13
0
livetrax/libs/glibmm2/glibmm/object.cc

313 lines
9.0 KiB
C++
Raw Normal View History

// -*- c++ -*-
/* $Id$ */
/* Copyright 1998-2002 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 <glibmm/object.h>
#include <glibmm/private/object_p.h>
#include <glibmm/property.h>
#include <glib.h>
#include <glib-object.h>
#include <gobject/gvaluecollector.h>
#include <cstdarg>
#include <cstring>
//Weak references:
//I'm not sure what the point of these are apart from being a hacky way out of circular references,
//but maybe we could make it easier to use them by making a Java Reference Object -style class like so:
// Glib::WeakRef<SomeDerivedObject> weakrefSomeObject(object1);
// ...
// if(weakrefSomeObject->isStillAlive())
// {
// weakrefSomeObject->some_method();
// }
// else
// {
// //Deal with it, maybe recreating the object.
// }
//
// Without this, the coder has to define his own signal handler which sets his own isStillAlive boolean.
// weakrefSomeObject<> could still have its own signal_destroyed signal so that coders can choose to deal
// with the destruction as soon as it happens instead of just checking later before they try to use it.
namespace Glib
{
ConstructParams::ConstructParams(const Glib::Class& glibmm_class_)
:
glibmm_class (glibmm_class_),
n_parameters (0),
parameters (0)
{}
/* The implementation is mostly copied from gobject.c, with some minor tweaks.
* Basically, it looks up each property name to get its GType, and then uses
* G_VALUE_COLLECT() to store the varargs argument in a GValue of the correct
* type.
*/
ConstructParams::ConstructParams(const Glib::Class& glibmm_class_,
const char* first_property_name, ...)
:
glibmm_class (glibmm_class_),
n_parameters (0),
parameters (0)
{
va_list var_args;
va_start(var_args, first_property_name);
GObjectClass *const g_class =
static_cast<GObjectClass*>(g_type_class_ref(glibmm_class.get_type()));
unsigned int n_alloced_params = 0;
char* collect_error = 0; // output argument of G_VALUE_COLLECT()
for(const char* name = first_property_name;
name != 0;
name = va_arg(var_args, char*))
{
GParamSpec *const pspec = g_object_class_find_property(g_class, name);
if(!pspec)
{
g_warning("Glib::ConstructParams::ConstructParams(): "
"object class `%s' has no property named `%s'",
g_type_name(glibmm_class.get_type()), name);
break;
}
if(n_parameters >= n_alloced_params)
parameters = g_renew(GParameter, parameters, n_alloced_params += 8);
GParameter& param = parameters[n_parameters];
param.name = name;
param.value.g_type = 0;
// Fill the GValue with the current vararg, and move on to the next one.
g_value_init(&param.value, G_PARAM_SPEC_VALUE_TYPE(pspec));
G_VALUE_COLLECT(&param.value, var_args, 0, &collect_error);
if(collect_error)
{
g_warning("Glib::ConstructParams::ConstructParams(): %s", collect_error);
g_free(collect_error);
g_value_unset(&param.value);
break;
}
++n_parameters;
}
g_type_class_unref(g_class);
va_end(var_args);
}
ConstructParams::~ConstructParams()
{
while(n_parameters > 0)
g_value_unset(&parameters[--n_parameters].value);
g_free(parameters);
}
/*
* Some compilers require the existance of a copy constructor in certain
* usage contexts. This implementation is fully functional, but unlikely
* to be ever actually called due to optimization.
*/
ConstructParams::ConstructParams(const ConstructParams& other)
:
glibmm_class (other.glibmm_class),
n_parameters (other.n_parameters),
parameters (g_new(GParameter, n_parameters))
{
for(unsigned int i = 0; i < n_parameters; ++i)
{
parameters[i].name = other.parameters[i].name;
parameters[i].value.g_type = 0;
g_value_init(&parameters[i].value, G_VALUE_TYPE(&other.parameters[i].value));
g_value_copy(&other.parameters[i].value, &parameters[i].value);
}
}
/**** Glib::Object_Class ***************************************************/
const Glib::Class& Object_Class::init()
{
if(!gtype_)
{
class_init_func_ = &Object_Class::class_init_function;
register_derived_type(G_TYPE_OBJECT);
}
return *this;
}
void Object_Class::class_init_function(void*, void*)
{}
Object* Object_Class::wrap_new(GObject* object)
{
return new Object(object);
}
/**** Glib::Object *********************************************************/
// static data
Object::CppClassType Object::object_class_;
Object::Object()
{
// This constructor is ONLY for derived classes that are NOT wrappers of
// derived C objects. For instance, Gtk::Object should NOT use this
// constructor.
//g_warning("Object::Object(): Did you really mean to call this?");
// If Glib::ObjectBase has been constructed with a custom typeid, we derive
// a new GType on the fly. This works because ObjectBase is a virtual base
// class, therefore its constructor is always executed first.
GType object_type = G_TYPE_OBJECT; // the default -- not very useful
if(custom_type_name_ && !is_anonymous_custom_())
{
object_class_.init();
object_type = object_class_.clone_custom_type(custom_type_name_); //A type that is derived from GObject.
}
// Create a new GObject with the specified array of construct properties.
// This works with custom types too, since those inherit the properties of
// their base class.
void *const new_object = g_object_newv(object_type, 0, 0);
// Connect the GObject and Glib::Object instances.
ObjectBase::initialize(static_cast<GObject*>(new_object));
}
Object::Object(const Glib::ConstructParams& construct_params)
{
GType object_type = construct_params.glibmm_class.get_type();
// If Glib::ObjectBase has been constructed with a custom typeid, we derive
// a new GType on the fly. This works because ObjectBase is a virtual base
// class, therefore its constructor is always executed first.
if(custom_type_name_ && !is_anonymous_custom_())
object_type = construct_params.glibmm_class.clone_custom_type(custom_type_name_);
// Create a new GObject with the specified array of construct properties.
// This works with custom types too, since those inherit the properties of
// their base class.
void *const new_object = g_object_newv(
object_type, construct_params.n_parameters, construct_params.parameters);
// Connect the GObject and Glib::Object instances.
ObjectBase::initialize(static_cast<GObject*>(new_object));
}
Object::Object(GObject* castitem)
{
//I disabled this check because libglademm really does need to do this.
//(actually it tells libglade to instantiate "gtkmm_" types.
//The 2nd instance bug will be caught elsewhere anyway.
/*
static const char gtkmm_prefix[] = "gtkmm__";
const char *const type_name = G_OBJECT_TYPE_NAME(castitem);
if(strncmp(type_name, gtkmm_prefix, sizeof(gtkmm_prefix) - 1) == 0)
{
g_warning("Glib::Object::Object(GObject*): "
"An object of type '%s' was created directly via g_object_new(). "
"The Object::Object(const Glib::ConstructParams&) constructor "
"should be used instead.\n"
"This could happen if the C instance lived longer than the C++ instance, so that "
"a second C++ instance was created automatically to wrap it. That would be a gtkmm bug that you should report.",
type_name);
}
*/
// Connect the GObject and Glib::Object instances.
ObjectBase::initialize(castitem);
}
Object::~Object()
{
cpp_destruction_in_progress_ = true;
}
/*
RefPtr<Object> Object::create()
{
// Derived classes will actually return RefPtr<>s that contain useful instances.
return RefPtr<Object>();
}
*/
GType Object::get_type()
{
return object_class_.init().get_type();
}
GType Object::get_base_type()
{
return G_TYPE_OBJECT;
}
// Data services
void* Object::get_data(const QueryQuark& id)
{
return g_object_get_qdata(gobj(),id);
}
void Object::set_data(const Quark& id, void* data)
{
g_object_set_qdata(gobj(),id,data);
}
void Object::set_data(const Quark& id, void* data, DestroyNotify destroy)
{
g_object_set_qdata_full(gobj(), id, data, destroy);
}
void Object::remove_data(const QueryQuark& id)
{
// missing in glib??
g_return_if_fail(id.id() > 0);
g_datalist_id_remove_data(&gobj()->qdata, id);
}
void* Object::steal_data(const QueryQuark& id)
{
return g_object_steal_qdata(gobj(), id);
}
} // namespace Glib