glade-command.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 * Copyright (C) 2002 Joaquín Cuenca Abela
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Authors:
 *   Joaquín Cuenca Abela <e98cuenc@yahoo.com>
 *   Archit Baweja <bighead@users.sourceforge.net>
 */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

/**
 * SECTION:glade-command
 * @Short_Description: An event filter to implement the Undo/Redo stack.
 *
 * The Glade Command api allows us to view user actions as items and execute 
 * and undo those items; each #GladeProject has its own Undo/Redo stack.
 */

#include <gtk/gtk.h>
#include <string.h>
#include <glib/gi18n-lib.h>
#include "glade.h"
#include "glade-project.h"
#include "glade-xml-utils.h"
#include "glade-widget.h"
#include "glade-palette.h"
#include "glade-command.h"
#include "glade-property.h"
#include "glade-property-class.h"
#include "glade-debug.h"
#include "glade-placeholder.h"
#include "glade-clipboard.h"
#include "glade-signal.h"
#include "glade-app.h"
#include "glade-fixed.h"

/* Concerning placeholders: we do not hold any reference to placeholders,
 * placeholders that are supplied by the backend are not reffed, placeholders
 * that are created by glade-command are temporarily owned by glade-command
 * untill they are added to a container; in which case it belongs to GTK+
 * and the backend (but I prefer to think of it as the backend).
 */
typedef struct {
	GladeWidget      *widget;
	GladeWidget      *parent;
	GladeProject     *project;
	GladePlaceholder *placeholder;
	gboolean          props_recorded;
	GList            *pack_props;
	gchar            *special_type;
	gulong            handler_id;
} CommandData;

static GObjectClass *parent_class = NULL;

/* Group description used for the current group
 */
static gchar        *gc_group_description = NULL;

/* Use an id to avoid grouping together consecutive groups
 */
static gint          gc_group_id          = 1;

/* Groups can be grouped together, push/pop must balance (duh!)
 */
static gint          gc_group_depth       = 0;


#define MAKE_TYPE(func, type, parent)			\
GType							\
func ## _get_type (void)				\
{							\
	static GType cmd_type = 0;			\
							\
	if (!cmd_type)					\
	{						\
		static const GTypeInfo info =		\
		{					\
			sizeof (type ## Class),		\
			(GBaseInitFunc) NULL,		\
			(GBaseFinalizeFunc) NULL,	\
			(GClassInitFunc) func ## _class_init,	\
			(GClassFinalizeFunc) NULL,	\
			NULL,				\
			sizeof (type),			\
			0,				\
			(GInstanceInitFunc) NULL	\
		};					\
							\
		cmd_type = g_type_register_static (parent, #type, &info, 0);	\
	}						\
							\
	return cmd_type;				\
}							\

static void
glade_command_finalize (GObject *obj)
{
        GladeCommand *cmd = (GladeCommand *) obj;
        g_return_if_fail (cmd != NULL);

	if (cmd->description)
		g_free (cmd->description);

        /* Call the base class dtor */
	(* G_OBJECT_CLASS (parent_class)->finalize) (obj);
}

static gboolean
glade_command_unifies_impl (GladeCommand *this_cmd, GladeCommand *other_cmd)
{
	return FALSE;
}

static void
glade_command_collapse_impl (GladeCommand *this_cmd, GladeCommand *other_cmd)
{
	g_return_if_reached ();
}

static void
glade_command_class_init (GladeCommandClass *klass)
{
	GObjectClass* object_class;

	object_class = G_OBJECT_CLASS (klass);
	parent_class = g_type_class_peek_parent (klass);

	object_class->finalize = glade_command_finalize;

	klass->undo            = NULL;
	klass->execute         = NULL;
	klass->unifies         = glade_command_unifies_impl;
	klass->collapse        = glade_command_collapse_impl;
}

/* compose the _get_type function for GladeCommand */
MAKE_TYPE (glade_command, GladeCommand, G_TYPE_OBJECT)


#define GLADE_MAKE_COMMAND(type, func)					\
static gboolean								\
func ## _undo (GladeCommand *me);					\
static gboolean								\
func ## _execute (GladeCommand *me);					\
static void								\
func ## _finalize (GObject *object);					\
static gboolean								\
func ## _unifies (GladeCommand *this_cmd, GladeCommand *other_cmd);		\
static void								\
func ## _collapse (GladeCommand *this_cmd, GladeCommand *other_cmd);		\
static void								\
func ## _class_init (gpointer parent_tmp, gpointer notused)		\
{									\
	GladeCommandClass *parent = parent_tmp;				\
	GObjectClass* object_class;					\
	object_class = G_OBJECT_CLASS (parent);				\
	parent->undo =  func ## _undo;					\
	parent->execute =  func ## _execute;				\
	parent->unifies =  func ## _unifies;				\
	parent->collapse =  func ## _collapse;				\
	object_class->finalize = func ## _finalize;			\
}									\
typedef struct {							\
	GladeCommandClass cmd;						\
} type ## Class;							\
static MAKE_TYPE(func, type, GLADE_TYPE_COMMAND)


/**
 * glade_command_execute:
 * @command: A #GladeCommand
 *
 * Executes @command
 *
 * Returns: whether the command was successfully executed
 */
gboolean
glade_command_execute (GladeCommand *command)
{
	g_return_val_if_fail (GLADE_IS_COMMAND (command), FALSE);
	return GLADE_COMMAND_GET_CLASS (command)->execute (command);
}


/**
 * glade_command_undo:
 * @command: A #GladeCommand
 *
 * Undo the effects of @command
 *
 * Returns: whether the command was successfully reversed
 */
gboolean
glade_command_undo (GladeCommand *command)
{
	g_return_val_if_fail (GLADE_IS_COMMAND (command), FALSE);
	return GLADE_COMMAND_GET_CLASS (command)->undo (command);
}

/**
 * glade_command_unifies:
 * @command: A #GladeCommand
 * @other: another #GladeCommand
 *
 * Checks whether @command and @other can be unified
 * to make one single command.
 *
 * Returns: whether they can be unified.
 */
gboolean
glade_command_unifies (GladeCommand *command,
		       GladeCommand *other)
{
	g_return_val_if_fail (command, FALSE);
	return GLADE_COMMAND_GET_CLASS (command)->unifies (command, other);
}

/**
 * glade_command_collapse:
 * @command: A #GladeCommand
 * @other: another #GladeCommand
 *
 * Merges @other into @command, so that @command now
 * covers both commands and @other can be dispensed with.
 */
void
glade_command_collapse (GladeCommand  *command,
			GladeCommand  *other)
{
	g_return_if_fail (command);
	GLADE_COMMAND_GET_CLASS (command)->collapse (command, other);
}

/**
 * glade_command_push_group:
 * @fmt:         The collective desctiption of the command group.
 *               only the description of the first group on the 
 *               stack is used when embedding groups.
 * @...: args to the format string.
 *
 * Marks the begining of a group.
 */
void
glade_command_push_group (const gchar *fmt, ...)
{
	va_list         args;

	g_return_if_fail (fmt);

	/* Only use the description for the first group.
	 */
	if (gc_group_depth++ == 0)
	{
		va_start (args, fmt);
		gc_group_description = g_strdup_vprintf (fmt, args);
		va_end (args);
	}
}

/**
 * glade_command_pop_group:
 *
 * Mark the end of a command group.
 */
void
glade_command_pop_group (void)
{
	if (gc_group_depth-- == 1)
	{
		gc_group_description = (g_free (gc_group_description), NULL);
		gc_group_id++;
	}

	if (gc_group_depth < 0)
		g_critical ("Unbalanced group stack detected in %s\n",
			    G_STRFUNC);
}

gint
glade_command_get_group_depth (void)
{
	return gc_group_depth;
}

static void
glade_command_check_group (GladeCommand *cmd)
{
	g_return_if_fail (GLADE_IS_COMMAND (cmd));
	if (gc_group_description)
	{
		cmd->description = 
			(g_free (cmd->description), g_strdup (gc_group_description));
		cmd->group_id = gc_group_id;
	}
}

/**************************************************/
/*******     GLADE_COMMAND_SET_PROPERTY     *******/
/**************************************************/

/* create a new GladeCommandSetProperty class.  Objects of this class will
 * encapsulate a "set property" operation */

typedef struct {
	GladeCommand  parent;
	gboolean      set_once;
	gboolean      undo;
	GList        *sdata;
} GladeCommandSetProperty;

/* standard macros */
GLADE_MAKE_COMMAND (GladeCommandSetProperty, glade_command_set_property);
#define GLADE_COMMAND_SET_PROPERTY_TYPE		(glade_command_set_property_get_type ())
#define GLADE_COMMAND_SET_PROPERTY(o)	  	(G_TYPE_CHECK_INSTANCE_CAST ((o), GLADE_COMMAND_SET_PROPERTY_TYPE, GladeCommandSetProperty))
#define GLADE_COMMAND_SET_PROPERTY_CLASS(k)	(G_TYPE_CHECK_CLASS_CAST ((k), GLADE_COMMAND_SET_PROPERTY_TYPE, GladeCommandSetPropertyClass))
#define GLADE_IS_COMMAND_SET_PROPERTY(o)	(G_TYPE_CHECK_INSTANCE_TYPE ((o), GLADE_COMMAND_SET_PROPERTY_TYPE))
#define GLADE_IS_COMMAND_SET_PROPERTY_CLASS(k)	(G_TYPE_CHECK_CLASS_TYPE ((k), GLADE_COMMAND_SET_PROPERTY_TYPE))

/* Undo the last "set property command" */
static gboolean
glade_command_set_property_undo (GladeCommand *cmd)
{
	return glade_command_set_property_execute (cmd);
}

/*
 * Execute the set property command and revert it. IE, after the execution of 
 * this function cmd will point to the undo action
 */
static gboolean
glade_command_set_property_execute (GladeCommand *cmd)
{
	GladeCommandSetProperty* me = (GladeCommandSetProperty*) cmd;
	GList *l;
	gboolean success;
	gboolean retval = FALSE;

	g_return_val_if_fail (me != NULL, FALSE);

	if (me->set_once != FALSE)
		glade_property_push_superuser ();

	for (l = me->sdata; l; l = l->next)
	{
		GValue new_value = { 0, };
		GCSetPropData *sdata = l->data;

		g_value_init (&new_value, G_VALUE_TYPE (sdata->new_value));
		
		if (me->undo)
			g_value_copy (sdata->old_value, &new_value);
		else
			g_value_copy (sdata->new_value, &new_value);

#if 0
		{
			gchar *str =
				glade_widget_adaptor_string_from_value
				(GLADE_WIDGET_ADAPTOR (sdata->property->klass->handle),
				 sdata->property->klass, &new_value);

			g_print ("Setting %s property of %s to %s (sumode: %d)\n",
				 sdata->property->klass->id,
				 sdata->property->widget->name,
				 str, glade_property_superuser ());

			g_free (str);
		}
#endif

		/* Packing properties need to be refreshed here since
		 * they are reset when they get added to containers.
		 */
		if (sdata->property->klass->packing)
		{
			GladeProperty *tmp_prop;

			tmp_prop = glade_widget_get_pack_property
				(sdata->property->widget, sdata->property->klass->id);

			if (sdata->property != tmp_prop)
			{
				g_object_unref (sdata->property);
				sdata->property = g_object_ref (tmp_prop);
				
			}
		}

		success = glade_property_set_value (sdata->property, &new_value);
		retval = retval || success;

		if (!me->set_once && success)
		{
			/* If some verify functions didnt pass on 
			 * the first go.. we need to record the actual
			 * properties here.
			 */
			g_value_copy (sdata->property->value, 
				      sdata->new_value);
		}


		g_value_unset (&new_value);


	}

	if (me->set_once != FALSE)
		glade_property_pop_superuser ();

	me->set_once = TRUE;
	me->undo     = !me->undo;

	return retval;
}

static void
glade_command_set_property_finalize (GObject *obj)
{
	GladeCommandSetProperty *me;
	GList *l;

	me = GLADE_COMMAND_SET_PROPERTY (obj);

	for (l = me->sdata; l; l = l->next)
	{
		GCSetPropData *sdata = l->data;
		
		if (sdata->property)
			g_object_unref (G_OBJECT (sdata->property));

		if (sdata->old_value)
		{
			if (G_VALUE_TYPE (sdata->old_value) != 0)
				g_value_unset (sdata->old_value);
			g_free (sdata->old_value);
		}
		if (G_VALUE_TYPE (sdata->new_value) != 0)
			g_value_unset (sdata->new_value);
		g_free (sdata->new_value);

	}
	glade_command_finalize (obj);
}

static gboolean
glade_command_set_property_unifies (GladeCommand *this_cmd, GladeCommand *other_cmd)
{
       GladeCommandSetProperty *cmd1,   *cmd2;
       GCSetPropData           *pdata1, *pdata2;
       GList                   *list, *l;

	if (!other_cmd)
	{
		if (GLADE_IS_COMMAND_SET_PROPERTY (this_cmd))
		{
			cmd1 = (GladeCommandSetProperty*) this_cmd;
			
			for (list = cmd1->sdata; list; list = list->next)
			{
				GladeProject *project;
				GladeProjectFormat fmt = GLADE_PROJECT_FORMAT_GTKBUILDER;
				pdata1 = list->data;
				
				if (pdata1->property->widget)
				{
					project = glade_widget_get_project (pdata1->property->widget);
					fmt     = glade_project_get_format (project);
				}

				if (glade_property_class_compare (pdata1->property->klass,
								  pdata1->old_value,
								  pdata1->new_value, fmt))
					return FALSE;
			}
			return TRUE;
				
		}
		return FALSE;
	}

       if (GLADE_IS_COMMAND_SET_PROPERTY (this_cmd) && 
	   GLADE_IS_COMMAND_SET_PROPERTY (other_cmd))
       {
               cmd1 = (GladeCommandSetProperty*) this_cmd;
               cmd2 = (GladeCommandSetProperty*) other_cmd;

	       if (g_list_length (cmd1->sdata) != 
		   g_list_length (cmd2->sdata))
		       return FALSE;

	       for (list = cmd1->sdata; list; list = list->next)
	       {
		       pdata1 = list->data;
		       for (l = cmd2->sdata; l; l = l->next)
		       {
			       pdata2 = l->data;

			       if (pdata1->property->widget == pdata2->property->widget &&
				   glade_property_class_match (pdata1->property->klass,
							       pdata2->property->klass))
				       break;
		       }
		       
		       /* If both lists are the same length, and one class type
			* is not found in the other list, then we cant unify.
			*/
		       if (l == NULL)
			       return FALSE;

	       }

	       return TRUE;
       }
       return FALSE;
}

static void
glade_command_set_property_collapse (GladeCommand *this_cmd, GladeCommand *other_cmd)
{
	GladeCommandSetProperty *cmd1,   *cmd2;
	GCSetPropData           *pdata1, *pdata2;
	GList                   *list, *l;
	
	g_return_if_fail (GLADE_IS_COMMAND_SET_PROPERTY (this_cmd) &&
			  GLADE_IS_COMMAND_SET_PROPERTY (other_cmd));
	
	cmd1 = (GladeCommandSetProperty*) this_cmd;
	cmd2 = (GladeCommandSetProperty*) other_cmd;


	for (list = cmd1->sdata; list; list = list->next)
	{
		pdata1 = list->data;
		for (l = cmd2->sdata; l; l = l->next)
		{
			pdata2 = l->data;
			
			if (glade_property_class_match (pdata1->property->klass,
							pdata2->property->klass))
			{
				/* Merge the GCSetPropData structs manually here
				 */
				g_value_copy (pdata2->new_value, pdata1->new_value);
				break;
			}
		}
	}

	/* Set the description
	 */
	g_free (this_cmd->description);
	this_cmd->description = other_cmd->description;
	other_cmd->description = NULL;

	glade_app_update_ui ();
}


#define MAX_UNDO_MENU_ITEM_VALUE_LEN	10
static gchar *
glade_command_set_property_description (GladeCommandSetProperty *me,
					GladeProjectFormat       fmt)
{
	GCSetPropData   *sdata;
	gchar *description = NULL;
	gchar *value_name;

	g_assert (me->sdata);

	if (g_list_length (me->sdata) > 1)
		description = g_strdup_printf (_("Setting multiple properties"));
	else 
	{
		sdata = me->sdata->data;
		value_name = glade_widget_adaptor_string_from_value
			(GLADE_WIDGET_ADAPTOR (sdata->property->klass->handle),
			 sdata->property->klass, sdata->new_value, fmt);

		if (!value_name || strlen (value_name) > MAX_UNDO_MENU_ITEM_VALUE_LEN
		    || strchr (value_name, '_')) {
			description = g_strdup_printf (_("Setting %s of %s"),
						       sdata->property->klass->name,
						       sdata->property->widget->name);
		} else {
			description = g_strdup_printf (_("Setting %s of %s to %s"),
						       sdata->property->klass->name,
						       sdata->property->widget->name, value_name);
		}
		g_free (value_name);
	}

	return description;
}


void
glade_command_set_properties_list (GladeProject *project, GList *props)
{
	GladeCommandSetProperty *me;
	GladeCommand  *cmd;
	GCSetPropData *sdata;
	GList         *list;
	gboolean       success;

	g_return_if_fail (GLADE_IS_PROJECT (project));
	g_return_if_fail (props);

	me = (GladeCommandSetProperty*) g_object_new (GLADE_COMMAND_SET_PROPERTY_TYPE, NULL);
	cmd = GLADE_COMMAND (me);

	/* Ref all props */
	for (list = props; list; list = list->next)
	{
		sdata = list->data;
		g_object_ref (G_OBJECT (sdata->property));
	}

	me->sdata        = props;
	cmd->description = NULL;

	glade_command_push_group (glade_command_set_property_description 
				  (me, glade_project_get_format (project)));
	glade_command_check_group (GLADE_COMMAND (me));

	/* Push onto undo stack only if it executes successfully. */
	success = glade_command_set_property_execute (GLADE_COMMAND (me));

	glade_command_pop_group ();
	
	if (success)
		glade_project_push_undo (GLADE_PROJECT (project),
					 GLADE_COMMAND (me));
	else
		/* No leaks on my shift! */
		g_object_unref (G_OBJECT (me));
}


void
glade_command_set_properties (GladeProperty *property, const GValue *old_value, const GValue *new_value, ...)
{
	GCSetPropData *sdata;
	GladeProperty *prop;
	GValue        *ovalue, *nvalue;
	GList         *list = NULL;
	va_list        vl;

	g_return_if_fail (GLADE_IS_PROPERTY (property));

	/* Add first set */
	sdata = g_new (GCSetPropData, 1);
	sdata->property = property;
	sdata->old_value = g_new0 (GValue, 1);
	sdata->new_value = g_new0 (GValue, 1);
	g_value_init (sdata->old_value, G_VALUE_TYPE (old_value));
	g_value_init (sdata->new_value, G_VALUE_TYPE (new_value));
	g_value_copy (old_value, sdata->old_value);
	g_value_copy (new_value, sdata->new_value);
	list = g_list_prepend (list, sdata);

	va_start (vl, new_value);
	while ((prop = va_arg (vl, GladeProperty *)) != NULL)
	{
		ovalue = va_arg (vl, GValue *);
		nvalue = va_arg (vl, GValue *);
		
		g_assert (GLADE_IS_PROPERTY (prop));
		g_assert (G_IS_VALUE (ovalue));
		g_assert (G_IS_VALUE (nvalue));

		sdata = g_new (GCSetPropData, 1);
		sdata->property = g_object_ref (G_OBJECT (prop));
		sdata->old_value = g_new0 (GValue, 1);
		sdata->new_value = g_new0 (GValue, 1);
		g_value_init (sdata->old_value, G_VALUE_TYPE (ovalue));
		g_value_init (sdata->new_value, G_VALUE_TYPE (nvalue));
		g_value_copy (ovalue, sdata->old_value);
		g_value_copy (nvalue, sdata->new_value);
		list = g_list_prepend (list, sdata);
	}	
	va_end (vl);

	glade_command_set_properties_list (property->widget->project, list);
}

void
glade_command_set_property_value (GladeProperty *property, const GValue* pvalue)
{

	/* Dont generate undo/redo items for unchanging property values.
	 */
	if (glade_property_equals_value (property, pvalue))
		return;

	glade_command_set_properties (property, property->value, pvalue, NULL);
}

void
glade_command_set_property (GladeProperty *property, ...)
{
	GValue *value;
	va_list args;
	
	g_return_if_fail (GLADE_IS_PROPERTY (property));

	va_start (args, property);
	value = glade_property_class_make_gvalue_from_vl (property->klass, args);
	va_end (args);
	
	glade_command_set_property_value (property, value);
}

/**************************************************/
/*******       GLADE_COMMAND_SET_NAME       *******/
/**************************************************/

/* create a new GladeCommandSetName class.  Objects of this class will
 * encapsulate a "set name" operation */
typedef struct {
	GladeCommand parent;

	GladeWidget *widget;
	gchar *old_name;
	gchar *name;
} GladeCommandSetName;

/* standard macros */
GLADE_MAKE_COMMAND (GladeCommandSetName, glade_command_set_name);
#define GLADE_COMMAND_SET_NAME_TYPE		(glade_command_set_name_get_type ())
#define GLADE_COMMAND_SET_NAME(o)	  	(G_TYPE_CHECK_INSTANCE_CAST ((o), GLADE_COMMAND_SET_NAME_TYPE, GladeCommandSetName))
#define GLADE_COMMAND_SET_NAME_CLASS(k)	(G_TYPE_CHECK_CLASS_CAST ((k), GLADE_COMMAND_SET_NAME_TYPE, GladeCommandSetNameClass))
#define GLADE_IS_COMMAND_SET_NAME(o)		(G_TYPE_CHECK_INSTANCE_TYPE ((o), GLADE_COMMAND_SET_NAME_TYPE))
#define GLADE_IS_COMMAND_SET_NAME_CLASS(k)	(G_TYPE_CHECK_CLASS_TYPE ((k), GLADE_COMMAND_SET_NAME_TYPE))

/* Undo the last "set name command" */
static gboolean
glade_command_set_name_undo (GladeCommand *cmd)
{
	return glade_command_set_name_execute (cmd);
}

/*
 * Execute the set name command and revert it.  Ie, after the execution of this
 * function cmd will point to the undo action
 */
static gboolean
glade_command_set_name_execute (GladeCommand *cmd)
{
	GladeCommandSetName* me = GLADE_COMMAND_SET_NAME (cmd);
	char* tmp;

	g_return_val_if_fail (me != NULL, TRUE);
	g_return_val_if_fail (me->widget != NULL, TRUE);
	g_return_val_if_fail (me->name != NULL, TRUE);

	glade_widget_set_name (me->widget, me->name);
	
	tmp = me->old_name;
	me->old_name = me->name;
	me->name = tmp;

	return TRUE;
}

static void
glade_command_set_name_finalize (GObject *obj)
{
	GladeCommandSetName* me;

	g_return_if_fail (GLADE_IS_COMMAND_SET_NAME (obj));

	me = GLADE_COMMAND_SET_NAME (obj);

	g_free (me->old_name);
	g_free (me->name);

	glade_command_finalize (obj);
}

static gboolean
glade_command_set_name_unifies (GladeCommand *this_cmd, GladeCommand *other_cmd)
{
	GladeCommandSetName *cmd1;
	GladeCommandSetName *cmd2;

	if (GLADE_IS_COMMAND_SET_NAME (this_cmd) && GLADE_IS_COMMAND_SET_NAME (other_cmd))
	{
		cmd1 = GLADE_COMMAND_SET_NAME (this_cmd);
		cmd2 = GLADE_COMMAND_SET_NAME (other_cmd);

		return (cmd1->widget == cmd2->widget);
	}

	return FALSE;
}

static void
glade_command_set_name_collapse (GladeCommand *this_cmd, GladeCommand *other_cmd)
{
	GladeCommandSetName *nthis = GLADE_COMMAND_SET_NAME (this_cmd);
	GladeCommandSetName *nother = GLADE_COMMAND_SET_NAME (other_cmd);

	g_return_if_fail (GLADE_IS_COMMAND_SET_NAME (this_cmd) && GLADE_IS_COMMAND_SET_NAME (other_cmd));

	g_free (nthis->old_name);
	nthis->old_name = nother->old_name;
	nother->old_name = NULL;

	g_free (this_cmd->description);
	this_cmd->description = g_strdup_printf (_("Renaming %s to %s"), nthis->name, nthis->old_name);

	glade_app_update_ui ();
}

/* this function takes the ownership of name */
void
glade_command_set_name (GladeWidget *widget, const gchar* name)
{
	GladeCommandSetName *me;
	GladeCommand *cmd;

	g_return_if_fail (GLADE_IS_WIDGET (widget));
	g_return_if_fail (name != NULL);

	/* Dont spam the queue with false name changes.
	 */
	if (!strcmp (widget->name, name))
		return;

	me = g_object_new (GLADE_COMMAND_SET_NAME_TYPE, NULL);
	cmd = GLADE_COMMAND (me);

	me->widget = widget;
	me->name = g_strdup (name);
	me->old_name = g_strdup (widget->name);

	cmd->description = g_strdup_printf (_("Renaming %s to %s"), me->old_name, me->name);

	glade_command_check_group (GLADE_COMMAND (me));

	if (glade_command_set_name_execute (GLADE_COMMAND (me)))
		glade_project_push_undo (GLADE_PROJECT (widget->project), GLADE_COMMAND (me));
	else
		g_object_unref (G_OBJECT (me));
}

/******************************************************************************
 * 
 * add/remove
 * 
 * These canonical commands add/remove a widget list to/from the project.
 * 
 *****************************************************************************/

typedef struct {
	GladeCommand	parent;
	GladeProject	*project;
	GList		*widgets;
	gboolean	add;
	gboolean        from_clipboard;
} GladeCommandAddRemove;


GLADE_MAKE_COMMAND (GladeCommandAddRemove, glade_command_add_remove);
#define GLADE_COMMAND_ADD_REMOVE_TYPE			(glade_command_add_remove_get_type ())
#define GLADE_COMMAND_ADD_REMOVE(o)	  			(G_TYPE_CHECK_INSTANCE_CAST ((o), GLADE_COMMAND_ADD_REMOVE_TYPE, GladeCommandAddRemove))
#define GLADE_COMMAND_ADD_REMOVE_CLASS(k)		(G_TYPE_CHECK_CLASS_CAST ((k), GLADE_COMMAND_ADD_REMOVE_TYPE, GladeCommandAddRemoveClass))
#define GLADE_IS_COMMAND_ADD_REMOVE(o)			(G_TYPE_CHECK_INSTANCE_TYPE ((o), GLADE_COMMAND_ADD_REMOVE_TYPE))
#define GLADE_IS_COMMAND_ADD_REMOVE_CLASS(k)	(G_TYPE_CHECK_CLASS_TYPE ((k), GLADE_COMMAND_ADD_REMOVE_TYPE))

static void 
glade_command_placeholder_destroyed (GtkObject *object, CommandData *cdata)
{
	if (GTK_OBJECT (cdata->placeholder) == object)
	{
		cdata->placeholder = NULL;
		cdata->handler_id = 0;
	}
}

static void
glade_command_placeholder_connect (CommandData *cdata,
				   GladePlaceholder *placeholder)
{
	g_assert (cdata && cdata->placeholder == NULL);

	/* Something like a no-op with no placeholder */
	if ((cdata->placeholder = placeholder) == NULL)
		return;

	cdata->handler_id = g_signal_connect 
		(placeholder, "destroy",
		 G_CALLBACK (glade_command_placeholder_destroyed), cdata);
}

/**
 * glade_command_add:
 * @widgets: a #Glist
 * @parent: a #GladeWidget
 * @placeholder: a #GladePlaceholder
 * @pasting: whether we are pasting an existing widget or creating a new one.
 *
 * Performs an add command on all widgets in @widgets to @parent, possibly
 * replacing @placeholder (note toplevels dont need a parent; the active project
 * will be used when pasting toplevel objects).
 * Pasted widgets will persist packing properties from thier cut/copy source
 * while newly added widgets will prefer packing defaults.
 *
 */
static void
glade_command_add (GList            *widgets, 
		   GladeWidget      *parent, 
		   GladePlaceholder *placeholder,
		   gboolean          pasting)
{
	GladeCommandAddRemove	*me;
	CommandData				*cdata;
	GladeWidget				*widget = NULL;
	GList					*l, *list, *children, *placeholders = NULL;
	GtkWidget				*child;

	g_return_if_fail (widgets && widgets->data);
	g_return_if_fail (parent == NULL || GLADE_IS_WIDGET (parent));

	me = g_object_new (GLADE_COMMAND_ADD_REMOVE_TYPE, NULL);
	me->add = TRUE;
	me->from_clipboard = pasting;

	/* Things can go wrong in this function if the dataset is inacurate,
	 * we make no real attempt here to recover, just g_critical() and
	 * fix the bugs as they pop up.
	 */
	widget = GLADE_WIDGET (widgets->data);
	if (placeholder && GTK_IS_WINDOW (widget->object) == FALSE)
	{
		GladeWidget *some_widget = glade_placeholder_get_parent (placeholder);
		me->project = glade_widget_get_project (some_widget);
	}
	else me->project = glade_app_get_project();

	GLADE_COMMAND (me)->description = 
		g_strdup_printf (_("Add %s"), g_list_length (widgets) == 1 ? 
				 widget->name : _("multiple"));

	for (list = widgets; list && list->data; list = list->next)
	{
		widget = list->data;
		cdata = g_new0 (CommandData, 1);
		if (widget->internal)
			g_critical ("Internal widget in Add");

		/* Widget */
		cdata->widget = g_object_ref (G_OBJECT (widget));
		
		/* Parent */
		if (parent == NULL)
			cdata->parent = glade_widget_get_parent (widget);
		else if (placeholder && GTK_IS_WINDOW (widget->object) == FALSE)
			cdata->parent = glade_placeholder_get_parent (placeholder);
		else if (GTK_IS_WINDOW (widget->object) == FALSE)
			cdata->parent = parent;
		if (cdata->parent == NULL && GTK_IS_WINDOW (widget->object) == FALSE)
			g_message ("Parentless non GtkWindow widget in Add");

		/* Placeholder */
		if (placeholder != NULL && g_list_length (widgets) == 1)
		{
			glade_command_placeholder_connect (cdata, placeholder);
		}
		else if (cdata->parent && 
			 glade_widget_placeholder_relation (cdata->parent, widget))
		{
			GtkContainer *cont = GTK_CONTAINER (cdata->parent->object);
			
			child = glade_util_get_placeholder_from_pointer (cont);
			if (child && g_list_find (placeholders, child) == NULL)
			{
				placeholders = g_list_append (placeholders, child);
				glade_command_placeholder_connect
						(cdata, GLADE_PLACEHOLDER (child));
			}
			else if ((children = glade_widget_adaptor_get_children
				 (cdata->parent->adaptor, cdata->parent->object)) != NULL)
			{
				for (l = children; l && l->data; l = l->next)
				{
					child = l->data;

					/* Find a placeholder for this child */
					if (GLADE_IS_PLACEHOLDER (child) &&
					    g_list_find (placeholders, child) == NULL)
					{
						placeholders = g_list_append (placeholders, child);
						glade_command_placeholder_connect
							(cdata, GLADE_PLACEHOLDER (child));
						break;
					}
				}
				g_list_free (children);
			}
		}

		/* 
		 * Save a copy of the original project so we can forward that to glade-project, 
		 * who'll copy in any resource files needed by any properties that are getting 
		 * cross-project pasted.
		 */
		cdata->project = cdata->widget->project;

		me->widgets = g_list_prepend (me->widgets, cdata);
	}

	glade_command_check_group (GLADE_COMMAND (me));

	/*
	 * Push it onto the undo stack only on success
	 */
	if (glade_command_add_remove_execute (GLADE_COMMAND (me)))
		glade_project_push_undo (glade_app_get_project(), GLADE_COMMAND (me));
	else
		g_object_unref (G_OBJECT (me));

	if (placeholders) 
		g_list_free (placeholders);
		
} /* end of glade_command_add() */



static void
glade_command_delete_prop_refs (GladeWidget *widget)
{
	GladeProperty *property;

	while (widget->prop_refs)
	{
		property = GLADE_PROPERTY (widget->prop_refs->data);
		glade_command_set_property (property, NULL);
	}
}


/**
 * glade_command_remove:
 * @widgets: a #GList of #GladeWidgets
 * @return_placeholders: whether or not to return a list of placehodlers
 *
 * Performs a remove command on all widgets in @widgets from @parent.
 */
static void
glade_command_remove (GList *widgets)
{
	GladeCommandAddRemove	*me;
	GladeWidget				*widget = NULL;
	CommandData				*cdata;
	GtkWidget                               *placeholder;
	GList					*list, *l;

	g_return_if_fail (widgets != NULL);

 	me = g_object_new (GLADE_COMMAND_ADD_REMOVE_TYPE, NULL);
	me->add = FALSE;
	me->from_clipboard = FALSE;

	/* internal children cannot be deleted. Notify the user. */
	for (list = widgets; list && list->data; list = list->next)
	{
		widget = list->data;
		if (widget->internal)
		{
			glade_util_ui_message (glade_app_get_window(),	
					       GLADE_UI_WARN, NULL,
					       _("You cannot remove a widget internal to a composite widget."));
			return;
		}
	}

	me->project = glade_widget_get_project (widget);
	GLADE_COMMAND (me)->description = g_strdup ("dummy");

	if (g_list_length (widgets) == 1)
		glade_command_push_group (_("Remove %s"), 
					  GLADE_WIDGET (widgets->data)->name);
	else
		glade_command_push_group (_("Remove multiple"));

	for (list = widgets; list && list->data; list = list->next)
	{
		widget         = list->data;

		cdata          = g_new0 (CommandData, 1);
		cdata->widget  = g_object_ref (G_OBJECT (widget));
		cdata->parent  = glade_widget_get_parent (widget);
		cdata->project = glade_widget_get_project (widget);
		
		/* Undoably unset any object properties that may point to the removed object */
		glade_command_delete_prop_refs (widget);

		if (widget->internal)
			g_critical ("Internal widget in Remove");

		if (cdata->parent != NULL &&