[gnome-photos] item-manager: Add "load-started" and "load-finished" signals

[Debarshi Ray <debarshir src gnome org>]

commit 8862e0a7bfe48d2441dd87402336a01e1547a5ea
Author: Debarshi Ray <debarshir gnome org>
Date:   Fri Sep 26 11:23:20 2014 +0200

    item-manager: Add "load-started" and "load-finished" signals
    
    This keeps the code in sync with gnome-documents.

 src/photos-embed.c        |   78 +++++++-----------------------------------
 src/photos-item-manager.c |   82 +++++++++++++++++++++++++++++++++++++++++++++
 src/photos-item-manager.h |    3 ++
 3 files changed, 98 insertions(+), 65 deletions(-)
---
diff --git a/src/photos-embed.c b/src/photos-embed.c
index 27e138b..62b1441 100644
--- a/src/photos-embed.c
+++ b/src/photos-embed.c
@@ -63,7 +63,6 @@ struct _PhotosEmbedSearchState
 struct _PhotosEmbedPrivate
 {
   GAction *search_action;
-  GCancellable *loader_cancellable;
   GtkWidget *collections;
   GtkWidget *favorites;
   GtkWidget *no_results;
@@ -213,28 +212,16 @@ photos_embed_prepare_for_preview (PhotosEmbed *self)
 
 
 static void
-photos_embed_item_load (GObject *source_object, GAsyncResult *res, gpointer user_data)
+photos_embed_load_finished (PhotosEmbed *self, PhotosBaseItem *item, GeglNode *node)
 {
-  PhotosEmbed *self = PHOTOS_EMBED (user_data);
   PhotosEmbedPrivate *priv = self->priv;
-  GError *error;
-  GeglNode *node;
   GtkListStore *model;
   GtkTreePath *current_path;
-  PhotosBaseItem *item = PHOTOS_BASE_ITEM (source_object);
   PhotosWindowMode mode;
 
   photos_embed_clear_load_timer (self);
-  g_clear_object (&priv->loader_cancellable);
-
-  error = NULL;
-  node = photos_base_item_load_finish (item, res, &error);
-  if (error != NULL)
-    {
-      g_warning ("Unable to load the item: %s", error->message);
-      g_error_free (error);
-      goto out;
-    }
+  if (node == NULL)
+    return;
 
   mode = photos_mode_controller_get_window_mode (priv->mode_cntrlr);
 
@@ -269,10 +256,6 @@ photos_embed_item_load (GObject *source_object, GAsyncResult *res, gpointer user
     photos_embed_prepare_for_preview (self);
 
   photos_mode_controller_set_can_fullscreen (priv->mode_cntrlr, TRUE);
-
- out:
-  g_clear_object (&node);
-  g_object_unref (self);
 }
 
 
@@ -291,6 +274,14 @@ photos_embed_load_show_timeout (gpointer user_data)
 
 
 static void
+photos_embed_load_started (PhotosEmbed *self)
+{
+  photos_embed_clear_load_timer (self);
+  self->priv->load_show_id = g_timeout_add (400, photos_embed_load_show_timeout, g_object_ref (self));
+}
+
+
+static void
 photos_embed_restore_search (PhotosEmbed *self)
 {
   PhotosEmbedPrivate *priv = self->priv;
@@ -352,22 +343,6 @@ photos_embed_active_changed (PhotosBaseManager *manager, GObject *object, gpoint
 
   state = g_variant_new ("b", show_search);
   g_action_change_state (priv->search_action, state);
-
-  if (object == NULL)
-    return;
-
-  photos_embed_clear_load_timer (self);
-
-  if (photos_base_item_is_collection (PHOTOS_BASE_ITEM (object)))
-    return;
-
-  priv->load_show_id = g_timeout_add (400, photos_embed_load_show_timeout, g_object_ref (self));
-
-  priv->loader_cancellable = g_cancellable_new ();
-  photos_base_item_load_async (PHOTOS_BASE_ITEM (object),
-                               priv->loader_cancellable,
-                               photos_embed_item_load,
-                               g_object_ref (self));
 }
 
 
@@ -453,13 +428,6 @@ photos_embed_prepare_for_collections (PhotosEmbed *self)
   PhotosEmbedPrivate *priv = self->priv;
 
   photos_base_manager_set_active_object (priv->item_mngr, NULL);
-
-  if (priv->loader_cancellable != NULL)
-    {
-      g_cancellable_cancel (priv->loader_cancellable);
-      g_clear_object (&priv->loader_cancellable);
-    }
-
   photos_spinner_box_stop (PHOTOS_SPINNER_BOX (priv->spinner_box));
   gtk_stack_set_visible_child_name (GTK_STACK (priv->stack), "collections");
 }
@@ -471,13 +439,6 @@ photos_embed_prepare_for_favorites (PhotosEmbed *self)
   PhotosEmbedPrivate *priv = self->priv;
 
   photos_base_manager_set_active_object (priv->item_mngr, NULL);
-
-  if (priv->loader_cancellable != NULL)
-    {
-      g_cancellable_cancel (priv->loader_cancellable);
-      g_clear_object (&priv->loader_cancellable);
-    }
-
   photos_spinner_box_stop (PHOTOS_SPINNER_BOX (priv->spinner_box));
   gtk_stack_set_visible_child_name (GTK_STACK (priv->stack), "favorites");
 }
@@ -489,13 +450,6 @@ photos_embed_prepare_for_overview (PhotosEmbed *self)
   PhotosEmbedPrivate *priv = self->priv;
 
   photos_base_manager_set_active_object (priv->item_mngr, NULL);
-
-  if (priv->loader_cancellable != NULL)
-    {
-      g_cancellable_cancel (priv->loader_cancellable);
-      g_clear_object (&priv->loader_cancellable);
-    }
-
   photos_spinner_box_stop (PHOTOS_SPINNER_BOX (priv->spinner_box));
   gtk_stack_set_visible_child_name (GTK_STACK (priv->stack), "overview");
 }
@@ -507,13 +461,6 @@ photos_embed_prepare_for_search (PhotosEmbed *self)
   PhotosEmbedPrivate *priv = self->priv;
 
   photos_base_manager_set_active_object (priv->item_mngr, NULL);
-
-  if (priv->loader_cancellable != NULL)
-    {
-      g_cancellable_cancel (priv->loader_cancellable);
-      g_clear_object (&priv->loader_cancellable);
-    }
-
   photos_spinner_box_stop (PHOTOS_SPINNER_BOX (priv->spinner_box));
   gtk_stack_set_visible_child_name (GTK_STACK (priv->stack), "search");
 }
@@ -647,7 +594,6 @@ photos_embed_dispose (GObject *object)
   photos_embed_clear_search (self);
 
   g_clear_object (&priv->ntfctn_mngr);
-  g_clear_object (&priv->loader_cancellable);
   g_clear_object (&priv->item_mngr);
   g_clear_object (&priv->src_mngr);
   g_clear_object (&priv->srch_mngr);
@@ -774,6 +720,8 @@ photos_embed_init (PhotosEmbed *self)
 
   priv->item_mngr = g_object_ref (state->item_mngr);
   g_signal_connect (priv->item_mngr, "active-changed", G_CALLBACK (photos_embed_active_changed), self);
+  g_signal_connect_swapped (priv->item_mngr, "load-finished", G_CALLBACK (photos_embed_load_finished), self);
+  g_signal_connect_swapped (priv->item_mngr, "load-started", G_CALLBACK (photos_embed_load_started), self);
 
   priv->src_mngr = g_object_ref (state->src_mngr);
   g_signal_connect_swapped (priv->src_mngr, "active-changed", G_CALLBACK (photos_embed_search_changed), 
self);
diff --git a/src/photos-item-manager.c b/src/photos-item-manager.c
index 967c174..a8f330e 100644
--- a/src/photos-item-manager.c
+++ b/src/photos-item-manager.c
@@ -25,6 +25,7 @@
 
 #include "config.h"
 
+#include <gio/gio.h>
 #include <glib.h>
 #include <tracker-sparql.h>
 
@@ -41,6 +42,7 @@
 
 struct _PhotosItemManagerPrivate
 {
+  GCancellable *loader_cancellable;
   GHashTable *collections;
   GIOExtensionPoint *extension_point;
   GQueue *collection_path;
@@ -51,6 +53,8 @@ struct _PhotosItemManagerPrivate
 enum
 {
   ACTIVE_COLLECTION_CHANGED,
+  LOAD_FINISHED,
+  LOAD_STARTED,
   LAST_SIGNAL
 };
 
@@ -171,6 +175,19 @@ photos_item_manager_changes_pending (PhotosItemManager *self, GHashTable *change
 
 
 static void
+photos_item_manager_clear_active_item_load (PhotosItemManager *self)
+{
+  PhotosItemManagerPrivate *priv = self->priv;
+
+  if (priv->loader_cancellable != NULL)
+    {
+      g_cancellable_cancel (priv->loader_cancellable);
+      g_clear_object (&priv->loader_cancellable);
+    }
+}
+
+
+static void
 photos_item_manager_collection_path_free_foreach (gpointer data, gpointer user_data)
 {
   g_clear_object (&data);
@@ -191,6 +208,33 @@ photos_item_manager_get_where (PhotosBaseManager *mngr, gint flags)
 
 
 static void
+photos_item_manager_item_load (GObject *source_object, GAsyncResult *res, gpointer user_data)
+{
+  PhotosItemManager *self = PHOTOS_ITEM_MANAGER (user_data);
+  PhotosItemManagerPrivate *priv = self->priv;
+  GError *error;
+  GeglNode *node = NULL;
+  PhotosBaseItem *item = PHOTOS_BASE_ITEM (source_object);
+
+  g_clear_object (&priv->loader_cancellable);
+
+  error = NULL;
+  node = photos_base_item_load_finish (item, res, &error);
+  if (error != NULL)
+    {
+      if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+        g_warning ("Unable to load the item: %s", error->message);
+      g_error_free (error);
+    }
+
+  g_signal_emit (self, signals[LOAD_FINISHED], 0, item, node);
+
+  g_clear_object (&node);
+  g_object_unref (self);
+}
+
+
+static void
 photos_item_manager_remove_object_by_id (PhotosBaseManager *mngr, const gchar *id)
 {
   PhotosItemManager *self = PHOTOS_ITEM_MANAGER (mngr);
@@ -237,6 +281,8 @@ photos_item_manager_set_active_object (PhotosBaseManager *manager, GObject *obje
         goto out;
     }
 
+  photos_item_manager_clear_active_item_load (self);
+
   /* This is when we are going back to the overview from the preview. */
   if (object == NULL)
     goto end;
@@ -273,6 +319,14 @@ photos_item_manager_set_active_object (PhotosBaseManager *manager, GObject *obje
       recent = gtk_recent_manager_get_default ();
       uri = photos_base_item_get_uri (PHOTOS_BASE_ITEM (object));
       gtk_recent_manager_add_item (recent, uri);
+
+      priv->loader_cancellable = g_cancellable_new ();
+      photos_base_item_load_async (PHOTOS_BASE_ITEM (object),
+                                   priv->loader_cancellable,
+                                   photos_item_manager_item_load,
+                                   g_object_ref (self));
+
+      g_signal_emit (self, signals[LOAD_STARTED], 0, PHOTOS_BASE_ITEM (object));
     }
 
  out:
@@ -294,6 +348,7 @@ photos_item_manager_dispose (GObject *object)
     }
 
   g_clear_pointer (&priv->collections, (GDestroyNotify) g_hash_table_unref);
+  g_clear_object (&priv->loader_cancellable);
   g_clear_object (&priv->active_collection);
   g_clear_object (&priv->monitor);
 
@@ -345,6 +400,31 @@ photos_item_manager_class_init (PhotosItemManagerClass *class)
                                                      G_TYPE_NONE,
                                                      1,
                                                      PHOTOS_TYPE_BASE_ITEM);
+
+  signals[LOAD_FINISHED] = g_signal_new ("load-finished",
+                                         G_TYPE_FROM_CLASS (class),
+                                         G_SIGNAL_RUN_LAST,
+                                         G_STRUCT_OFFSET (PhotosItemManagerClass,
+                                                          load_finished),
+                                         NULL, /*accumulator */
+                                         NULL, /*accu_data */
+                                         g_cclosure_marshal_generic,
+                                         G_TYPE_NONE,
+                                         2,
+                                         PHOTOS_TYPE_BASE_ITEM,
+                                         GEGL_TYPE_NODE);
+
+  signals[LOAD_STARTED] = g_signal_new ("load-started",
+                                        G_TYPE_FROM_CLASS (class),
+                                        G_SIGNAL_RUN_LAST,
+                                        G_STRUCT_OFFSET (PhotosItemManagerClass,
+                                                         load_started),
+                                        NULL, /*accumulator */
+                                        NULL, /*accu_data */
+                                        g_cclosure_marshal_VOID__OBJECT,
+                                        G_TYPE_NONE,
+                                        1,
+                                        PHOTOS_TYPE_BASE_ITEM);
 }
 
 
@@ -361,6 +441,8 @@ photos_item_manager_activate_previous_collection (PhotosItemManager *self)
   PhotosItemManagerPrivate *priv = self->priv;
   gpointer *collection;
 
+  photos_item_manager_clear_active_item_load (self);
+
   collection = g_queue_pop_head (priv->collection_path);
   g_assert (collection == NULL || PHOTOS_IS_BASE_ITEM (collection));
 
diff --git a/src/photos-item-manager.h b/src/photos-item-manager.h
index d176c51..43f6155 100644
--- a/src/photos-item-manager.h
+++ b/src/photos-item-manager.h
@@ -25,6 +25,7 @@
 #ifndef PHOTOS_ITEM_MANAGER_H
 #define PHOTOS_ITEM_MANAGER_H
 
+#include <gegl.h>
 #include <gtk/gtk.h>
 #include <tracker-sparql.h>
 
@@ -71,6 +72,8 @@ struct _PhotosItemManagerClass
 
   /* signals */
   void (*active_collection_changed) (PhotosItemManager *self, PhotosBaseItem *collection);
+  void (*load_finished)             (PhotosItemManager *self, PhotosBaseItem *item, GeglNode *node);
+  void (*load_started)              (PhotosItemManager *self, PhotosBaseItem *item);
 };
 
 GType                     photos_item_manager_get_type           (void) G_GNUC_CONST;