[gnome-photos/wip/rishi/collection: 30/35] Support explicitly specifying the BaseItem sub-class to create

[Debarshi Ray <debarshir src gnome org>]

commit 4bffa56f579acb645fecde96bacd9c6e4536aeaa
Author: Debarshi Ray <debarshir gnome org>
Date:   Wed Jan 24 13:43:16 2018 +0100

    Support explicitly specifying the BaseItem sub-class to create
    
    The specific BaseItem sub-class that gets instantiated from a
    TrackerSparqlCursor used to be auto-detected based on the
    nao:identifier. Each sub-class had a matching Source, and a Tracker
    miner that set an nao:identifier with an unique prefix that identified
    the sub-class.
    
    However, it is not going to be possible to differentiate between local
    BaseItems already present on the system and those that are on a
    removable device because both are going to be indexed by Tracker's
    filesystem miner. Fortunately the cases where one needs to create a
    DeviceItem, as opposed to a LocalItem, are very well defined.
    Therefore, it's desirable to be able to specify the GType of the
    sub-class and override the auto-detection machinery.

 src/photos-application.c             |   2 +-
 src/photos-collection-icon-watcher.c |   2 +-
 src/photos-item-manager.c            | 104 +++++++++++++++++++++++++----------
 src/photos-item-manager.h            |   3 +
 src/photos-tracker-controller.c      |   8 ++-
 src/photos-tracker-controller.h      |   2 +
 6 files changed, 89 insertions(+), 32 deletions(-)
---
diff --git a/src/photos-application.c b/src/photos-application.c
index bd78fde7..66af55f7 100644
--- a/src/photos-application.c
+++ b/src/photos-application.c
@@ -791,7 +791,7 @@ photos_application_activate_query_executed (GObject *source_object, GAsyncResult
   if (cursor == NULL)
     goto out;
 
-  photos_item_manager_add_item (PHOTOS_ITEM_MANAGER (self->state->item_mngr), cursor, TRUE);
+  photos_item_manager_add_item (PHOTOS_ITEM_MANAGER (self->state->item_mngr), G_TYPE_NONE, cursor, TRUE);
 
   identifier = tracker_sparql_cursor_get_string (cursor, PHOTOS_QUERY_COLUMNS_URN, NULL);
   item = photos_base_manager_get_object_by_id (self->state->item_mngr, identifier);
diff --git a/src/photos-collection-icon-watcher.c b/src/photos-collection-icon-watcher.c
index 96d14092..9cbb548a 100644
--- a/src/photos-collection-icon-watcher.c
+++ b/src/photos-collection-icon-watcher.c
@@ -177,7 +177,7 @@ photos_collection_icon_watcher_to_query_executed (GObject *source_object, GAsync
     {
       PhotosBaseItem *item;
 
-      item = photos_item_manager_create_item (PHOTOS_ITEM_MANAGER (self->item_mngr), cursor);
+      item = photos_item_manager_create_item (PHOTOS_ITEM_MANAGER (self->item_mngr), G_TYPE_NONE, cursor);
       self->items = g_list_prepend (self->items, item);
     }
 
diff --git a/src/photos-item-manager.c b/src/photos-item-manager.c
index 2da064fc..5deb007a 100644
--- a/src/photos-item-manager.c
+++ b/src/photos-item-manager.c
@@ -270,6 +270,7 @@ photos_item_manager_info_updated (PhotosBaseItem *item, gpointer user_data)
 
 static void
 photos_item_manager_add_cursor_for_mode (PhotosItemManager *self,
+                                         GType base_item_type,
                                          TrackerSparqlCursor *cursor,
                                          PhotosWindowMode mode,
                                          gboolean force)
@@ -280,6 +281,9 @@ photos_item_manager_add_cursor_for_mode (PhotosItemManager *self,
   const gchar *id;
 
   g_return_if_fail (PHOTOS_IS_ITEM_MANAGER (self));
+  g_return_if_fail (base_item_type == G_TYPE_NONE
+                    || (base_item_type != PHOTOS_TYPE_BASE_ITEM
+                        && g_type_is_a (base_item_type, PHOTOS_TYPE_BASE_ITEM)));
   g_return_if_fail (TRACKER_SPARQL_IS_CURSOR (cursor));
   g_return_if_fail (mode != PHOTOS_WINDOW_MODE_NONE);
   g_return_if_fail (mode != PHOTOS_WINDOW_MODE_EDIT);
@@ -313,7 +317,7 @@ photos_item_manager_add_cursor_for_mode (PhotosItemManager *self,
         }
       else
         {
-          item = photos_item_manager_create_item (self, cursor);
+          item = photos_item_manager_create_item (self, base_item_type, cursor);
           if (photos_base_item_is_collection (item))
             g_hash_table_insert (self->collections, g_strdup (id), g_object_ref (item));
 
@@ -371,7 +375,7 @@ photos_item_manager_item_created_executed (GObject *source_object, GAsyncResult
   if (cursor == NULL)
     goto out;
 
-  photos_item_manager_add_item (self, cursor, FALSE);
+  photos_item_manager_add_item (self, G_TYPE_NONE, cursor, FALSE);
 
   if (!photos_item_manager_cursor_is_collection (cursor))
     {
@@ -975,12 +979,18 @@ photos_item_manager_new (void)
 
 
 void
-photos_item_manager_add_item (PhotosItemManager *self, TrackerSparqlCursor *cursor, gboolean force)
+photos_item_manager_add_item (PhotosItemManager *self,
+                              GType base_item_type,
+                              TrackerSparqlCursor *cursor,
+                              gboolean force)
 {
   PhotosItemManagerHiddenItem *old_hidden_item;
   const gchar *id;
 
   g_return_if_fail (PHOTOS_IS_ITEM_MANAGER (self));
+  g_return_if_fail (base_item_type == G_TYPE_NONE
+                    || (base_item_type != PHOTOS_TYPE_BASE_ITEM
+                        && g_type_is_a (base_item_type, PHOTOS_TYPE_BASE_ITEM)));
   g_return_if_fail (TRACKER_SPARQL_IS_CURSOR (cursor));
 
   id = tracker_sparql_cursor_get_string (cursor, PHOTOS_QUERY_COLUMNS_URN, NULL);
@@ -992,14 +1002,28 @@ photos_item_manager_add_item (PhotosItemManager *self, TrackerSparqlCursor *curs
 
   if (photos_item_manager_cursor_is_collection (cursor))
     {
-      photos_item_manager_add_cursor_for_mode (self, cursor, PHOTOS_WINDOW_MODE_COLLECTIONS, force);
+      photos_item_manager_add_cursor_for_mode (self,
+                                               base_item_type,
+                                               cursor,
+                                               PHOTOS_WINDOW_MODE_COLLECTIONS,
+                                               force);
     }
   else
     {
       if (photos_item_manager_cursor_is_favorite (cursor))
-        photos_item_manager_add_cursor_for_mode (self, cursor, PHOTOS_WINDOW_MODE_FAVORITES, force);
+        {
+          photos_item_manager_add_cursor_for_mode (self,
+                                                   base_item_type,
+                                                   cursor,
+                                                   PHOTOS_WINDOW_MODE_FAVORITES,
+                                                   force);
+        }
 
-      photos_item_manager_add_cursor_for_mode (self, cursor, PHOTOS_WINDOW_MODE_OVERVIEW, force);
+      photos_item_manager_add_cursor_for_mode (self,
+                                               base_item_type,
+                                               cursor,
+                                               PHOTOS_WINDOW_MODE_OVERVIEW,
+                                               force);
     }
 
  out:
@@ -1008,11 +1032,18 @@ photos_item_manager_add_item (PhotosItemManager *self, TrackerSparqlCursor *curs
 
 
 void
-photos_item_manager_add_item_for_mode (PhotosItemManager *self, PhotosWindowMode mode, TrackerSparqlCursor 
*cursor)
+photos_item_manager_add_item_for_mode (PhotosItemManager *self,
+                                       GType base_item_type,
+                                       PhotosWindowMode mode,
+                                       TrackerSparqlCursor *cursor)
 {
   PhotosItemManagerHiddenItem *old_hidden_item;
   const gchar *id;
 
+  g_return_if_fail (base_item_type == G_TYPE_NONE
+                    || (base_item_type != PHOTOS_TYPE_BASE_ITEM
+                        && g_type_is_a (base_item_type, PHOTOS_TYPE_BASE_ITEM)));
+
   id = tracker_sparql_cursor_get_string (cursor, PHOTOS_QUERY_COLUMNS_URN, NULL);
   g_return_if_fail (id != NULL && id[0] != '\0');
 
@@ -1020,7 +1051,7 @@ photos_item_manager_add_item_for_mode (PhotosItemManager *self, PhotosWindowMode
   if (old_hidden_item != NULL)
     goto out;
 
-  photos_item_manager_add_cursor_for_mode (self, cursor, mode, FALSE);
+  photos_item_manager_add_cursor_for_mode (self, base_item_type, cursor, mode, FALSE);
 
  out:
   return;
@@ -1087,44 +1118,59 @@ photos_item_manager_clear (PhotosItemManager *self, PhotosWindowMode mode)
 
 
 PhotosBaseItem *
-photos_item_manager_create_item (PhotosItemManager *self, TrackerSparqlCursor *cursor)
+photos_item_manager_create_item (PhotosItemManager *self, GType base_item_type, TrackerSparqlCursor *cursor)
 {
-  GIOExtension *extension;
-  g_auto (GStrv) split_identifier = NULL;
   GType type;
   PhotosBaseItem *ret_val = NULL;
-  const gchar *extension_name = "local";
-  g_autofree gchar *identifier = NULL;
 
   g_return_val_if_fail (PHOTOS_IS_ITEM_MANAGER (self), NULL);
+  g_return_val_if_fail (base_item_type == G_TYPE_NONE
+                        || (base_item_type != PHOTOS_TYPE_BASE_ITEM
+                            && g_type_is_a (base_item_type, PHOTOS_TYPE_BASE_ITEM)), NULL);
   g_return_val_if_fail (TRACKER_SPARQL_IS_CURSOR (cursor), NULL);
 
-  identifier = g_strdup (tracker_sparql_cursor_get_string (cursor, PHOTOS_QUERY_COLUMNS_IDENTIFIER, NULL));
-  if (identifier != NULL)
+  if (base_item_type == G_TYPE_NONE)
     {
-      split_identifier = g_strsplit (identifier, ":", 4);
+      GIOExtension *extension;
+      g_auto (GStrv) split_identifier = NULL;
+      const gchar *extension_name = "local";
+      g_autofree gchar *identifier = NULL;
 
-      if (photos_item_manager_cursor_is_collection (cursor))
+      identifier = g_strdup (tracker_sparql_cursor_get_string (cursor, PHOTOS_QUERY_COLUMNS_IDENTIFIER, 
NULL));
+      if (identifier != NULL)
         {
-          /* Its a collection. */
-          extension_name = split_identifier[2];
+          split_identifier = g_strsplit (identifier, ":", 4);
+
+          if (photos_item_manager_cursor_is_collection (cursor))
+            {
+              /* Its a collection. */
+              extension_name = split_identifier[2];
+            }
+          else
+            {
+              /* Its a normal photo item. */
+              if (g_strv_length (split_identifier) > 1)
+                extension_name = split_identifier[0];
+            }
         }
-      else
+
+      extension = g_io_extension_point_get_extension_by_name (self->extension_point, extension_name);
+      if (G_UNLIKELY (extension == NULL))
         {
-          /* Its a normal photo item. */
-          if (g_strv_length (split_identifier) > 1)
-            extension_name = split_identifier[0];
+          g_warning ("Unable to find extension %s for identifier: %s", extension_name, identifier);
+          goto out;
         }
-    }
 
-  extension = g_io_extension_point_get_extension_by_name (self->extension_point, extension_name);
-  if (G_UNLIKELY (extension == NULL))
+      type = g_io_extension_get_type (extension);
+    }
+  else
     {
-      g_warning ("Unable to find extension %s for identifier: %s", extension_name, identifier);
-      goto out;
+      type = base_item_type;
     }
 
-  type = g_io_extension_get_type (extension);
+  g_return_val_if_fail (type != G_TYPE_NONE, NULL);
+  g_return_val_if_fail (type != PHOTOS_TYPE_BASE_ITEM && g_type_is_a (type, PHOTOS_TYPE_BASE_ITEM), NULL);
+
   ret_val = PHOTOS_BASE_ITEM (g_object_new (type,
                                             "cursor", cursor,
                                             "failed-thumbnailing", FALSE,
diff --git a/src/photos-item-manager.h b/src/photos-item-manager.h
index fe203c02..bd5b06e8 100644
--- a/src/photos-item-manager.h
+++ b/src/photos-item-manager.h
@@ -71,10 +71,12 @@ typedef struct _PhotosItemManagerClass PhotosModeControllerClass;
 PhotosBaseManager        *photos_item_manager_new                          (void);
 
 void                      photos_item_manager_add_item                     (PhotosItemManager *self,
+                                                                            GType base_item_type,
                                                                             TrackerSparqlCursor *cursor,
                                                                             gboolean force);
 
 void                      photos_item_manager_add_item_for_mode            (PhotosItemManager *self,
+                                                                            GType base_item_type,
                                                                             PhotosWindowMode mode,
                                                                             TrackerSparqlCursor *cursor);
 
@@ -82,6 +84,7 @@ void                      photos_item_manager_clear                        (Phot
                                                                             PhotosWindowMode mode);
 
 PhotosBaseItem           *photos_item_manager_create_item                  (PhotosItemManager *self,
+                                                                            GType base_item_type,
                                                                             TrackerSparqlCursor *cursor);
 
 PhotosBaseItem           *photos_item_manager_get_active_collection        (PhotosItemManager *self);
diff --git a/src/photos-tracker-controller.c b/src/photos-tracker-controller.c
index ccf81aba..6bcd05be 100644
--- a/src/photos-tracker-controller.c
+++ b/src/photos-tracker-controller.c
@@ -233,7 +233,11 @@ photos_tracker_controller_cursor_next (GObject *source_object, GAsyncResult *res
   now = g_get_monotonic_time ();
   photos_debug (PHOTOS_DEBUG_TRACKER, "Query Cursor: %" G_GINT64_FORMAT, (now - priv->last_query_time) / 
1000000);
 
-  photos_item_manager_add_item_for_mode (PHOTOS_ITEM_MANAGER (priv->item_mngr), priv->mode, cursor);
+  photos_item_manager_add_item_for_mode (PHOTOS_ITEM_MANAGER (priv->item_mngr),
+                                         PHOTOS_TRACKER_CONTROLLER_GET_CLASS (self)->base_item_type,
+                                         priv->mode,
+                                         cursor);
+
   tracker_sparql_cursor_next_async (cursor,
                                     priv->cancellable,
                                     photos_tracker_controller_cursor_next,
@@ -578,6 +582,8 @@ photos_tracker_controller_class_init (PhotosTrackerControllerClass *class)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (class);
 
+  class->base_item_type = G_TYPE_NONE;
+
   object_class->constructed = photos_tracker_controller_constructed;
   object_class->dispose = photos_tracker_controller_dispose;
   object_class->set_property = photos_tracker_controller_set_property;
diff --git a/src/photos-tracker-controller.h b/src/photos-tracker-controller.h
index 1cb597f5..5f4028f0 100644
--- a/src/photos-tracker-controller.h
+++ b/src/photos-tracker-controller.h
@@ -39,6 +39,8 @@ struct _PhotosTrackerControllerClass
 {
   GObjectClass parent_class;
 
+  GType base_item_type;
+
   /* virtual methods */
   PhotosOffsetController *(*get_offset_controller) (PhotosTrackerController *self);
   PhotosQuery *(*get_query) (PhotosTrackerController *self);