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]));
204 list = g_list_sort(list, (GCompareFunc)g_strcmp0);
205 for (GList *cur = list; cur; cur = cur->next)
206 while (cur->next && g_str_equal(cur->data,cur->next->data)) {
207 GList *tmp = cur->next;
208 list = g_list_remove_link(list, cur);
216 * @plugins: the plugins source
217 * @name: the name of the plugin to load
218 * @viewer: a #GisViewer to pass to the plugins constructor
219 * @prefs: a #GisPrefs to pass to the plugins constructor
221 * @name should be the name of the shared object without the file extension.
222 * This is the same as what is returned by gis_plugins_available().
224 * When loading plugins, the @prefs argument is used, not the #GisPrefs stored
227 * Returns: the new plugin
229 GisPlugin *gis_plugins_load(GisPlugins *plugins, const char *name,
230 GisViewer *viewer, GisPrefs *prefs)
232 g_debug("GisPlugins: load %s", name);
233 gchar *path = g_strdup_printf("%s/%s.%s", plugins->dir, name, G_MODULE_SUFFIX);
234 g_debug("GisPlugins: load - trying %s", path);
235 if (!g_file_test(path, G_FILE_TEST_EXISTS)) {
237 path = g_strdup_printf("%s/%s.%s", PLUGINSDIR, name, G_MODULE_SUFFIX);
239 g_debug("GisPlugins: load - trying %s", path);
240 if (!g_file_test(path, G_FILE_TEST_EXISTS)) {
241 g_warning("Module %s not found", name);
245 GModule *module = g_module_open(path, G_MODULE_BIND_LAZY);
247 if (module == NULL) {
248 g_warning("Unable to load module %s: %s", name, g_module_error());
252 gpointer constructor_ptr; // GCC 4.1 fix?
253 gchar *constructor_str = g_strconcat("gis_plugin_", name, "_new", NULL);
254 if (!g_module_symbol(module, constructor_str, &constructor_ptr)) {
255 g_warning("Unable to load symbol %s from %s: %s",
256 constructor_str, name, g_module_error());
257 g_module_close(module);
258 g_free(constructor_str);
261 g_free(constructor_str);
262 GisPluginConstructor constructor = constructor_ptr;
264 GisPluginStore *store = g_new0(GisPluginStore, 1);
265 store->name = g_strdup(name);
266 store->plugin = constructor(viewer, prefs);
267 plugins->plugins = g_list_prepend(plugins->plugins, store);
268 return store->plugin;
272 * gis_plugins_enable:
273 * @plugins: the plugins source
274 * @name: the name of the plugin to load
275 * @viewer: a #GisViewer to pass to the plugins constructor
276 * @prefs: a #GisPrefs to pass to the plugins constructor
278 * Load a plugin and save it's loaded/unloaded state in the #GisPrefs stored in
281 * See also: gis_plugins_load()
283 * Returns: the new plugin
285 GisPlugin *gis_plugins_enable(GisPlugins *plugins, const char *name,
286 GisViewer *viewer, GisPrefs *prefs)
288 GisPlugin *plugin = gis_plugins_load(plugins, name, viewer, prefs);
289 gis_prefs_set_boolean_v(plugins->prefs, "plugins", name, TRUE);
294 * gis_plugins_load_enabled:
295 * @plugins: the plugins source
296 * @viewer: a #GisViewer to pass to the plugins constructor
297 * @prefs: a #GisPrefs to pass to the plugins constructor
299 * Load all enabled which have previously been enabled.
301 * See also: gis_plugins_load()
303 * Returns: a list of all loaded plugins
305 GList *gis_plugins_load_enabled(GisPlugins *plugins,
306 GisViewer *viewer, GisPrefs *prefs)
308 GList *loaded = NULL;
309 for (GList *cur = gis_plugins_available(plugins); cur; cur = cur->next) {
310 gchar *name = cur->data;
311 if (gis_prefs_get_boolean_v(plugins->prefs, "plugins", name, NULL)) {
312 GisPlugin *plugin = gis_plugins_load(plugins, name, viewer, prefs);
313 loaded = g_list_prepend(loaded, plugin);
320 * gis_plugins_unload:
321 * @plugins: the plugins source
322 * @name: the name of the plugin to unload
324 * Unload a plugin and free any associated data.
328 gboolean gis_plugins_unload(GisPlugins *plugins, const char *name)
330 g_debug("GisPlugins: unload %s", name);
331 for (GList *cur = plugins->plugins; cur; cur = cur->next) {
332 GisPluginStore *store = cur->data;
333 if (g_str_equal(store->name, name)) {
334 g_object_unref(store->plugin);
337 plugins->plugins = g_list_delete_link(plugins->plugins, cur);
344 * gis_plugins_disable:
345 * @plugins: the plugins source
346 * @name: the name of the plugin to unload
348 * Unload a plugin and save it's loaded/unloaded state in the #GisPrefs stored
351 * See also: gis_plugins_unload()
355 gboolean gis_plugins_disable(GisPlugins *plugins, const char *name)
357 gis_prefs_set_boolean_v(plugins->prefs, "plugins", name, FALSE);
358 gis_plugins_unload(plugins, name);
363 * gis_plugins_foreach:
364 * @plugins: the plugins source
365 * @callback: a function to call on each plugin
366 * @user_data: user data to pass to the function
368 * Iterate over all plugins loaded by the plugins source
370 void gis_plugins_foreach(GisPlugins *plugins, GCallback _callback, gpointer user_data)
372 g_debug("GisPlugins: foreach");
375 typedef void (*CBFunc)(GisPlugin *, const gchar *, gpointer);
376 CBFunc callback = (CBFunc)_callback;
377 for (GList *cur = plugins->plugins; cur; cur = cur->next) {
378 GisPluginStore *store = cur->data;
379 callback(store->plugin, store->name, user_data);