2 * Copyright (C) 2009-2010 Andy Spencer <andy753421@gmail.com>
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 * @short_description: Plugin support
22 * A plugin in libgis is a GObject which implements the GisPlugin interface. Additionally, each
23 * plugin is compiled to a separate shared object and loaded conditionally at runtime when the
24 * plugin is enabled. Each such shared object should define a GisPluginConstructor() function named
25 * gis_plugin_NAME_new which will be called when loading the plugin.
27 * Almost all libgis functionality is provided by a set of plugins. Each plugin can how however much
28 * it likes. The interface between plugins and the rest of libgis is intentionally very thin. Since
29 * libgis is the library, plugins must manually do everything. For instance, to draw something in
30 * the world, the plugin must add an object to the viewer. Likewise, plugins need to register
31 * callbacks on the viewer in order to receive updates, very little happens automagically.
33 * That being said, one thing that plugins do do automagically, is provide a configuration area.
34 * Since the plugin doesn't know what application is is being loaded form, it is better for the
35 * application to ask the plugin for it's confirmation area, not the other way around.
41 #include "gis-plugin.h"
46 static void gis_plugin_base_init(gpointer g_class)
48 static gboolean is_initialized = FALSE;
49 if (!is_initialized) {
50 /* add properties and signals to the interface here */
51 is_initialized = TRUE;
55 GType gis_plugin_get_type()
57 static GType type = 0;
59 static const GTypeInfo info = {
60 sizeof(GisPluginInterface),
64 type = g_type_register_static(G_TYPE_INTERFACE,
65 "GisPlugin", &info, 0);
71 * gis_plugin_get_name:
74 * Get a short human readable name for a plugin, this is not necessarily the
75 * same as the name of the shared object.
77 * Returns: a short name for the plugin
79 const gchar *gis_plugin_get_name(GisPlugin *plugin)
81 if (!GIS_IS_PLUGIN(plugin))
83 return GIS_PLUGIN_GET_INTERFACE(plugin)->name;
87 * gis_plugin_get_description:
90 * Get a description of a plugin
92 * Returns: a description of the plugin
94 const gchar *gis_plugin_get_description(GisPlugin *plugin)
96 if (!GIS_IS_PLUGIN(plugin))
98 return GIS_PLUGIN_GET_INTERFACE(plugin)->description;
102 * gis_plugin_get_config:
103 * @plugin: the plugin
105 * Each plugin can provide a configuration area. Applications using libgis
106 * should display this configuration area to the user so they can modify the
107 * behavior of the plugin.
109 * Returns: a configuration widget for the plugin
111 GtkWidget *gis_plugin_get_config(GisPlugin *plugin)
113 if (!GIS_IS_PLUGIN(plugin))
115 GisPluginInterface *iface = GIS_PLUGIN_GET_INTERFACE(plugin);
116 return iface->get_config ? iface->get_config(plugin) : NULL;
130 * @dir: the directory to search for plugins in
131 * @prefs: a #GisPrefs to save the state of plugins, or NULL
133 * Create a new plugin source. If @prefs is not %NULL, the state of the plugins
134 * will be saved when they are either enabled or disabled.
136 * Returns: the new plugin source
138 GisPlugins *gis_plugins_new(const gchar *dir, GisPrefs *prefs)
140 g_debug("GisPlugins: new - dir=%s", dir);
141 GisPlugins *plugins = g_new0(GisPlugins, 1);
142 plugins->prefs = prefs;
144 plugins->dir = g_strdup(dir);
150 * @plugins: the #GisPlugins to free
152 * Free data used by a plugin source
154 void gis_plugins_free(GisPlugins *plugins)
156 g_debug("GisPlugins: free");
157 for (GList *cur = plugins->plugins; cur; cur = cur->next) {
158 GisPluginStore *store = cur->data;
159 g_debug("GisPlugin: freeing %s refs=%d->%d", store->name,
160 G_OBJECT(store->plugin)->ref_count,
161 G_OBJECT(store->plugin)->ref_count-1);
162 g_object_unref(store->plugin);
166 g_list_free(plugins->plugins);
168 g_free(plugins->dir);
173 * gis_plugins_available:
174 * @plugins: the plugin source
176 * Search the plugin directory for shared objects which can be loaded as
179 * Returns: the list of available plugins
181 GList *gis_plugins_available(GisPlugins *plugins)
183 g_debug("GisPlugins: available");
185 gchar *dirs[] = {plugins->dir, PLUGINSDIR};
186 g_debug("pluginsdir=%s", PLUGINSDIR);
187 for (int i = 0; i<2; i++) {
190 GDir *dir = g_dir_open(dirs[i], 0, NULL);
193 g_debug(" checking %s", dirs[i]);
195 while ((name = g_dir_read_name(dir))) {
196 if (g_pattern_match_simple("*." G_MODULE_SUFFIX, name)) {
197 gchar **parts = g_strsplit(name, ".", 2);
198 list = g_list_prepend(list, g_strdup(parts[0]));
209 * @plugins: the plugins source
210 * @name: the name of the plugin to load
211 * @viewer: a #GisViewer to pass to the plugins constructor
212 * @prefs: a #GisPrefs to pass to the plugins constructor
214 * @name should be the name of the shared object without the file extension.
215 * This is the same as what is returned by gis_plugins_available().
217 * When loading plugins, the @prefs argument is used, not the #GisPrefs stored
220 * Returns: the new plugin
222 GisPlugin *gis_plugins_load(GisPlugins *plugins, const char *name,
223 GisViewer *viewer, GisPrefs *prefs)
225 g_debug("GisPlugins: load %s", name);
226 gchar *path = g_strdup_printf("%s/%s.%s", plugins->dir, name, G_MODULE_SUFFIX);
227 g_debug("GisPlugins: load - trying %s", path);
228 if (!g_file_test(path, G_FILE_TEST_EXISTS)) {
230 path = g_strdup_printf("%s/%s.%s", PLUGINSDIR, name, G_MODULE_SUFFIX);
232 g_debug("GisPlugins: load - trying %s", path);
233 if (!g_file_test(path, G_FILE_TEST_EXISTS)) {
234 g_warning("Module %s not found", name);
238 GModule *module = g_module_open(path, G_MODULE_BIND_LAZY);
240 if (module == NULL) {
241 g_warning("Unable to load module %s: %s", name, g_module_error());
245 gpointer constructor_ptr; // GCC 4.1 fix?
246 gchar *constructor_str = g_strconcat("gis_plugin_", name, "_new", NULL);
247 if (!g_module_symbol(module, constructor_str, &constructor_ptr)) {
248 g_warning("Unable to load symbol %s from %s: %s",
249 constructor_str, name, g_module_error());
250 g_module_close(module);
251 g_free(constructor_str);
254 g_free(constructor_str);
255 GisPluginConstructor constructor = constructor_ptr;
257 GisPluginStore *store = g_new0(GisPluginStore, 1);
258 store->name = g_strdup(name);
259 store->plugin = constructor(viewer, prefs);
260 plugins->plugins = g_list_prepend(plugins->plugins, store);
261 return store->plugin;
265 * gis_plugins_enable:
266 * @plugins: the plugins source
267 * @name: the name of the plugin to load
268 * @viewer: a #GisViewer to pass to the plugins constructor
269 * @prefs: a #GisPrefs to pass to the plugins constructor
271 * Load a plugin and save it's loaded/unloaded state in the #GisPrefs stored in
274 * See also: gis_plugins_load()
276 * Returns: the new plugin
278 GisPlugin *gis_plugins_enable(GisPlugins *plugins, const char *name,
279 GisViewer *viewer, GisPrefs *prefs)
281 GisPlugin *plugin = gis_plugins_load(plugins, name, viewer, prefs);
282 gis_prefs_set_boolean_v(plugins->prefs, "plugins", name, TRUE);
287 * gis_plugins_load_enabled:
288 * @plugins: the plugins source
289 * @viewer: a #GisViewer to pass to the plugins constructor
290 * @prefs: a #GisPrefs to pass to the plugins constructor
292 * Load all enabled which have previously been enabled.
294 * See also: gis_plugins_load()
296 * Returns: a list of all loaded plugins
298 GList *gis_plugins_load_enabled(GisPlugins *plugins,
299 GisViewer *viewer, GisPrefs *prefs)
301 GList *loaded = NULL;
302 for (GList *cur = gis_plugins_available(plugins); cur; cur = cur->next) {
303 gchar *name = cur->data;
304 if (gis_prefs_get_boolean_v(plugins->prefs, "plugins", name, NULL)) {
305 GisPlugin *plugin = gis_plugins_load(plugins, name, viewer, prefs);
306 loaded = g_list_prepend(loaded, plugin);
313 * gis_plugins_unload:
314 * @plugins: the plugins source
315 * @name: the name of the plugin to unload
317 * Unload a plugin and free any associated data.
321 gboolean gis_plugins_unload(GisPlugins *plugins, const char *name)
323 g_debug("GisPlugins: unload %s", name);
324 for (GList *cur = plugins->plugins; cur; cur = cur->next) {
325 GisPluginStore *store = cur->data;
326 if (g_str_equal(store->name, name)) {
327 g_object_unref(store->plugin);
330 plugins->plugins = g_list_delete_link(plugins->plugins, cur);
337 * gis_plugins_disable:
338 * @plugins: the plugins source
339 * @name: the name of the plugin to unload
341 * Unload a plugin and save it's loaded/unloaded state in the #GisPrefs stored
344 * See also: gis_plugins_unload()
348 gboolean gis_plugins_disable(GisPlugins *plugins, const char *name)
350 gis_prefs_set_boolean_v(plugins->prefs, "plugins", name, FALSE);
351 gis_plugins_unload(plugins, name);
356 * gis_plugins_foreach:
357 * @plugins: the plugins source
358 * @callback: a function to call on each plugin
359 * @user_data: user data to pass to the function
361 * Iterate over all plugins loaded by the plugins source
363 void gis_plugins_foreach(GisPlugins *plugins, GCallback _callback, gpointer user_data)
365 g_debug("GisPlugins: foreach");
368 typedef void (*CBFunc)(GisPlugin *, const gchar *, gpointer);
369 CBFunc callback = (CBFunc)_callback;
370 for (GList *cur = plugins->plugins; cur; cur = cur->next) {
371 GisPluginStore *store = cur->data;
372 callback(store->plugin, store->name, user_data);