path: root/e-util/e-event.c

/*
 * 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/>
 *
 *
 * Authors:
 *      Michael Zucchi <notzed@ximian.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h>
#include <stdlib.h>

#include <gtk/gtk.h>

#include "e-event.h"

#include <glib/gi18n.h>

#define E_EVENT_GET_PRIVATE(obj) \
    (G_TYPE_INSTANCE_GET_PRIVATE \
    ((obj), E_TYPE_EVENT, EEventPrivate))

#define d(x)

struct _event_node {
    GSList *events;
    gpointer data;
    EEventItemsFunc freefunc;
};

struct _event_info {
    struct _event_node *parent;
    EEventItem *item;
};

struct _EEventPrivate {
    GQueue events;
    GSList *sorted;     /* sorted list of struct _event_info's */
};

G_DEFINE_TYPE (
    EEvent,
    e_event,
    G_TYPE_OBJECT)

static void
event_finalize (GObject *object)
{
    EEvent *event = (EEvent *) object;
    EEventPrivate *p = event->priv;

    if (event->target)
        e_event_target_free (event, event->target);

    g_free (event->id);

    while (!g_queue_is_empty (&p->events)) {
        struct _event_node *node;

        node = g_queue_pop_head (&p->events);

        if (node->freefunc != NULL)
            node->freefunc (event, node->events, node->data);

        g_free (node);
    }

    g_slist_foreach (p->sorted, (GFunc) g_free, NULL);
    g_slist_free (p->sorted);

    /* Chain up to parent's finalize() method. */
    G_OBJECT_CLASS (e_event_parent_class)->finalize (object);
}

static void
event_target_free (EEvent *event,
                   EEventTarget *target)
{
    g_free (target);
    g_object_unref (event);
}

static void
e_event_class_init (EEventClass *class)
{
    GObjectClass *object_class;

    g_type_class_add_private (class, sizeof (EEventPrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->finalize = event_finalize;

    class->target_free = event_target_free;
}

static void
e_event_init (EEvent *event)
{
    event->priv = E_EVENT_GET_PRIVATE (event);

    g_queue_init (&event->priv->events);
}

/**
 * e_event_construct:
 * @ep: An instantiated but uninitialised EEvent.
 * @id: Event manager id.
 *
 * Construct the base event instance with standard parameters.
 *
 * Return value: Returns @ep.
 **/
EEvent *e_event_construct (EEvent *ep, const gchar *id)
{
    ep->id = g_strdup (id);

    return ep;
}

/**
 * e_event_add_items:
 * @event: An initialised EEvent structure.
 * @items: A list of EEventItems event listeners to register on this event manager.
 * @freefunc: A function called when the @items list is no longer needed.
 * @data: callback data for @freefunc and for item event handlers.
 *
 * Adds @items to the list of events listened to on the event manager @event.
 *
 * Return value: An opaque key which can later be passed to remove_items.
 **/
gpointer
e_event_add_items (EEvent *event,
                   GSList *items,
                   EEventItemsFunc freefunc,
                   gpointer data)
{
    struct _event_node *node;

    node = g_malloc (sizeof (*node));
    node->events = items;
    node->freefunc = freefunc;
    node->data = data;

    g_queue_push_tail (&event->priv->events, node);

    if (event->priv->sorted) {
        g_slist_foreach (event->priv->sorted, (GFunc) g_free, NULL);
        g_slist_free (event->priv->sorted);
        event->priv->sorted = NULL;
    }

    return (gpointer) node;
}

/**
 * e_event_remove_items:
 * @event: an #EEvent
 * @handle: an opaque key returned by e_event_add_items()
 *
 * Remove items previously added.  They MUST have been previously
 * added, and may only be removed once.
 **/
void
e_event_remove_items (EEvent *event,
                      gpointer handle)
{
    struct _event_node *node = handle;

    g_queue_remove (&event->priv->events, node);

    if (node->freefunc)
        node->freefunc (event, node->events, node->data);
    g_free (node);

    if (event->priv->sorted) {
        g_slist_foreach (event->priv->sorted, (GFunc) g_free, NULL);
        g_slist_free (event->priv->sorted);
        event->priv->sorted = NULL;
    }
}

static gint
ee_cmp (gconstpointer ap,
        gconstpointer bp)
{
    gint a = ((struct _event_info **) ap)[0]->item->priority;
    gint b = ((struct _event_info **) bp)[0]->item->priority;

    if (a < b)
        return 1;
    else if (a > b)
        return -1;
    else
        return 0;
}

/**
 * e_event_emit:
 * @ee: An initialised EEvent, potentially with registered event listeners.
 * @id: Event name.  This will be compared against EEventItem.id.
 * @target: The target describing the event context.  This will be
 * implementation defined.
 *
 * Emit an event.  @target will automatically be freed once its
 * emission is complete.
 **/
void
e_event_emit (EEvent *event,
              const gchar *id,
              EEventTarget *target)
{
    EEventPrivate *p = event->priv;
    GSList *events;

    d (printf ("emit event %s\n", id));

    if (event->target != NULL) {
        g_warning ("Event already in progress.\n");
        return;
    }

    event->target = target;
    events = p->sorted;
    if (events == NULL) {
        GList *link = g_queue_peek_head_link (&p->events);

        while (link != NULL) {
            struct _event_node *node = link->data;
            GSList *l = node->events;

            for (; l; l = g_slist_next (l)) {
                struct _event_info *info;

                info = g_malloc0 (sizeof (*info));
                info->parent = node;
                info->item = l->data;
                events = g_slist_prepend (events, info);
            }

            link = g_list_next (link);
        }

        p->sorted = events = g_slist_sort (events, ee_cmp);
    }

    for (; events; events = g_slist_next (events)) {
        struct _event_info *info = events->data;
        EEventItem *item = info->item;

        if (item->enable & target->mask)
            continue;

        if (strcmp (item->id, id) == 0) {
            item->handle (event, item, info->parent->data);

            if (item->type == E_EVENT_SINK)
                break;
        }
    }

    e_event_target_free (event, target);
    event->target = NULL;
}

/**
 * e_event_target_new:
 * @ep: An initialised EEvent instance.
 * @type: type, up to implementor
 * @size: The size of memory to allocate.  This must be >= sizeof(EEventTarget).
 *
 * Allocate a new event target suitable for this class.  It is up to
 * the implementation to define the available target types and their
 * structure.
 **/
gpointer
e_event_target_new (EEvent *event,
                    gint type,
                    gsize size)
{
    EEventTarget *target;

    if (size < sizeof (EEventTarget)) {
        g_warning ("Size is less than the size of EEventTarget\n");
        size = sizeof (EEventTarget);
    }

    target = g_malloc0 (size);
    target->event = g_object_ref (event);
    target->type = type;

    return target;
}

/**
 * e_event_target_free:
 * @ep: An initialised EEvent instance on which this target was allocated.
 * @o: The target to free.
 *
 * Free a target.  This invokes the virtual free method on the EEventClass.
 **/
void
e_event_target_free (EEvent *event,
                     gpointer object)
{
    EEventTarget *target = object;

    E_EVENT_GET_CLASS (event)->target_free (event, target);
}

/* ********************************************************************** */

/* Event menu plugin handler */

/*
 * <e-plugin
 *  class="org.gnome.mail.plugin.event:1.0"
 *  id="org.gnome.mail.plugin.event.item:1.0"
 *  type="shlib"
 *  location="/opt/gnome2/lib/camel/1.0/libcamelimap.so"
 *  name="imap"
 *  description="IMAP4 and IMAP4v1 mail store">
 *  <hook class="org.gnome.mail.eventMenu:1.0"
 *      handler="HandleEvent">
 *   <menu id="any" target="select">
 *   <item
 *    type="item|toggle|radio|image|submenu|bar"
 *    active
 *    path="foo/bar"
 *    label="label"
 *    icon="foo"
 *    mask="select_one"
 *    activate="ep_view_emacs"/>
 *   </menu>
 *  </hook>
 *
 * <hook class="org.gnome.evolution.mail.events:1.0">
 * <event id=".folder.changed"
 *  target=""
 *  priority="0"
 *  handle="gotevent"
 *  enable="new"
 *  />
 * <event id=".message.read"
 *  priority="0"
 *  handle="gotevent"
 *  mask="new"
 *  />
 * </hook>
 *
 */

#define emph ((EEventHook *)eph)

/* must have 1:1 correspondence with e-event types in order */
static const EPluginHookTargetKey emph_item_types[] = {
    { "pass", E_EVENT_PASS },
    { "sink", E_EVENT_SINK },
    { NULL }
};

G_DEFINE_TYPE (
    EEventHook,
    e_event_hook,
    E_TYPE_PLUGIN_HOOK)

static void
emph_event_handle (EEvent *ee,
                   EEventItem *item,
                   gpointer data)
{
    EEventHook *hook = data;

    /* FIXME We could/should just remove the items
     *       we added to the event handler. */
    if (!hook->hook.plugin->enabled)
        return;

    e_plugin_invoke (
        hook->hook.plugin, (gchar *) item->user_data, ee->target);
}

static void
emph_free_item (EEventItem *item)
{
    g_free ((gchar *) item->id);
    g_free (item->user_data);
    g_free (item);
}

static void
emph_free_items (EEvent *ee,
                 GSList *items,
                 gpointer data)
{
    /*EPluginHook *eph = data;*/

    g_slist_foreach (items, (GFunc) emph_free_item, NULL);
    g_slist_free (items);
}

static EEventItem *
emph_construct_item (EPluginHook *eph,
                     xmlNodePtr root,
                     EEventHookClass *class)
{
    EEventItem *item;
    EEventHookTargetMap *map;
    gchar *tmp;

    item = g_malloc0 (sizeof (*item));

    tmp = (gchar *) xmlGetProp (root, (const guchar *)"target");
    if (tmp == NULL)
        goto error;
    map = g_hash_table_lookup (class->target_map, tmp);
    xmlFree (tmp);
    if (map == NULL)
        goto error;
    item->target_type = map->id;
    item->type = e_plugin_hook_id (root, emph_item_types, "type");
    if (item->type == -1)
        item->type = E_EVENT_PASS;
    item->priority = e_plugin_xml_int (root, "priority", 0);
    item->id = e_plugin_xml_prop (root, "id");
    item->enable = e_plugin_hook_mask (root, map->mask_bits, "enable");
    item->user_data = e_plugin_xml_prop (root, "handle");

    if (item->user_data == NULL || item->id == NULL)
        goto error;

    item->handle = emph_event_handle;

    return item;
error:
    emph_free_item (item);
    return NULL;
}

static gint
emph_construct (EPluginHook *eph,
                EPlugin *ep,
                xmlNodePtr root)
{
    xmlNodePtr node;
    EEventHookClass *class;
    GSList *items = NULL;

    d (printf ("loading event hook\n"));

    if (((EPluginHookClass *) e_event_hook_parent_class)->
        construct (eph, ep, root) == -1)
        return -1;

    class = E_EVENT_HOOK_GET_CLASS (eph);
    g_return_val_if_fail (class->event != NULL, -1);

    node = root->children;
    while (node) {
        if (strcmp ((gchar *) node->name, "event") == 0) {
            EEventItem *item;

            item = emph_construct_item (eph, node, class);
            if (item)
                items = g_slist_prepend (items, item);
        }
        node = node->next;
    }

    eph->plugin = ep;

    if (items)
        e_event_add_items (class->event, items, emph_free_items, eph);

    return 0;
}

static void
e_event_hook_class_init (EEventHookClass *class)
{
    EPluginHookClass *plugin_hook_class;

    plugin_hook_class = E_PLUGIN_HOOK_CLASS (class);
    plugin_hook_class->id = "org.gnome.evolution.event:1.0";
    plugin_hook_class->construct = emph_construct;

    class->target_map = g_hash_table_new (g_str_hash, g_str_equal);
}

static void
e_event_hook_init (EEventHook *hook)
{
}

/**
 * e_event_hook_class_add_target_map:
 * @class: The derived EEventHook class.
 * @map: A map used to describe a single EEventTarget type for this
 * class.
 *
 * Add a target map to a concrete derived class of EEvent.  The target
 * map enumerates a single target type and th eenable mask bit names,
 * so that the type can be loaded automatically by the base EEvent class.
 **/
void e_event_hook_class_add_target_map (EEventHookClass *class,
                                        const EEventHookTargetMap *map)
{
    g_hash_table_insert (
        class->target_map, (gpointer) map->type, (gpointer) map);
}