[gnome-photos/wip/rishi/import-3: 4/7] item-manager: Add photos_item_manager_wait_for_file_async

[Debarshi Ray <debarshir src gnome org>]

commit 730c92015326a0ced0c476c1ed09b523d708169a
Author: Debarshi Ray <debarshir gnome org>
Date:   Wed Feb 7 00:24:01 2018 +0100

    item-manager: Add photos_item_manager_wait_for_file_async
    
    This is meant to wait for a newly created native GFile to be indexed
    and entered into Tracker's database, and will return the corresponding
    new URN. It will be used to get the URN of content imported from
    attached devices.
    
    https://gitlab.gnome.org/GNOME/gnome-photos/issues/29

 src/photos-item-manager.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++
 src/photos-item-manager.h | 10 ++++++++++
 2 files changed, 61 insertions(+)
---
diff --git a/src/photos-item-manager.c b/src/photos-item-manager.c
index fd163bd1..c4d83aa5 100644
--- a/src/photos-item-manager.c
+++ b/src/photos-item-manager.c
@@ -1420,6 +1420,57 @@ photos_item_manager_unhide_item (PhotosItemManager *self, PhotosBaseItem *item)
 }
 
 
+void
+photos_item_manager_wait_for_file_async (PhotosItemManager *self,
+                                         GFile *file,
+                                         GCancellable *cancellable,
+                                         GAsyncReadyCallback callback,
+                                         gpointer user_data)
+{
+  GList *tasks;
+  g_autoptr (GTask) task = NULL;
+  g_autofree gchar *uri = NULL;
+
+  g_return_if_fail (PHOTOS_IS_ITEM_MANAGER (self));
+  g_return_if_fail (G_IS_FILE (file));
+  g_return_if_fail (g_file_is_native (file));
+  g_return_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable));
+
+  task = g_task_new (self, cancellable, callback, user_data);
+  g_task_set_source_tag (task, photos_item_manager_wait_for_file_async);
+
+  uri = g_file_get_uri (file);
+  tasks = (GList *) g_hash_table_lookup (self->wait_for_changes_table, uri);
+  tasks = g_list_copy_deep (tasks, (GCopyFunc) g_object_ref, NULL);
+  tasks = g_list_prepend (tasks, g_object_ref (task));
+  g_hash_table_insert (self->wait_for_changes_table, g_strdup (uri), tasks);
+
+  photos_item_manager_remove_timeout (self);
+  self->wait_for_changes_id = g_timeout_add_seconds (WAIT_FOR_CHANGES_TIMEOUT,
+                                                     photos_item_manager_wait_for_changes_timeout,
+                                                     self);
+
+  photos_debug (PHOTOS_DEBUG_TRACKER, "Waiting for %s", uri);
+}
+
+
+gchar *
+photos_item_manager_wait_for_file_finish (PhotosItemManager *self, GAsyncResult *res, GError **error)
+{
+  GTask *task;
+
+  g_return_val_if_fail (PHOTOS_IS_ITEM_MANAGER (self), NULL);
+
+  g_return_val_if_fail (g_task_is_valid (res, self), NULL);
+  task = G_TASK (res);
+
+  g_return_val_if_fail (g_task_get_source_tag (task) == photos_item_manager_wait_for_file_async, NULL);
+  g_return_val_if_fail (error == NULL || *error == NULL, NULL);
+
+  return g_task_propagate_pointer (task, error);
+}
+
+
 void
 photos_item_manager_wait_for_changes_async (PhotosItemManager *self,
                                             PhotosBaseItem *item,
diff --git a/src/photos-item-manager.h b/src/photos-item-manager.h
index fe203c02..0e7f279d 100644
--- a/src/photos-item-manager.h
+++ b/src/photos-item-manager.h
@@ -100,6 +100,16 @@ void                      photos_item_manager_set_constraints_for_mode     (Phot
                                                                             gboolean constrain,
                                                                             PhotosWindowMode mode);
 
+void                      photos_item_manager_wait_for_file_async          (PhotosItemManager *self,
+                                                                            GFile *file,
+                                                                            GCancellable *cancellable,
+                                                                            GAsyncReadyCallback callback,
+                                                                            gpointer user_data);
+
+gchar                    *photos_item_manager_wait_for_file_finish         (PhotosItemManager *self,
+                                                                            GAsyncResult *res,
+                                                                            GError **error);
+
 void                      photos_item_manager_wait_for_changes_async       (PhotosItemManager *self,
                                                                             PhotosBaseItem *item,
                                                                             GCancellable *cancellable,