path: root/e-util/e-component-listener.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 * Component listener.
 *
 * Author:
 *   Rodrigo Moya <rodrigo@ximian.com>
 *
 * Copyright 2002, Ximian, Inc.
 */

#include <bonobo/bonobo-exception.h>
#include <bonobo/bonobo-object.h>
#include "e-component-listener.h"
#include <libgnome/gnome-i18n.h>

#define PARENT_TYPE GTK_TYPE_OBJECT
#define DEFAULT_PING_DELAY 10000

struct _EComponentListenerPrivate {
    Bonobo_Unknown component;
    int ping_delay;
    int ping_timeout_id;
};

static void e_component_listener_class_init (EComponentListenerClass *klass);
static void e_component_listener_init       (EComponentListener *cl, EComponentListenerClass *klass);
static void e_component_listener_finalize   (GObject *object);

static GObjectClass *parent_class = NULL;

enum {
    COMPONENT_DIED,
    LAST_SIGNAL
};

static guint comp_listener_signals[LAST_SIGNAL];

static void
e_component_listener_class_init (EComponentListenerClass *klass)
{
    GObjectClass *object_class = G_OBJECT_CLASS (klass);

    parent_class = g_type_class_peek_parent (klass);

    object_class->finalize = e_component_listener_finalize;
    klass->component_died = NULL;

    comp_listener_signals[COMPONENT_DIED] =
        g_signal_new ("component_died",
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_FIRST,
                  G_STRUCT_OFFSET (EComponentListenerClass, component_died),
                  NULL, NULL,
                  g_cclosure_marshal_VOID__VOID,
                  G_TYPE_NONE, 0);
}

static void
e_component_listener_init (EComponentListener *cl, EComponentListenerClass *klass)
{
    /* allocate internal structure */
    cl->priv = g_new (EComponentListenerPrivate, 1);
    cl->priv->component = CORBA_OBJECT_NIL;
    cl->priv->ping_delay = DEFAULT_PING_DELAY;
    cl->priv->ping_timeout_id = -1;
}

static void
e_component_listener_finalize (GObject *object)
{
    EComponentListener *cl = (EComponentListener *) object;

    g_return_if_fail (E_IS_COMPONENT_LISTENER (cl));

    cl->priv->component = CORBA_OBJECT_NIL;

    if (cl->priv->ping_timeout_id != -1) {
        g_source_remove (cl->priv->ping_timeout_id);
        cl->priv->ping_timeout_id = -1;
    }

    /* free memory */
    g_free (cl->priv);
    cl->priv = NULL;

    if (G_OBJECT_CLASS (parent_class)->finalize)
        (* G_OBJECT_CLASS (parent_class)->finalize) (object);
}

GType
e_component_listener_get_type (void)
{
    static GType type = 0;

    if (!type) {
        static GTypeInfo info = {
                        sizeof (EComponentListenerClass),
                        (GBaseInitFunc) NULL,
                        (GBaseFinalizeFunc) NULL,
                        (GClassInitFunc) e_component_listener_class_init,
                        NULL, NULL,
                        sizeof (EComponentListener),
                        0,
                        (GInstanceInitFunc) e_component_listener_init
                };
        type = g_type_register_static (G_TYPE_OBJECT, "EComponentListener", &info, 0);
    }

    return type;
}

static gboolean
ping_component_callback (gpointer user_data)
{
    gboolean alive;
    int is_nil;
    CORBA_Environment ev;
    EComponentListener *cl = (EComponentListener *) user_data;

    g_return_val_if_fail (E_IS_COMPONENT_LISTENER (cl), FALSE);

    if (cl->priv->component == CORBA_OBJECT_NIL)
        return FALSE;

    CORBA_exception_init (&ev);
    is_nil = CORBA_Object_is_nil (cl->priv->component, &ev);
    if (BONOBO_EX (&ev)) {
        g_message (_("ping_timeout_callback: could not determine if the "
                 "CORBA object is nil or not"));
        goto out;
    }

    if (is_nil)
        goto out;

    alive = bonobo_unknown_ping (cl->priv->component, &ev);
    if (alive) {
        CORBA_exception_free (&ev);
        return TRUE;
    }

 out:
    /* the component has died, so we notify and close the timeout */
    CORBA_exception_free (&ev);

    /* we ref the object just in case it gets destroyed in the callbacks */
    g_object_ref (G_OBJECT (cl));
    g_signal_emit (G_OBJECT (cl), comp_listener_signals[COMPONENT_DIED], 0);

    cl->priv->component = CORBA_OBJECT_NIL;
    cl->priv->ping_timeout_id = -1;

    g_object_unref (G_OBJECT (cl));

    return FALSE;
}

static void
setup_ping_timeout (EComponentListener *cl)
{
    if (cl->priv->ping_timeout_id != -1)
        g_source_remove (cl->priv->ping_timeout_id);

    cl->priv->ping_timeout_id = g_timeout_add (cl->priv->ping_delay,
                           ping_component_callback,
                           cl);
}

/**
 * e_component_listener_new
 * @comp: Component to listen for.
 * @ping_delay: Delay (in ms) for pinging the component.
 *
 * Create a new #EComponentListener object, which allows to listen
 * for a given component and get notified when that component dies.
 *
 * Returns: a component listener object.
 */
EComponentListener *
e_component_listener_new (Bonobo_Unknown comp, int ping_delay)
{
    EComponentListener *cl;

    cl = g_object_new (E_COMPONENT_LISTENER_TYPE, NULL);
    cl->priv->component = comp;

    /* set up the timeout function */
    cl->priv->ping_delay = ping_delay > 0 ? ping_delay : DEFAULT_PING_DELAY;
    setup_ping_timeout (cl);

    return cl;
}

/**
 * e_component_listener_get_ping_delay
 * @cl: A #EComponentListener object.
 *
 * Get the ping delay being used to listen for an object.
 */
int
e_component_listener_get_ping_delay (EComponentListener *cl)
{
    g_return_val_if_fail (E_IS_COMPONENT_LISTENER (cl), -1);
    return cl->priv->ping_delay;
}

void
e_component_listener_set_ping_delay (EComponentListener *cl, int ping_delay)
{
    g_return_if_fail (E_IS_COMPONENT_LISTENER (cl));
    g_return_if_fail (ping_delay > 0);

    cl->priv->ping_delay = ping_delay;
    setup_ping_timeout (cl);
}

Bonobo_Unknown
e_component_listener_get_component (EComponentListener *cl)
{
    g_return_val_if_fail (E_IS_COMPONENT_LISTENER (cl), CORBA_OBJECT_NIL);
    return cl->priv->component;
}

void
e_component_listener_set_component (EComponentListener *cl, Bonobo_Unknown comp)
{
    g_return_if_fail (E_IS_COMPONENT_LISTENER (cl));

    cl->priv->component = comp;
    setup_ping_timeout (cl);
}