path: root/calendar/pcs/cal-factory.c

/* Evolution calendar factory
 *
 * Copyright (C) 2000 Helix Code, Inc.
 * Copyright (C) 2000 Ximian, Inc.
 *
 * Author: Federico Mena-Quintero <federico@ximian.com>
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 */

#include <config.h>
#include <ctype.h>
#include <stdio.h>
#include <gtk/gtksignal.h>
#include <liboaf/liboaf.h>
#include "cal.h"
#include "cal-backend.h"
#include "cal-factory.h"
#include "job.h"

#define PARENT_TYPE         BONOBO_X_OBJECT_TYPE
#define CAL_FACTORY_OAF_ID "OAFIID:GNOME_Evolution_Wombat_CalendarFactory"

static BonoboXObjectClass *parent_class;

/* Private part of the CalFactory structure */
struct _CalFactoryPrivate {
    /* Hash table from URI method strings to GtkType * for backend class types */
    GHashTable *methods;

    /* Hash table from GnomeVFSURI structures to CalBackend objects */
    GHashTable *backends;

    /* Whether we have been registered with OAF yet */
    guint registered : 1;
};

/* Signal IDs */
enum SIGNALS {
    LAST_CALENDAR_GONE,
    LAST_SIGNAL
};

static guint signals[LAST_SIGNAL];

/* Frees a method/GtkType * pair from the methods hash table */
static void
free_method (gpointer key, gpointer value, gpointer data)
{
    char *method;
    GtkType *type;

    method = key;
    type = value;

    g_free (method);
    g_free (type);
}

/* Frees a uri/backend pair from the backends hash table */
static void
free_backend (gpointer key, gpointer value, gpointer data)
{
    GnomeVFSURI *uri;
    CalBackend *backend;

    uri = key;
    backend = value;

    gnome_vfs_uri_unref (uri);
    gtk_object_unref (GTK_OBJECT (backend));
}

/* Opening calendars */

/* Looks up a calendar backend in a factory's hash table of uri->cal */
static CalBackend *
lookup_backend (CalFactory *factory, GnomeVFSURI *uri)
{
    CalFactoryPrivate *priv;
    CalBackend *backend;

    priv = factory->priv;

    backend = g_hash_table_lookup (priv->backends, uri);
    return backend;
}

/* Callback used when a backend loses its last connected client */
static void
backend_last_client_gone_cb (CalBackend *backend, gpointer data)
{
    CalFactory *factory;
    CalFactoryPrivate *priv;
    GnomeVFSURI *uri;
    gpointer orig_key;
    gboolean result;
    GnomeVFSURI *orig_uri;

    fprintf (stderr, "backend_last_client_gone_cb() called!\n");

    factory = CAL_FACTORY (data);
    priv = factory->priv;

    /* Remove the backend from the hash table */

    uri = cal_backend_get_uri (backend);
    g_assert (uri != NULL);

    result = g_hash_table_lookup_extended (priv->backends, uri, &orig_key, NULL);
    g_assert (result != FALSE);

    orig_uri = orig_key;

    g_hash_table_remove (priv->backends, orig_uri);
    gnome_vfs_uri_unref (orig_uri);

    gtk_object_unref (GTK_OBJECT (backend));

    /* Notify upstream if there are no more backends */

    if (g_hash_table_size (priv->backends) == 0)
        gtk_signal_emit (GTK_OBJECT (factory), signals[LAST_CALENDAR_GONE]);
}

/* Adds a backend to the calendar factory's hash table */
static void
add_backend (CalFactory *factory, GnomeVFSURI *uri, CalBackend *backend)
{
    CalFactoryPrivate *priv;

    priv = factory->priv;

    gnome_vfs_uri_ref (uri);
    g_hash_table_insert (priv->backends, uri, backend);

    gtk_signal_connect (GTK_OBJECT (backend), "last_client_gone",
                GTK_SIGNAL_FUNC (backend_last_client_gone_cb),
                factory);
}

/* Tries to launch a backend for the method of the specified URI.  If there is
 * no such method registered in the factory, it sends the listener the
 * MethodNotSupported error code.
 */
static CalBackend *
launch_backend_for_uri (CalFactory *factory, GnomeVFSURI *uri, GNOME_Evolution_Calendar_Listener listener)
{
    CalFactoryPrivate *priv;
    char *method;
    GtkType *type;
    CalBackend *backend;

    priv = factory->priv;

    /* FIXME: add an accessor function to gnome-vfs */
    method = uri->method_string;

    type = g_hash_table_lookup (priv->methods, method);

    if (!type) {
        CORBA_Environment ev;

        CORBA_exception_init (&ev);
        GNOME_Evolution_Calendar_Listener_notifyCalOpened (
            listener,
            GNOME_Evolution_Calendar_Listener_METHOD_NOT_SUPPORTED,
            CORBA_OBJECT_NIL,
            &ev);

        if (ev._major != CORBA_NO_EXCEPTION)
            g_message ("launch_backend_for_uri(): could not notify the listener");

        CORBA_exception_free (&ev);
        return NULL;
    }

    backend = gtk_type_new (*type);
    if (!backend)
        g_message ("launch_backend_for_uri(): could not launch the backend");

    return backend;
}

/* Opens a calendar backend and puts it in the factory's backend hash table */
static CalBackend *
open_backend (CalFactory *factory, GnomeVFSURI *uri, gboolean only_if_exists,
          GNOME_Evolution_Calendar_Listener listener)
{
    CalFactoryPrivate *priv;
    CalBackend *backend;
    CalBackendOpenStatus status;
    CORBA_Environment ev;

    priv = factory->priv;

    backend = launch_backend_for_uri (factory, uri, listener);
    if (!backend)
        return NULL;

    status = cal_backend_open (backend, uri, only_if_exists);

    switch (status) {
    case CAL_BACKEND_OPEN_SUCCESS:
        add_backend (factory, uri, backend);
        return backend;

    case CAL_BACKEND_OPEN_ERROR:
        gtk_object_unref (GTK_OBJECT (backend));

        CORBA_exception_init (&ev);
        GNOME_Evolution_Calendar_Listener_notifyCalOpened (
            listener,
            GNOME_Evolution_Calendar_Listener_ERROR,
            CORBA_OBJECT_NIL,
            &ev);

        if (ev._major != CORBA_NO_EXCEPTION)
            g_message ("open_backend(): could not notify the listener");

        CORBA_exception_free (&ev);
        return NULL;

    case CAL_BACKEND_OPEN_NOT_FOUND:
        gtk_object_unref (GTK_OBJECT (backend));

        CORBA_exception_init (&ev);
        GNOME_Evolution_Calendar_Listener_notifyCalOpened (
            listener,
            GNOME_Evolution_Calendar_Listener_NOT_FOUND,
            CORBA_OBJECT_NIL,
            &ev);

        if (ev._major != CORBA_NO_EXCEPTION)
            g_message ("open_backend(): could not notify the listener");

        CORBA_exception_free (&ev);
        return NULL;

    default:
        g_assert_not_reached ();
        return NULL;
    }
}

/* Adds a listener to a calendar backend by creating a calendar client interface
 * object.
 */
static void
add_calendar_client (CalFactory *factory, CalBackend *backend, GNOME_Evolution_Calendar_Listener listener)
{
    Cal *cal;
    CORBA_Environment ev;

    cal = cal_new (backend, listener);
    if (!cal) {
        g_message ("add_calendar_client(): could not create the calendar client interface");

        CORBA_exception_init (&ev);
        GNOME_Evolution_Calendar_Listener_notifyCalOpened (
            listener,
            GNOME_Evolution_Calendar_Listener_ERROR,
            CORBA_OBJECT_NIL,
            &ev);
        if (ev._major != CORBA_NO_EXCEPTION)
            g_message ("add_calendar_client(): could not notify the listener");

        CORBA_exception_free (&ev);
        return;
    }

    cal_backend_add_cal (backend, cal);

    CORBA_exception_init (&ev);
    GNOME_Evolution_Calendar_Listener_notifyCalOpened (
        listener,
        GNOME_Evolution_Calendar_Listener_SUCCESS,
        BONOBO_OBJREF (cal),
        &ev);

    if (ev._major != CORBA_NO_EXCEPTION) {
        g_message ("add_calendar_client(): could not notify the listener");
        bonobo_object_unref (BONOBO_OBJECT (cal));
    }

    CORBA_exception_free (&ev);
}

/* Job data */
typedef struct {
    CalFactory *factory;
    char *uri;
    gboolean only_if_exists;
    GNOME_Evolution_Calendar_Listener listener;
} OpenJobData;

/* Job handler for the open calendar command */
static void
open_fn (gpointer data)
{
    OpenJobData *jd;
    CalFactory *factory;
    GnomeVFSURI *uri;
    gboolean only_if_exists;
    GNOME_Evolution_Calendar_Listener listener;
    CalBackend *backend;
    CORBA_Environment ev;

    jd = data;
    g_assert (jd->uri != NULL);

    /* Check the URI */

    uri = gnome_vfs_uri_new (jd->uri);
    g_free (jd->uri);

    only_if_exists = jd->only_if_exists;
    factory = jd->factory;
    listener = jd->listener;
    g_free (jd);

    if (!uri) {
        CORBA_exception_init (&ev);
        GNOME_Evolution_Calendar_Listener_notifyCalOpened (
            listener,
            GNOME_Evolution_Calendar_Listener_ERROR,
            CORBA_OBJECT_NIL,
            &ev);

        if (ev._major != CORBA_NO_EXCEPTION)
            g_message ("open_fn(): Could not notify the listener!");

        CORBA_exception_free (&ev);
        goto out;
    }

    /* Look up the backend and create it if needed */

    backend = lookup_backend (factory, uri);

    if (!backend)
        backend = open_backend (factory, uri, only_if_exists, listener);

    gnome_vfs_uri_unref (uri);

    if (backend)
        add_calendar_client (factory, backend, listener);

 out:

    CORBA_exception_init (&ev);
    CORBA_Object_release (listener, &ev);

    if (ev._major != CORBA_NO_EXCEPTION)
        g_message ("open_fn(): could not release the listener");

    CORBA_exception_free (&ev);
}



static void
impl_CalFactory_open (PortableServer_Servant servant,
              const CORBA_char *uri,
              CORBA_boolean only_if_exists,
              GNOME_Evolution_Calendar_Listener listener,
              CORBA_Environment *ev)
{
    CalFactory *factory;
    CalFactoryPrivate *priv;
    CORBA_Environment ev2;
    gboolean result;
    OpenJobData *jd;
    GNOME_Evolution_Calendar_Listener listener_copy;

    factory = CAL_FACTORY (bonobo_object_from_servant (servant));
    priv = factory->priv;

    CORBA_exception_init (&ev2);
    result = CORBA_Object_is_nil (listener, &ev2);

    if (ev2._major != CORBA_NO_EXCEPTION || result) {
        CORBA_exception_set (ev, CORBA_USER_EXCEPTION,
                     ex_GNOME_Evolution_Calendar_CalFactory_NilListener,
                     NULL);

        CORBA_exception_free (&ev2);
        return;
    }
    CORBA_exception_free (&ev2);

    CORBA_exception_init (&ev2);
    listener_copy = CORBA_Object_duplicate (listener, &ev2);

    if (ev2._major != CORBA_NO_EXCEPTION) {
        g_message ("CalFactory_open(): could not duplicate the listener");
        CORBA_exception_free (&ev2);
        CORBA_exception_set (ev, CORBA_USER_EXCEPTION,
                     ex_GNOME_Evolution_Calendar_CalFactory_NilListener,
                     NULL);
        return;
    }

    CORBA_exception_free (&ev2);

    jd = g_new (OpenJobData, 1);
    jd->factory = factory;
    jd->uri = g_strdup (uri);
    jd->only_if_exists = only_if_exists;
    jd->listener = listener_copy;

    job_add (open_fn, jd);
}



/**
 * cal_factory_new:
 * @void:
 *
 * Creates a new #CalFactory object.
 *
 * Return value: A newly-created #CalFactory, or NULL if its corresponding CORBA
 * object could not be created.
 **/
CalFactory *
cal_factory_new (void)
{
    CalFactory *factory;

    factory = gtk_type_new (CAL_FACTORY_TYPE);

    return factory;
}

/* Destroy handler for the calendar */
static void
cal_factory_destroy (GtkObject *object)
{
    CalFactory *factory;
    CalFactoryPrivate *priv;

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

    factory = CAL_FACTORY (object);
    priv = factory->priv;

    g_hash_table_foreach (priv->methods, free_method, NULL);
    g_hash_table_destroy (priv->methods);
    priv->methods = NULL;

    /* Should we assert that there are no more backends? */

    g_hash_table_foreach (priv->backends, free_backend, NULL);
    g_hash_table_destroy (priv->backends);
    priv->backends = NULL;

    if (priv->registered) {
        oaf_active_server_unregister (CAL_FACTORY_OAF_ID, BONOBO_OBJREF (factory));
        priv->registered = FALSE;
    }

    g_free (priv);
    factory->priv = NULL;

    if (GTK_OBJECT_CLASS (parent_class)->destroy)
        (* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
}

/* Class initialization function for the calendar factory */
static void
cal_factory_class_init (CalFactoryClass *klass)
{
    GtkObjectClass *object_class = (GtkObjectClass *) klass;
    POA_GNOME_Evolution_Calendar_CalFactory__epv *epv = &klass->epv;

    parent_class = gtk_type_class (bonobo_object_get_type ());

    signals[LAST_CALENDAR_GONE] =
        gtk_signal_new ("last_calendar_gone",
                GTK_RUN_FIRST,
                object_class->type,
                GTK_SIGNAL_OFFSET (CalFactoryClass, last_calendar_gone),
                gtk_marshal_NONE__NONE,
                GTK_TYPE_NONE, 0);

    gtk_object_class_add_signals (object_class, signals, LAST_SIGNAL);

    /* Class method overrides */
    object_class->destroy = cal_factory_destroy;

    /* Epv methods */
    epv->open = impl_CalFactory_open;
}

/* Object initialization function for the calendar factory */
static void
cal_factory_init (CalFactory *factory)
{
    CalFactoryPrivate *priv;

    priv = g_new0 (CalFactoryPrivate, 1);
    factory->priv = priv;

    priv->methods = g_hash_table_new (g_str_hash, g_str_equal);
    priv->backends = g_hash_table_new (gnome_vfs_uri_hash, gnome_vfs_uri_hequal);
    priv->registered = FALSE;
}

BONOBO_X_TYPE_FUNC_FULL (CalFactory,
             GNOME_Evolution_Calendar_CalFactory,
             PARENT_TYPE,
             cal_factory);

/* Returns the lowercase version of a string */
static char *
str_tolower (const char *s)
{
    char *str;
    unsigned char *p;

    str = g_strdup (s);
    for (p = str; *p; p++)
        if (isalpha (*p))
            *p = tolower (*p);

    return str;
}

/**
 * cal_factory_oaf_register:
 * @factory: A calendar factory.
 * 
 * Registers a calendar factory with the OAF object activation daemon.  This
 * function must be called before any clients can activate the factory.
 * 
 * Return value: TRUE on success, FALSE otherwise.
 **/
gboolean
cal_factory_oaf_register (CalFactory *factory)
{
    CalFactoryPrivate *priv;
    OAF_RegistrationResult result;

    g_return_val_if_fail (factory != NULL, FALSE);
    g_return_val_if_fail (IS_CAL_FACTORY (factory), FALSE);

    priv = factory->priv;

    g_return_val_if_fail (!priv->registered, FALSE);

    result = oaf_active_server_register (CAL_FACTORY_OAF_ID, BONOBO_OBJREF (factory));

    switch (result) {
    case OAF_REG_SUCCESS:
        priv->registered = TRUE;
        return TRUE;

    case OAF_REG_NOT_LISTED:
        g_message ("cal_factory_oaf_register(): Cannot register the calendar factory: "
               "not listed");
        break;

    case OAF_REG_ALREADY_ACTIVE:
        g_message ("cal_factory_oaf_register(): Cannot register the calendar factory: "
               "already active");
        break;

    case OAF_REG_ERROR:
    default:
        g_message ("cal_factory_oaf_register(): Cannot register the calendar factory: "
               "generic error");
        break;
    }

    return FALSE;
}

/**
 * cal_factory_register_method:
 * @factory: A calendar factory.
 * @method: Method for the URI, i.e. "http", "file", etc.
 * @backend_type: Class type of the backend to create for this @method.
 * 
 * Registers the type of a #CalBackend subclass that will be used to handle URIs
 * with a particular method.  When the factory is asked to open a particular
 * URI, it will look in its list of registered methods and create a backend of
 * the appropriate type.
 **/
void
cal_factory_register_method (CalFactory *factory, const char *method, GtkType backend_type)
{
    CalFactoryPrivate *priv;
    GtkType *type;
    char *method_str;

    g_return_if_fail (factory != NULL);
    g_return_if_fail (IS_CAL_FACTORY (factory));
    g_return_if_fail (method != NULL);
    g_return_if_fail (backend_type != 0);
    g_return_if_fail (gtk_type_is_a (backend_type, CAL_BACKEND_TYPE));

    priv = factory->priv;

    method_str = str_tolower (method);

    type = g_hash_table_lookup (priv->methods, method_str);
    if (type) {
        g_message ("cal_factory_register_method(): Method `%s' already registered!",
               method_str);
        g_free (method_str);
        return;
    }

    type = g_new (GtkType, 1);
    *type = backend_type;

    g_hash_table_insert (priv->methods, method_str, type);
}

/**
 * cal_factory_get_n_backends:
 * @factory: A calendar factory.
 * 
 * Queries the number of running calendar backends in a calendar factory.
 * 
 * Return value: Number of running backends.
 **/
int
cal_factory_get_n_backends (CalFactory *factory)
{
    CalFactoryPrivate *priv;

    g_return_val_if_fail (factory != NULL, -1);
    g_return_val_if_fail (IS_CAL_FACTORY (factory), -1);

    priv = factory->priv;
    return g_hash_table_size (priv->backends);
}