[gnome-photos] preview-view: Use the right API to detect if a BaseItem is a collection

[Debarshi Ray <debarshir src gnome org>]

commit 9f6b1e3a73c09d1d6d73e0f2a353d9ff5a9c4b4b
Author: Debarshi Ray <debarshir gnome org>
Date:   Wed Aug 24 16:21:01 2016 +0200

    preview-view: Use the right API to detect if a BaseItem is a collection
    
    Some collections might not have a nao:identifier. eg., the built-in
    nfo:image-category-screenshot. This hasn't been a problem so far
    because such collections do not (that's a bug) show up in search
    results.

 src/photos-preview-model.c |    8 +-------
 1 files changed, 1 insertions(+), 7 deletions(-)
---
diff --git a/src/photos-preview-model.c b/src/photos-preview-model.c
index 7cecae5..2148951 100644
--- a/src/photos-preview-model.c
+++ b/src/photos-preview-model.c
@@ -26,7 +26,6 @@
 #include "photos-base-item.h"
 #include "photos-base-manager.h"
 #include "photos-preview-model.h"
-#include "photos-query.h"
 #include "photos-search-context.h"
 #include "photos-view-model.h"
 
@@ -52,7 +51,6 @@ photos_preview_model_visible (GtkTreeModel *model, GtkTreeIter *iter, gpointer u
   PhotosPreviewModel *self = PHOTOS_PREVIEW_MODEL (user_data);
   PhotosBaseItem *item;
   gboolean ret_val = FALSE;
-  const gchar *identifier;
   gchar *id;
 
   gtk_tree_model_get (model, iter, PHOTOS_VIEW_MODEL_URN, &id, -1);
@@ -60,11 +58,7 @@ photos_preview_model_visible (GtkTreeModel *model, GtkTreeIter *iter, gpointer u
     goto out;
 
   item = PHOTOS_BASE_ITEM (photos_base_manager_get_object_by_id (self->item_mngr, id));
-  identifier = photos_base_item_get_identifier (item);
-  if (identifier != NULL && g_str_has_prefix (identifier, PHOTOS_QUERY_COLLECTIONS_IDENTIFIER))
-    goto out;
-
-  ret_val = TRUE;
+  ret_val = !photos_base_item_is_collection (item);
 
  out:
   g_free (id);