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.
43 #include "gis-plugin.h"
48 static void gis_plugin_base_init(gpointer g_class)
50 static gboolean is_initialized = FALSE;
51 if (!is_initialized) {
52 /* add properties and signals to the interface here */
53 is_initialized = TRUE;
57 GType gis_plugin_get_type()
59 static GType type = 0;
61 static const GTypeInfo info = {
62 sizeof(GisPluginInterface),
66 type = g_type_register_static(G_TYPE_INTERFACE,
67 "GisPlugin", &info, 0);
73 * gis_plugin_get_name:
76 * Get a short human readable name for a plugin, this is not necessarily the
77 * same as the name of the shared object.
79 * Returns: a short name for the plugin
81 const gchar *gis_plugin_get_name(GisPlugin *plugin)
83 if (!GIS_IS_PLUGIN(plugin))
85 return GIS_PLUGIN_GET_INTERFACE(plugin)->name;
89 * gis_plugin_get_description:
92 * Get a description of a plugin
94 * Returns: a description of the plugin
96 const gchar *gis_plugin_get_description(GisPlugin *plugin)
98 if (!GIS_IS_PLUGIN(plugin))
100 return GIS_PLUGIN_GET_INTERFACE(plugin)->description;
104 * gis_plugin_get_config:
105 * @plugin: the plugin
107 * Each plugin can provide a configuration area. Applications using libgis
108 * should display this configuration area to the user so they can modify the
109 * behavior of the plugin.
111 * Returns: a configuration widget for the plugin
113 GtkWidget *gis_plugin_get_config(GisPlugin *plugin)
115 if (!GIS_IS_PLUGIN(plugin))
117 GisPluginInterface *iface = GIS_PLUGIN_GET_INTERFACE(plugin);
118 return iface->get_config ? iface->get_config(plugin) : NULL;
132 * @dir: the directory to search for plugins in
133 * @prefs: a #GisPrefs to save the state of plugins, or NULL
135 * Create a new plugin source. If @prefs is not %NULL, the state of the plugins
136 * will be saved when they are either enabled or disabled.
138 * Returns: the new plugin source
140 GisPlugins *gis_plugins_new(const gchar *dir, GisPrefs *prefs)
142 g_debug("GisPlugins: new - dir=%s", dir);
143 GisPlugins *plugins = g_new0(GisPlugins, 1);
144 plugins->prefs = prefs;
146 plugins->dir = g_strdup(dir);
152 * @plugins: the #GisPlugins to free
154 * Free data used by a plugin source
156 void gis_plugins_free(GisPlugins *plugins)
158 g_debug("GisPlugins: free");
159 for (GList *cur = plugins->plugins; cur; cur = cur->next) {
160 GisPluginStore *store = cur->data;
161 g_debug("GisPlugin: freeing %s refs=%d->%d", store->name,
162 G_OBJECT(store->plugin)->ref_count,
163 G_OBJECT(store->plugin)->ref_count-1);
164 g_object_unref(store->plugin);
168 g_list_free(plugins->plugins);
170 g_free(plugins->dir);
175 * gis_plugins_available:
176 * @plugins: the plugin source
178 * Search the plugin directory for shared objects which can be loaded as
181 * Returns: the list of available plugins
183 GList *gis_plugins_available(GisPlugins *plugins)
185 g_debug("GisPlugins: available");
187 gchar *dirs[] = {plugins->dir, PLUGINSDIR};
188 g_debug("pluginsdir=%s", PLUGINSDIR);
189 for (int i = 0; i<2; i++) {
192 GDir *dir = g_dir_open(dirs[i], 0, NULL);
195 g_debug(" checking %s", dirs[i]);
197 while ((name = g_dir_read_name(dir))) {
198 if (g_pattern_match_simple("*." G_MODULE_SUFFIX, name)) {
199 gchar **parts = g_strsplit(name, ".", 2);
200 list = g_list_prepend(list, g_strdup(parts[0]));
206 list = g_list_sort(list, (GCompareFunc)strcmp);
207 for (GList *cur = list; cur; cur = cur->next)
208 while (cur->next && g_str_equal(cur->data,cur->next->data)) {
209 GList *tmp = cur->next;
210 list = g_list_remove_link(list, cur);
218 * @plugins: the plugins source
219 * @name: the name of the plugin to load
220 * @viewer: a #GisViewer to pass to the plugins constructor
221 * @prefs: a #GisPrefs to pass to the plugins constructor
223 * @name should be the name of the shared object without the file extension.
224 * This is the same as what is returned by gis_plugins_available().
226 * When loading plugins, the @prefs argument is used, not the #GisPrefs stored
229 * Returns: the new plugin
231 GisPlugin *gis_plugins_load(GisPlugins *plugins, const char *name,
232 GisViewer *viewer, GisPrefs *prefs)
234 g_debug("GisPlugins: load %s", name);
235 gchar *path = g_strdup_printf("%s/%s.%s", plugins->dir, name, G_MODULE_SUFFIX);
236 g_debug("GisPlugins: load - trying %s", path);
237 if (!g_file_test(path, G_FILE_TEST_EXISTS)) {
239 path = g_strdup_printf("%s/%s.%s", PLUGINSDIR, name, G_MODULE_SUFFIX);
241 g_debug("GisPlugins: load - trying %s", path);
242 if (!g_file_test(path, G_FILE_TEST_EXISTS)) {
243 g_warning("Module %s not found", name);
247 GModule *module = g_module_open(path, G_MODULE_BIND_LAZY);
249 if (module == NULL) {
250 g_warning("Unable to load module %s: %s", name, g_module_error());
254 gpointer constructor_ptr; // GCC 4.1 fix?
255 gchar *constructor_str = g_strconcat("gis_plugin_", name, "_new", NULL);
256 if (!g_module_symbol(module, constructor_str, &constructor_ptr)) {
257 g_warning("Unable to load symbol %s from %s: %s",
258 constructor_str, name, g_module_error());
259 g_module_close(module);
260 g_free(constructor_str);
263 g_free(constructor_str);
264 GisPluginConstructor constructor = constructor_ptr;
266 GisPluginStore *store = g_new0(GisPluginStore, 1);
267 store->name = g_strdup(name);
268 store->plugin = constructor(viewer, prefs);
269 plugins->plugins = g_list_prepend(plugins->plugins, store);
270 return store->plugin;
274 * gis_plugins_enable:
275 * @plugins: the plugins source
276 * @name: the name of the plugin to load
277 * @viewer: a #GisViewer to pass to the plugins constructor
278 * @prefs: a #GisPrefs to pass to the plugins constructor
280 * Load a plugin and save it's loaded/unloaded state in the #GisPrefs stored in
283 * See also: gis_plugins_load()
285 * Returns: the new plugin
287 GisPlugin *gis_plugins_enable(GisPlugins *plugins, const char *name,
288 GisViewer *viewer, GisPrefs *prefs)
290 GisPlugin *plugin = gis_plugins_load(plugins, name, viewer, prefs);
291 gis_prefs_set_boolean_v(plugins->prefs, "plugins", name, TRUE);
296 * gis_plugins_load_enabled:
297 * @plugins: the plugins source
298 * @viewer: a #GisViewer to pass to the plugins constructor
299 * @prefs: a #GisPrefs to pass to the plugins constructor
301 * Load all enabled which have previously been enabled.
303 * See also: gis_plugins_load()
305 * Returns: a list of all loaded plugins
307 GList *gis_plugins_load_enabled(GisPlugins *plugins,
308 GisViewer *viewer, GisPrefs *prefs)
310 GList *loaded = NULL;
311 for (GList *cur = gis_plugins_available(plugins); cur; cur = cur->next) {
312 gchar *name = cur->data;
313 if (gis_prefs_get_boolean_v(plugins->prefs, "plugins", name, NULL)) {
314 GisPlugin *plugin = gis_plugins_load(plugins, name, viewer, prefs);
315 loaded = g_list_prepend(loaded, plugin);
322 * gis_plugins_unload:
323 * @plugins: the plugins source
324 * @name: the name of the plugin to unload
326 * Unload a plugin and free any associated data.
330 gboolean gis_plugins_unload(GisPlugins *plugins, const char *name)
332 g_debug("GisPlugins: unload %s", name);
333 for (GList *cur = plugins->plugins; cur; cur = cur->next) {
334 GisPluginStore *store = cur->data;
335 if (g_str_equal(store->name, name)) {
336 g_object_unref(store->plugin);
339 plugins->plugins = g_list_delete_link(plugins->plugins, cur);
346 * gis_plugins_disable:
347 * @plugins: the plugins source
348 * @name: the name of the plugin to unload
350 * Unload a plugin and save it's loaded/unloaded state in the #GisPrefs stored
353 * See also: gis_plugins_unload()
357 gboolean gis_plugins_disable(GisPlugins *plugins, const char *name)
359 gis_prefs_set_boolean_v(plugins->prefs, "plugins", name, FALSE);
360 gis_plugins_unload(plugins, name);
365 * gis_plugins_foreach:
366 * @plugins: the plugins source
367 * @callback: a function to call on each plugin
368 * @user_data: user data to pass to the function
370 * Iterate over all plugins loaded by the plugins source
372 void gis_plugins_foreach(GisPlugins *plugins, GCallback _callback, gpointer user_data)
374 g_debug("GisPlugins: foreach");
377 typedef void (*CBFunc)(GisPlugin *, const gchar *, gpointer);
378 CBFunc callback = (CBFunc)_callback;
379 for (GList *cur = plugins->plugins; cur; cur = cur->next) {
380 GisPluginStore *store = cur->data;
381 callback(store->plugin, store->name, user_data);