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livetrax/libs/glibmm2/glib/glibmm/objectbase.cc

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// -*- c++ -*-
/* $Id: objectbase.cc,v 1.8 2006/11/10 02:24:49 murrayc Exp $ */
/* Copyright 2002 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 <glib-object.h>
#include <glibmm/quark.h>
#include <glibmm/objectbase.h>
#include <glibmm/propertyproxy_base.h> //For PropertyProxyConnectionNode
namespace
{
// Used by the Glib::ObjectBase default ctor. Using an explicitly defined
// char array rather than a string literal allows for fast pointer comparison,
// which is otherwise not guaranteed to work.
static const char anonymous_custom_type_name[] = "gtkmm__anonymous_custom_type";
} // anonymous namespace
namespace Glib
{
/**** Glib::ObjectBase *****************************************************/
ObjectBase::ObjectBase()
:
gobject_ (0),
custom_type_name_ (anonymous_custom_type_name),
cpp_destruction_in_progress_ (false)
{}
ObjectBase::ObjectBase(const char* custom_type_name)
:
gobject_ (0),
custom_type_name_ (custom_type_name),
cpp_destruction_in_progress_ (false)
{}
ObjectBase::ObjectBase(const std::type_info& custom_type_info)
:
gobject_ (0),
custom_type_name_ (custom_type_info.name()),
cpp_destruction_in_progress_ (false)
{}
// initialize() actually initializes the wrapper. Glib::ObjectBase is used
// as virtual base class, which means the most-derived class' ctor invokes
// the Glib::ObjectBase ctor -- thus it's useless for Glib::Object.
//
void ObjectBase::initialize(GObject* castitem)
{
if(gobject_)
{
// initialize() might be called twice when used with MI, e.g. by the ctors
// of Glib::Object and Glib::Interface. However, they must both refer to
// the same underlying GObject instance.
//
g_assert(gobject_ == castitem);
// TODO: Think about it. Will this really be called twice?
g_printerr("ObjectBase::initialize() called twice for the same GObject\n");
return; // Don't initialize the wrapper twice.
}
//g_print("%s : %s\n", G_GNUC_PRETTY_FUNCTION, G_OBJECT_TYPE_NAME(castitem));
gobject_ = castitem;
_set_current_wrapper(castitem);
}
ObjectBase::~ObjectBase()
{
// Normally, gobject_ should always be 0 at this point, because:
//
// a) Gtk::Object handles memory management on its own and always resets
// the gobject_ pointer in its destructor.
//
// b) Glib::Object instances that aren't Gtk::Objects will always be
// deleted by the destroy_notify_() virtual method. Calling delete
// on a Glib::Object is a programming error.
//
// The *only* situation where gobject_ is validly not 0 at this point
// happens if a derived class's ctor throws an exception. In that case
// we have to call g_object_unref() on our own.
//
if(GObject *const gobject = gobject_)
{
#ifdef GLIBMM_DEBUG_REFCOUNTING
g_warning("(Glib::ObjectBase::~ObjectBase): gobject_ = %p", (void*) gobject_);
#endif
gobject_ = 0;
#ifdef GLIBMM_DEBUG_REFCOUNTING
g_warning("(Glib::ObjectBase::~ObjectBase): before g_object_steal_qdata()");
#endif
// Remove the pointer to the wrapper from the underlying instance.
// This does _not_ cause invocation of the destroy_notify callback.
g_object_steal_qdata(gobject, quark_);
#ifdef GLIBMM_DEBUG_REFCOUNTING
g_warning("(Glib::ObjectBase::~ObjectBase): calling g_object_unref()");
#endif
g_object_unref(gobject);
}
}
void ObjectBase::reference() const
{
GLIBMM_DEBUG_REFERENCE(this, gobject_);
g_object_ref(gobject_);
}
void ObjectBase::unreference() const
{
GLIBMM_DEBUG_UNREFERENCE(this, gobject_);
g_object_unref(gobject_);
}
GObject* ObjectBase::gobj_copy() const
{
reference();
return gobject_;
}
void ObjectBase::_set_current_wrapper(GObject* object)
{
// Store a pointer to this wrapper in the underlying instance, so that we
// never create a second wrapper for the same underlying instance. Also,
// specify a callback that will tell us when it's time to delete this C++
// wrapper instance:
if(object)
{
if(!g_object_get_qdata(object, Glib::quark_))
{
g_object_set_qdata_full(object, Glib::quark_, this, &destroy_notify_callback_);
}
else
{
g_warning("This object, of type %s, already has a wrapper.\n"
"You should use wrap() instead of a constructor.",
G_OBJECT_TYPE_NAME(object));
}
}
}
// static
ObjectBase* ObjectBase::_get_current_wrapper(GObject* object)
{
if(object)
return static_cast<ObjectBase*>(g_object_get_qdata(object, Glib::quark_));
else
return 0;
}
// static
void ObjectBase::destroy_notify_callback_(void* data)
{
//GLIBMM_LIFECYCLE
// This method is called (indirectly) from g_object_run_dispose().
// Get the C++ instance associated with the C instance:
ObjectBase* cppObject = static_cast<ObjectBase*>(data); //Previously set with g_object_set_qdata_full().
#ifdef GLIBMM_DEBUG_REFCOUNTING
g_warning("ObjectBase::destroy_notify_callback_: cppObject = %p, gobject_ = %p, gtypename = %s",
(void*) cppObject, (void*) cppObject->gobject_, cppObject->gobject_);
#endif
if(cppObject) //This will be 0 if the C++ destructor has already run.
{
cppObject->destroy_notify_(); //Virtual - it does different things for GObject and GtkObject.
}
}
void ObjectBase::destroy_notify_()
{
// The C instance is about to be disposed, making it unusable. Now is a
// good time to delete the C++ wrapper of the C instance. There is no way
// to force the disposal of the GObject (though GtkObject has
// gtk_object_destroy()), So this is the *only* place where we delete the
// C++ wrapper.
//
// This will only happen after the last unreference(), which will be done by
// the RefPtr<> destructor. There should be no way to access the wrapper or
// the undobjecterlying instance after that, so it's OK to delete this.
#ifdef GLIBMM_DEBUG_REFCOUNTING
g_warning("Glib::ObjectBase::destroy_notify_: gobject_ = %p", (void*) gobject_);
#endif
gobject_ = 0; // Make sure we don't unref it again in the dtor.
delete this;
}
bool ObjectBase::is_anonymous_custom_() const
{
// Doing high-speed pointer comparison is OK here.
return (custom_type_name_ == anonymous_custom_type_name);
}
bool ObjectBase::is_derived_() const
{
// gtkmmproc-generated classes initialize this to 0 by default.
return (custom_type_name_ != 0);
}
void ObjectBase::set_manage()
{
// This is a private method and Gtk::manage() is a template function.
// Thus this will probably never run, unless you do something like:
//
// manage(static_cast<Gtk::Object*>(refptr.operator->()));
g_error("Glib::ObjectBase::set_manage(): "
"only Gtk::Object instances can be managed");
}
bool ObjectBase::_cpp_destruction_is_in_progress() const
{
return cpp_destruction_in_progress_;
}
void ObjectBase::set_property_value(const Glib::ustring& property_name, const Glib::ValueBase& value)
{
g_object_set_property(gobj(), property_name.c_str(), value.gobj());
}
void ObjectBase::get_property_value(const Glib::ustring& property_name, Glib::ValueBase& value) const
{
g_object_get_property(const_cast<GObject*>(gobj()), property_name.c_str(), value.gobj());
}
void ObjectBase::connect_property_changed(const Glib::ustring& property_name, const sigc::slot<void>& slot)
{
// Create a proxy to hold our connection info
// This will be deleted by destroy_notify_handler.
PropertyProxyConnectionNode* pConnectionNode = new PropertyProxyConnectionNode(slot, gobj());
// connect it to gtk+
// pConnectionNode will be passed as the data argument to the callback.
// The callback will then call the virtual Object::property_change_notify() method,
// which will contain a switch/case statement which will examine the property name.
const Glib::ustring notify_signal_name = "notify::" + property_name;
pConnectionNode->connection_id_ = g_signal_connect_data(gobj(),
notify_signal_name.c_str(), (GCallback)(&PropertyProxyConnectionNode::callback), pConnectionNode,
&PropertyProxyConnectionNode::destroy_notify_handler,
G_CONNECT_AFTER);
}
bool _gobject_cppinstance_already_deleted(GObject* gobject)
{
//This function is used to prevent calling wrap() on a GTK+ instance whose gtkmm instance has been deleted.
if(gobject)
return (bool)g_object_get_qdata(gobject, Glib::quark_cpp_wrapper_deleted_); //true means that something is odd.
else
return false; //Nothing is particularly wrong.
}
} // namespace Glib