPTIONS_ENABLED
  bool add_from_string(const Glib::ustring& buffer);
  #else
  bool add_from_string(const Glib::ustring& buffer, std::auto_ptr<Glib::Error>& error);
  #endif //GLIBMM_EXCEPTIONS_ENABLED

  _WRAP_METHOD(bool add_from_string(const char* buffer, gsize length), gtk_builder_add_from_string, errthrow)

  //TODO: Custom-implement this and prevent it from being used with GTK_WIDGET-derived types?
  _WRAP_METHOD(Glib::RefPtr<Glib::Object> get_object(const Glib::ustring& name), gtk_builder_get_object, refreturn)

  /** Get a widget from the Builder file.
   * For instance:
   * @code
   * Gtk::Table* pTable = 0;
   * refXml->get_widget("mytable", pTable);
   * @endcode
   * This method prints a warning message to the console if the widget
   * doesn't exist or has the wrong type, so you don't need to check that
   * manually.
   *
   * Note that you are responsible for deleting top-level widgets (windows and
   * dialogs) instantiated by the Builder object. Other widgets are instantiated as
   * managed so they will be deleted automatically if you add them to a
   * container widget.
   *
   * @param name The name of the widget.
   * @retval widget A pointer to the widget, or <tt>0</tt> on failure.
   */
  template <class T_Widget> inline
  void get_widget(const Glib::ustring& name, T_Widget*& widget)
  {
    // Initialize output parameter:
    widget = 0;

    // The dynamic_cast<> should never fail if get_widget_checked() succeeded.
    widget = dynamic_cast<T_Widget*>(this->get_widget_checked(name, T_Widget::get_base_type()));

    if(!widget)
      g_critical("Gtk::Builder::get_widget(): dynamic_cast<> failed.");
  }

  /** This provides a pointer to a widget whose details are specified in the GtkBuilder file, but which is implemented
   * by your own derived class. Your class must have a constructor like so:
   * @code
   * DerivedDialog::DerivedDialog(BaseObjectType* cobject, const Glib::RefPtr<Gtk::Builder>& refBuilder)
   * : Gtk::Dialog(cobject) //Calls the base class constructor
   * @endcode
   *
   * For instance:
   * @code
   * Gtk::DerivedBox* pBox = 0;
   * refXml->get_widget_derived("mybox", pBox);
   * @endcode
   *
   * @param name The name of the widget.
   * @retval widget A pointer to the widget, or <tt>0</tt> on failure.
   */
  template <class T_Widget> inline
  void get_widget_derived(const Glib::ustring& name, T_Widget*& widget)
  {
     // Initialize output parameter:
     widget = 0;
     
     // Get the widget from the glade file.
     typedef typename T_Widget::BaseObjectType cwidget_type;
     cwidget_type* pCWidget = (cwidget_type*)get_cwidget(name);

     //The error was already reported by get_cwidget().
     if(!pCWidget)
       return;

     //Check whether there is already a C++ wrapper instance associated with this C instance:
     Glib::ObjectBase* pObjectBase = ObjectBase::_get_current_wrapper((GObject*)pCWidget);

     //If there is already a C++ instance, then return it again:
     if(pObjectBase)
     {
       widget = dynamic_cast<T_Widget*>( Glib::wrap((GtkWidget*)pCWidget) );
       //Newer, more spec-complaint, versions of g++ cannot resolve a specific wrap() function in a template.

       //The dynamic cast checks that it is of the correct type.
       //Somebody might be trying to call get_widget_derived() after already calling get_widget(),
       //or after already calling get_widget_derived() with a different derived C++ type.
       if(!widget)
        g_critical("Gtk::Builder::get_widget_derived(): dynamic_cast<> failed. An existing C++ instance, of a different type, seems to exist.");      
     }
     else
     {
       //Create a new C++ instance to wrap the existing C instance:
       
       //Set the output variable. We needed to do this because we can not template the return type.
       Glib::RefPtr<Gtk::Builder> refThis(this);
       refThis->reference(); //take a copy.
       widget = new T_Widget(pCWidget, refThis);
     }
  }


  //TODO:_WRAP_METHOD(GSList* get_objects(), gtk_builder_get_objects)
  //_WRAP_METHOD(void connect_signals(gpointer       user_data), gtk_builder_connect_signals)
  //_WRAP_METHOD(void connect_signals_full(GtkBuilderConnectFunc func, gpointer       user_data), gtk_builder_connect_signals_full)
  _WRAP_METHOD(void set_translation_domain(const Glib::ustring& domain), gtk_builder_set_translation_domain)
  _WRAP_METHOD(Glib::ustring get_translation_domain() const, gtk_builder_get_translation_domain)
  
  //We ignore gtk_builder_get_type_from_name() because it only seems useful when implementing GtkBuildable for widgets.
  _IGNORE(gtk_builder_get_type_from_name)

protected:
  Gtk::Widget* get_widget_checked(const Glib::ustring& name, GType type);
  GtkWidget* get_cwidget(const Glib::ustring& name);

#m4begin
dnl Custom-coded vfunc:
dnl
  _PUSH(SECTION_PCC_CLASS_INIT_VFUNCS)
  klass->get_type_from_name = &get_type_from_name_vfunc_callback;
  _POP()
#m4end

  // TODO: Make sure this is actually invoked even with disabled vfuncs so
  // that glade creates gtkmm's GObjects.
};

} // namespace Gtk

