Merge pull request #1133 from techee/readme_rst

[geany-mirror.git] / src / plugins.c

/*
 *      plugins.c - this file is part of Geany, a fast and lightweight IDE
 *
 *      Copyright 2007-2012 Enrico Tröger <enrico(dot)troeger(at)uvena(dot)de>
 *      Copyright 2007-2012 Nick Treleaven <nick(dot)treleaven(at)btinternet(dot)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.,
 *      51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

/* Code to manage, load and unload plugins. */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#ifdef HAVE_PLUGINS

#include "plugins.h"

#include "app.h"
#include "dialogs.h"
#include "encodings.h"
#include "geanyobject.h"
#include "geanywraplabel.h"
#include "highlighting.h"
#include "keybindingsprivate.h"
#include "keyfile.h"
#include "main.h"
#include "msgwindow.h"
#include "navqueue.h"
#include "plugindata.h"
#include "pluginprivate.h"
#include "pluginutils.h"
#include "prefs.h"
#include "sciwrappers.h"
#include "stash.h"
#include "support.h"
#include "symbols.h"
#include "templates.h"
#include "toolbar.h"
#include "ui_utils.h"
#include "utils.h"
#include "win32.h"

#include "gtkcompat.h"

#include <string.h>


GList *active_plugin_list = NULL; /* list of only actually loaded plugins, always valid */


static gboolean want_plugins = FALSE;

/* list of all available, loadable plugins, only valid as long as the plugin manager dialog is
 * opened, afterwards it will be destroyed */
static GList *plugin_list = NULL;
static gchar **active_plugins_pref = NULL;      /* list of plugin filenames to load at startup */
static GList *failed_plugins_list = NULL;       /* plugins the user wants active but can't be used */

static GtkWidget *menu_separator = NULL;

static gchar *get_plugin_path(void);
static void pm_show_dialog(GtkMenuItem *menuitem, gpointer user_data);

typedef struct {
        gchar           extension[8];
        Plugin          *plugin; /* &builtin_so_proxy_plugin for native plugins */
} PluginProxy;


static gpointer plugin_load_gmodule(GeanyPlugin *proxy, GeanyPlugin *plugin, const gchar *filename, gpointer pdata);
static void plugin_unload_gmodule(GeanyPlugin *proxy, GeanyPlugin *plugin, gpointer load_data, gpointer pdata);

static Plugin builtin_so_proxy_plugin = {
        .proxy_cbs = {
                .load = plugin_load_gmodule,
                .unload = plugin_unload_gmodule,
        },
        /* rest of Plugin can be NULL/0 */
};

static PluginProxy builtin_so_proxy = {
        .extension = G_MODULE_SUFFIX,
        .plugin = &builtin_so_proxy_plugin,
};

static GQueue active_proxies = G_QUEUE_INIT;

static void plugin_free(Plugin *plugin);

static GeanyData geany_data;

static void
geany_data_init(void)
{
        GeanyData gd = {
                app,
                &main_widgets,
                documents_array,
                filetypes_array,
                &prefs,
                &interface_prefs,
                &toolbar_prefs,
                &editor_prefs,
                &file_prefs,
                &search_prefs,
                &tool_prefs,
                &template_prefs,
                NULL, /* Remove field on next ABI break (abi-todo) */
                filetypes_by_title,
                geany_object,
        };

        geany_data = gd;
}


/* In order to have nested proxies work the count of dependent plugins must propagate up.
 * This prevents that any plugin in the tree is unloaded while a leaf plugin is active. */
static void proxied_count_inc(Plugin *proxy)
{
        do
        {
                proxy->proxied_count += 1;
                proxy = proxy->proxy;
        } while (proxy != NULL);
}


static void proxied_count_dec(Plugin *proxy)
{
        g_warn_if_fail(proxy->proxied_count > 0);

        do
        {
                proxy->proxied_count -= 1;
                proxy = proxy->proxy;
        } while (proxy != NULL);
}


/* Prevent the same plugin filename being loaded more than once.
 * Note: g_module_name always returns the .so name, even when Plugin::filename is a .la file. */
static gboolean
plugin_loaded(Plugin *plugin)
{
        gchar *basename_module, *basename_loaded;
        GList *item;

        basename_module = g_path_get_basename(plugin->filename);
        for (item = plugin_list; item != NULL; item = g_list_next(item))
        {
                basename_loaded = g_path_get_basename(((Plugin*)item->data)->filename);

                if (utils_str_equal(basename_module, basename_loaded))
                {
                        g_free(basename_loaded);
                        g_free(basename_module);
                        return TRUE;
                }
                g_free(basename_loaded);
        }
        /* Look also through the list of active plugins. This prevents problems when we have the same
         * plugin in libdir/geany/ AND in configdir/plugins/ and the one in libdir/geany/ is loaded
         * as active plugin. The plugin manager list would only take the one in configdir/geany/ and
         * the plugin manager would list both plugins. Additionally, unloading the active plugin
         * would cause a crash. */
        for (item = active_plugin_list; item != NULL; item = g_list_next(item))
        {
                basename_loaded = g_path_get_basename(((Plugin*)item->data)->filename);

                if (utils_str_equal(basename_module, basename_loaded))
                {
                        g_free(basename_loaded);
                        g_free(basename_module);
                        return TRUE;
                }
                g_free(basename_loaded);
        }
        g_free(basename_module);
        return FALSE;
}


static Plugin *find_active_plugin_by_name(const gchar *filename)
{
        GList *item;

        g_return_val_if_fail(filename, FALSE);

        for (item = active_plugin_list; item != NULL; item = g_list_next(item))
        {
                if (utils_str_equal(filename, ((Plugin*)item->data)->filename))
                        return item->data;
        }

        return NULL;
}


/* Mimics plugin_version_check() of legacy plugins for use with plugin_check_version() below */
#define PLUGIN_VERSION_CODE(api, abi) ((abi) != GEANY_ABI_VERSION ? -1 : (api))

static gboolean
plugin_check_version(Plugin *plugin, int plugin_version_code)
{
        gboolean ret = TRUE;
        if (plugin_version_code < 0)
        {
                gchar *name = g_path_get_basename(plugin->filename);
                msgwin_status_add(_("The plugin \"%s\" is not binary compatible with this "
                        "release of Geany - please recompile it."), name);
                geany_debug("Plugin \"%s\" is not binary compatible with this "
                        "release of Geany - recompile it.", name);
                ret = FALSE;
                g_free(name);
        }
        else if (plugin_version_code > GEANY_API_VERSION)
        {
                gchar *name = g_path_get_basename(plugin->filename);
                geany_debug("Plugin \"%s\" requires a newer version of Geany (API >= v%d).",
                        name, plugin_version_code);
                ret = FALSE;
                g_free(name);
        }

        return ret;
}


static void add_callbacks(Plugin *plugin, PluginCallback *callbacks)
{
        PluginCallback *cb;
        guint i, len = 0;

        while (TRUE)
        {
                cb = &callbacks[len];
                if (!cb->signal_name || !cb->callback)
                        break;
                len++;
        }
        if (len == 0)
                return;

        for (i = 0; i < len; i++)
        {
                cb = &callbacks[i];

                /* Pass the callback data as default user_data if none was set by the plugin itself */
                plugin_signal_connect(&plugin->public, NULL, cb->signal_name, cb->after,
                        cb->callback, cb->user_data ? cb->user_data : plugin->cb_data);
        }
}


static void read_key_group(Plugin *plugin)
{
        GeanyKeyGroupInfo *p_key_info;
        GeanyKeyGroup **p_key_group;
        GModule *module = plugin->proxy_data;

        g_module_symbol(module, "plugin_key_group_info", (void *) &p_key_info);
        g_module_symbol(module, "plugin_key_group", (void *) &p_key_group);
        if (p_key_info && p_key_group)
        {
                GeanyKeyGroupInfo *key_info = p_key_info;

                if (*p_key_group)
                        geany_debug("Ignoring plugin_key_group symbol for plugin '%s' - "
                                "use plugin_set_key_group() instead to allocate keybindings dynamically.",
                                plugin->info.name);
                else
                {
                        if (key_info->count)
                        {
                                GeanyKeyGroup *key_group =
                                        plugin_set_key_group(&plugin->public, key_info->name, key_info->count, NULL);
                                if (key_group)
                                        *p_key_group = key_group;
                        }
                        else
                                geany_debug("Ignoring plugin_key_group_info symbol for plugin '%s' - "
                                        "count field is zero. Maybe use plugin_set_key_group() instead?",
                                        plugin->info.name);
                }
        }
        else if (p_key_info || p_key_group)
                geany_debug("Ignoring only one of plugin_key_group[_info] symbols defined for plugin '%s'. "
                        "Maybe use plugin_set_key_group() instead?",
                        plugin->info.name);
}


static gint cmp_plugin_names(gconstpointer a, gconstpointer b)
{
        const Plugin *pa = a;
        const Plugin *pb = b;

        return strcmp(pa->info.name, pb->info.name);
}


/** Register a plugin to Geany.
 *
 * The plugin will show up in the plugin manager. The user can interact with
 * it based on the functions it provides and installed GUI elements.
 *
 * You must initialize the info and funcs fields of @ref GeanyPlugin
 * appropriately prior to calling this, otherwise registration will fail. For
 * info at least a valid name must be set (possibly localized). For funcs,
 * at least init() and cleanup() functions must be implemented and set.
 *
 * The return value must be checked. It may be FALSE if the plugin failed to register which can
 * mainly happen for two reasons (future Geany versions may add new failure conditions):
 *  - Not all mandatory fields of GeanyPlugin have been set.
 *  - The ABI or API versions reported by the plugin are incompatible with the running Geany.
 *
 * Do not call this directly. Use GEANY_PLUGIN_REGISTER() instead which automatically
 * handles @a api_version and @a abi_version.
 *
 * @param plugin The plugin provided by Geany
 * @param api_version The API version the plugin is compiled against (pass GEANY_API_VERSION)
 * @param min_api_version The minimum API version required by the plugin
 * @param abi_version The exact ABI version the plugin is compiled against (pass GEANY_ABI_VERSION)
 *
 * @return TRUE if the plugin was successfully registered. Otherwise FALSE.
 *
 * @since 1.26 (API 225)
 * @see GEANY_PLUGIN_REGISTER()
 **/
GEANY_API_SYMBOL
gboolean geany_plugin_register(GeanyPlugin *plugin, gint api_version, gint min_api_version,
                               gint abi_version)
{
        Plugin *p;
        GeanyPluginFuncs *cbs = plugin->funcs;

        g_return_val_if_fail(plugin != NULL, FALSE);

        p = plugin->priv;
        /* already registered successfully */
        g_return_val_if_fail(!PLUGIN_LOADED_OK(p), FALSE);

        /* Prevent registering incompatible plugins. */
        if (! plugin_check_version(p, PLUGIN_VERSION_CODE(api_version, abi_version)))
                return FALSE;

        /* Only init and cleanup callbacks are truly mandatory. */
        if (! cbs->init || ! cbs->cleanup)
        {
                gchar *name = g_path_get_basename(p->filename);
                geany_debug("Plugin '%s' has no %s function - ignoring plugin!", name,
                            cbs->init ? "cleanup" : "init");
                g_free(name);
        }
        else
        {
                /* Yes, name is checked again later on, however we want return FALSE here
                 * to signal the error back to the plugin (but we don't print the message twice) */
                if (! EMPTY(p->info.name))
                        p->flags = LOADED_OK;
        }

        /* If it ever becomes necessary we can save the api version in Plugin
         * and apply compat code on a per-plugin basis, because we learn about
         * the requested API version here. For now it's not necessary. */

        return PLUGIN_LOADED_OK(p);
}


/** Register a plugin to Geany, with plugin-defined data.
 *
 * This is a variant of geany_plugin_register() that also allows to set the plugin-defined data.
 * Refer to that function for more details on registering in general.
 *
 * @p pdata is the pointer going to be passed to the individual plugin callbacks
 * of GeanyPlugin::funcs. When the plugin module is unloaded, @p free_func is invoked on
 * @p pdata, which connects the data to the plugin's module life time.
 *
 * You cannot use geany_plugin_set_data() after registering with this function. Use
 * geany_plugin_register() if you need to.
 *
 * Do not call this directly. Use GEANY_PLUGIN_REGISTER_FULL() instead which automatically
 * handles @p api_version and @p abi_version.
 *
 * @param plugin The plugin provided by Geany.
 * @param api_version The API version the plugin is compiled against (pass GEANY_API_VERSION).
 * @param min_api_version The minimum API version required by the plugin.
 * @param abi_version The exact ABI version the plugin is compiled against (pass GEANY_ABI_VERSION).
 * @param pdata Pointer to the plugin-defined data. Must not be @c NULL.
 * @param free_func Function used to deallocate @a pdata, may be @c NULL.
 *
 * @return TRUE if the plugin was successfully registered. Otherwise FALSE.
 *
 * @since 1.26 (API 225)
 * @see GEANY_PLUGIN_REGISTER_FULL()
 * @see geany_plugin_register()
 **/
GEANY_API_SYMBOL
gboolean geany_plugin_register_full(GeanyPlugin *plugin, gint api_version, gint min_api_version,
                                                                        gint abi_version, gpointer pdata, GDestroyNotify free_func)
{
        if (geany_plugin_register(plugin, api_version, min_api_version, abi_version))
        {
                geany_plugin_set_data(plugin, pdata, free_func);
                /* We use LOAD_DATA to indicate that pdata cb_data was set during loading/registration
                 * as opposed to during GeanyPluginFuncs::init(). In the latter case we call free_func
                 * after GeanyPluginFuncs::cleanup() */
                plugin->priv->flags |= LOAD_DATA;
                return TRUE;
        }
        return FALSE;
}

struct LegacyRealFuncs
{
        void       (*init) (GeanyData *data);
        GtkWidget* (*configure) (GtkDialog *dialog);
        void       (*help) (void);
        void       (*cleanup) (void);
};

/* Wrappers to support legacy plugins are below */
static gboolean legacy_init(GeanyPlugin *plugin, gpointer pdata)
{
        struct LegacyRealFuncs *h = pdata;
        h->init(plugin->geany_data);
        return TRUE;
}

static void legacy_cleanup(GeanyPlugin *plugin, gpointer pdata)
{
        struct LegacyRealFuncs *h = pdata;
        /* Can be NULL because it's optional for legacy plugins */
        if (h->cleanup)
                h->cleanup();
}

static void legacy_help(GeanyPlugin *plugin, gpointer pdata)
{
        struct LegacyRealFuncs *h = pdata;
        h->help();
}

static GtkWidget *legacy_configure(GeanyPlugin *plugin, GtkDialog *parent, gpointer pdata)
{
        struct LegacyRealFuncs *h = pdata;
        return h->configure(parent);
}

static void free_legacy_cbs(gpointer data)
{
        g_slice_free(struct LegacyRealFuncs, data);
}

/* This function is the equivalent of geany_plugin_register() for legacy-style
 * plugins which we continue to load for the time being. */
static void register_legacy_plugin(Plugin *plugin, GModule *module)
{
        gint (*p_version_check) (gint abi_version);
        void (*p_set_info) (PluginInfo *info);
        void (*p_init) (GeanyData *geany_data);
        GeanyData **p_geany_data;
        struct LegacyRealFuncs *h;

#define CHECK_FUNC(__x)                                                                   \
        if (! g_module_symbol(module, "plugin_" #__x, (void *) (&p_##__x)))                   \
        {                                                                                     \
                geany_debug("Plugin \"%s\" has no plugin_" #__x "() function - ignoring plugin!", \
                                g_module_name(module));                                                   \
                return;                                                                           \
        }
        CHECK_FUNC(version_check);
        CHECK_FUNC(set_info);
        CHECK_FUNC(init);
#undef CHECK_FUNC

        /* We must verify the version first. If the plugin has become incompatible any
         * further actions should be considered invalid and therefore skipped. */
        if (! plugin_check_version(plugin, p_version_check(GEANY_ABI_VERSION)))
                return;

        h = g_slice_new(struct LegacyRealFuncs);

        /* Since the version check passed we can proceed with setting basic fields and
         * calling its set_info() (which might want to call Geany functions already). */
        g_module_symbol(module, "geany_data", (void *) &p_geany_data);
        if (p_geany_data)
                *p_geany_data = &geany_data;
        /* Read plugin name, etc. name is mandatory but that's enforced in the common code. */
        p_set_info(&plugin->info);

        /* If all went well we can set the remaining callbacks and let it go for good. */
        h->init = p_init;
        g_module_symbol(module, "plugin_configure", (void *) &h->configure);
        g_module_symbol(module, "plugin_configure_single", (void *) &plugin->configure_single);
        g_module_symbol(module, "plugin_help", (void *) &h->help);
        g_module_symbol(module, "plugin_cleanup", (void *) &h->cleanup);
        /* pointer to callbacks struct can be stored directly, no wrapper necessary */
        g_module_symbol(module, "plugin_callbacks", (void *) &plugin->cbs.callbacks);
        if (app->debug_mode)
        {
                if (h->configure && plugin->configure_single)
                        g_warning("Plugin '%s' implements plugin_configure_single() unnecessarily - "
                                "only plugin_configure() will be used!",
                                plugin->info.name);
                if (h->cleanup == NULL)
                        g_warning("Plugin '%s' has no plugin_cleanup() function - there may be memory leaks!",
                                plugin->info.name);
        }

        plugin->cbs.init = legacy_init;
        plugin->cbs.cleanup = legacy_cleanup;
        plugin->cbs.configure = h->configure ? legacy_configure : NULL;
        plugin->cbs.help = h->help ? legacy_help : NULL;

        plugin->flags = LOADED_OK | IS_LEGACY;
        geany_plugin_set_data(&plugin->public, h, free_legacy_cbs);
}


static gboolean
plugin_load(Plugin *plugin)
{
        gboolean init_ok = TRUE;

        /* Start the plugin. Legacy plugins require additional cruft. */
        if (PLUGIN_IS_LEGACY(plugin) && plugin->proxy == &builtin_so_proxy_plugin)
        {
                GeanyPlugin **p_geany_plugin;
                PluginInfo **p_info;
                PluginFields **plugin_fields;
                GModule *module = plugin->proxy_data;
                /* set these symbols before plugin_init() is called
                 * we don't set geany_data since it is set directly by plugin_new() */
                g_module_symbol(module, "geany_plugin", (void *) &p_geany_plugin);
                if (p_geany_plugin)
                        *p_geany_plugin = &plugin->public;
                g_module_symbol(module, "plugin_info", (void *) &p_info);
                if (p_info)
                        *p_info = &plugin->info;
                g_module_symbol(module, "plugin_fields", (void *) &plugin_fields);
                if (plugin_fields)
                        *plugin_fields = &plugin->fields;
                read_key_group(plugin);

                /* Legacy plugin_init() cannot fail. */
                plugin->cbs.init(&plugin->public, plugin->cb_data);

                /* now read any plugin-owned data that might have been set in plugin_init() */
                if (plugin->fields.flags & PLUGIN_IS_DOCUMENT_SENSITIVE)
                {
                        ui_add_document_sensitive(plugin->fields.menu_item);
                }
        }
        else
        {
                init_ok = plugin->cbs.init(&plugin->public, plugin->cb_data);
        }

        if (! init_ok)
                return FALSE;

        /* new-style plugins set their callbacks in geany_load_module() */
        if (plugin->cbs.callbacks)
                add_callbacks(plugin, plugin->cbs.callbacks);

        /* remember which plugins are active.
         * keep list sorted so tools menu items and plugin preference tabs are
         * sorted by plugin name */
        active_plugin_list = g_list_insert_sorted(active_plugin_list, plugin, cmp_plugin_names);
        proxied_count_inc(plugin->proxy);

        geany_debug("Loaded:   %s (%s)", plugin->filename, plugin->info.name);
        return TRUE;
}


static gpointer plugin_load_gmodule(GeanyPlugin *proxy, GeanyPlugin *subplugin, const gchar *fname, gpointer pdata)
{
        GModule *module;
        void (*p_geany_load_module)(GeanyPlugin *);

        g_return_val_if_fail(g_module_supported(), NULL);
        /* Don't use G_MODULE_BIND_LAZY otherwise we can get unresolved symbols at runtime,
         * causing a segfault. Without that flag the module will safely fail to load.
         * G_MODULE_BIND_LOCAL also helps find undefined symbols e.g. app when it would
         * otherwise not be detected due to the shadowing of Geany's app variable.
         * Also without G_MODULE_BIND_LOCAL calling public functions e.g. the old info()
         * function from a plugin will be shadowed. */
        module = g_module_open(fname, G_MODULE_BIND_LOCAL);
        if (!module)
        {
                geany_debug("Can't load plugin: %s", g_module_error());
                return NULL;
        }

        /*geany_debug("Initializing plugin '%s'", plugin->info.name);*/
        g_module_symbol(module, "geany_load_module", (void *) &p_geany_load_module);
        if (p_geany_load_module)
        {
                /* set this here already so plugins can call i.e. plugin_module_make_resident()
                 * right from their geany_load_module() */
                subplugin->priv->proxy_data = module;

                /* This is a new style plugin. It should fill in plugin->info and then call
                 * geany_plugin_register() in its geany_load_module() to successfully load.
                 * The ABI and API checks are performed by geany_plugin_register() (i.e. by us).
                 * We check the LOADED_OK flag separately to protect us against buggy plugins
                 * who ignore the result of geany_plugin_register() and register anyway */
                p_geany_load_module(subplugin);
        }
        else
        {
                /* This is the legacy / deprecated code path. It does roughly the same as
                 * geany_load_module() and geany_plugin_register() together for the new ones */
                register_legacy_plugin(subplugin->priv, module);
        }
        /* We actually check the LOADED_OK flag later */
        return module;
}


static void plugin_unload_gmodule(GeanyPlugin *proxy, GeanyPlugin *subplugin, gpointer load_data, gpointer pdata)
{
        GModule *module = (GModule *) load_data;

        g_return_if_fail(module != NULL);

        if (! g_module_close(module))
                g_warning("%s: %s", subplugin->priv->filename, g_module_error());
}


/* Load and optionally init a plugin.
 * load_plugin decides whether the plugin's plugin_init() function should be called or not. If it is
 * called, the plugin will be started, if not the plugin will be read only (for the list of
 * available plugins in the plugin manager).
 * When add_to_list is set, the plugin will be added to the plugin manager's plugin_list. */
static Plugin*
plugin_new(Plugin *proxy, const gchar *fname, gboolean load_plugin, gboolean add_to_list)
{
        Plugin *plugin;

        g_return_val_if_fail(fname, NULL);
        g_return_val_if_fail(proxy, NULL);

        /* find the plugin in the list of already loaded, active plugins and use it, otherwise
         * load the module */
        plugin = find_active_plugin_by_name(fname);
        if (plugin != NULL)
        {
                geany_debug("Plugin \"%s\" already loaded.", fname);
                if (add_to_list)
                {
                        /* do not add to the list twice */
                        if (g_list_find(plugin_list, plugin) != NULL)
                                return NULL;

                        plugin_list = g_list_prepend(plugin_list, plugin);
                }
                return plugin;
        }

        plugin = g_new0(Plugin, 1);
        plugin->filename = g_strdup(fname);
        plugin->proxy = proxy;
        plugin->public.geany_data = &geany_data;
        plugin->public.priv = plugin;
        /* Fields of plugin->info/funcs must to be initialized by the plugin */
        plugin->public.info = &plugin->info;
        plugin->public.funcs = &plugin->cbs;
        plugin->public.proxy_funcs = &plugin->proxy_cbs;

        if (plugin_loaded(plugin))
        {
                geany_debug("Plugin \"%s\" already loaded.", fname);
                goto err;
        }

        /* Load plugin, this should read its name etc. It must also call
         * geany_plugin_register() for the following PLUGIN_LOADED_OK condition */
        plugin->proxy_data = proxy->proxy_cbs.load(&proxy->public, &plugin->public, fname, proxy->cb_data);

        if (! PLUGIN_LOADED_OK(plugin))
        {
                geany_debug("Failed to load \"%s\" - ignoring plugin!", fname);
                goto err;
        }

        /* The proxy assumes success, therefore we have to call unload from here
         * on in case of errors */
        if (EMPTY(plugin->info.name))
        {
                geany_debug("No plugin name set for \"%s\" - ignoring plugin!", fname);
                goto err_unload;
        }

        /* cb_data_destroy() frees plugin->cb_data. If that pointer also passed to unload() afterwards
         * then that would become a use-after-free. Disallow this combination. If a proxy
         * needs the same pointer it must not use a destroy func but free manually in its unload(). */
        if (plugin->proxy_data == proxy->cb_data && plugin->cb_data_destroy)
        {
                geany_debug("Proxy of plugin \"%s\" specified invalid data - ignoring plugin!", fname);
                plugin->proxy_data = NULL;
                goto err_unload;
        }

        if (load_plugin && !plugin_load(plugin))
        {
                /* Handle failing init same as failing to load for now. In future we
                 * could present a informational UI or something */
                geany_debug("Plugin failed to initialize \"%s\" - ignoring plugin!", fname);
                goto err_unload;
        }

        if (add_to_list)
                plugin_list = g_list_prepend(plugin_list, plugin);

        return plugin;

err_unload:
        if (plugin->cb_data_destroy)
                plugin->cb_data_destroy(plugin->cb_data);
        proxy->proxy_cbs.unload(&proxy->public, &plugin->public, plugin->proxy_data, proxy->cb_data);
err:
        g_free(plugin->filename);
        g_free(plugin);
        return NULL;
}


static void on_object_weak_notify(gpointer data, GObject *old_ptr)
{
        Plugin *plugin = data;
        guint i = 0;

        g_return_if_fail(plugin && plugin->signal_ids);

        for (i = 0; i < plugin->signal_ids->len; i++)
        {
                SignalConnection *sc = &g_array_index(plugin->signal_ids, SignalConnection, i);

                if (sc->object == old_ptr)
                {
                        g_array_remove_index_fast(plugin->signal_ids, i);
                        /* we can break the loop right after finding the first match,
                         * because we will get one notification per connected signal */
                        break;
                }
        }
}


/* add an object to watch for destruction, and release pointers to it when destroyed.
 * this should only be used by plugin_signal_connect() to add a watch on
 * the object lifetime and nuke out references to it in plugin->signal_ids */
void plugin_watch_object(Plugin *plugin, gpointer object)
{
        g_object_weak_ref(object, on_object_weak_notify, plugin);
}


static void remove_callbacks(Plugin *plugin)
{
        GArray *signal_ids = plugin->signal_ids;
        SignalConnection *sc;

        if (signal_ids == NULL)
                return;

        foreach_array(SignalConnection, sc, signal_ids)
        {
                g_signal_handler_disconnect(sc->object, sc->handler_id);
                g_object_weak_unref(sc->object, on_object_weak_notify, plugin);
        }

        g_array_free(signal_ids, TRUE);
}


static void remove_sources(Plugin *plugin)
{
        GList *item;

        item = plugin->sources;
        while (item != NULL)
        {
                GList *next = item->next; /* cache the next pointer because current item will be freed */

                g_source_destroy(item->data);
                item = next;
        }
        /* don't free the list here, it is allocated inside each source's data */
}


/* Make the GModule backing plugin resident (if it's GModule-backed at all) */
void plugin_make_resident(Plugin *plugin)
{
        if (plugin->proxy == &builtin_so_proxy_plugin)
        {
                g_return_if_fail(plugin->proxy_data != NULL);
                g_module_make_resident(plugin->proxy_data);
        }
        else
                g_warning("Skipping g_module_make_resident() for non-native plugin");
}


/* Retrieve the address of a symbol sym located in plugin, if it's GModule-backed */
gpointer plugin_get_module_symbol(Plugin *plugin, const gchar *sym)
{
        gpointer symbol;

        if (plugin->proxy == &builtin_so_proxy_plugin)
        {
                g_return_val_if_fail(plugin->proxy_data != NULL, NULL);
                if (g_module_symbol(plugin->proxy_data, sym, &symbol))
                        return symbol;
                else
                        g_warning("Failed to locate signal handler for '%s': %s",
                                sym, g_module_error());
        }
        else /* TODO: Could possibly support this via a new proxy hook */
                g_warning("Failed to locate signal handler for '%s': Not supported for non-native plugins",
                        sym);
        return NULL;
}


static gboolean is_active_plugin(Plugin *plugin)
{
        return (g_list_find(active_plugin_list, plugin) != NULL);
}


/* Clean up anything used by an active plugin  */
static void
plugin_cleanup(Plugin *plugin)
{
        GtkWidget *widget;

        /* With geany_register_plugin cleanup is mandatory */
        plugin->cbs.cleanup(&plugin->public, plugin->cb_data);

        remove_callbacks(plugin);
        remove_sources(plugin);

        if (plugin->key_group)
                keybindings_free_group(plugin->key_group);

        widget = plugin->toolbar_separator.widget;
        if (widget)
                gtk_widget_destroy(widget);

        if (!PLUGIN_HAS_LOAD_DATA(plugin) && plugin->cb_data_destroy)
        {
                /* If the plugin has used geany_plugin_set_data(), destroy the data here. But don't
                 * if it was already set through geany_plugin_register_full() because we couldn't call
                 * its init() anymore (not without completely reloading it anyway). */
                plugin->cb_data_destroy(plugin->cb_data);
                plugin->cb_data = NULL;
                plugin->cb_data_destroy = NULL;
        }

        proxied_count_dec(plugin->proxy);
        geany_debug("Unloaded: %s", plugin->filename);
}


/* Remove all plugins that proxy is a proxy for from plugin_list (and free) */
static void free_subplugins(Plugin *proxy)
{
        GList *item;

        item = plugin_list;
        while (item)
        {
                GList *next = g_list_next(item);
                if (proxy == ((Plugin *) item->data)->proxy)
                {
                        /* plugin_free modifies plugin_list */
                        plugin_free((Plugin *) item->data);
                }
                item = next;
        }
}


/* Returns true if the removal was successful (=> never for non-proxies) */
static gboolean unregister_proxy(Plugin *proxy)
{
        gboolean is_proxy = FALSE;
        GList *node;

        /* Remove the proxy from the proxy list first. It might appear more than once (once
         * for each extension), but if it doesn't appear at all it's not actually a proxy */
        foreach_list_safe(node, active_proxies.head)
        {
                PluginProxy *p = node->data;
                if (p->plugin == proxy)
                {
                        is_proxy = TRUE;
                        g_queue_delete_link(&active_proxies, node);
                }
        }
        return is_proxy;
}


/* Cleanup a plugin and free all resources allocated on behalf of it.
 *
 * If the plugin is a proxy then this also takes special care to unload all
 * subplugin loaded through it (make sure none of them is active!) */
static void
plugin_free(Plugin *plugin)
{
        Plugin *proxy;

        g_return_if_fail(plugin);
        g_return_if_fail(plugin->proxy);
        g_return_if_fail(plugin->proxied_count == 0);

        proxy = plugin->proxy;
        /* If this a proxy remove all depending subplugins. We can assume none of them is *activated*
         * (but potentially loaded). Note that free_subplugins() might call us through recursion */
        if (is_active_plugin(plugin))
        {
                if (unregister_proxy(plugin))
                        free_subplugins(plugin);
                plugin_cleanup(plugin);
        }

        active_plugin_list = g_list_remove(active_plugin_list, plugin);
        plugin_list = g_list_remove(plugin_list, plugin);

        /* cb_data_destroy might be plugin code and must be called before unloading the module. */
        if (plugin->cb_data_destroy)
                plugin->cb_data_destroy(plugin->cb_data);
        proxy->proxy_cbs.unload(&proxy->public, &plugin->public, plugin->proxy_data, proxy->cb_data);

        g_free(plugin->filename);
        g_free(plugin);
}


static gchar *get_custom_plugin_path(const gchar *plugin_path_config,
                                                                         const gchar *plugin_path_system)
{
        gchar *plugin_path_custom;

        if (EMPTY(prefs.custom_plugin_path))
                return NULL;

        plugin_path_custom = utils_get_locale_from_utf8(prefs.custom_plugin_path);
        utils_tidy_path(plugin_path_custom);

        /* check whether the custom plugin path is one of the system or user plugin paths
         * and abort if so */
        if (utils_str_equal(plugin_path_custom, plugin_path_config) ||
                utils_str_equal(plugin_path_custom, plugin_path_system))
        {
                g_free(plugin_path_custom);
                return NULL;
        }
        return plugin_path_custom;
}


/* all 3 paths Geany looks for plugins in can change (even system path on Windows)
 * so we need to check active plugins are in the right place before loading */
static gboolean check_plugin_path(const gchar *fname)
{
        gchar *plugin_path_config;
        gchar *plugin_path_system;
        gchar *plugin_path_custom;
        gboolean ret = FALSE;

        plugin_path_config = g_build_filename(app->configdir, "plugins", NULL);
        if (g_str_has_prefix(fname, plugin_path_config))
                ret = TRUE;

        plugin_path_system = get_plugin_path();
        if (g_str_has_prefix(fname, plugin_path_system))
                ret = TRUE;

        plugin_path_custom = get_custom_plugin_path(plugin_path_config, plugin_path_system);
        if (plugin_path_custom)
        {
                if (g_str_has_prefix(fname, plugin_path_custom))
                        ret = TRUE;

                g_free(plugin_path_custom);
        }
        g_free(plugin_path_config);
        g_free(plugin_path_system);
        return ret;
}


/* Returns NULL if this ain't a plugin,
 * otherwise it returns the appropriate PluginProxy instance to load it */
static PluginProxy* is_plugin(const gchar *file)
{
        GList *node;
        const gchar *ext;

        /* extract file extension to avoid g_str_has_suffix() in the loop */
        ext = (const gchar *)strrchr(file, '.');
        if (ext == NULL)
                return FALSE;
        /* ensure the dot is really part of the filename */
        else if (strchr(ext, G_DIR_SEPARATOR) != NULL)
                return FALSE;

        ext += 1;
        /* O(n*m), (m being extensions per proxy) doesn't scale very well in theory
         * but not a problem in practice yet */
        foreach_list(node, active_proxies.head)
        {
                PluginProxy *proxy = node->data;
                if (utils_str_casecmp(ext, proxy->extension) == 0)
                {
                        Plugin *p = proxy->plugin;
                        gint ret = PROXY_MATCHED;

                        if (p->proxy_cbs.probe)
                                ret = p->proxy_cbs.probe(&p->public, file, p->cb_data);
                        switch (ret)
                        {
                                case PROXY_MATCHED:
                                        return proxy;
                                case PROXY_MATCHED|PROXY_NOLOAD:
                                        return NULL;
                                default:
                                        if (ret != PROXY_IGNORED)
                                                g_warning("Ignoring bogus return from proxy probe!\n");
                                        continue;
                        }
                }
        }
        return NULL;
}


/* load active plugins at startup */
static void
load_active_plugins(void)
{
        guint i, len, proxies;

        if (active_plugins_pref == NULL || (len = g_strv_length(active_plugins_pref)) == 0)
                return;

        /* If proxys are loaded we have to restart to load plugins that sort before their proxy */
        do
        {
                proxies = active_proxies.length;
                g_list_free_full(failed_plugins_list, (GDestroyNotify) g_free);
                failed_plugins_list = NULL;
                for (i = 0; i < len; i++)
                {
                        gchar *fname = active_plugins_pref[i];

#ifdef G_OS_WIN32
                        /* ensure we have canonical paths */
                        gchar *p = fname;
                        while ((p = strchr(p, '/')) != NULL)
                                *p = G_DIR_SEPARATOR;
#endif

                        if (!EMPTY(fname) && g_file_test(fname, G_FILE_TEST_EXISTS))
                        {
                                PluginProxy *proxy = NULL;
                                if (check_plugin_path(fname))
                                        proxy = is_plugin(fname);
                                if (proxy == NULL || plugin_new(proxy->plugin, fname, TRUE, FALSE) == NULL)
                                        failed_plugins_list = g_list_prepend(failed_plugins_list, g_strdup(fname));
                        }
                }
        } while (proxies != active_proxies.length);
}


static void
load_plugins_from_path(const gchar *path)
{
        GSList *list, *item;
        gint count = 0;

        list = utils_get_file_list(path, NULL, NULL);

        for (item = list; item != NULL; item = g_slist_next(item))
        {
                gchar *fname = g_build_filename(path, item->data, NULL);
                PluginProxy *proxy = is_plugin(fname);

                if (proxy != NULL && plugin_new(proxy->plugin, fname, FALSE, TRUE))
                        count++;

                g_free(fname);
        }

        g_slist_foreach(list, (GFunc) g_free, NULL);
        g_slist_free(list);

        if (count)
                geany_debug("Added %d plugin(s) in '%s'.", count, path);
}


static gchar *get_plugin_path(void)
{
        return g_strdup(utils_resource_dir(RESOURCE_DIR_PLUGIN));
}


/* See load_all_plugins(), this simply sorts items with lower hierarchy level first
 * (where hierarchy level == number of intermediate proxies before the builtin so loader) */
static gint cmp_plugin_by_proxy(gconstpointer a, gconstpointer b)
{
        const Plugin *pa = a;
        const Plugin *pb = b;

        while (TRUE)
        {
                if (pa->proxy == pb->proxy)
                        return 0;
                else if (pa->proxy == &builtin_so_proxy_plugin)
                        return -1;
                else if (pb->proxy == &builtin_so_proxy_plugin)
                        return 1;

                pa = pa->proxy;
                pb = pb->proxy;
        }
}


/* Load (but don't initialize) all plugins for the Plugin Manager dialog */
static void load_all_plugins(void)
{
        gchar *plugin_path_config;
        gchar *plugin_path_system;
        gchar *plugin_path_custom;

        plugin_path_config = g_build_filename(app->configdir, "plugins", NULL);
        plugin_path_system = get_plugin_path();

        /* first load plugins in ~/.config/geany/plugins/ */
        load_plugins_from_path(plugin_path_config);

        /* load plugins from a custom path */
        plugin_path_custom = get_custom_plugin_path(plugin_path_config, plugin_path_system);
        if (plugin_path_custom)
        {
                load_plugins_from_path(plugin_path_custom);
                g_free(plugin_path_custom);
        }

        /* finally load plugins from $prefix/lib/geany */
        load_plugins_from_path(plugin_path_system);

        /* It is important to sort any plugins that are proxied after their proxy because
         * pm_populate() needs the proxy to be loaded and active (if selected by user) in order
         * to properly set the value for the PLUGIN_COLUMN_CAN_UNCHECK column. The order between
         * sub-plugins does not matter, only between sub-plugins and their proxy, thus
         * sorting by hierarchy level is perfectly sufficient */
        plugin_list = g_list_sort(plugin_list, cmp_plugin_by_proxy);

        g_free(plugin_path_config);
        g_free(plugin_path_system);
}


static void on_tools_menu_show(GtkWidget *menu_item, G_GNUC_UNUSED gpointer user_data)
{
        GList *item, *list = gtk_container_get_children(GTK_CONTAINER(menu_item));
        guint i = 0;
        gboolean have_plugin_menu_items = FALSE;

        for (item = list; item != NULL; item = g_list_next(item))
        {
                if (item->data == menu_separator)
                {
                        if (i < g_list_length(list) - 1)
                        {
                                have_plugin_menu_items = TRUE;
                                break;
                        }
                }
                i++;
        }
        g_list_free(list);

        ui_widget_show_hide(menu_separator, have_plugin_menu_items);
}


/* Calling this starts up plugin support */
void plugins_load_active(void)
{
        GtkWidget *widget;

        want_plugins = TRUE;

        geany_data_init();

        widget = gtk_separator_menu_item_new();
        gtk_widget_show(widget);
        gtk_container_add(GTK_CONTAINER(main_widgets.tools_menu), widget);

        widget = gtk_menu_item_new_with_mnemonic(_("_Plugin Manager"));
        gtk_container_add(GTK_CONTAINER(main_widgets.tools_menu), widget);
        gtk_widget_show(widget);
        g_signal_connect(widget, "activate", G_CALLBACK(pm_show_dialog), NULL);

        menu_separator = gtk_separator_menu_item_new();
        gtk_container_add(GTK_CONTAINER(main_widgets.tools_menu), menu_separator);
        g_signal_connect(main_widgets.tools_menu, "show", G_CALLBACK(on_tools_menu_show), NULL);

        load_active_plugins();
}


/* Update the global active plugins list so it's up-to-date when configuration
 * is saved. Called in response to GeanyObject's "save-settings" signal. */
static void update_active_plugins_pref(void)
{
        gint i = 0;
        GList *list;
        gsize count;

        /* if plugins are disabled, don't clear list of active plugins */
        if (!want_plugins)
                return;

        count = g_list_length(active_plugin_list) + g_list_length(failed_plugins_list);

        g_strfreev(active_plugins_pref);

        if (count == 0)
        {
                active_plugins_pref = NULL;
                return;
        }

        active_plugins_pref = g_new0(gchar*, count + 1);

        for (list = g_list_first(active_plugin_list); list != NULL; list = list->next)
        {
                Plugin *plugin = list->data;

                active_plugins_pref[i] = g_strdup(plugin->filename);
                i++;
        }
        for (list = g_list_first(failed_plugins_list); list != NULL; list = list->next)
        {
                const gchar *fname = list->data;

                active_plugins_pref[i] = g_strdup(fname);
                i++;
        }
        active_plugins_pref[i] = NULL;
}


/* called even if plugin support is disabled */
void plugins_init(void)
{
        StashGroup *group;
        gchar *path;

        path = get_plugin_path();
        geany_debug("System plugin path: %s", path);
        g_free(path);

        group = stash_group_new("plugins");
        configuration_add_pref_group(group, TRUE);

        stash_group_add_toggle_button(group, &prefs.load_plugins,
                "load_plugins", TRUE, "check_plugins");
        stash_group_add_entry(group, &prefs.custom_plugin_path,
                "custom_plugin_path", "", "extra_plugin_path_entry");

        g_signal_connect(geany_object, "save-settings", G_CALLBACK(update_active_plugins_pref), NULL);
        stash_group_add_string_vector(group, &active_plugins_pref, "active_plugins", NULL);

        g_queue_push_head(&active_proxies, &builtin_so_proxy);
}


/* Same as plugin_free(), except it does nothing for proxies-in-use, to be called on
 * finalize in a loop */
static void plugin_free_leaf(Plugin *p)
{
        if (p->proxied_count == 0)
                plugin_free(p);
}


/* called even if plugin support is disabled */
void plugins_finalize(void)
{
        if (failed_plugins_list != NULL)
        {
                g_list_foreach(failed_plugins_list, (GFunc) g_free,     NULL);
                g_list_free(failed_plugins_list);
        }
        /* Have to loop because proxys cannot be unloaded until after all their
         * plugins are unloaded as well (the second loop should should catch all the remaining ones) */
        while (active_plugin_list != NULL)
                g_list_foreach(active_plugin_list, (GFunc) plugin_free_leaf, NULL);

        g_strfreev(active_plugins_pref);
}


/* Check whether there are any plugins loaded which provide a configure symbol */
gboolean plugins_have_preferences(void)
{
        GList *item;

        if (active_plugin_list == NULL)
                return FALSE;

        foreach_list(item, active_plugin_list)
        {
                Plugin *plugin = item->data;
                if (plugin->configure_single != NULL || plugin->cbs.configure != NULL)
                        return TRUE;
        }

        return FALSE;
}


/* Plugin Manager */

enum
{
        PLUGIN_COLUMN_CHECK = 0,
        PLUGIN_COLUMN_CAN_UNCHECK,
        PLUGIN_COLUMN_PLUGIN,
        PLUGIN_N_COLUMNS,
        PM_BUTTON_KEYBINDINGS,
        PM_BUTTON_CONFIGURE,
        PM_BUTTON_HELP
};

typedef struct
{
        GtkWidget *dialog;
        GtkWidget *tree;
        GtkTreeStore *store;
        GtkWidget *filter_entry;
        GtkWidget *configure_button;
        GtkWidget *keybindings_button;
        GtkWidget *help_button;
        GtkWidget *popup_menu;
        GtkWidget *popup_configure_menu_item;
        GtkWidget *popup_keybindings_menu_item;
        GtkWidget *popup_help_menu_item;
}
PluginManagerWidgets;

static PluginManagerWidgets pm_widgets;


static void pm_update_buttons(Plugin *p)
{
        gboolean has_configure = FALSE;
        gboolean has_help = FALSE;
        gboolean has_keybindings = FALSE;

        if (p != NULL && is_active_plugin(p))
        {
                has_configure = p->cbs.configure || p->configure_single;
                has_help = p->cbs.help != NULL;
                has_keybindings = p->key_group && p->key_group->plugin_key_count;
        }

        gtk_widget_set_sensitive(pm_widgets.configure_button, has_configure);
        gtk_widget_set_sensitive(pm_widgets.help_button, has_help);
        gtk_widget_set_sensitive(pm_widgets.keybindings_button, has_keybindings);

        gtk_widget_set_sensitive(pm_widgets.popup_configure_menu_item, has_configure);
        gtk_widget_set_sensitive(pm_widgets.popup_help_menu_item, has_help);
        gtk_widget_set_sensitive(pm_widgets.popup_keybindings_menu_item, has_keybindings);
}


static void pm_selection_changed(GtkTreeSelection *selection, gpointer user_data)
{
        GtkTreeIter iter;
        GtkTreeModel *model;
        Plugin *p;

        if (gtk_tree_selection_get_selected(selection, &model, &iter))
        {
                gtk_tree_model_get(model, &iter, PLUGIN_COLUMN_PLUGIN, &p, -1);

                if (p != NULL)
                        pm_update_buttons(p);
        }
}


static gboolean find_iter_for_plugin(Plugin *p, GtkTreeModel *model, GtkTreeIter *iter)
{
        Plugin *pp;
        gboolean valid;

        for (valid = gtk_tree_model_get_iter_first(model, iter);
             valid;
             valid = gtk_tree_model_iter_next(model, iter))
        {
                gtk_tree_model_get(model, iter, PLUGIN_COLUMN_PLUGIN, &pp, -1);
                if (p == pp)
                        return TRUE;
        }

        return FALSE;
}


static void pm_populate(GtkTreeStore *store);


static void pm_plugin_toggled(GtkCellRendererToggle *cell, gchar *pth, gpointer data)
{
        gboolean old_state, state;
        gchar *file_name;
        GtkTreeIter iter;
        GtkTreeIter store_iter;
        GtkTreePath *path = gtk_tree_path_new_from_string(pth);
        GtkTreeModel *model = gtk_tree_view_get_model(GTK_TREE_VIEW(pm_widgets.tree));
        Plugin *p;
        Plugin *proxy;
        guint prev_num_proxies;

        gtk_tree_model_get_iter(model, &iter, path);

        gtk_tree_model_get(model, &iter,
                PLUGIN_COLUMN_CHECK, &old_state,
                PLUGIN_COLUMN_PLUGIN, &p, -1);

        /* no plugins item */
        if (p == NULL)
        {
                gtk_tree_path_free(path);
                return;
        }

        gtk_tree_model_filter_convert_iter_to_child_iter(
                GTK_TREE_MODEL_FILTER(model), &store_iter, &iter);

        state = ! old_state; /* toggle the state */

        /* save the filename and proxy of the plugin */
        file_name = g_strdup(p->filename);
        proxy = p->proxy;
        prev_num_proxies = active_proxies.length;

        /* unload plugin module */
        if (!state)
                /* save shortcuts (only need this group, but it doesn't take long) */
                keybindings_write_to_file();

        /* plugin_new() below may cause a tree view refresh with invalid p - set to NULL */
        gtk_tree_store_set(pm_widgets.store, &store_iter,
                PLUGIN_COLUMN_PLUGIN, NULL, -1);
        plugin_free(p);

        /* reload plugin module and initialize it if item is checked */
        p = plugin_new(proxy, file_name, state, TRUE);
        if (!p)
        {
                /* plugin file may no longer be on disk, or is now incompatible */
                gtk_tree_store_remove(pm_widgets.store, &store_iter);
        }
        else
        {
                if (state)
                        keybindings_load_keyfile();             /* load shortcuts */

                /* update model */
                gtk_tree_store_set(pm_widgets.store, &store_iter,
                        PLUGIN_COLUMN_CHECK, state,
                        PLUGIN_COLUMN_PLUGIN, p, -1);

                /* set again the sensitiveness of the configure and help buttons */
                pm_update_buttons(p);

                /* Depending on the state disable the checkbox for the proxy of this plugin, and
                 * only re-enable if the proxy is not used by any other plugin */
                if (p->proxy != &builtin_so_proxy_plugin)
                {
                        GtkTreeIter parent;
                        gboolean can_uncheck;
                        GtkTreePath *store_path = gtk_tree_model_filter_convert_path_to_child_path(
                                                        GTK_TREE_MODEL_FILTER(model), path);

                        g_warn_if_fail(store_path != NULL);
                        if (gtk_tree_path_up(store_path))
                        {
                                gtk_tree_model_get_iter(GTK_TREE_MODEL(pm_widgets.store), &parent, store_path);

                                if (state)
                                        can_uncheck = FALSE;
                                else
                                        can_uncheck = p->proxy->proxied_count == 0;

                                gtk_tree_store_set(pm_widgets.store, &parent,
                                        PLUGIN_COLUMN_CAN_UNCHECK, can_uncheck, -1);
                        }
                        gtk_tree_path_free(store_path);
                }
        }
        /* We need to find out if a proxy was added or removed because that affects the plugin list
         * presented by the plugin manager */
        if (prev_num_proxies != active_proxies.length)
        {
                /* Rescan the plugin list as we now support more. Gives some "already loaded" warnings
                 * they are unproblematic */
                if (prev_num_proxies < active_proxies.length)
                        load_all_plugins();

                pm_populate(pm_widgets.store);
                gtk_tree_view_expand_row(GTK_TREE_VIEW(pm_widgets.tree), path, FALSE);
        }

        gtk_tree_path_free(path);
        g_free(file_name);
}

static void pm_populate(GtkTreeStore *store)
{
        GtkTreeIter iter;
        GList *list;

        gtk_tree_store_clear(store);
        list = g_list_first(plugin_list);
        if (list == NULL)
        {
                gtk_tree_store_append(store, &iter, NULL);
                gtk_tree_store_set(store, &iter, PLUGIN_COLUMN_CHECK, FALSE,
                                PLUGIN_COLUMN_PLUGIN, NULL, -1);
        }
        else
        {
                for (; list != NULL; list = list->next)
                {
                        Plugin *p = list->data;
                        GtkTreeIter parent;

                        if (p->proxy != &builtin_so_proxy_plugin
                                && find_iter_for_plugin(p->proxy, GTK_TREE_MODEL(pm_widgets.store), &parent))
                                gtk_tree_store_append(store, &iter, &parent);
                        else
                                gtk_tree_store_append(store, &iter, NULL);

                        gtk_tree_store_set(store, &iter,
                                PLUGIN_COLUMN_CHECK, is_active_plugin(p),
                                PLUGIN_COLUMN_PLUGIN, p,
                                PLUGIN_COLUMN_CAN_UNCHECK, (p->proxied_count == 0),
                                -1);
                }
        }
}

static gboolean pm_treeview_query_tooltip(GtkWidget *widget, gint x, gint y,
                gboolean keyboard_mode, GtkTooltip *tooltip, gpointer user_data)
{
        GtkTreeModel *model;
        GtkTreeIter iter;
        GtkTreePath *path;
        Plugin *p = NULL;
        gboolean can_uncheck = TRUE;

        if (! gtk_tree_view_get_tooltip_context(GTK_TREE_VIEW(widget), &x, &y, keyboard_mode,
                        &model, &path, &iter))
                return FALSE;

        gtk_tree_model_get(model, &iter, PLUGIN_COLUMN_PLUGIN, &p, PLUGIN_COLUMN_CAN_UNCHECK, &can_uncheck, -1);
        if (p != NULL)
        {
                gchar *prefix, *suffix, *details, *markup;
                const gchar *uchk;

                uchk = can_uncheck ?
                       "" : _("\n<i>Other plugins depend on this. Disable them first to allow deactivation.</i>\n");
                /* Four allocations is less than ideal but meh */
                details = g_strdup_printf(_("Version:\t%s\nAuthor(s):\t%s\nFilename:\t%s"),
                        p->info.version, p->info.author, p->filename);
                prefix = g_markup_printf_escaped("<b>%s</b>\n%s\n", p->info.name, p->info.description);
                suffix = g_markup_printf_escaped("<small><i>\n%s</i></small>", details);
                markup = g_strconcat(prefix, uchk, suffix, NULL);

                gtk_tooltip_set_markup(tooltip, markup);
                gtk_tree_view_set_tooltip_row(GTK_TREE_VIEW(widget), tooltip, path);

                g_free(details);
                g_free(suffix);
                g_free(prefix);
                g_free(markup);
        }
        gtk_tree_path_free(path);

        return p != NULL;
}


static void pm_treeview_text_cell_data_func(GtkTreeViewColumn *column, GtkCellRenderer *cell,
                GtkTreeModel *model, GtkTreeIter *iter, gpointer data)
{
        Plugin *p;

        gtk_tree_model_get(model, iter, PLUGIN_COLUMN_PLUGIN, &p, -1);

        if (p == NULL)
                g_object_set(cell, "text", _("No plugins available."), NULL);
        else
        {
                gchar *markup = g_markup_printf_escaped("<b>%s</b>\n%s", p->info.name, p->info.description);

                g_object_set(cell, "markup", markup, NULL);
                g_free(markup);
        }
}


static gboolean pm_treeview_button_press_cb(GtkWidget *widget, GdkEventButton *event,
                G_GNUC_UNUSED gpointer user_data)
{
        if (event->button == 3)
        {
                gtk_menu_popup(GTK_MENU(pm_widgets.popup_menu), NULL, NULL, NULL, NULL,
                                event->button, event->time);
        }
        return FALSE;
}


static gint pm_tree_sort_func(GtkTreeModel *model, GtkTreeIter *a, GtkTreeIter *b,
                gpointer user_data)
{
        Plugin *pa, *pb;

        gtk_tree_model_get(model, a, PLUGIN_COLUMN_PLUGIN, &pa, -1);
        gtk_tree_model_get(model, b, PLUGIN_COLUMN_PLUGIN, &pb, -1);

        if (pa && pb)
                return strcmp(pa->info.name, pb->info.name);
        else
                return pa - pb;
}


static gboolean pm_tree_search(const gchar *key, const gchar *haystack)
{
        gchar *normalized_string = NULL;
        gchar *normalized_key = NULL;
        gchar *case_normalized_string = NULL;
        gchar *case_normalized_key = NULL;
        gboolean matched = TRUE;

        normalized_string = g_utf8_normalize(haystack, -1, G_NORMALIZE_ALL);
        normalized_key = g_utf8_normalize(key, -1, G_NORMALIZE_ALL);

        if (normalized_string != NULL && normalized_key != NULL)
        {
                GString *stripped_key;
                gchar **subkey, **subkeys;

                case_normalized_string = g_utf8_casefold(normalized_string, -1);
                case_normalized_key = g_utf8_casefold(normalized_key, -1);
                stripped_key = g_string_new(case_normalized_key);
                do {} while (utils_string_replace_all(stripped_key, "  ", " "));
                subkeys = g_strsplit(stripped_key->str, " ", -1);
                g_string_free(stripped_key, TRUE);
                foreach_strv(subkey, subkeys)
                {
                        if (strstr(case_normalized_string, *subkey) == NULL)
                        {
                                matched = FALSE;
                                break;
                        }
                }
                g_strfreev(subkeys);
        }

        g_free(normalized_key);
        g_free(normalized_string);
        g_free(case_normalized_key);
        g_free(case_normalized_string);

        return matched;
}


static gboolean pm_tree_filter_func(GtkTreeModel *model, GtkTreeIter *iter, gpointer user_data)
{
        Plugin *plugin;
        gboolean matched;
        const gchar *key;
        gchar *haystack, *filename;

        gtk_tree_model_get(model, iter, PLUGIN_COLUMN_PLUGIN, &plugin, -1);

        if (!plugin)
                return FALSE;
        key = gtk_entry_get_text(GTK_ENTRY(pm_widgets.filter_entry));

        filename = g_path_get_basename(plugin->filename);
        haystack = g_strjoin(" ", plugin->info.name, plugin->info.description,
                                        plugin->info.author, filename, NULL);
        matched = pm_tree_search(key, haystack);
        g_free(haystack);
        g_free(filename);

        return matched;
}


static void on_pm_tree_filter_entry_changed_cb(GtkEntry *entry, gpointer user_data)
{
        GtkTreeModel *filter_model = gtk_tree_view_get_model(GTK_TREE_VIEW(pm_widgets.tree));
        gtk_tree_model_filter_refilter(GTK_TREE_MODEL_FILTER(filter_model));
}


static void on_pm_tree_filter_entry_icon_release_cb(GtkEntry *entry, GtkEntryIconPosition icon_pos,
                GdkEvent *event, gpointer user_data)
{
        if (event->button.button == 1 && icon_pos == GTK_ENTRY_ICON_PRIMARY)
                on_pm_tree_filter_entry_changed_cb(entry, user_data);
}


static void pm_prepare_treeview(GtkWidget *tree, GtkTreeStore *store)
{
        GtkCellRenderer *text_renderer, *checkbox_renderer;
        GtkTreeViewColumn *column;
        GtkTreeModel *filter_model;
        GtkTreeSelection *sel;

        g_signal_connect(tree, "query-tooltip", G_CALLBACK(pm_treeview_query_tooltip), NULL);
        gtk_widget_set_has_tooltip(tree, TRUE);
        gtk_tree_view_set_headers_visible(GTK_TREE_VIEW(tree), FALSE);

        checkbox_renderer = gtk_cell_renderer_toggle_new();
        column = gtk_tree_view_column_new_with_attributes(
                _("Active"), checkbox_renderer,
                "active", PLUGIN_COLUMN_CHECK, "activatable", PLUGIN_COLUMN_CAN_UNCHECK, NULL);
        gtk_tree_view_append_column(GTK_TREE_VIEW(tree), column);
        g_signal_connect(checkbox_renderer, "toggled", G_CALLBACK(pm_plugin_toggled), NULL);

        text_renderer = gtk_cell_renderer_text_new();
        g_object_set(text_renderer, "ellipsize", PANGO_ELLIPSIZE_END, NULL);
        column = gtk_tree_view_column_new_with_attributes(_("Plugin"), text_renderer, NULL);
        gtk_tree_view_column_set_cell_data_func(column, text_renderer,
                pm_treeview_text_cell_data_func, NULL, NULL);
        gtk_tree_view_append_column(GTK_TREE_VIEW(tree), column);

        gtk_tree_view_set_rules_hint(GTK_TREE_VIEW(tree), TRUE);
        gtk_tree_view_set_enable_search(GTK_TREE_VIEW(tree), FALSE);
        gtk_tree_sortable_set_sort_func(GTK_TREE_SORTABLE(store), PLUGIN_COLUMN_PLUGIN,
                pm_tree_sort_func, NULL, NULL);
        gtk_tree_sortable_set_sort_column_id(
                GTK_TREE_SORTABLE(store), PLUGIN_COLUMN_PLUGIN, GTK_SORT_ASCENDING);

        /* selection handling */
        sel = gtk_tree_view_get_selection(GTK_TREE_VIEW(tree));
        gtk_tree_selection_set_mode(sel, GTK_SELECTION_SINGLE);
        g_signal_connect(sel, "changed", G_CALLBACK(pm_selection_changed), NULL);

        g_signal_connect(tree, "button-press-event", G_CALLBACK(pm_treeview_button_press_cb), NULL);

        /* filter */
        filter_model = gtk_tree_model_filter_new(GTK_TREE_MODEL(store), NULL);
        gtk_tree_model_filter_set_visible_func(
                GTK_TREE_MODEL_FILTER(filter_model), pm_tree_filter_func, NULL, NULL);

        /* set model to tree view */
        gtk_tree_view_set_model(GTK_TREE_VIEW(tree), filter_model);
        g_object_unref(filter_model);

        pm_populate(store);
}


static void pm_on_plugin_button_clicked(G_GNUC_UNUSED GtkButton *button, gpointer user_data)
{
        GtkTreeModel *model;
        GtkTreeSelection *selection;
        GtkTreeIter iter;
        Plugin *p;

        selection = gtk_tree_view_get_selection(GTK_TREE_VIEW(pm_widgets.tree));
        if (gtk_tree_selection_get_selected(selection, &model, &iter))
        {
                gtk_tree_model_get(model, &iter, PLUGIN_COLUMN_PLUGIN, &p, -1);

                if (p != NULL)
                {
                        if (GPOINTER_TO_INT(user_data) == PM_BUTTON_CONFIGURE)
                                plugin_show_configure(&p->public);
                        else if (GPOINTER_TO_INT(user_data) == PM_BUTTON_HELP)
                                p->cbs.help(&p->public, p->cb_data);
                        else if (GPOINTER_TO_INT(user_data) == PM_BUTTON_KEYBINDINGS && p->key_group && p->key_group->plugin_key_count > 0)
                                keybindings_dialog_show_prefs_scroll(p->info.name);
                }
        }
}


static void
free_non_active_plugin(gpointer data, gpointer user_data)
{
        Plugin *plugin = data;

        /* don't do anything when closing the plugin manager and it is an active plugin */
        if (is_active_plugin(plugin))
                return;

        plugin_free(plugin);
}


/* Callback when plugin manager dialog closes, responses GTK_RESPONSE_CLOSE and
 * GTK_RESPONSE_DELETE_EVENT are treated the same. */
static void pm_dialog_response(GtkDialog *dialog, gint response, gpointer user_data)
{
        switch (response)
        {
                case GTK_RESPONSE_CLOSE:
                case GTK_RESPONSE_DELETE_EVENT:
                        if (plugin_list != NULL)
                        {
                                /* remove all non-active plugins from the list */
                                g_list_foreach(plugin_list, free_non_active_plugin, NULL);
                                g_list_free(plugin_list);
                                plugin_list = NULL;
                        }
                        gtk_widget_destroy(GTK_WIDGET(dialog));

                        configuration_save();
                        break;
                case PM_BUTTON_CONFIGURE:
                case PM_BUTTON_HELP:
                case PM_BUTTON_KEYBINDINGS:
                        /* forward event to the generic handler */
                        pm_on_plugin_button_clicked(NULL, GINT_TO_POINTER(response));
                        break;
        }
}


static void pm_show_dialog(GtkMenuItem *menuitem, gpointer user_data)
{
        GtkWidget *vbox, *vbox2, *swin, *label, *menu_item, *filter_entry;

        /* before showing the dialog, we need to create the list of available plugins */
        load_all_plugins();

        pm_widgets.dialog = gtk_dialog_new();
        gtk_window_set_title(GTK_WINDOW(pm_widgets.dialog), _("Plugins"));
        gtk_window_set_transient_for(GTK_WINDOW(pm_widgets.dialog), GTK_WINDOW(main_widgets.window));
        gtk_window_set_destroy_with_parent(GTK_WINDOW(pm_widgets.dialog), TRUE);

        vbox = ui_dialog_vbox_new(GTK_DIALOG(pm_widgets.dialog));
        gtk_widget_set_name(pm_widgets.dialog, "GeanyDialog");
        gtk_box_set_spacing(GTK_BOX(vbox), 6);

        gtk_window_set_default_size(GTK_WINDOW(pm_widgets.dialog), 500, 450);

        pm_widgets.help_button = gtk_dialog_add_button(
                GTK_DIALOG(pm_widgets.dialog), GTK_STOCK_HELP, PM_BUTTON_HELP);
        pm_widgets.configure_button = gtk_dialog_add_button(
                GTK_DIALOG(pm_widgets.dialog), GTK_STOCK_PREFERENCES, PM_BUTTON_CONFIGURE);
        pm_widgets.keybindings_button = gtk_dialog_add_button(
                GTK_DIALOG(pm_widgets.dialog), _("Keybindings"), PM_BUTTON_KEYBINDINGS);
        gtk_dialog_add_button(GTK_DIALOG(pm_widgets.dialog), GTK_STOCK_CLOSE, GTK_RESPONSE_CLOSE);
        gtk_dialog_set_default_response(GTK_DIALOG(pm_widgets.dialog), GTK_RESPONSE_CLOSE);

        /* filter */
        pm_widgets.filter_entry = filter_entry = gtk_entry_new();
        gtk_entry_set_icon_from_stock(GTK_ENTRY(filter_entry), GTK_ENTRY_ICON_PRIMARY, GTK_STOCK_FIND);
        ui_entry_add_clear_icon(GTK_ENTRY(filter_entry));
        g_signal_connect(filter_entry, "changed", G_CALLBACK(on_pm_tree_filter_entry_changed_cb), NULL);
        g_signal_connect(filter_entry, "icon-release",
                G_CALLBACK(on_pm_tree_filter_entry_icon_release_cb), NULL);

        /* prepare treeview */
        pm_widgets.tree = gtk_tree_view_new();
        pm_widgets.store = gtk_tree_store_new(
                PLUGIN_N_COLUMNS, G_TYPE_BOOLEAN, G_TYPE_BOOLEAN, G_TYPE_POINTER);
        pm_prepare_treeview(pm_widgets.tree, pm_widgets.store);
        gtk_tree_view_expand_all(GTK_TREE_VIEW(pm_widgets.tree));
        g_object_unref(pm_widgets.store);

        swin = gtk_scrolled_window_new(NULL, NULL);
        gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(swin),
                GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
        gtk_scrolled_window_set_shadow_type(GTK_SCROLLED_WINDOW(swin), GTK_SHADOW_IN);
        gtk_container_add(GTK_CONTAINER(swin), pm_widgets.tree);

        label = geany_wrap_label_new(_("Choose which plugins should be loaded at startup:"));

        /* plugin popup menu */
        pm_widgets.popup_menu = gtk_menu_new();

        menu_item = gtk_image_menu_item_new_from_stock(GTK_STOCK_PREFERENCES, NULL);
        gtk_container_add(GTK_CONTAINER(pm_widgets.popup_menu), menu_item);
        g_signal_connect(menu_item, "activate",
                        G_CALLBACK(pm_on_plugin_button_clicked), GINT_TO_POINTER(PM_BUTTON_CONFIGURE));
        pm_widgets.popup_configure_menu_item = menu_item;

        menu_item = gtk_image_menu_item_new_with_mnemonic(_("Keybindings"));
        gtk_container_add(GTK_CONTAINER(pm_widgets.popup_menu), menu_item);
        g_signal_connect(menu_item, "activate",
                        G_CALLBACK(pm_on_plugin_button_clicked), GINT_TO_POINTER(PM_BUTTON_KEYBINDINGS));
        pm_widgets.popup_keybindings_menu_item = menu_item;

        menu_item = gtk_image_menu_item_new_from_stock(GTK_STOCK_HELP, NULL);
        gtk_container_add(GTK_CONTAINER(pm_widgets.popup_menu), menu_item);
        g_signal_connect(menu_item, "activate",
                        G_CALLBACK(pm_on_plugin_button_clicked), GINT_TO_POINTER(PM_BUTTON_HELP));
        pm_widgets.popup_help_menu_item = menu_item;

        /* put it together */
        vbox2 = gtk_vbox_new(FALSE, 6);
        gtk_box_pack_start(GTK_BOX(vbox2), label, FALSE, FALSE, 0);
        gtk_box_pack_start(GTK_BOX(vbox2), filter_entry, FALSE, FALSE, 0);
        gtk_box_pack_start(GTK_BOX(vbox2), swin, TRUE, TRUE, 0);

        g_signal_connect(pm_widgets.dialog, "response", G_CALLBACK(pm_dialog_response), NULL);

        gtk_box_pack_start(GTK_BOX(vbox), vbox2, TRUE, TRUE, 0);
        gtk_widget_show_all(pm_widgets.dialog);
        gtk_widget_show_all(pm_widgets.popup_menu);

        /* set initial plugin buttons state, pass NULL as no plugin is selected by default */
        pm_update_buttons(NULL);
        gtk_widget_grab_focus(pm_widgets.filter_entry);
}


/** Register the plugin as a proxy for other plugins
 *
 * Proxy plugins register a list of file extensions and a set of callbacks that are called
 * appropriately. A plugin can be a proxy for multiple types of sub-plugins by handling
 * separate file extensions, however they must share the same set of hooks, because this
 * function can only be called at most once per plugin.
 *
 * Each callback receives the plugin-defined data as parameter (see geany_plugin_register()). The
 * callbacks must be set prior to calling this, by assigning to @a plugin->proxy_funcs.
 * GeanyProxyFuncs::load and GeanyProxyFuncs::unload must be implemented.
 *
 * Nested proxies are unsupported at this point (TODO).
 *
 * @note It is entirely up to the proxy to provide access to Geany's plugin API. Native code
 * can naturally call Geany's API directly, for interpreted languages the proxy has to
 * implement some kind of bindings that the plugin can use.
 *
 * @see proxy for detailed documentation and an example.
 *
 * @param plugin The pointer to the plugin's GeanyPlugin instance
 * @param extensions A @c NULL-terminated string array of file extensions, excluding the dot.
 * @return @c TRUE if the proxy was successfully registered, otherwise @c FALSE
 *
 * @since 1.26 (API 226)
 */
GEANY_API_SYMBOL
gboolean geany_plugin_register_proxy(GeanyPlugin *plugin, const gchar **extensions)
{
        Plugin *p;
        const gchar **ext;
        PluginProxy *proxy;
        GList *node;

        g_return_val_if_fail(plugin != NULL, FALSE);
        g_return_val_if_fail(extensions != NULL, FALSE);
        g_return_val_if_fail(*extensions != NULL, FALSE);
        g_return_val_if_fail(plugin->proxy_funcs->load != NULL, FALSE);
        g_return_val_if_fail(plugin->proxy_funcs->unload != NULL, FALSE);

        p = plugin->priv;
        /* Check if this was called already. We want to reserve for the use case of calling
         * this again to set new supported extensions (for example, based on proxy configuration). */
        foreach_list(node, active_proxies.head)
        {
                proxy = node->data;
                g_return_val_if_fail(p != proxy->plugin, FALSE);
        }

        foreach_strv(ext, extensions)
        {
                proxy = g_new(PluginProxy, 1);
                g_strlcpy(proxy->extension, *ext, sizeof(proxy->extension));
                proxy->plugin = p;
                /* prepend, so that plugins automatically override core providers for a given extension */
                g_queue_push_head(&active_proxies, proxy);
        }

        return TRUE;
}

#endif