gtkobject.c

gtk是linux一款强大的夸平台的图形化开发工具

/* GTK - The GIMP Toolkit
 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * 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., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/*
 * Modified by the GTK+ Team and others 1997-1999.  See the AUTHORS
 * file for a list of people on the GTK+ Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GTK+ at ftp://ftp.gtk.org/pub/gtk/. 
 */

#include <stdarg.h>
#include <string.h>
#include <stdio.h>
#include "gtkobject.h"
#include "gtksignal.h"


enum {
  DESTROY,
  LAST_SIGNAL
};
enum {
  ARG_0,
  ARG_USER_DATA,
  ARG_SIGNAL,
  ARG_SIGNAL_AFTER,
  ARG_OBJECT_SIGNAL,
  ARG_OBJECT_SIGNAL_AFTER
};


void		      gtk_object_init_type       (void);
static void           gtk_object_base_class_init (GtkObjectClass *klass);
static void           gtk_object_class_init      (GtkObjectClass *klass);
static void           gtk_object_init            (GtkObject      *object,
						  GtkObjectClass *klass);
static void           gtk_object_set_arg         (GtkObject      *object,
						  GtkArg         *arg,
						  guint		  arg_id);
static void           gtk_object_get_arg         (GtkObject      *object,
						  GtkArg         *arg,
						  guint		  arg_id);
static void           gtk_object_shutdown        (GtkObject      *object);
static void           gtk_object_real_destroy    (GtkObject      *object);
static void           gtk_object_finalize        (GtkObject      *object);
static void           gtk_object_notify_weaks    (GtkObject      *object);

static guint object_signals[LAST_SIGNAL] = { 0 };

static GHashTable *object_arg_info_ht = NULL;

static GQuark quark_user_data = 0;
static GQuark quark_weakrefs = 0;
static GQuark quark_carg_history = 0;


#ifdef G_ENABLE_DEBUG
static guint obj_count = 0;
static GHashTable *living_objs_ht = NULL;
static void
gtk_object_debug_foreach (gpointer key, gpointer value, gpointer user_data)
{
  GtkObject *object;
  
  object = (GtkObject*) value;
  g_message ("[%p] %s\tref_count=%d%s%s",
	     object,
	     gtk_type_name (GTK_OBJECT_TYPE (object)),
	     object->ref_count,
	     GTK_OBJECT_FLOATING (object) ? " (floating)" : "",
	     GTK_OBJECT_DESTROYED (object) ? " (destroyed)" : "");
}
static void
gtk_object_debug (void)
{
  if (living_objs_ht)
    g_hash_table_foreach (living_objs_ht, gtk_object_debug_foreach, NULL);
  
  g_message ("living objects count = %d", obj_count);
}
#endif	/* G_ENABLE_DEBUG */

void
gtk_object_post_arg_parsing_init (void)
{
#ifdef G_ENABLE_DEBUG
  if (gtk_debug_flags & GTK_DEBUG_OBJECTS)
    g_atexit (gtk_object_debug);
#endif	/* G_ENABLE_DEBUG */
}

/****************************************************
 * GtkObject type, class and instance initialization
 *
 ****************************************************/

void
gtk_object_init_type (void)
{
  static const GtkTypeInfo object_info =
  {
    "GtkObject",
    sizeof (GtkObject),
    sizeof (GtkObjectClass),
    (GtkClassInitFunc) gtk_object_class_init,
    (GtkObjectInitFunc) gtk_object_init,
    /* reserved_1 */ NULL,
    /* reserved_2 */ NULL,
    (GtkClassInitFunc) gtk_object_base_class_init,
  };
  GtkType object_type;

  object_type = gtk_type_unique (0, &object_info);
  g_assert (object_type == GTK_TYPE_OBJECT);
}

GtkType
gtk_object_get_type (void)
{
  return GTK_TYPE_OBJECT;
}

static void
gtk_object_base_class_init (GtkObjectClass *class)
{
  /* reset instance specific fields that don't get inherited */
  class->signals = NULL;
  class->nsignals = 0;
  class->n_args = 0;
  class->construct_args = NULL;

  /* reset instance specifc methods that don't get inherited */
  class->get_arg = NULL;
  class->set_arg = NULL;
}

static void
gtk_object_class_init (GtkObjectClass *class)
{
  quark_carg_history = g_quark_from_static_string ("gtk-construct-arg-history");

  gtk_object_add_arg_type ("GtkObject::user_data",
			   GTK_TYPE_POINTER,
			   GTK_ARG_READWRITE,
			   ARG_USER_DATA);
  gtk_object_add_arg_type ("GtkObject::signal",
			   GTK_TYPE_SIGNAL,
			   GTK_ARG_WRITABLE,
			   ARG_SIGNAL);
  gtk_object_add_arg_type ("GtkObject::signal_after",
			   GTK_TYPE_SIGNAL,
			   GTK_ARG_WRITABLE,
			   ARG_SIGNAL_AFTER);
  gtk_object_add_arg_type ("GtkObject::object_signal",
			   GTK_TYPE_SIGNAL,
			   GTK_ARG_WRITABLE,
			   ARG_OBJECT_SIGNAL);
  gtk_object_add_arg_type ("GtkObject::object_signal_after",
			   GTK_TYPE_SIGNAL,
			   GTK_ARG_WRITABLE,
			   ARG_OBJECT_SIGNAL_AFTER);

  object_signals[DESTROY] =
    gtk_signal_new ("destroy",
                    GTK_RUN_LAST | GTK_RUN_NO_HOOKS,
                    class->type,
                    GTK_SIGNAL_OFFSET (GtkObjectClass, destroy),
                    gtk_marshal_NONE__NONE,
		    GTK_TYPE_NONE, 0);

  gtk_object_class_add_signals (class, object_signals, LAST_SIGNAL);

  class->get_arg = gtk_object_get_arg;
  class->set_arg = gtk_object_set_arg;
  class->shutdown = gtk_object_shutdown;
  class->destroy = gtk_object_real_destroy;
  class->finalize = gtk_object_finalize;
}

static void
gtk_object_init (GtkObject      *object,
		 GtkObjectClass *klass)
{
  gboolean needs_construction = FALSE;

  GTK_OBJECT_FLAGS (object) = GTK_FLOATING;
  do
    {
      needs_construction |= klass->construct_args != NULL;
      klass = gtk_type_parent_class (klass->type);
    }
  while (klass && !needs_construction);
  if (!needs_construction)
    GTK_OBJECT_FLAGS (object) |= GTK_CONSTRUCTED;

  object->ref_count = 1;
  g_datalist_init (&object->object_data);

#ifdef G_ENABLE_DEBUG
  if (gtk_debug_flags & GTK_DEBUG_OBJECTS)
    {
      obj_count++;
      
      if (!living_objs_ht)
	living_objs_ht = g_hash_table_new (g_direct_hash, NULL);

      g_hash_table_insert (living_objs_ht, object, object);
    }
#endif /* G_ENABLE_DEBUG */
}

/********************************************
 * Functions to end a GtkObject's life time
 *
 ********************************************/
void
gtk_object_destroy (GtkObject *object)
{
  g_return_if_fail (object != NULL);
  g_return_if_fail (GTK_IS_OBJECT (object));
  g_return_if_fail (GTK_OBJECT_CONSTRUCTED (object));
  
  if (!GTK_OBJECT_DESTROYED (object))
    {
      /* we will hold a reference on the object in this place, so
       * to ease all classes shutdown and destroy implementations.
       * i.e. they don't have to bother about referencing at all.
       */
      gtk_object_ref (object);
      object->klass->shutdown (object);
      gtk_object_unref (object);
    }
}

static void
gtk_object_shutdown (GtkObject *object)
{
  GTK_OBJECT_SET_FLAGS (object, GTK_DESTROYED);
  gtk_signal_emit (object, object_signals[DESTROY]);
}

static void
gtk_object_real_destroy (GtkObject *object)
{
  if (GTK_OBJECT_CONNECTED (object))
    gtk_signal_handlers_destroy (object);
}

static void
gtk_object_finalize (GtkObject *object)
{
  gtk_object_notify_weaks (object);

  g_datalist_clear (&object->object_data);
  
  gtk_type_free (GTK_OBJECT_TYPE (object), object);
}

/*****************************************
 * GtkObject argument handlers
 *
 *****************************************/

static void
gtk_object_set_arg (GtkObject *object,
		    GtkArg    *arg,
		    guint      arg_id)
{
  guint n = 0;

  switch (arg_id)
    {
      gchar *arg_name;

    case ARG_USER_DATA:
      gtk_object_set_user_data (object, GTK_VALUE_POINTER (*arg));
      break;
    case ARG_OBJECT_SIGNAL_AFTER:
      n += 6;
    case ARG_OBJECT_SIGNAL:
      n += 1;
    case ARG_SIGNAL_AFTER:
      n += 6;
    case ARG_SIGNAL:
      n += 6;
      arg_name = gtk_arg_name_strip_type (arg->name);
      if (arg_name &&
	  arg_name[n] == ':' &&
	  arg_name[n + 1] == ':' &&
	  arg_name[n + 2] != 0)
	{
	  gtk_signal_connect_full (object,
				   arg_name + n + 2,
				   GTK_VALUE_SIGNAL (*arg).f, NULL,
				   GTK_VALUE_SIGNAL (*arg).d,
				   NULL,
				   (arg_id == ARG_OBJECT_SIGNAL ||
				    arg_id == ARG_OBJECT_SIGNAL_AFTER),
				   (arg_id == ARG_OBJECT_SIGNAL_AFTER ||
				    arg_id == ARG_SIGNAL_AFTER));
	}
      else
	g_warning ("gtk_object_set_arg(): invalid signal argument: \"%s\"\n", arg->name);
      break;
    default:
      break;
    }
}

static void
gtk_object_get_arg (GtkObject *object,
		    GtkArg    *arg,
		    guint      arg_id)
{
  switch (arg_id)
    {
    case ARG_USER_DATA:
      GTK_VALUE_POINTER (*arg) = gtk_object_get_user_data (object);
      break;
    case ARG_SIGNAL:
    case ARG_OBJECT_SIGNAL:
    default:
      arg->type = GTK_TYPE_INVALID;
      break;
    }
}

/*****************************************
 * gtk_object_class_add_signals:
 *
 *   arguments:
 *
 *   results:
 *****************************************/

void
gtk_object_class_add_signals (GtkObjectClass *class,
			      guint          *signals,
			      guint           nsignals)
{
  g_return_if_fail (GTK_IS_OBJECT_CLASS (class));
  if (!nsignals)
    return;
  g_return_if_fail (signals != NULL);
  
  class->signals = g_renew (guint, class->signals, class->nsignals + nsignals);
  memcpy (class->signals + class->nsignals, signals, nsignals * sizeof (guint));
  class->nsignals += nsignals;
}

guint
gtk_object_class_user_signal_new (GtkObjectClass     *class,
				  const gchar        *name,
				  GtkSignalRunType    signal_flags,
				  GtkSignalMarshaller marshaller,
				  GtkType             return_val,
				  guint               nparams,
				  ...)
{
  GtkType *params;
  guint i;
  va_list args;
  guint signal_id;

  g_return_val_if_fail (class != NULL, 0);

  if (nparams > 0)
    {
      params = g_new (GtkType, nparams);

      va_start (args, nparams);

      for (i = 0; i < nparams; i++)
	params[i] = va_arg (args, GtkType);

      va_end (args);
    }
  else
    params = NULL;

  signal_id = gtk_signal_newv (name,
			       signal_flags,
			       class->type,
			       0,
			       marshaller,
			       return_val,
			       nparams,
			       params);

  g_free (params);

  if (signal_id)
    gtk_object_class_add_signals (class, &signal_id, 1);

  return signal_id;
}

guint
gtk_object_class_user_signal_newv (GtkObjectClass     *class,
				   const gchar        *name,
				   GtkSignalRunType    signal_flags,
				   GtkSignalMarshaller marshaller,
				   GtkType             return_val,
				   guint               nparams,
				   GtkType	      *params)
{
  guint signal_id;

  g_return_val_if_fail (class != NULL, 0);

  if (nparams > 0)
    g_return_val_if_fail (params != NULL, 0);

  signal_id = gtk_signal_newv (name,
			       signal_flags,
			       class->type,
			       0,
			       marshaller,
			       return_val,
			       nparams,
			       params);

  if (signal_id)
    gtk_object_class_add_signals (class, &signal_id, 1);

  return signal_id;
}

/*****************************************
 * gtk_object_sink:
 *
 *   arguments:
 *
 *   results:
 *****************************************/

void
gtk_object_sink (GtkObject *object)
{
  g_return_if_fail (object != NULL);
  g_return_if_fail (GTK_IS_OBJECT (object));

  if (GTK_OBJECT_FLOATING (object))
    {
      GTK_OBJECT_UNSET_FLAGS (object, GTK_FLOATING);
      gtk_object_unref (object);
    }
}

/*****************************************
 * Weak references.
 *
 * Weak refs are very similar to the old "destroy" signal.  They allow
 * one to register a callback that is called when the weakly
 * referenced object is finalized.
 *  
 * They are not implemented as a signal because they really are
 * special and need to be used with great care.  Unlike signals, which
 * should be able to execute any code whatsoever.
 * 
 * A weakref callback is not allowed to retain a reference to the
 * object.  Object data keys may be retrieved in a weak reference
 * callback.
 * 
 * A weakref callback is called at most once.
 *
 *****************************************/

typedef struct _GtkWeakRef	GtkWeakRef;

struct _GtkWeakRef
{
  GtkWeakRef	   *next;
  GtkDestroyNotify  notify;
  gpointer          data;
};

void
gtk_object_weakref (GtkObject        *object,
		    GtkDestroyNotify  notify,
		    gpointer          data)
{
  GtkWeakRef *weak;

  g_return_if_fail (object != NULL);
  g_return_if_fail (notify != NULL);
  g_return_if_fail (GTK_IS_OBJECT (object));

  if (!quark_weakrefs)
    quark_weakrefs = g_quark_from_static_string ("gtk-weakrefs");

  weak = g_new (GtkWeakRef, 1);
  weak->next = gtk_object_get_data_by_id (object, quark_weakrefs);
  weak->notify = notify;
  weak->data = data;
  gtk_object_set_data_by_id (object, quark_weakrefs, weak);
}

void
gtk_object_weakunref (GtkObject        *object,
		      GtkDestroyNotify  notify,
		      gpointer          data)
{
  GtkWeakRef *weaks, *w, **wp;

  g_return_if_fail (object != NULL);
  g_return_if_fail (GTK_IS_OBJECT (object));

  if (!quark_weakrefs)
    return;

  weaks = gtk_object_get_data_by_id (object, quark_weakrefs);
  for (wp = &weaks; *wp; wp = &(*wp)->next)
    {
      w = *wp;
      if (w->notify == notify && w->data == data)
	{
	  if (w == weaks)
	    gtk_object_set_data_by_id (object, quark_weakrefs, w->next);
	  else
	    *wp = w->next;
	  g_free (w);
	  return;
	}
    }
}

static void
gtk_object_notify_weaks (GtkObject *object)
{
  if (quark_weakrefs)
    {
      GtkWeakRef *w1, *w2;
      
      w1 = gtk_object_get_data_by_id (object, quark_weakrefs);
      
      while (w1)
	{
	  w1->notify (w1->data);
	  w2 = w1->next;
	  g_free (w1);
	  w1 = w2;
	}
    }
}

/****************************************************
 * GtkObject argument mechanism and object creation
 *
 ****************************************************/

GtkObject*
gtk_object_new (GtkType      object_type,
		const gchar *first_arg_name,
		...)
{
  GtkObject *object;
  va_list var_args;
  GSList *arg_list = NULL;
  GSList *info_list = NULL;
  gchar *error;

  g_return_val_if_fail (GTK_FUNDAMENTAL_TYPE (object_type) == GTK_TYPE_OBJECT, NULL);

  object = gtk_type_new (object_type);

  va_start (var_args, first_arg_name);
  error = gtk_object_args_collect (GTK_OBJECT_TYPE (object),
				   &arg_list,
				   &info_list,
				   first_arg_name,
				   var_args);
  va_end (var_args);
  
  if (error)
    {
      g_warning ("gtk_object_new(): %s", error);
      g_free (error);
    }
  else
    {
      GSList *slist_arg;
      GSList *slist_info;
      
      slist_arg = arg_list;
      slist_info = info_list;
      while (slist_arg)
	{
	  gtk_object_arg_set (object, slist_arg->data, slist_info->data);
	  slist_arg = slist_arg->next;
	  slist_info = slist_info->next;
	}
      gtk_args_collect_cleanup (arg_list, info_list);
    }

  if (!GTK_OBJECT_CONSTRUCTED (object))
    gtk_object_default_construct (object);

  return object;
}

GtkObject*
gtk_object_newv (GtkType  object_type,
		 guint    n_args,
		 GtkArg  *args)