[nautilus-actions] Fix na_io_provider_get_io_providers_list() so that write order is better respected

[Pierre Wieser <pwieser src gnome org>]

commit 5abad96e2ff2960861f6d3116136e3fc34c1d959
Author: Pierre Wieser <pwieser trychlos org>
Date:   Wed Sep 11 20:59:15 2013 +0200

    Fix na_io_provider_get_io_providers_list() so that write order is better respected

 ChangeLog                 |    7 +
 src/core/na-io-provider.c |  454 ++++++++++++++++++++++-----------------------
 2 files changed, 230 insertions(+), 231 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index b093fd1..a0d9eee 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2013-09-11 Pierre Wieser <pwieser trychlos org>
+
+       * src/core/na-io-provider.c (na_io_provider_get_io_providers_list):
+       - Fix so that the first listed I/O provider has most probability to be
+       writable.
+       - Do not reread preferences for write order.
+
 2013-09-10 Pierre Wieser <pwieser trychlos org>
 
        * src/nact/nact-main-toolbar.c:
diff --git a/src/core/na-io-provider.c b/src/core/na-io-provider.c
index f79048d..8b3f485 100644
--- a/src/core/na-io-provider.c
+++ b/src/core/na-io-provider.c
@@ -370,8 +370,8 @@ na_io_provider_find_io_provider_by_id( const NAPivot *pivot, const gchar *id )
  * na_io_provider_get_io_providers_list:
  * @pivot: the current #NAPivot instance.
  *
- * Build (if not already done) the ordered list of currently avialable
- * NAIOProvider objects.
+ * Build (if not already done) the write-ordered list of currently
+ * available NAIOProvider objects.
  *
  * A NAIOProvider object may be created:
  * - either because we have loaded a plugin which claims to implement the
@@ -403,6 +403,227 @@ na_io_provider_get_io_providers_list( const NAPivot *pivot )
 }
 
 /*
+ * adding from write-order means we only create NAIOProvider objects
+ * without having any pointer to the underlying NAIIOProvider (if it exists)
+ */
+static GList *
+io_providers_list_add_from_write_order( const NAPivot *pivot, GList *objects_list )
+{
+       GList *merged;
+       GSList *io_providers, *it;
+       const gchar *id;
+
+       merged = objects_list;
+       io_providers = na_settings_get_string_list( NA_IPREFS_IO_PROVIDERS_WRITE_ORDER, NULL, NULL );
+
+       for( it = io_providers ; it ; it = it->next ){
+               id = ( const gchar * ) it->data;
+               merged = io_providers_list_append_object( pivot, merged, NULL, id );
+       }
+
+       na_core_utils_slist_free( io_providers );
+
+       return( merged );
+}
+
+/*
+ * add to the list a NAIOProvider object for each loaded plugin which claim
+ * to implement the NAIIOProvider interface
+ */
+static GList *
+io_providers_list_add_from_plugins( const NAPivot *pivot, GList *objects_list )
+{
+       static const gchar *thisfn = "na_io_provider_io_providers_list_add_from_plugins";
+       GList *merged;
+       GList *modules_list, *im;
+       gchar *id;
+       NAIIOProvider *provider_module;
+
+       merged = objects_list;
+       modules_list = na_pivot_get_providers( pivot, NA_TYPE_IIO_PROVIDER );
+
+       for( im = modules_list ; im ; im = im->next ){
+
+               id = NULL;
+               provider_module = NA_IIO_PROVIDER( im->data );
+
+               if( NA_IIO_PROVIDER_GET_INTERFACE( provider_module )->get_id ){
+                       id = NA_IIO_PROVIDER_GET_INTERFACE( provider_module )->get_id( provider_module );
+                       if( !id || !strlen( id )){
+                               g_warning( "%s: NAIIOProvider %p get_id() interface returns null or empty 
id", thisfn, ( void * ) im->data );
+                               g_free( id );
+                               id = NULL;
+                       }
+               } else {
+                       g_warning( "%s: NAIIOProvider %p doesn't support get_id() interface", thisfn, ( void 
* ) im->data );
+               }
+
+               if( id ){
+                       merged = io_providers_list_append_object( pivot, merged, provider_module, id );
+                       g_free( id );
+               }
+       }
+
+       na_pivot_free_providers( modules_list );
+
+       return( merged );
+}
+
+/*
+ * add to the list NAIOProvider objects for the identifiers we may find
+ * in preferences without having found the plugin itself
+ *
+ * preferences come from the io-providers status.
+ */
+static GList *
+io_providers_list_add_from_prefs( const NAPivot *pivot, GList *objects_list )
+{
+       GList *merged;
+       const gchar *id;
+       GSList *io_providers, *it;
+
+       merged = objects_list;
+       io_providers = io_providers_get_from_prefs();
+
+       for( it = io_providers ; it ; it = it->next ){
+               id = ( const gchar * ) it->data;
+               merged = io_providers_list_append_object( pivot, merged, NULL, id );
+       }
+
+       na_core_utils_slist_free( io_providers );
+
+       return( merged );
+}
+
+/*
+ * io_providers_get_from_prefs:
+ *
+ * Searches in preferences system for all mentions of an i/o provider.
+ * This does not mean in any way that the i/o provider is active,
+ * available or so, but just that is mentioned here.
+ *
+ * I/o provider identifiers returned in the list are not supposed
+ * to be unique, nor sorted.
+ *
+ * Returns: a list of i/o provider identifiers found in preferences
+ * system; this list should be na_core_utils_slist_free() by the caller.
+ *
+ * Since: 3.1
+ */
+static GSList *
+io_providers_get_from_prefs( void )
+{
+       GSList *providers;
+       GSList *groups;
+       GSList *it;
+       const gchar *name;
+       gchar *group_prefix;
+       guint prefix_len;
+
+       providers = NULL;
+       groups = na_settings_get_groups();
+       group_prefix = g_strdup_printf( "%s ", NA_IPREFS_IO_PROVIDER_GROUP );
+       prefix_len = strlen( group_prefix );
+
+       for( it = groups ; it ; it = it->next ){
+               name = ( const gchar * ) it->data;
+               if( g_str_has_prefix( name, group_prefix )){
+                       providers = g_slist_prepend( providers, g_strdup( name+prefix_len ));
+               }
+       }
+
+       g_free( group_prefix );
+       na_core_utils_slist_free( groups );
+
+       return( providers );
+}
+
+/*
+ * add to the list a NAIOProvider object for the specified module and id
+ * if it does not have been already registered
+ */
+static GList *
+io_providers_list_append_object( const NAPivot *pivot, GList *list, NAIIOProvider *module, const gchar *id )
+{
+       GList *merged;
+       NAIOProvider *object;
+
+       merged = list;
+       object = peek_provider_by_id( list, id );
+
+       if( !object ){
+               object = io_provider_new( pivot, module, id );
+               merged = g_list_append( merged, object );
+
+       } else if( module && !object->private->provider ){
+               io_providers_list_set_module( pivot, object, module );
+       }
+
+       return( merged );
+}
+
+static NAIOProvider *
+peek_provider_by_id( const GList *providers, const gchar *id )
+{
+       NAIOProvider *provider = NULL;
+       const GList *ip;
+
+       for( ip = providers ; ip && !provider ; ip = ip->next ){
+               if( !strcmp( NA_IO_PROVIDER( ip->data )->private->id, id )){
+                       provider = NA_IO_PROVIDER( ip->data );
+               }
+       }
+
+       return( provider );
+}
+
+/*
+ * allocate a new NAIOProvider object for the specified module and id
+ *
+ * id is mandatory here
+ * module may be NULL
+ */
+static NAIOProvider *
+io_provider_new( const NAPivot *pivot, NAIIOProvider *module, const gchar *id )
+{
+       NAIOProvider *object;
+
+       g_return_val_if_fail( id && strlen( id ), NULL );
+
+       object = g_object_new( NA_IO_PROVIDER_TYPE, IO_PROVIDER_PROP_ID, id, NULL );
+
+       if( module ){
+               io_providers_list_set_module( pivot, object, module );
+       }
+
+       return( object );
+}
+
+/*
+ * when a IIOProvider plugin is associated with the NAIOProvider object,
+ * we connect the NAPivot callback to the 'item-changed' signal
+ */
+static void
+io_providers_list_set_module( const NAPivot *pivot, NAIOProvider *provider_object, NAIIOProvider 
*provider_module )
+{
+       provider_object->private->provider = g_object_ref( provider_module );
+
+       provider_object->private->item_changed_handler =
+                       g_signal_connect(
+                                       provider_module, IO_PROVIDER_SIGNAL_ITEM_CHANGED,
+                                       ( GCallback ) na_pivot_on_item_changed_handler, ( gpointer ) pivot );
+
+       provider_object->private->writable =
+                       is_finally_writable( provider_object, pivot, &provider_object->private->reason );
+
+       g_debug( "na_io_provider_list_set_module: provider_module=%p (%s), writable=%s, reason=%d",
+                       ( void * ) provider_module,
+                       provider_object->private->id,
+                       provider_object->private->writable ? "True":"False",
+                       provider_object->private->reason );
+}
+
+/*
  * na_io_provider_unref_io_providers_list:
  *
  * Called by on #NAPivot dispose(), free here resources allocated to
@@ -720,220 +941,6 @@ dump_providers_list( GList *providers )
 }
 #endif
 
-/*
- * allocate a new NAIOProvider object for the specified module and id
- *
- * id is mandatory here
- * module may be NULL
- */
-static NAIOProvider *
-io_provider_new( const NAPivot *pivot, NAIIOProvider *module, const gchar *id )
-{
-       NAIOProvider *object;
-
-       g_return_val_if_fail( id && strlen( id ), NULL );
-
-       object = g_object_new( NA_IO_PROVIDER_TYPE, IO_PROVIDER_PROP_ID, id, NULL );
-
-       if( module ){
-               io_providers_list_set_module( pivot, object, module );
-       }
-
-       return( object );
-}
-
-/*
- * add to the list a NAIOProvider object for each loaded plugin which claim
- * to implement the NAIIOProvider interface
- */
-static GList *
-io_providers_list_add_from_plugins( const NAPivot *pivot, GList *objects_list )
-{
-       static const gchar *thisfn = "na_io_provider_io_providers_list_add_from_plugins";
-       GList *merged;
-       GList *modules_list, *im;
-       gchar *id;
-       NAIIOProvider *provider_module;
-
-       merged = objects_list;
-       modules_list = na_pivot_get_providers( pivot, NA_TYPE_IIO_PROVIDER );
-
-       for( im = modules_list ; im ; im = im->next ){
-
-               id = NULL;
-               provider_module = NA_IIO_PROVIDER( im->data );
-
-               if( NA_IIO_PROVIDER_GET_INTERFACE( provider_module )->get_id ){
-                       id = NA_IIO_PROVIDER_GET_INTERFACE( provider_module )->get_id( provider_module );
-                       if( !id || !strlen( id )){
-                               g_warning( "%s: NAIIOProvider %p get_id() interface returns null or empty 
id", thisfn, ( void * ) im->data );
-                               g_free( id );
-                               id = NULL;
-                       }
-               } else {
-                       g_warning( "%s: NAIIOProvider %p doesn't support get_id() interface", thisfn, ( void 
* ) im->data );
-               }
-
-               if( id ){
-                       merged = io_providers_list_append_object( pivot, merged, provider_module, id );
-                       g_free( id );
-               }
-       }
-
-       na_pivot_free_providers( modules_list );
-
-       return( merged );
-}
-
-/*
- * add to the list NAIOProvider objects for the identifiers we may find
- * in preferences without having found the plugin itself
- *
- * preferences may come from the 'write-order' list, or from the io-providers
- * status.
- */
-static GList *
-io_providers_list_add_from_prefs( const NAPivot *pivot, GList *objects_list )
-{
-       GList *merged;
-       const gchar *id;
-       GSList *io_providers, *it;
-
-       merged = objects_list;
-       io_providers = io_providers_get_from_prefs();
-
-       for( it = io_providers ; it ; it = it->next ){
-               id = ( const gchar * ) it->data;
-               merged = io_providers_list_append_object( pivot, merged, NULL, id );
-       }
-
-       na_core_utils_slist_free( io_providers );
-
-       return( merged );
-}
-
-/*
- * io_providers_get_from_prefs:
- *
- * Searches in preferences system for all mentions of an i/o provider.
- * This does not mean in any way that the i/o provider is active,
- * available or so, but just that is mentioned here.
- *
- * I/o provider identifiers returned in the list are not supposed
- * to be unique, nor sorted.
- *
- * Returns: a list of i/o provider identifiers found in preferences
- * system; this list should be na_core_utils_slist_free() by the caller.
- *
- * Since: 3.1
- */
-static GSList *
-io_providers_get_from_prefs( void )
-{
-       GSList *providers;
-       GSList *write_order, *groups;
-       GSList *it;
-       const gchar *name;
-       gchar *group_prefix;
-       guint prefix_len;
-
-       providers = NULL;
-
-       write_order = na_settings_get_string_list( NA_IPREFS_IO_PROVIDERS_WRITE_ORDER, NULL, NULL );
-       for( it = write_order ; it ; it = it->next ){
-               name = ( const gchar * ) it->data;
-               providers = g_slist_prepend( providers, g_strdup( name ));
-       }
-       na_core_utils_slist_free( write_order );
-
-       groups = na_settings_get_groups();
-
-       group_prefix = g_strdup_printf( "%s ", NA_IPREFS_IO_PROVIDER_GROUP );
-       prefix_len = strlen( group_prefix );
-       for( it = groups ; it ; it = it->next ){
-               name = ( const gchar * ) it->data;
-               if( g_str_has_prefix( name, group_prefix )){
-                       providers = g_slist_prepend( providers, g_strdup( name+prefix_len ));
-               }
-       }
-       g_free( group_prefix );
-       na_core_utils_slist_free( groups );
-
-       return( providers );
-}
-
-/*
- * adding from write-order means we only create NAIOProvider objects
- * without having any pointer to the underlying NAIIOProvider (if it exists)
- */
-static GList *
-io_providers_list_add_from_write_order( const NAPivot *pivot, GList *objects_list )
-{
-       GList *merged;
-       GSList *io_providers, *it;
-       const gchar *id;
-
-       merged = objects_list;
-       io_providers = na_settings_get_string_list( NA_IPREFS_IO_PROVIDERS_WRITE_ORDER, NULL, NULL );
-
-       for( it = io_providers ; it ; it = it->next ){
-               id = ( const gchar * ) it->data;
-               merged = io_providers_list_append_object( pivot, merged, NULL, id );
-       }
-
-       na_core_utils_slist_free( io_providers );
-
-       return( merged );
-}
-
-/*
- * add to the list a NAIOProvider object for the specified module and id
- * if it does not have been already registered
- */
-static GList *
-io_providers_list_append_object( const NAPivot *pivot, GList *list, NAIIOProvider *module, const gchar *id )
-{
-       GList *merged;
-       NAIOProvider *object;
-
-       merged = list;
-       object = peek_provider_by_id( list, id );
-
-       if( !object ){
-               object = io_provider_new( pivot, module, id );
-               merged = g_list_append( merged, object );
-
-       } else if( module && !object->private->provider ){
-               io_providers_list_set_module( pivot, object, module );
-       }
-
-       return( merged );
-}
-
-/*
- * when a IIOProvider plugin is associated with the NAIOProvider object,
- * we connect the NAPivot callback to the 'item-changed' signal
- */
-static void
-io_providers_list_set_module( const NAPivot *pivot, NAIOProvider *provider_object, NAIIOProvider 
*provider_module )
-{
-       provider_object->private->provider = g_object_ref( provider_module );
-
-       provider_object->private->item_changed_handler =
-                       g_signal_connect(
-                                       provider_module, IO_PROVIDER_SIGNAL_ITEM_CHANGED,
-                                       ( GCallback ) na_pivot_on_item_changed_handler, ( gpointer ) pivot );
-
-       provider_object->private->writable =
-                       is_finally_writable( provider_object, pivot, &provider_object->private->reason );
-
-       g_debug( "na_io_provider_list_set_module: provider_module=%p (%s), writable=%s, reason=%d",
-                       ( void * ) provider_module,
-                       provider_object->private->id,
-                       provider_object->private->writable ? "True":"False",
-                       provider_object->private->reason );
-}
-
 static gboolean
 is_conf_writable( const NAIOProvider *provider, const NAPivot *pivot, gboolean *mandatory )
 {
@@ -1216,21 +1223,6 @@ peek_item_by_id_compare( const NAObject *obj, const gchar *id )
        return( ret );
 }
 
-static NAIOProvider *
-peek_provider_by_id( const GList *providers, const gchar *id )
-{
-       NAIOProvider *provider = NULL;
-       const GList *ip;
-
-       for( ip = providers ; ip && !provider ; ip = ip->next ){
-               if( !strcmp( NA_IO_PROVIDER( ip->data )->private->id, id )){
-                       provider = NA_IO_PROVIDER( ip->data );
-               }
-       }
-
-       return( provider );
-}
-
 /*
  * na_io_provider_write_item:
  * @provider: this #NAIOProvider object.