Convert junk filtering EPlugins to EExtensions.

We now have a proper junk mail filtering API.  All junk filtering
extensions must subclass EMailJunkFilter for user preferences and
availability testing, and implement the CamelJunkFilter interface
for the actual junk filtering and learning operations.

The bogofilter module should be feature-equivalent to its former
EPlugin.  The spamassassin module is far more complex.  It's nearly
feature-equivalent to its former EPlugin, but I ditched the spamd
respawning code since it seemed unnecessary for a mail client to
have to deal with.  If there's a huge outcry from users about it
I'll reluctantly put it back, but I don't expect one.

This gets us a step closer to killing off EConfig, and eventually
the EPlugin framework itself.

1 files changed, 231 insertions, 42 deletions

diff --git a/mail/e-mail-session.c b/mail/e-mail-session.c
index 44bbd8d0aa..8a3072447a 100644
--- a/mail/e-mail-session.c
+++ b/mail/e-mail-session.c
@@ -50,9 +50,12 @@
 #include "e-util/e-util.h"
 #include "e-util/e-account-utils.h"
 #include "e-util/e-alert-dialog.h"
+#include "e-util/e-extensible.h"
 #include "e-util/e-util-private.h"
+#include "e-util/gconf-bridge.h"
 
 #include "e-mail-folder-utils.h"
+#include "e-mail-junk-filter.h"
 #include "e-mail-local.h"
 #include "e-mail-session.h"
 #include "em-composer-utils.h"
@@ -78,7 +81,7 @@ struct _EMailSessionPrivate {
 	MailFolderCache *folder_cache;
 
 	FILE *filter_logfile;
-	GList *junk_plugins;
+	GHashTable *junk_filters;
 };
 
 struct _AsyncContext {
@@ -93,7 +96,8 @@ struct _AsyncContext {
 
 enum {
 	PROP_0,
-	PROP_FOLDER_CACHE
+	PROP_FOLDER_CACHE,
+	PROP_JUNK_FILTER_NAME
 };
 
 static gchar *mail_data_dir;
@@ -103,10 +107,11 @@ static gchar *mail_config_dir;
 static MailMsgInfo ms_thread_info_dummy = { sizeof (MailMsg) };
 #endif
 
-G_DEFINE_TYPE (
+G_DEFINE_TYPE_WITH_CODE (
 	EMailSession,
 	e_mail_session,
-	CAMEL_TYPE_SESSION)
+	CAMEL_TYPE_SESSION,
+	G_IMPLEMENT_INTERFACE (E_TYPE_EXTENSIBLE, NULL))
 
 /* Support for CamelSession.alert_user() *************************************/
 
@@ -546,6 +551,84 @@ mail_session_check_junk_notify (GConfClient *gconf,
 	}
 }
 
+static const gchar *
+mail_session_get_junk_filter_name (EMailSession *session)
+{
+	CamelJunkFilter *junk_filter;
+	GHashTableIter iter;
+	gpointer key, value;
+
+	/* XXX This property can be removed once Evolution moves to
+	 *     GSettings and can use transform functions when binding
+	 *     properties to settings.  That's why this is private. */
+
+	g_hash_table_iter_init (&iter, session->priv->junk_filters);
+	junk_filter = camel_session_get_junk_filter (CAMEL_SESSION (session));
+
+	while (g_hash_table_iter_next (&iter, &key, &value)) {
+		if (junk_filter == CAMEL_JUNK_FILTER (value))
+			return (const gchar *) key;
+	}
+
+	if (junk_filter != NULL)
+		g_warning (
+			"Camel is using a junk filter "
+			"unknown to Evolution of type %s",
+			G_OBJECT_TYPE_NAME (junk_filter));
+
+	return "";  /* GConfBridge doesn't like NULL strings */
+}
+
+static void
+mail_session_set_junk_filter_name (EMailSession *session,
+                                   const gchar *junk_filter_name)
+{
+	CamelJunkFilter *junk_filter = NULL;
+
+	/* XXX This property can be removed once Evolution moves to
+	 *     GSettings and can use transform functions when binding
+	 *     properties to settings.  That's why this is private. */
+
+	/* An empty string is equivalent to a NULL string. */
+	if (junk_filter_name != NULL && *junk_filter_name == '\0')
+		junk_filter_name = NULL;
+
+	if (junk_filter_name != NULL) {
+		junk_filter = g_hash_table_lookup (
+			session->priv->junk_filters, junk_filter_name);
+		if (junk_filter != NULL) {
+			if (!e_mail_junk_filter_available (
+				E_MAIL_JUNK_FILTER (junk_filter)))
+				junk_filter = NULL;
+		} else {
+			g_warning (
+				"Unrecognized junk filter name "
+				"'%s' in GConf", junk_filter_name);
+		}
+	}
+
+	camel_session_set_junk_filter (CAMEL_SESSION (session), junk_filter);
+
+	/* XXX We emit the "notify" signal in mail_session_notify(). */
+}
+
+static void
+mail_session_set_property (GObject *object,
+                           guint property_id,
+                           const GValue *value,
+                           GParamSpec *pspec)
+{
+	switch (property_id) {
+		case PROP_JUNK_FILTER_NAME:
+			mail_session_set_junk_filter_name (
+				E_MAIL_SESSION (object),
+				g_value_get_string (value));
+			return;
+	}
+
+	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+}
+
 static void
 mail_session_get_property (GObject *object,
                            guint property_id,
@@ -559,6 +642,13 @@ mail_session_get_property (GObject *object,
 				e_mail_session_get_folder_cache (
 				E_MAIL_SESSION (object)));
 			return;
+
+		case PROP_JUNK_FILTER_NAME:
+			g_value_set_string (
+				value,
+				mail_session_get_junk_filter_name (
+				E_MAIL_SESSION (object)));
+			return;
 	}
 
 	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
@@ -583,8 +673,13 @@ mail_session_dispose (GObject *object)
 static void
 mail_session_finalize (GObject *object)
 {
+	EMailSessionPrivate *priv;
 	GConfClient *client;
 
+	priv = E_MAIL_SESSION_GET_PRIVATE (object);
+
+	g_hash_table_destroy (priv->junk_filters);
+
 	client = gconf_client_get_default ();
 
 	if (session_check_junk_notify_id != 0) {
@@ -606,6 +701,87 @@ mail_session_finalize (GObject *object)
 	G_OBJECT_CLASS (e_mail_session_parent_class)->finalize (object);
 }
 
+static void
+mail_session_notify (GObject *object,
+                     GParamSpec *pspec)
+{
+	/* GObject does not implement this method; do not chain up. */
+
+	/* XXX Delete this once Evolution moves to GSettings and
+	 *     we're able to get rid of PROP_JUNK_FILTER_NAME. */
+	if (g_strcmp0 (pspec->name, "junk-filter") == 0)
+		g_object_notify (object, "junk-filter-name");
+}
+
+static void
+mail_session_constructed (GObject *object)
+{
+	EMailSessionPrivate *priv;
+	EExtensible *extensible;
+	GType extension_type;
+	GList *list, *iter;
+
+	priv = E_MAIL_SESSION_GET_PRIVATE (object);
+
+	/* Chain up to parent's constructed() method. */
+	G_OBJECT_CLASS (e_mail_session_parent_class)->constructed (object);
+
+	extensible = E_EXTENSIBLE (object);
+	e_extensible_load_extensions (extensible);
+
+	/* Add junk filter extensions to an internal hash table. */
+
+	extension_type = E_TYPE_MAIL_JUNK_FILTER;
+	list = e_extensible_list_extensions (extensible, extension_type);
+
+	for (iter = list; iter != NULL; iter = g_list_next (iter)) {
+		EMailJunkFilter *junk_filter;
+		EMailJunkFilterClass *class;
+
+		junk_filter = E_MAIL_JUNK_FILTER (iter->data);
+		class = E_MAIL_JUNK_FILTER_GET_CLASS (junk_filter);
+
+		if (!CAMEL_IS_JUNK_FILTER (junk_filter)) {
+			g_warning (
+				"Skipping %s: Does not implement "
+				"CamelJunkFilterInterface",
+				G_OBJECT_TYPE_NAME (junk_filter));
+			continue;
+		}
+
+		if (class->filter_name == NULL) {
+			g_warning (
+				"Skipping %s: filter_name unset",
+				G_OBJECT_TYPE_NAME (junk_filter));
+			continue;
+		}
+
+		if (class->display_name == NULL) {
+			g_warning (
+				"Skipping %s: display_name unset",
+				G_OBJECT_TYPE_NAME (junk_filter));
+			continue;
+		}
+
+		/* No need to reference the EMailJunkFilter since
+		 * EMailSession owns the reference to it already. */
+		g_hash_table_insert (
+			priv->junk_filters,
+			(gpointer) class->filter_name,
+			junk_filter);
+	}
+
+	g_list_free (list);
+
+	/* Bind the "/apps/evolution/mail/junk/default_plugin"
+	 * GConf key to our "junk-filter-name" property. */
+
+	gconf_bridge_bind_property (
+		gconf_bridge_get (),
+		"/apps/evolution/mail/junk/default_plugin",
+		object, "junk-filter-name");
+}
+
 static gchar *
 mail_session_get_password (CamelSession *session,
                            CamelService *service,
@@ -928,9 +1104,12 @@ e_mail_session_class_init (EMailSessionClass *class)
 	g_type_class_add_private (class, sizeof (EMailSessionPrivate));
 
 	object_class = G_OBJECT_CLASS (class);
+	object_class->set_property = mail_session_set_property;
 	object_class->get_property = mail_session_get_property;
 	object_class->dispose = mail_session_dispose;
 	object_class->finalize = mail_session_finalize;
+	object_class->notify = mail_session_notify;
+	object_class->constructed = mail_session_constructed;
 
 	session_class = CAMEL_SESSION_CLASS (class);
 	session_class->get_password = mail_session_get_password;
@@ -948,7 +1127,22 @@ e_mail_session_class_init (EMailSessionClass *class)
 			NULL,
 			NULL,
 			MAIL_TYPE_FOLDER_CACHE,
-			G_PARAM_READABLE));
+			G_PARAM_READABLE |
+			G_PARAM_STATIC_STRINGS));
+
+	/* XXX This property can be removed once Evolution moves to
+	 *     GSettings and can use transform functions when binding
+	 *     properties to settings. */
+	g_object_class_install_property (
+		object_class,
+		PROP_JUNK_FILTER_NAME,
+		g_param_spec_string (
+			"junk-filter-name",
+			NULL,
+			NULL,
+			NULL,
+			G_PARAM_READWRITE |
+			G_PARAM_STATIC_STRINGS));
 }
 
 static void
@@ -958,6 +1152,8 @@ e_mail_session_init (EMailSession *session)
 
 	session->priv = E_MAIL_SESSION_GET_PRIVATE (session);
 	session->priv->folder_cache = mail_folder_cache_new ();
+	session->priv->junk_filters = g_hash_table_new (
+		(GHashFunc) g_str_hash, (GEqualFunc) g_str_equal);
 
 	/* Initialize the EAccount setup. */
 	e_account_writable (NULL, E_ACCOUNT_SOURCE_SAVE_PASSWD);
@@ -974,7 +1170,6 @@ e_mail_session_init (EMailSession *session)
 		client, "/apps/evolution/mail/junk",
 		(GConfClientNotifyFunc) mail_session_check_junk_notify,
 		session, NULL, NULL);
-	CAMEL_SESSION (session)->junk_plugin = NULL;
 
 	mail_config_reload_junk_headers (session);
 
@@ -1003,6 +1198,36 @@ e_mail_session_get_folder_cache (EMailSession *session)
 	return session->priv->folder_cache;
 }
 
+GList *
+e_mail_session_get_available_junk_filters (EMailSession *session)
+{
+	GList *list, *link;
+	GQueue trash = G_QUEUE_INIT;
+
+	g_return_val_if_fail (E_IS_MAIL_SESSION (session), NULL);
+
+	list = g_hash_table_get_values (session->priv->junk_filters);
+
+	/* Discard unavailable junk filters.  (e.g. Junk filter
+	 * requires Bogofilter but Bogofilter is not installed,
+	 * hence the junk filter is unavailable.) */
+
+	for (link = list; link != NULL; link = g_list_next (link)) {
+		EMailJunkFilter *junk_filter;
+
+		junk_filter = E_MAIL_JUNK_FILTER (link->data);
+		if (!e_mail_junk_filter_available (junk_filter))
+			g_queue_push_tail (&trash, link);
+	}
+
+	while ((link = g_queue_pop_head (&trash)) != NULL)
+		list = g_list_delete_link (list, link);
+
+	/* Sort the remaining junk filters by display name. */
+
+	return g_list_sort (list, (GCompareFunc) e_mail_junk_filter_compare);
+}
+
 static void
 mail_session_get_inbox_thread (GSimpleAsyncResult *simple,
                                EMailSession *session,
@@ -1327,42 +1552,6 @@ mail_session_flush_filter_log (EMailSession *session)
 		fflush (session->priv->filter_logfile);
 }
 
-void
-mail_session_add_junk_plugin (EMailSession *session,
-                              const gchar *plugin_name,
-                              CamelJunkPlugin *junk_plugin)
-{
-	GConfClient *client;
-	gchar *def_plugin;
-	const gchar *key;
-
-	g_return_if_fail (E_IS_MAIL_SESSION (session));
-
-	client = gconf_client_get_default ();
-	key = "/apps/evolution/mail/junk/default_plugin";
-	def_plugin = gconf_client_get_string (client, key, NULL);
-	g_object_unref (client);
-
-	session->priv->junk_plugins = g_list_append (
-		session->priv->junk_plugins, junk_plugin);
-	if (def_plugin && plugin_name) {
-		if (!strcmp (def_plugin, plugin_name)) {
-			CAMEL_SESSION (session)->junk_plugin = junk_plugin;
-			camel_junk_plugin_init (junk_plugin);
-		}
-	}
-
-	g_free (def_plugin);
-}
-
-const GList *
-mail_session_get_junk_plugins (EMailSession *session)
-{
-	g_return_val_if_fail (E_IS_MAIL_SESSION (session), NULL);
-
-	return session->priv->junk_plugins;
-}
-
 const gchar *
 mail_session_get_data_dir (void)
 {