[nautilus-actions] Improve writability management of provider and item

[Pierre Wieser <pwieser src gnome org>]

commit ccc0e96a59216c3b988b78ae133f60385348a74d
Author: Pierre Wieser <pwieser trychlos org>
Date:   Sun Dec 13 02:13:19 2009 +0100

    Improve writability management of provider and item

 ChangeLog                                  |   14 +++++++
 TODO                                       |   17 ++++----
 nautilus-actions/api/na-iio-provider.h     |   14 ++++++-
 nautilus-actions/nact/nact-iactions-list.c |   11 ++---
 nautilus-actions/nact/nact-main-menubar.c  |   42 +++++++++++--------
 nautilus-actions/nact/nact-window.c        |   57 ++++++++++++++++----------
 nautilus-actions/nact/nact-window.h        |    3 +-
 nautilus-actions/runtime/na-io-provider.c  |   59 ++++++++++++++++++++++++----
 nautilus-actions/runtime/na-io-provider.h  |   16 ++++----
 nautilus-actions/runtime/na-pivot.c        |   28 +++++++++++++
 nautilus-actions/runtime/na-pivot.h        |    1 +
 11 files changed, 188 insertions(+), 74 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 58a0761..7305113 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,20 @@
 2009-12-12 Pierre Wieser <pwieser trychlos org>
 
 	* nautilus-actions/nact/nact-window.c:
+	* nautilus-actions/nact/nact-window.h
+	(nact_window_is_lockdown): Removed function.
+	(nact_window_is_writable_provider, nact_window_has_writable_providers):
+	New functions.
+
+	* nautilus-actions/runtime/na-io-provider.c:
+	* nautilus-actions/runtime/na-io-provider.h
+	(na_io_provider_is_willing_to_write): New function.
+
+	* nautilus-actions/runtime/na-pivot.c:
+	* nautilus-actions/runtime/na-pivot.h (na_pivot_has_writable_providers):
+	New function.
+
+	* nautilus-actions/nact/nact-window.c:
 	* nautilus-actions/nact/nact-window.h (nact_window_is_lockdown):
 	Check if the provider of the current item is locked down.
 
diff --git a/TODO b/TODO
index ae5cf0a..5b2a01f 100644
--- a/TODO
+++ b/TODO
@@ -99,14 +99,13 @@
 
 - desktop provider: fix default toolbar label
 
-- lockdown:
-  all entry fields should be readonly
+- readonly_item or locked_provider:
+  all entry/button fields should be readonly
 
-- actually, each provider may be unwritable
-  a) because it returns FALSE on na_io_provider_is_writable
-  b) because the sysadmin has put a special key in GConf to lock this provider
-  So:
-  - each provider must be adressable by an id
-  - we have mandatory/io-provider/id/lockdown key
+- add get_id/get_version to module api
 
-- add a get_version to module api
+- when duplicating a profile
+  na_object_item_is_readonly: assertion `NA_IS_OBJECT_ITEM( item )' failed
+  GLib-GObject-WARNING **: invalid cast from `NAObjectProfile' to `NAObjectItem'
+
+- new/edit options depend of writability status of the parent menu if any
diff --git a/nautilus-actions/api/na-iio-provider.h b/nautilus-actions/api/na-iio-provider.h
index 1fe2cac..014f4b8 100644
--- a/nautilus-actions/api/na-iio-provider.h
+++ b/nautilus-actions/api/na-iio-provider.h
@@ -73,7 +73,9 @@ typedef struct {
 	 * To avoid any collision, the IO provider id is allocated by the
 	 * Nautilus-Actions maintainer team. If you wish develop a new IO
 	 * provider, and so need a new provider id, please contact the
-	 * maintainers (see nautilus-actions.doap)
+	 * maintainers (see nautilus-actions.doap).
+	 *
+	 * The provider must implement this function.
 	 */
 	gchar *  ( *get_id )             ( const NAIIOProvider *instance );
 
@@ -82,6 +84,8 @@ typedef struct {
 	 * @instance: the #NAIIOProvider provider.
 	 *
 	 * Returns: the version of this API supported by the IO provider.
+	 *
+	 * The provider must implement this function.
 	 */
 	guint    ( *get_version )        ( const NAIIOProvider *instance );
 
@@ -110,7 +114,13 @@ typedef struct {
 	 *
 	 * Note that the I/O provider may return a positive writability
 	 * flag when considering the whole I/O storage subsystem, while not
-	 * being able to update/write/delete a particular item.
+	 * being able to update/write/delete a particular item
+	 * (see is_writable function below).
+	 *
+	 * Note also that, even if the I/O provider is willing to write,
+	 * a sysadmin may have locked down it, by putting a 'true' value
+	 * in the key '/apps/nautilus-actions/mandatory/<provider_id>/locked'
+	 * (see na_io_provider_is_willing_to_write).
 	 */
 	gboolean ( *is_willing_to_write )( const NAIIOProvider *instance );
 
diff --git a/nautilus-actions/nact/nact-iactions-list.c b/nautilus-actions/nact/nact-iactions-list.c
index af888b5..dff13f8 100644
--- a/nautilus-actions/nact/nact-iactions-list.c
+++ b/nautilus-actions/nact/nact-iactions-list.c
@@ -1634,15 +1634,13 @@ display_label( GtkTreeViewColumn *column, GtkCellRenderer *cell, GtkTreeModel *m
 	gboolean modified = FALSE;
 	gboolean valid = TRUE;
 	IActionsListInstanceData *ialid;
-	gboolean locked;
-	gboolean readonly;
+	gboolean writable_provider;
+	gboolean readonly_item;
 
 	gtk_tree_model_get( model, iter, IACTIONS_LIST_NAOBJECT_COLUMN, &object, -1 );
 	g_object_unref( object );
 	g_return_if_fail( NA_IS_OBJECT( object ));
 
-	locked = nact_window_is_locked( NACT_WINDOW( instance ), NA_OBJECT_ITEM( object ));
-
 	ialid = get_instance_data( instance );
 	label = na_object_get_label( object );
 	g_object_set( cell, "style-set", FALSE, NULL );
@@ -1652,7 +1650,8 @@ display_label( GtkTreeViewColumn *column, GtkCellRenderer *cell, GtkTreeModel *m
 
 		modified = na_object_is_modified( object );
 		valid = na_object_is_valid( object );
-		readonly = na_object_is_readonly( object );
+		readonly_item = na_object_is_readonly( object );
+		writable_provider = nact_window_is_writable_provider( NACT_WINDOW( instance ), NA_OBJECT_ITEM( object ));
 
 		if( modified ){
 			g_object_set( cell, "style", PANGO_STYLE_ITALIC, "style-set", TRUE, NULL );
@@ -1660,7 +1659,7 @@ display_label( GtkTreeViewColumn *column, GtkCellRenderer *cell, GtkTreeModel *m
 		if( !valid ){
 			g_object_set( cell, "foreground", "Red", "foreground-set", TRUE, NULL );
 		}
-		if( !locked && !readonly ){
+		if( writable_provider && !readonly_item ){
 			g_object_set( cell, "editable", TRUE, NULL );
 		}
 	}
diff --git a/nautilus-actions/nact/nact-main-menubar.c b/nautilus-actions/nact/nact-main-menubar.c
index c9797ae..f10bf19 100644
--- a/nautilus-actions/nact/nact-main-menubar.c
+++ b/nautilus-actions/nact/nact-main-menubar.c
@@ -606,13 +606,16 @@ on_update_sensitivities( NactMainWindow *window, gpointer user_data )
 	gboolean delete_enabled;
 	gboolean clipboard_is_empty;
 	gboolean new_item_enabled;
-	gboolean readonly;
-	gboolean locked;
+	gboolean readonly_item;
+	gboolean writable_provider;
+	gboolean writable_item;
+	gboolean has_writables;
 
 	g_debug( "%s: window=%p", thisfn, ( void * ) window );
 	g_return_if_fail( NACT_IS_MAIN_WINDOW( window ));
 
 	mis = ( MenubarIndicatorsStruct * ) g_object_get_data( G_OBJECT( window ), MENUBAR_PROP_INDICATORS );
+	has_writables = nact_window_has_writable_providers( NACT_WINDOW( window ));
 
 	g_object_get(
 			G_OBJECT( window ),
@@ -624,17 +627,19 @@ on_update_sensitivities( NactMainWindow *window, gpointer user_data )
 	g_return_if_fail( !profile || NA_IS_OBJECT_PROFILE( profile ));
 
 	has_modified = nact_main_window_has_modified_items( window );
-	readonly = item ? na_object_is_readonly( item ) : FALSE;
-	locked = item ? nact_window_is_lockdown( NACT_WINDOW( window ), NA_OBJECT_ITEM( item )) : FALSE;
+	readonly_item = item ? na_object_is_readonly( item ) : FALSE;
+	writable_provider = item ? nact_window_is_writable_provider( NACT_WINDOW( window ), NA_OBJECT_ITEM( item )) : FALSE;
+	writable_item = writable_provider && !readonly_item;
 
 	/* new menu enabled if selection is a menu or an action */
 	/* new action enabled if selection is a menu or an action */
 	new_item_enabled = ( selected_row == NULL || NA_IS_OBJECT_ITEM( selected_row ));
-	enable_item( window, "NewMenuItem", new_item_enabled && !locked );
-	enable_item( window, "NewActionItem", new_item_enabled && !locked );
+	enable_item( window, "NewMenuItem", new_item_enabled && has_writables );
+	enable_item( window, "NewActionItem", new_item_enabled && has_writables );
 
 	/* new profile enabled if selection is relative to only one writable action */
-	enable_item( window, "NewProfileItem", item != NULL && !NA_IS_OBJECT_MENU( item ) && !readonly && !locked );
+	enable_item( window, "NewProfileItem",
+			item != NULL && !NA_IS_OBJECT_MENU( item ) && writable_item );
 
 	/* save enabled if at least one item has been modified */
 	enable_item( window, "SaveItem", has_modified || mis->level_zero_order_changed );
@@ -649,22 +654,22 @@ on_update_sensitivities( NactMainWindow *window, gpointer user_data )
 
 	/* cut/copy/duplicate/delete enabled when selection not empty */
 	/* cut/delete require a writable item */
-	cut_enabled = ( mis->treeview_has_focus || mis->popup_handler ) && count_selected > 0 && !readonly &&!locked;
-	copy_enabled = ( mis->treeview_has_focus || mis->popup_handler ) && count_selected > 0;
-	duplicate_enabled = ( mis->treeview_has_focus || mis->popup_handler ) && count_selected > 0 && !locked;
-	delete_enabled = ( mis->treeview_has_focus || mis->popup_handler ) && count_selected > 0 && !readonly && !locked;
+	cut_enabled = ( mis->treeview_has_focus || mis->popup_handler ) && count_selected > 0 && writable_item && has_writables;
+	copy_enabled = ( mis->treeview_has_focus || mis->popup_handler ) && count_selected > 0 && has_writables;
+	duplicate_enabled = ( mis->treeview_has_focus || mis->popup_handler ) && count_selected > 0 && has_writables;
+	delete_enabled = ( mis->treeview_has_focus || mis->popup_handler ) && count_selected > 0 && writable_item;
 
 	/* paste enabled if
 	 * - simple selection
 	 * - clipboard contains only profiles, and current selection is a profile
 	 * - clipboard contains actions or menus, and current selection is a menu or an action */
 	paste_enabled = FALSE;
-	if(( mis->treeview_has_focus || mis->popup_handler ) && count_selected <= 1 && !locked ){
+	if(( mis->treeview_has_focus || mis->popup_handler ) && count_selected <= 1 ){
 		if( !clipboard_is_empty ){
 			if( mis->clipboard_profiles ){
-				paste_enabled = item && NA_IS_OBJECT_ACTION( item ) && !readonly;
+				paste_enabled = item && NA_IS_OBJECT_ACTION( item ) && writable_item;
 			} else {
-				paste_enabled = ( item != NULL );
+				paste_enabled = ( item != NULL ) && has_writables;
 			}
 		}
 	}
@@ -675,13 +680,13 @@ on_update_sensitivities( NactMainWindow *window, gpointer user_data )
 	 * - or current item is a menu
 	 * do not paste into if current selection is a profile */
 	paste_into_enabled = FALSE;
-	if(( mis->treeview_has_focus || mis->popup_handler ) && count_selected <= 1 && !locked ){
+	if(( mis->treeview_has_focus || mis->popup_handler ) && count_selected <= 1 ){
 		if( mis->selected_menus + mis->selected_actions ){
 			if( !clipboard_is_empty ){
 				if( mis->clipboard_profiles ){
-					paste_into_enabled = item && NA_IS_OBJECT_ACTION( item ) && !readonly;
+					paste_into_enabled = item && NA_IS_OBJECT_ACTION( item ) && writable_item;
 				} else {
-					paste_into_enabled = item && NA_IS_OBJECT_MENU( item );
+					paste_into_enabled = item && NA_IS_OBJECT_MENU( item ) && writable_item && has_writables;
 				}
 			}
 		}
@@ -703,7 +708,8 @@ on_update_sensitivities( NactMainWindow *window, gpointer user_data )
 	enable_item( window, "ExpandAllItem", count_list > 0 );
 	enable_item( window, "CollapseAllItem", count_list > 0 );
 
-	/* import item always enabled */
+	/* import item enabled if at least one writable provider */
+	enable_item( window, "ImportItem", has_writables );
 
 	/* export item enabled if IActionsList store contains actions */
 	enable_item( window, "ExportItem", mis->have_exportables );
diff --git a/nautilus-actions/nact/nact-window.c b/nautilus-actions/nact/nact-window.c
index f556824..782f91f 100644
--- a/nautilus-actions/nact/nact-window.c
+++ b/nautilus-actions/nact/nact-window.c
@@ -38,7 +38,6 @@
 #include <api/na-iio-provider.h>
 #include <api/na-object-api.h>
 
-#include <runtime/na-gconf-utils.h>
 #include <runtime/na-io-provider.h>
 #include <runtime/na-iprefs.h>
 #include <runtime/na-utils.h>
@@ -198,49 +197,63 @@ nact_window_get_pivot( NactWindow *window )
 }
 
 /**
- * nact_window_is_lockdown:
+ * nact_window_is_writable_provider:
  * @window: this #NactWindow instance.
  * @item: the current item.
  *
- * Returns: %TRUE if the configuration of the item's provider is locked
- * to be read-only, %FALSE else.
+ * Returns: %TRUE if the item's provider is willing to write, %FALSE else.
  *
  * If the provider item has not yet any provider, i.e. has never been
  * saved elsewhere, then we return %FALSE, assuming that we eventually
- * find a willing-to-write provider.
+ * find at least one willing-to-write provider.
  */
 gboolean
-nact_window_is_lockdown( NactWindow *window, const NAObjectItem *item )
+nact_window_is_writable_provider( NactWindow *window, const NAObjectItem *item )
 {
-	static const gchar *thisfn = "nact_window_is_lockdown";
-	gboolean locked;
+	gboolean writable;
 	NAPivot *pivot;
 	NAIIOProvider *provider;
-	gchar *id;
-	gchar *key;
-	GConfClient *gconf;
 
-	locked = FALSE;
+	writable = FALSE;
 
-	g_return_val_if_fail( NACT_IS_WINDOW( window ), locked );
-	g_return_val_if_fail( NA_IS_OBJECT_ITEM( item ), locked );
+	g_return_val_if_fail( NACT_IS_WINDOW( window ), writable );
+	g_return_val_if_fail( NA_IS_OBJECT_ITEM( item ), writable );
 
 	if( !window->private->dispose_has_run ){
 
 		pivot = nact_window_get_pivot( window );
 		provider = na_object_get_provider( item );
 		if( provider ){
-			id = na_io_provider_get_id( pivot, provider );
-			key = g_strdup_printf( "%s/mandatory/%s/lockdown", NAUTILUS_ACTIONS_GCONF_BASEDIR, id );
-			gconf = na_iprefs_get_gconf_client( NA_IPREFS( pivot ));
-			locked = na_gconf_utils_read_bool( gconf, key, TRUE, locked );
-			g_debug( "%s: id=%s, locked=%s", thisfn, id, locked ? "True":"False" );
-			g_free( key );
-			g_free( id );
+			writable = na_io_provider_is_willing_to_write( pivot, provider );
 		}
 	}
 
-	return( locked );
+	return( writable );
+}
+
+/**
+ * nact_window_has_writable_providers:
+ * @window: this #NactWindow instance.
+ *
+ * Returns: %TRUE if at least one I/O provider is writable, %FALSE else.
+ */
+gboolean
+nact_window_has_writable_providers( NactWindow *window )
+{
+	gboolean has_writables;
+	NAPivot *pivot;
+
+	has_writables = FALSE;
+
+	g_return_val_if_fail( NACT_IS_WINDOW( window ), has_writables );
+
+	if( !window->private->dispose_has_run ){
+
+		pivot = nact_window_get_pivot( window );
+		has_writables = na_pivot_has_writable_providers( pivot );
+	}
+
+	return( has_writables );
 }
 
 /**
diff --git a/nautilus-actions/nact/nact-window.h b/nautilus-actions/nact/nact-window.h
index 64b2bba..f586d5b 100644
--- a/nautilus-actions/nact/nact-window.h
+++ b/nautilus-actions/nact/nact-window.h
@@ -75,7 +75,8 @@ GType    nact_window_get_type( void );
 
 NAPivot *nact_window_get_pivot( NactWindow *window );
 
-gboolean nact_window_is_lockdown( NactWindow *window, const NAObjectItem *item );
+gboolean nact_window_is_writable_provider( NactWindow *window, const NAObjectItem *item );
+gboolean nact_window_has_writable_providers( NactWindow *window );
 
 gboolean nact_window_save_item( NactWindow *window, NAObjectItem *item );
 gboolean nact_window_delete_item( NactWindow *window, const NAObjectItem *item );
diff --git a/nautilus-actions/runtime/na-io-provider.c b/nautilus-actions/runtime/na-io-provider.c
index 4fce93e..b4d4e49 100644
--- a/nautilus-actions/runtime/na-io-provider.c
+++ b/nautilus-actions/runtime/na-io-provider.c
@@ -37,6 +37,7 @@
 #include <api/na-iio-provider.h>
 #include <api/na-object-api.h>
 
+#include "na-gconf-utils.h"
 #include "na-io-provider.h"
 #include "na-iprefs.h"
 #include "na-utils.h"
@@ -77,6 +78,7 @@ na_io_provider_register_callbacks( const NAPivot *pivot )
 
 /**
  * na_io_provider_get_id:
+ * @pivot: the current #NAPivot instance.
  * @provider: the #NAIIOProvider whose id is to be returned.
  *
  * Returns: the provider's id as a newly allocated string which should
@@ -96,7 +98,26 @@ na_io_provider_get_id( const NAPivot *pivot, const NAIIOProvider *provider )
 }
 
 /**
+ * na_io_provider_get_name:
+ * @pivot: the current #NAPivot instance.
+ * @provider: the #NAIIOProvider whose name is to be returned.
+ *
+ * Returns: a displayble name for the provider, as a newly allocated
+ * string which should be g_free() by the caller.
+ */
+gchar *
+na_io_provider_get_name( const NAPivot *pivot, const NAIIOProvider *provider )
+{
+	gchar *name;
+
+	name = na_pivot_get_module_name( pivot, G_OBJECT( provider ));
+
+	return( name );
+}
+
+/**
  * na_io_provider_get_version:
+ * @pivot: the current #NAPivot instance.
  * @provider: the #NAIIOProvider whose id is to be returned.
  *
  * Returns: the API's version the provider supports.
@@ -115,20 +136,42 @@ na_io_provider_get_version( const NAPivot *pivot, const NAIIOProvider *provider
 }
 
 /**
- * na_io_provider_get_name:
+ * na_io_provider_is_willing_to_write:
+ * @pivot: the current #NAPivot instance.
  * @provider: the #NAIIOProvider whose name is to be returned.
  *
- * Returns: a displayble name for the provider, as a newly allocated
- * string which should be g_free() by the caller.
+ * Returns: %TRUE if the I/O provider is willing to write _and_ it didn't
+ * has been locked down by a sysadmin.
  */
-gchar *
-na_io_provider_get_name( const NAPivot *pivot, const NAIIOProvider *provider )
+gboolean
+na_io_provider_is_willing_to_write( const NAPivot *pivot, const NAIIOProvider *provider )
 {
-	gchar *name;
+	static const gchar *thisfn = "na_io_provider_is_willing_to_write";
+	gboolean writable;
+	gboolean locked;
+	GConfClient *gconf;
+	gchar *id;
+	gchar *key;
 
-	name = na_pivot_get_module_name( pivot, G_OBJECT( provider ));
+	writable = FALSE;
+	locked = FALSE;
 
-	return( name );
+	if( NA_IIO_PROVIDER_GET_INTERFACE( provider )->is_willing_to_write ){
+
+		writable = NA_IIO_PROVIDER_GET_INTERFACE( provider )->is_willing_to_write( provider );
+
+		if( writable ){
+			id = na_io_provider_get_id( pivot, provider );
+			key = g_strdup_printf( "%s/mandatory/%s/locked", NAUTILUS_ACTIONS_GCONF_BASEDIR, id );
+			gconf = na_iprefs_get_gconf_client( NA_IPREFS( pivot ));
+			locked = na_gconf_utils_read_bool( gconf, key, TRUE, locked );
+			g_debug( "%s: id=%s, locked=%s", thisfn, id, locked ? "True":"False" );
+			g_free( key );
+			g_free( id );
+		}
+	}
+
+	return( writable && !locked );
 }
 
 /**
diff --git a/nautilus-actions/runtime/na-io-provider.h b/nautilus-actions/runtime/na-io-provider.h
index 97d9191..52f0456 100644
--- a/nautilus-actions/runtime/na-io-provider.h
+++ b/nautilus-actions/runtime/na-io-provider.h
@@ -44,16 +44,16 @@
 
 G_BEGIN_DECLS
 
-void   na_io_provider_register_callbacks( const NAPivot *pivot );
+void     na_io_provider_register_callbacks( const NAPivot *pivot );
 
-gchar *na_io_provider_get_id( const NAPivot *pivot, const NAIIOProvider *provider );
-guint  na_io_provider_get_version( const NAPivot *pivot, const NAIIOProvider *provider );
+gchar   *na_io_provider_get_id( const NAPivot *pivot, const NAIIOProvider *provider );
+gchar   *na_io_provider_get_name( const NAPivot *pivot, const NAIIOProvider *provider );
+guint    na_io_provider_get_version( const NAPivot *pivot, const NAIIOProvider *provider );
+gboolean na_io_provider_is_willing_to_write( const NAPivot *pivot, const NAIIOProvider *provider );
 
-gchar *na_io_provider_get_name( const NAPivot *pivot, const NAIIOProvider *provider );
-
-GList *na_io_provider_read_items( const NAPivot *pivot, GSList **messages );
-guint  na_io_provider_write_item( const NAPivot *pivot, NAObjectItem *item, GSList **messages );
-guint  na_io_provider_delete_item( const NAPivot *pivot, const NAObjectItem *item, GSList **messages );
+GList   *na_io_provider_read_items( const NAPivot *pivot, GSList **messages );
+guint    na_io_provider_write_item( const NAPivot *pivot, NAObjectItem *item, GSList **messages );
+guint    na_io_provider_delete_item( const NAPivot *pivot, const NAObjectItem *item, GSList **messages );
 
 G_END_DECLS
 
diff --git a/nautilus-actions/runtime/na-pivot.c b/nautilus-actions/runtime/na-pivot.c
index 16a3a5c..beeb670 100644
--- a/nautilus-actions/runtime/na-pivot.c
+++ b/nautilus-actions/runtime/na-pivot.c
@@ -474,6 +474,34 @@ na_pivot_free_providers( GList *providers )
 }
 
 /**
+ * na_pivot_has_writable_providers:
+ * @pivot: this #NAPivot instance.
+ *
+ * Returns: %TRUE if at least one I/O provider is writable, %FALSE else.
+ */
+gboolean
+na_pivot_has_writable_providers( const NAPivot *pivot )
+{
+	gboolean has_writable;
+	GList *providers, *ip;
+
+	has_writable = FALSE;
+
+	g_return_val_if_fail( NA_IS_PIVOT( pivot ), has_writable );
+
+	if( !pivot->private->dispose_has_run ){
+
+		providers = na_pivot_get_providers( pivot, NA_IIO_PROVIDER_TYPE );
+		for( ip = providers ; ip && !has_writable ; ip = ip->next ){
+			has_writable = na_io_provider_is_willing_to_write( pivot, NA_IIO_PROVIDER( ip->data ));
+		}
+		na_pivot_free_providers( providers );
+	}
+
+	return( has_writable );
+}
+
+/**
  * na_pivot_get_items:
  * @pivot: this #NAPivot instance.
  *
diff --git a/nautilus-actions/runtime/na-pivot.h b/nautilus-actions/runtime/na-pivot.h
index 98087c9..5cd7813 100644
--- a/nautilus-actions/runtime/na-pivot.h
+++ b/nautilus-actions/runtime/na-pivot.h
@@ -127,6 +127,7 @@ GList        *na_pivot_get_providers( const NAPivot *pivot, GType type );
 GObject      *na_pivot_get_provider( const NAPivot *pivot, GType type );
 void          na_pivot_release_provider( const GObject *provider );
 void          na_pivot_free_providers( GList *providers );
+gboolean      na_pivot_has_writable_providers( const NAPivot *pivot );
 
 GList        *na_pivot_get_items( const NAPivot *pivot );
 void          na_pivot_load_items( NAPivot *pivot );