Initial revision

git-svn-id: svn://localhost/trunk/ardour2@4 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/glibmm2/glibmm/object.cc

@@ -0,0 +1,312 @@
+// -*- 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
+