1 /* ncmpc (Ncurses MPD Client)
2 * (c) 2004-2009 The Music Player Daemon Project
3 * Project homepage: http://musicpd.org
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
20 #ifndef PLUGIN_H
21 #define PLUGIN_H
23 #include <glib.h>
24 #include <stdbool.h>
26 /**
27 * A list of registered plugins.
28 */
29 struct plugin_list {
30 GPtrArray *plugins;
31 };
33 /**
34 * When a plugin cycle is finished, this function is called. In any
35 * case, plugin_stop() has to be called to free all memory.
36 *
37 * @param result the plugin's output (stdout) on success; NULL on failure
38 * @param data the caller defined pointer passed to plugin_run()
39 */
40 typedef void (*plugin_callback_t)(const GString *result, void *data);
42 /**
43 * This object represents a cycle through all available plugins, until
44 * a plugin returns a positive result.
45 */
46 struct plugin_cycle;
48 /**
49 * Initialize an empty plugin_list structure.
50 */
51 static inline void
52 plugin_list_init(struct plugin_list *list)
53 {
54 list->plugins = g_ptr_array_new();
55 }
57 /**
58 * Load all plugins (executables) in a directory.
59 */
60 bool
61 plugin_list_load_directory(struct plugin_list *list, const char *path);
63 /**
64 * Frees all memory held by the plugin_list object (but not the
65 * pointer itself).
66 */
67 void plugin_list_deinit(struct plugin_list *list);
69 /**
70 * Run plugins in this list, until one returns success (or until the
71 * plugin list is exhausted).
72 *
73 * @param list the plugin list
74 * @param args NULL terminated command line arguments passed to the
75 * plugin programs
76 * @param callback the callback function which will be called when a
77 * result is available
78 * @param callback_data caller defined pointer which is passed to the
79 * callback function
80 */
81 struct plugin_cycle *
82 plugin_run(struct plugin_list *list, const char *const*args,
83 plugin_callback_t callback, void *callback_data);
85 /**
86 * Stops the plugin cycle and frees resources. This can be called to
87 * abort the current cycle, or after the plugin_callback_t has been
88 * invoked.
89 */
90 void
91 plugin_stop(struct plugin_cycle *invocation);
93 #endif