/*
 * e-shell-backend.h
 *
 * This program 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 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

/**
 * SECTION: e-shell-backend
 * @short_description: dynamically loaded capabilities
 * @include: shell/e-shell-backend.h
 **/

#ifndef E_SHELL_BACKEND_H
#define E_SHELL_BACKEND_H

#include <shell/e-shell-common.h>
#include <widgets/misc/e-activity.h>

/* Standard GObject macros */
#define E_TYPE_SHELL_BACKEND \
	(e_shell_backend_get_type ())
#define E_SHELL_BACKEND(obj) \
	(G_TYPE_CHECK_INSTANCE_CAST \
	((obj), E_TYPE_SHELL_BACKEND, EShellBackend))
#define E_SHELL_BACKEND_CLASS(cls) \
	(G_TYPE_CHECK_CLASS_CAST \
	((cls), E_TYPE_SHELL_BACKEND, EShellBackendClass))
#define E_IS_SHELL_BACKEND(obj) \
	(G_TYPE_CHECK_INSTANCE_TYPE \
	((obj), E_TYPE_SHELL_BACKEND))
#define E_IS_SHELL_BACKEND_CLASS(cls) \
	(G_TYPE_CHECK_CLASS_TYPE \
	((cls), E_TYPE_SHELL_BACKEND))
#define E_SHELL_BACKEND_GET_CLASS(obj) \
	(G_TYPE_INSTANCE_GET_CLASS \
	((obj), E_TYPE_SHELL_BACKEND, EShellBackendClass))

G_BEGIN_DECLS

/* Avoid including <e-shell.h>, because it includes us! */
struct _EShell;

typedef struct _EShellBackend EShellBackend;
typedef struct _EShellBackendClass EShellBackendClass;
typedef struct _EShellBackendPrivate EShellBackendPrivate;

/**
 * EShellBackend:
 *
 * Contains only private data that should be read and manipulated using the
 * functions below.
 **/
struct _EShellBackend {
	GObject parent;
	EShellBackendPrivate *priv;
};

/**
 * EShellBackendClass:
 * @parent_class:	The parent class structure.
 * @name:		The name of the backend.  Also becomes the name of
 * 			the corresponding #EShellView subclass that the
 * 			backend will register.
 * @aliases:		Colon-separated list of aliases that can be used
 * 			when referring to a backend by name.
 * @schemes:		Colon-separated list of URI schemes.  The #EShell
 * 			will forward command-line URIs to the appropriate
 * 			backend based on this list.
 * @sort_order:		Used to determine the order of backends listed in
 * 			the main menu and in the switcher.  See
 * 			e_shell_backend_compare().
 * @shell_view_type:	#GType for the corresponding #EShellView subclass.
 * @start:		Method for notifying the backend to begin loading
 * 			data and running background tasks.  This is called
 * 			just before the first instantiation of the
 * 			corresponding #EShellView subclass.  It allows the
 * 			backend to delay initialization steps that consume
 * 			significant resources until they are actually needed.
 * @is_busy:		Method for querying whether the backend has operations
 * 			in progress that cannot be cancelled or finished
 * 			immediately.  Returning %TRUE prevents the application
 * 			from shutting down.
 * @shutdown:		Method for notifying the backend to begin shutting
 * 			down.  Returning %FALSE indicates there are still
 * 			unfinished operations and the #EShell should check
 * 			back shortly.
 * @migrate:		Method for notifying the backend to migrate data and
 * 			settings from the given version.  Returns %TRUE if the
 * 			migration was successful or if no action was necessary.
 * 			Returns %FALSE and sets a #GError if the migration
 * 			failed.
 *
 * #EShellBackendClass contains a number of important settings for subclasses.
 **/
struct _EShellBackendClass {
	GObjectClass parent_class;

	GType shell_view_type;

	const gchar *name;
	const gchar *aliases;
	const gchar *schemes;
	gint sort_order;

	/* Methods */
	void		(*start)		(EShellBackend *shell_backend);
	gboolean	(*is_busy)		(EShellBackend *shell_backend);
	gboolean	(*shutdown)		(EShellBackend *shell_backend);
	gboolean	(*migrate)		(EShellBackend *shell_backend,
						 gint major,
						 gint minor,
						 gint micro,
						 GError **error);
};

GType		e_shell_backend_get_type		(void);
gint		e_shell_backend_compare		(EShellBackend *shell_backend_a,
						 EShellBackend *shell_backend_b);
const gchar *	e_shell_backend_get_config_dir	(EShellBackend *shell_backend);
const gchar *	e_shell_backend_get_data_dir	(EShellBackend *shell_backend);
const gchar *	e_shell_backend_get_filename	(EShellBackend *shell_backend);
struct _EShell *e_shell_backend_get_shell	(EShellBackend *shell_backend);
void		e_shell_backend_add_activity	(EShellBackend *shell_backend,
						 EActivity *activity);
void		e_shell_backend_start		(EShellBackend *shell_backend);
gboolean	e_shell_backend_is_busy		(EShellBackend *shell_backend);
gboolean	e_shell_backend_shutdown	(EShellBackend *shell_backend);
gboolean	e_shell_backend_migrate		(EShellBackend *shell_backend,
						 gint major,
						 gint minor,
						 gint micro,
						 GError **error);

G_END_DECLS

#endif /* E_SHELL_BACKEND_H */