path: root/e-util/e-popup.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-popup.h"

#include <glib/gi18n.h>

#define d(x)

struct _EPopupFactory {
    struct _EPopupFactory *next, *prev;

    gchar *menuid;
    EPopupFactoryFunc factory;
    gpointer factory_data;
};

/* Used for the "activate" signal callback data to re-map to the api */
struct _item_node {
    struct _item_node *next; /* tree pointers */
    struct _item_node *prev;
    struct _item_node *parent;
    EDList children;

    struct _item_node *link; /* for freeing */

    EPopupItem *item;
    struct _menu_node *menu;
};

/* Stores all the items added */
struct _menu_node {
    struct _menu_node *next, *prev;

    EPopup *popup;

    GSList *menu;
    gchar *domain;
    EPopupItemsFunc freefunc;
    gpointer data;

    struct _item_node *items;
};

struct _EPopupPrivate {
    EDList menus;
};

static GObjectClass *ep_parent;

static void
ep_init(GObject *o)
{
    EPopup *emp = (EPopup *)o;
    struct _EPopupPrivate *p;

    p = emp->priv = g_malloc0(sizeof(struct _EPopupPrivate));

    e_dlist_init(&p->menus);
}

static void
ep_finalise(GObject *o)
{
    EPopup *emp = (EPopup *)o;
    struct _EPopupPrivate *p = emp->priv;
    struct _menu_node *mnode, *nnode;

    mnode = (struct _menu_node *)p->menus.head;
    nnode = mnode->next;
    while (nnode) {
        struct _item_node *inode;

        if (mnode->freefunc)
            mnode->freefunc(emp, mnode->menu, mnode->data);

        g_free(mnode->domain);

        /* free item activate callback data */
        inode = mnode->items;
        while (inode) {
            /* This was declared as _menu_node above already */
            struct _item_node *nnode = inode->link;

            g_free(inode);
            inode = nnode;
        }

        g_free(mnode);
        mnode = nnode;
        nnode = nnode->next;
    }

    if (emp->target)
        e_popup_target_free(emp, emp->target);

    g_free(emp->menuid);

    g_free(p);

    ((GObjectClass *)ep_parent)->finalize(o);
}

static void
ep_target_free(EPopup *ep, EPopupTarget *t)
{
    g_free(t);
    g_object_unref(ep);
}

static void
ep_class_init(GObjectClass *klass)
{
    d(printf("EPopup class init %p '%s'\n", klass, g_type_name(((GObjectClass *)klass)->g_type_class.g_type)));

    klass->finalize = ep_finalise;
    ((EPopupClass *)klass)->target_free = ep_target_free;
}

static void
ep_base_init(GObjectClass *klass)
{
    e_dlist_init(&((EPopupClass *)klass)->factories);
}

/**
 * e_popup_get_type:
 *
 * Standard GObject type function.
 *
 * Return value: The EPopup object type.
 **/
GType
e_popup_get_type(void)
{
    static GType type = 0;

    if (type == 0) {
        static const GTypeInfo info = {
            sizeof(EPopupClass),
            (GBaseInitFunc)ep_base_init, NULL,
            (GClassInitFunc)ep_class_init, NULL, NULL,
            sizeof(EPopup), 0,
            (GInstanceInitFunc)ep_init
        };
        ep_parent = g_type_class_ref(G_TYPE_OBJECT);
        type = g_type_register_static(G_TYPE_OBJECT, "EPopup", &info, 0);
    }

    return type;
}

/**
 * e_popup_new - Create an targetless popup menu manager.
 * @menuid: Unique ID for this menu.
 *
 * Create a targetless popup menu object.  This can be used as a
 * helper for creating popup menu's with no target.  Such popup menu's
 * wont be very pluggable.
 *
 * Return value: A new EPopup.
 **/
EPopup *e_popup_new(const gchar *menuid)
{
    EPopup *ep = g_object_new(e_popup_get_type(), NULL);

    e_popup_construct(ep, menuid);

    return ep;
}

/**
 * e_popup_construct:
 * @ep: An instantiated but uninitialised EPopup.
 * @menuid: The menu identifier.
 *
 * Construct the base popup instance with standard parameters.
 *
 * Return value: Returns @ep.
 **/
EPopup *e_popup_construct(EPopup *ep, const gchar *menuid)
{
    ep->menuid = g_strdup(menuid);

    return ep;
}

/**
 * e_popup_add_items:
 * @emp: An EPopup derived object.
 * @items: A list of EPopupItem's to add to the current popup menu.
 * @domain: Translation domain for translating labels.
 * @freefunc: A function which will be called when the items are no
 * longer needed.
 * @data: user-data passed to @freefunc, and passed to all activate
 * methods.
 *
 * Add new EPopupItems to the menus.  Any with the same path
 * will override previously defined menu items, at menu building
 * time.  This may be called any number of times before the menu is
 * built to create a complex heirarchy of menus.
 **/
void
e_popup_add_items(EPopup *emp, GSList *items, const gchar *domain, EPopupItemsFunc freefunc, gpointer data)
{
    struct _menu_node *node;

    node = g_malloc0(sizeof(*node));
    node->menu = items;
    node->domain = g_strdup(domain);
    node->freefunc = freefunc;
    node->data = data;
    node->popup = emp;

    e_dlist_addtail(&emp->priv->menus, (EDListNode *)node);
}

static void
ep_add_static_items(EPopup *emp)
{
    struct _EPopupFactory *f;
    EPopupClass *klass = (EPopupClass *)G_OBJECT_GET_CLASS(emp);

    if (emp->menuid == NULL || emp->target == NULL)
        return;

    /* setup the menu itself */
    f = (struct _EPopupFactory *)klass->factories.head;
    while (f->next) {
        if (f->menuid == NULL
            || !strcmp(f->menuid, emp->menuid)) {
            f->factory(emp, f->factory_data);
        }
        f = f->next;
    }
}

static gint
ep_cmp(gconstpointer ap, gconstpointer bp)
{
    struct _item_node *a = *((gpointer *)ap);
    struct _item_node *b = *((gpointer *)bp);

    return strcmp(a->item->path, b->item->path);
}

static void
ep_activate(GtkWidget *w, struct _item_node *inode)
{
    EPopupItem *item = inode->item;
    guint32 type = item->type & E_POPUP_TYPE_MASK;

    /* this is a bit hackish, use the item->type to transmit the
       active state, presumes we can write to this memory ...  The
       alternative is the EMenu idea of different callbacks, but
       thats painful for breaking type-safety on callbacks */

    if (type == E_POPUP_TOGGLE || type == E_POPUP_RADIO) {
        if (gtk_check_menu_item_get_active((GtkCheckMenuItem *)w))
            item->type |= E_POPUP_ACTIVE;
        else
            item->type &= ~E_POPUP_ACTIVE;
    }

    item->activate(inode->menu->popup, item, inode->menu->data);
}

static void
ep_prune_tree(EDList *head)
{
    struct _item_node *inode, *nnode;

    /* need to do two scans, first to find out if the subtree's
     * are empty, then to remove any unecessary bars which may
     * become unecessary after the first scan */

    inode = (struct _item_node *)head->head;
    nnode = inode->next;
    while (nnode) {
        struct _EPopupItem *item = inode->item;

        ep_prune_tree(&inode->children);

        if ((item->type & E_POPUP_TYPE_MASK) == E_POPUP_SUBMENU) {
            if (e_dlist_empty(&inode->children))
                e_dlist_remove((EDListNode *)inode);
        }

        inode = nnode;
        nnode = nnode->next;
    }

    inode = (struct _item_node *)head->head;
    nnode = inode->next;
    while (nnode) {
        struct _EPopupItem *item = inode->item;

        if ((item->type & E_POPUP_TYPE_MASK) == E_POPUP_BAR) {
            if (inode->prev->prev == NULL
                || nnode->next == NULL
                || (nnode->item->type & E_POPUP_TYPE_MASK) == E_POPUP_BAR)
                e_dlist_remove((EDListNode *)inode);
        }

        inode = nnode;
        nnode = nnode->next;
    }
}

static GtkMenu *
ep_build_tree(struct _item_node *inode, guint32 mask)
{
    struct _item_node *nnode;
    GtkMenu *topmenu;
    GHashTable *group_hash = g_hash_table_new(g_str_hash, g_str_equal);

    topmenu = (GtkMenu *)gtk_menu_new();

    nnode = inode->next;
    while (nnode) {
        GtkWidget *label;
        struct _EPopupItem *item = inode->item;
        GtkMenuItem *menuitem;

        switch (item->type & E_POPUP_TYPE_MASK) {
        case E_POPUP_ITEM:
            if (item->image) {
                GtkWidget *image;

                image = gtk_image_new_from_icon_name (
                    (gchar *) item->image, GTK_ICON_SIZE_MENU);
                gtk_widget_show(image);
                menuitem = (GtkMenuItem *)gtk_image_menu_item_new();
                gtk_image_menu_item_set_image((GtkImageMenuItem *)menuitem, image);
            } else {
                menuitem = (GtkMenuItem *)gtk_menu_item_new();
            }
            break;
        case E_POPUP_TOGGLE:
            menuitem = (GtkMenuItem *)gtk_check_menu_item_new();
            if (item->type & E_POPUP_INCONSISTENT)
                gtk_check_menu_item_set_inconsistent (GTK_CHECK_MENU_ITEM (menuitem), TRUE);
            else
                gtk_check_menu_item_set_active (GTK_CHECK_MENU_ITEM (menuitem), item->type & E_POPUP_ACTIVE);

            if (item->image)
                gtk_widget_show (item->image);
            break;
        case E_POPUP_RADIO: {
            gchar *ppath = inode->parent?inode->parent->item->path:NULL;

            menuitem = (GtkMenuItem *)gtk_radio_menu_item_new(g_hash_table_lookup(group_hash, ppath));
            g_hash_table_insert(group_hash, ppath, gtk_radio_menu_item_get_group((GtkRadioMenuItem *)menuitem));
            gtk_check_menu_item_set_active((GtkCheckMenuItem *)menuitem, item->type & E_POPUP_ACTIVE);
            break; }
        case E_POPUP_IMAGE:
            menuitem = (GtkMenuItem *)gtk_image_menu_item_new();
            gtk_image_menu_item_set_image((GtkImageMenuItem *)menuitem, item->image);
            break;
        case E_POPUP_SUBMENU: {
            GtkMenu *submenu = ep_build_tree((struct _item_node *)inode->children.head, mask);

            menuitem = (GtkMenuItem *)gtk_menu_item_new();
            gtk_menu_item_set_submenu(menuitem, (GtkWidget *)submenu);
            break; }
        case E_POPUP_BAR:
            menuitem = (GtkMenuItem *)gtk_separator_menu_item_new();
            break;
        default:
            continue;
        }

        if (item->label) {
            label = gtk_label_new_with_mnemonic(dgettext(inode->menu->domain, item->label));
            gtk_misc_set_alignment((GtkMisc *)label, 0.0, 0.5);
            gtk_widget_show(label);
            if (item->image && (item->type & E_POPUP_TYPE_MASK) == E_POPUP_TOGGLE) {
                GtkWidget *hbox = gtk_hbox_new (FALSE, 4);

                gtk_box_pack_start (GTK_BOX (hbox), item->image, FALSE, FALSE, 0);
                gtk_box_pack_start (GTK_BOX (hbox), label,       TRUE,  TRUE,  0);
                gtk_widget_show (hbox);
                gtk_container_add (GTK_CONTAINER (menuitem), hbox);
            } else
                gtk_container_add((GtkContainer *)menuitem, label);
        } else if (item->image && (item->type & E_POPUP_TYPE_MASK) == E_POPUP_TOGGLE) {
            gtk_container_add (GTK_CONTAINER (menuitem), item->image);
        }

        if (item->activate)
            g_signal_connect(menuitem, "activate", G_CALLBACK(ep_activate), inode);

        gtk_menu_shell_append((GtkMenuShell *)topmenu, (GtkWidget *)menuitem);

        if (item->enable & mask)
            gtk_widget_set_sensitive((GtkWidget *)menuitem, FALSE);

        gtk_widget_show((GtkWidget *)menuitem);

        inode = nnode;
        nnode = nnode->next;
    }

    g_hash_table_destroy(group_hash);

    return topmenu;
}

/**
 * e_popup_create:
 * @emp: An EPopup derived object.
 * @target: popup target, if set, then factories will be invoked.
 * This is then owned by the menu.
 * @mask: If supplied, overrides the target specified mask or provides
 * a mask if no target is supplied.  Used to enable or show menu
 * items.
 *
 * All of the menu items registered on @emp are sorted by path, and
 * then converted into a menu heirarchy.
 *
 *
 * Return value: A GtkMenu which can be popped up when ready.
 **/
GtkMenu *
e_popup_create_menu(EPopup *emp, EPopupTarget *target, guint32 mask)
{
    struct _EPopupPrivate *p = emp->priv;
    struct _menu_node *mnode, *nnode;
    GPtrArray *items = g_ptr_array_new();
    GSList *l;
    GString *ppath = g_string_new("");
    GHashTable *tree_hash = g_hash_table_new(g_str_hash, g_str_equal);
    EDList head = E_DLIST_INITIALISER(head);
    gint i;

    emp->target = target;
    ep_add_static_items(emp);

    if (target && mask == 0)
        mask = target->mask;

    /* Note: This code vastly simplifies memory management by
     * keeping a linked list of all temporary tree nodes on the
     * menu's tree until the epopup is destroyed */

    /* FIXME: need to override old ones with new names */
    mnode = (struct _menu_node *)p->menus.head;
    nnode = mnode->next;
    while (nnode) {
        for (l=mnode->menu; l; l = l->next) {
            struct _item_node *inode;
            struct _EPopupItem *item = l->data;

            /* we calculate bar/submenu visibility based on calculated set */
            if (item->visible) {
                if ((item->type & E_POPUP_TYPE_MASK) != E_POPUP_BAR
                    && (item->type & E_POPUP_TYPE_MASK) != E_POPUP_SUBMENU
                    && item->visible & mask) {
                    d(printf("%s not visible\n", item->path));
                    continue;
                }
            }

            inode = g_malloc0(sizeof(*inode));
            inode->item = l->data;
            inode->menu = mnode;
            e_dlist_init(&inode->children);
            inode->link = mnode->items;
            mnode->items = inode;

            g_ptr_array_add(items, inode);
        }
        mnode = nnode;
        nnode = nnode->next;
    }

    /* this makes building the tree in the right order easier */
    qsort(items->pdata, items->len, sizeof(items->pdata[0]), ep_cmp);

    /* create tree structure */
    for (i=0;i<items->len;i++) {
        struct _item_node *inode = items->pdata[i], *pnode;
        struct _item_node *nextnode = (i + 1 < items->len) ? items->pdata[i+1] : NULL;
        struct _EPopupItem *item = inode->item;
        const gchar *tmp;

        if (nextnode && !strcmp (nextnode->item->path, item->path)) {
            d(printf ("skipping item %s\n", item->path));
            continue;
        }

        g_string_truncate(ppath, 0);
        tmp = strrchr(item->path, '/');
        if (tmp) {
            g_string_append_len(ppath, item->path, tmp-item->path);
            pnode = g_hash_table_lookup(tree_hash, ppath->str);
            if (pnode == NULL) {
                g_warning("No parent defined for node '%s'", item->path);
                e_dlist_addtail(&head, (EDListNode *)inode);
            } else {
                e_dlist_addtail(&pnode->children, (EDListNode *)inode);
                inode->parent = pnode;
            }
        } else {
            e_dlist_addtail(&head, (EDListNode *)inode);
        }

        if ((item->type & E_POPUP_TYPE_MASK) == E_POPUP_SUBMENU)
            g_hash_table_insert(tree_hash, item->path, inode);
    }

    g_string_free(ppath, TRUE);
    g_ptr_array_free(items, TRUE);
    g_hash_table_destroy(tree_hash);

    /* prune unnecessary items */
    ep_prune_tree(&head);

    /* & build it */
    return ep_build_tree((struct _item_node *)head.head, mask);
}

static void
ep_popup_done(GtkWidget *w, EPopup *emp)
{
    gtk_widget_destroy(w);
    if (emp->target) {
        e_popup_target_free(emp, emp->target);
        emp->target = NULL;
    }
    g_object_unref(emp);
}

/**
 * e_popup_create_menu_once:
 * @emp: EPopup, once the menu is shown, this cannot be
 * considered a valid pointer.
 * @target: If set, the target of the selection.  Static menu
 * items will be added.  The target will be freed once complete.
 * @mask: Enable/disable and visibility mask.
 *
 * Like popup_create_menu, but automatically sets up the menu
 * so that it is destroyed once a selection takes place, and
 * the EPopup is unreffed.  This is the normal entry point as it
 * automates most memory management for popup menus.
 *
 * Return value: A menu, to popup.
 **/
GtkMenu *
e_popup_create_menu_once(EPopup *emp, EPopupTarget *target, guint32 mask)
{
    GtkMenu *menu;

    menu = e_popup_create_menu(emp, target, mask);

    g_signal_connect(menu, "selection_done", G_CALLBACK(ep_popup_done), emp);

    return menu;
}

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

/**
 * e_popup_class_add_factory:
 * @klass: The EPopup derived class which you're interested in.
 * @menuid: The identifier of the menu you're interested in, or NULL
 * to be called for all menus on this class.
 * @func: The factory called when the menu @menuid is being created.
 * @data: User-data for the factory callback.
 *
 * This is a class-static method used to register factory callbacks
 * against specific menu's.
 *
 * The factory method will be invoked before the menu is created.
 * This way, the factory may add any additional menu items it wishes
 * based on the context supplied in the @target.
 *
 * Return value: A handle to the factory which can be used to remove
 * it later.
 **/
EPopupFactory *
e_popup_class_add_factory(EPopupClass *klass, const gchar *menuid, EPopupFactoryFunc func, gpointer data)
{
    struct _EPopupFactory *f = g_malloc0(sizeof(*f));

    f->menuid = g_strdup(menuid);
    f->factory = func;
    f->factory_data = data;
    e_dlist_addtail(&klass->factories, (EDListNode *)f);

    return f;
}

/**
 * e_popup_class_remove_factory:
 * @klass: The EPopup derived class.
 * @f: The factory handle returned by e_popup_class_add_factory().
 *
 * Remove a popup menu factory. If it has not been added, or it has
 * already been removed, then the result is undefined (i.e. it will
 * crash).
 *
 * Generally factories are static for the life of the application, and
 * so do not need to be removed.
 **/
void
e_popup_class_remove_factory(EPopupClass *klass, EPopupFactory *f)
{
    e_dlist_remove((EDListNode *)f);
    g_free(f->menuid);
    g_free(f);
}

/**
 * e_popup_target_new:
 * @ep: An EPopup derived object.
 * @type: type, defined by the implementing class.
 * @size: The size of memory to allocate for the target.  It must be
 * equal or greater than the size of EPopupTarget.
 *
 * Allocate a new popup target suitable for this popup type.
 **/
gpointer e_popup_target_new(EPopup *ep, gint type, gsize size)
{
    EPopupTarget *t;

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

    t = g_malloc0(size);
    t->popup = ep;
    g_object_ref(ep);
    t->type = type;

    return t;
}

/**
 * e_popup_target_free:
 * @ep: An EPopup derived object.
 * @o: The target, previously allocated by e_popup_target_new().
 *
 * Free the target against @ep. Note that targets are automatically
 * freed if they are passed to the menu creation functions, so this is
 * only required if you are using the target for other purposes.
 **/
void
e_popup_target_free(EPopup *ep, gpointer o)
{
    EPopupTarget *t = o;

    ((EPopupClass *)G_OBJECT_GET_CLASS(ep))->target_free(ep, t);
}

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

/* Popup menu plugin handler */

/*
<e-plugin
  class="org.gnome.mail.plugin.popup:1.0"
  id="org.gnome.mail.plugin.popup.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.popupMenu:1.0"
        handler="HandlePopup">
  <menu id="any" target="select" factory="funcspec"?>
   <item
    type="item|toggle|radio|image|submenu|bar"
    active
    path="foo/bar"
    label="label"
    icon="foo"
    visible="select_one"
    activate="ep_view_emacs"/> *
  </menu>
  </extension>

*/

static gpointer emph_parent_class;
#define emph ((EPopupHook *)eph)

/* must have 1:1 correspondence with e-popup types in order */
static const EPluginHookTargetKey emph_item_types[] = {
    { "item", E_POPUP_ITEM },
    { "toggle", E_POPUP_TOGGLE },
    { "radio", E_POPUP_RADIO },
    { "image", E_POPUP_IMAGE },
    { "submenu", E_POPUP_SUBMENU },
    { "bar", E_POPUP_BAR },
    { NULL }
};

static void
emph_popup_activate(EPopup *ep, EPopupItem *item, gpointer data)
{
    EPopupHook *hook = data;

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

static void
emph_popup_factory(EPopup *emp, gpointer data)
{
    struct _EPopupHookMenu *menu = data;

    d(printf("popup factory called %s mask %08x\n", menu->id?menu->id:"all menus", emp->target->mask));

    /* If we're disabled, then don't add the menu's. */
    if (emp->target->type != menu->target_type
        || !menu->hook->hook.plugin->enabled)
        return;

    if (menu->items)
        e_popup_add_items(emp, menu->items, menu->hook->hook.plugin->domain, NULL, menu->hook);

    if (menu->factory)
        e_plugin_invoke(menu->hook->hook.plugin, menu->factory, emp->target);
}

static void
emph_free_item(struct _EPopupItem *item)
{
    g_free(item->path);
    g_free(item->label);
    g_free(item->image);
    g_free(item->user_data);
    g_free(item);
}

static void
emph_free_menu(struct _EPopupHookMenu *menu)
{
    g_slist_foreach(menu->items, (GFunc)emph_free_item, NULL);
    g_slist_free(menu->items);

    g_free(menu->factory);
    g_free(menu->id);
    g_free(menu);
}

static struct _EPopupItem *
emph_construct_item(EPluginHook *eph, EPopupHookMenu *menu, xmlNodePtr root, EPopupHookTargetMap *map)
{
    struct _EPopupItem *item;

    d(printf("  loading menu item\n"));
    item = g_malloc0(sizeof(*item));
    if ((item->type = e_plugin_hook_id(root, emph_item_types, "type")) == -1
        || item->type == E_POPUP_IMAGE)
        goto error;
    item->path = e_plugin_xml_prop(root, "path");
    item->label = e_plugin_xml_prop_domain(root, "label", eph->plugin->domain);
    item->image = e_plugin_xml_prop(root, "icon");
    item->visible = e_plugin_hook_mask(root, map->mask_bits, "visible");
    item->enable = e_plugin_hook_mask(root, map->mask_bits, "enable");
    item->user_data = e_plugin_xml_prop(root, "activate");

    item->activate = emph_popup_activate;

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

    d(printf("   path=%s\n", item->path));
    d(printf("   label=%s\n", item->label));

    return item;
error:
    d(printf("error!\n"));
    emph_free_item(item);
    return NULL;
}

static struct _EPopupHookMenu *
emph_construct_menu(EPluginHook *eph, xmlNodePtr root)
{
    struct _EPopupHookMenu *menu;
    xmlNodePtr node;
    EPopupHookTargetMap *map;
    EPopupHookClass *klass = (EPopupHookClass *)G_OBJECT_GET_CLASS(eph);
    gchar *tmp;

    d(printf(" loading menu\n"));
    menu = g_malloc0(sizeof(*menu));
    menu->hook = (EPopupHook *)eph;

    tmp = (gchar *)xmlGetProp(root, (const guchar *)"target");
    if (tmp == NULL)
        goto error;
    map = g_hash_table_lookup(klass->target_map, tmp);
    xmlFree(tmp);
    if (map == NULL)
        goto error;

    menu->target_type = map->id;
    menu->id = e_plugin_xml_prop(root, "id");
    if (menu->id == NULL) {
        g_warning("Plugin '%s' missing 'id' field in popup for '%s'\n", eph->plugin->name,
              ((EPluginHookClass *)G_OBJECT_GET_CLASS(eph))->id);
        goto error;
    }

    menu->factory = e_plugin_xml_prop(root, "factory");

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

            item = emph_construct_item(eph, menu, node, map);
            if (item)
                menu->items = g_slist_append(menu->items, item);
        }
        node = node->next;
    }

    return menu;
error:
    emph_free_menu(menu);
    return NULL;
}

static gint
emph_construct(EPluginHook *eph, EPlugin *ep, xmlNodePtr root)
{
    xmlNodePtr node;
    EPopupClass *klass;

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

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

    klass = ((EPopupHookClass *)G_OBJECT_GET_CLASS(eph))->popup_class;

    node = root->children;
    while (node) {
        if (strcmp((gchar *)node->name, "menu") == 0) {
            struct _EPopupHookMenu *menu;

            menu = emph_construct_menu(eph, node);
            if (menu) {
                e_popup_class_add_factory(klass, menu->id, emph_popup_factory, menu);
                emph->menus = g_slist_append(emph->menus, menu);
            }
        }
        node = node->next;
    }

    eph->plugin = ep;

    return 0;
}

static void
emph_finalise(GObject *o)
{
    EPluginHook *eph = (EPluginHook *)o;

    g_slist_foreach(emph->menus, (GFunc)emph_free_menu, NULL);
    g_slist_free(emph->menus);

    ((GObjectClass *)emph_parent_class)->finalize(o);
}

static void
emph_class_init(EPluginHookClass *klass)
{
    ((GObjectClass *)klass)->finalize = emph_finalise;
    klass->construct = emph_construct;

    /* this is actually an abstract implementation but list it anyway */
    klass->id = "org.gnome.evolution.popup:1.0";

    d(printf("EPopupHook: init class %p '%s'\n", klass, g_type_name(((GObjectClass *)klass)->g_type_class.g_type)));

    ((EPopupHookClass *)klass)->target_map = g_hash_table_new(g_str_hash, g_str_equal);
    ((EPopupHookClass *)klass)->popup_class = g_type_class_ref(e_popup_get_type());
}

/**
 * e_popup_hook_get_type:
 *
 * Standard GObject function to get the object type.  Used to subclass
 * EPopupHook.
 *
 * Return value: The type of the popup hook class.
 **/
GType
e_popup_hook_get_type(void)
{
    static GType type = 0;

    if (!type) {
        static const GTypeInfo info = {
            sizeof(EPopupHookClass), NULL, NULL, (GClassInitFunc) emph_class_init, NULL, NULL,
            sizeof(EPopupHook), 0, (GInstanceInitFunc) NULL,
        };

        emph_parent_class = g_type_class_ref(e_plugin_hook_get_type());
        type = g_type_register_static(e_plugin_hook_get_type(), "EPopupHook", &info, 0);
    }

    return type;
}

/**
 * e_popup_hook_class_add_target_map:
 * @klass: The derived EPopupHook class.
 * @map: A map used to describe a single EPopupTarget type for this
 * class.
 *
 * Add a target map to a concrete derived class of EPopup.  The target
 * map enumerates a single target type and the enable mask bit names,
 * so that the type can be loaded automatically by the EPopup class.
 **/
void e_popup_hook_class_add_target_map(EPopupHookClass *klass, const EPopupHookTargetMap *map)
{
    g_hash_table_insert(klass->target_map, (gpointer)map->type, (gpointer)map);
}