/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */

/*

 * gtksourceundomanager.c

 * This file is part of GtkSourceView

 *

 * Copyright (C) 1998, 1999 Alex Roberts, Evan Lawrence

 * Copyright (C) 2000, 2001 Chema Celorio, Paolo Maggi

 * Copyright (C) 2002-2005  Paolo Maggi

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <glib.h>

#include <stdlib.h>

#include <string.h>

#include "gtksourceundomanager.h"

/**

 * SECTION:undomanager

 * @short_description: Undo manager interface for GtkSourceView

 * @title: GtkSourceUndoManager

 * @see_also: #GtkTextBuffer, #GtkSourceView

 *

 * For most uses it isn't needed to use #GtkSourceUndoManager. #GtkSourceBuffer

 * already provides an API and a default implementation for the undo/redo.

 *

 * For specific needs, the #GtkSourceUndoManager interface can be implemented to

 * provide custom undo management. Use gtk_source_buffer_set_undo_manager() to

 * install a custom undo manager for a particular #GtkSourceBuffer.

 *

 * Use gtk_source_undo_manager_can_undo_changed() and

 * gtk_source_undo_manager_can_redo_changed() when respectively the undo state

 * or redo state of the undo stack has changed.

 *

 * Since: 2.10

 */

enum

{

	CAN_UNDO_CHANGED,

	CAN_REDO_CHANGED,

	N_SIGNALS

};

static guint signals[N_SIGNALS];

typedef GtkSourceUndoManagerIface GtkSourceUndoManagerInterface;

G_DEFINE_INTERFACE (GtkSourceUndoManager, gtk_source_undo_manager, G_TYPE_OBJECT)

static gboolean

gtk_source_undo_manager_can_undo_default (GtkSourceUndoManager *manager)

{

	return FALSE;

}

static gboolean

gtk_source_undo_manager_can_redo_default (GtkSourceUndoManager *manager)

{

	return FALSE;

}

static void

gtk_source_undo_manager_undo_default (GtkSourceUndoManager *manager)

{

}

static void

gtk_source_undo_manager_redo_default (GtkSourceUndoManager *manager)

{

}

static void

gtk_source_undo_manager_begin_not_undoable_action_default (GtkSourceUndoManager *manager)

{

}

static void

gtk_source_undo_manager_end_not_undoable_action_default (GtkSourceUndoManager *manager)

{

}

static void

gtk_source_undo_manager_default_init (GtkSourceUndoManagerIface *iface)

{

	iface->can_undo = gtk_source_undo_manager_can_undo_default;

	iface->can_redo = gtk_source_undo_manager_can_redo_default;

	iface->undo = gtk_source_undo_manager_undo_default;

	iface->redo = gtk_source_undo_manager_redo_default;

	iface->begin_not_undoable_action = gtk_source_undo_manager_begin_not_undoable_action_default;

	iface->end_not_undoable_action = gtk_source_undo_manager_end_not_undoable_action_default;

	/**

	 * GtkSourceUndoManager::can-undo-changed:

	 * @manager: The #GtkSourceUndoManager

	 *

	 * Emitted when the ability to undo has changed.

	 *

	 * Since: 2.10

	 *

	 */

	signals[CAN_UNDO_CHANGED] =

		g_signal_new ("can-undo-changed",

			      G_TYPE_FROM_INTERFACE (iface),

			      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,

			      G_STRUCT_OFFSET (GtkSourceUndoManagerIface, can_undo_changed),

			      NULL, NULL, NULL,

			      G_TYPE_NONE,

			      0);

	/**

	 * GtkSourceUndoManager::can-redo-changed:

	 * @manager: The #GtkSourceUndoManager

	 *

	 * Emitted when the ability to redo has changed.

	 *

	 * Since: 2.10

	 *

	 */

	signals[CAN_REDO_CHANGED] =

		g_signal_new ("can-redo-changed",

			      G_TYPE_FROM_INTERFACE (iface),

			      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,

			      G_STRUCT_OFFSET (GtkSourceUndoManagerIface, can_redo_changed),

			      NULL, NULL, NULL,

			      G_TYPE_NONE,

			      0);

}

/**

 * gtk_source_undo_manager_can_undo:

 * @manager: a #GtkSourceUndoManager.

 *

 * Get whether there are undo operations available.

 *

 * Returns: %TRUE if there are undo operations available, %FALSE otherwise

 *

 * Since: 2.10

 */

gboolean

gtk_source_undo_manager_can_undo (GtkSourceUndoManager *manager)

{

	g_return_val_if_fail (GTK_SOURCE_IS_UNDO_MANAGER (manager), FALSE);

	return GTK_SOURCE_UNDO_MANAGER_GET_INTERFACE (manager)->can_undo (manager);

}

/**

 * gtk_source_undo_manager_can_redo:

 * @manager: a #GtkSourceUndoManager.

 *

 * Get whether there are redo operations available.

 *

 * Returns: %TRUE if there are redo operations available, %FALSE otherwise

 *

 * Since: 2.10

 */

gboolean

gtk_source_undo_manager_can_redo (GtkSourceUndoManager *manager)

{

	g_return_val_if_fail (GTK_SOURCE_IS_UNDO_MANAGER (manager), FALSE);

	return GTK_SOURCE_UNDO_MANAGER_GET_INTERFACE (manager)->can_redo (manager);

}

/**

 * gtk_source_undo_manager_undo:

 * @manager: a #GtkSourceUndoManager.

 *

 * Perform a single undo. Calling this function when there are no undo operations

 * available is an error. Use gtk_source_undo_manager_can_undo() to find out

 * if there are undo operations available.

 *

 * Since: 2.10

 */

void

gtk_source_undo_manager_undo (GtkSourceUndoManager *manager)

{

	g_return_if_fail (GTK_SOURCE_IS_UNDO_MANAGER (manager));

	GTK_SOURCE_UNDO_MANAGER_GET_INTERFACE (manager)->undo (manager);

}

/**

 * gtk_source_undo_manager_redo:

 * @manager: a #GtkSourceUndoManager.

 *

 * Perform a single redo. Calling this function when there are no redo operations

 * available is an error. Use gtk_source_undo_manager_can_redo() to find out

 * if there are redo operations available.

 *

 * Since: 2.10

 */

void

gtk_source_undo_manager_redo (GtkSourceUndoManager *manager)

{

	g_return_if_fail (GTK_SOURCE_IS_UNDO_MANAGER (manager));

	GTK_SOURCE_UNDO_MANAGER_GET_INTERFACE (manager)->redo (manager);

}

/**

 * gtk_source_undo_manager_begin_not_undoable_action:

 * @manager: a #GtkSourceUndoManager.

 *

 * Begin a not undoable action on the buffer. All changes between this call

 * and the call to gtk_source_undo_manager_end_not_undoable_action() cannot

 * be undone. This function should be re-entrant.

 *

 * Since: 2.10

 */

void

gtk_source_undo_manager_begin_not_undoable_action (GtkSourceUndoManager *manager)

{

	g_return_if_fail (GTK_SOURCE_IS_UNDO_MANAGER (manager));

	GTK_SOURCE_UNDO_MANAGER_GET_INTERFACE (manager)->begin_not_undoable_action (manager);

}

/**

 * gtk_source_undo_manager_end_not_undoable_action:

 * @manager: a #GtkSourceUndoManager.

 *

 * Ends a not undoable action on the buffer.

 *

 * Since: 2.10

 */

void

gtk_source_undo_manager_end_not_undoable_action (GtkSourceUndoManager *manager)

{

	g_return_if_fail (GTK_SOURCE_IS_UNDO_MANAGER (manager));

	GTK_SOURCE_UNDO_MANAGER_GET_INTERFACE (manager)->end_not_undoable_action (manager);

}

/**

 * gtk_source_undo_manager_can_undo_changed:

 * @manager: a #GtkSourceUndoManager.

 *

 * Emits the #GtkSourceUndoManager::can-undo-changed signal.

 *

 * Since: 2.10

 **/

void

gtk_source_undo_manager_can_undo_changed (GtkSourceUndoManager *manager)

{

	g_return_if_fail (GTK_SOURCE_IS_UNDO_MANAGER (manager));

	g_signal_emit (manager, signals[CAN_UNDO_CHANGED], 0);

}

/**

 * gtk_source_undo_manager_can_redo_changed:

 * @manager: a #GtkSourceUndoManager.

 *

 * Emits the #GtkSourceUndoManager::can-redo-changed signal.

 *

 * Since: 2.10

 **/

void

gtk_source_undo_manager_can_redo_changed (GtkSourceUndoManager *manager)

{

	g_return_if_fail (GTK_SOURCE_IS_UNDO_MANAGER (manager));

	g_signal_emit (manager, signals[CAN_REDO_CHANGED], 0);

}