[empathy] Allow cancellation of avatar load operations

[Philip Withnall <pwithnall src gnome org>]

commit 015070caec0ec80ac53127c619bde516081670e6
Author: Philip Withnall <philip withnall collabora co uk>
Date:   Wed Aug 18 18:13:02 2010 +0100

    Allow cancellation of avatar load operations
    
    Automatically cancel all pending avatar load operations when disposing of
    an EmpathyIndividualStore. This prevents crashes when linking individuals in
    the case that the EmpathyIndividualStore in the linking dialogue gets
    notified of the new linked individual just before it's destroyed.

 libempathy-gtk/empathy-individual-store.c |   57 ++++++++++++++++++++++++-----
 libempathy-gtk/empathy-ui-utils.c         |    7 ++--
 libempathy-gtk/empathy-ui-utils.h         |    3 +-
 3 files changed, 54 insertions(+), 13 deletions(-)
---
diff --git a/libempathy-gtk/empathy-individual-store.c b/libempathy-gtk/empathy-individual-store.c
index 1617872..26b5695 100644
--- a/libempathy-gtk/empathy-individual-store.c
+++ b/libempathy-gtk/empathy-individual-store.c
@@ -71,6 +71,8 @@ typedef struct
   guint setup_idle_id;
   gboolean dispose_has_run;
   GHashTable *status_icons;
+  /* List of owned GCancellables for each pending avatar load operation */
+  GList *avatar_cancellables;
 } EmpathyIndividualStorePriv;
 
 typedef struct
@@ -552,13 +554,16 @@ individual_store_contact_active_cb (ShowActiveData *data)
   return FALSE;
 }
 
+typedef struct {
+  EmpathyIndividualStore *store; /* weak */
+  GCancellable *cancellable; /* owned */
+} LoadAvatarData;
+
 static void
-individual_avatar_pixbuf_received_cb (GObject *object,
+individual_avatar_pixbuf_received_cb (FolksIndividual *individual,
     GAsyncResult *result,
-    gpointer user_data)
+    LoadAvatarData *data)
 {
-  FolksIndividual *individual = FOLKS_INDIVIDUAL (object);
-  EmpathyIndividualStore *self = user_data;
   GError *error = NULL;
   GdkPixbuf *pixbuf;
 
@@ -572,18 +577,32 @@ individual_avatar_pixbuf_received_cb (GObject *object,
           error->message);
       g_clear_error (&error);
     }
-  else
+  else if (data->store != NULL)
     {
       GList *iters, *l;
 
-      iters = individual_store_find_contact (self, individual);
+      iters = individual_store_find_contact (data->store, individual);
       for (l = iters; l; l = l->next)
         {
-          gtk_tree_store_set (GTK_TREE_STORE (self), l->data,
+          gtk_tree_store_set (GTK_TREE_STORE (data->store), l->data,
               EMPATHY_INDIVIDUAL_STORE_COL_PIXBUF_AVATAR, pixbuf,
               -1);
         }
     }
+
+  /* Free things */
+  if (data->store != NULL)
+    {
+      EmpathyIndividualStorePriv *priv = GET_PRIV (data->store);
+
+      g_object_remove_weak_pointer (G_OBJECT (data->store),
+          (gpointer *) &data->store);
+      priv->avatar_cancellables = g_list_remove (priv->avatar_cancellables,
+          data->cancellable);
+    }
+
+  g_object_unref (data->cancellable);
+  g_slice_free (LoadAvatarData, data);
 }
 
 static void
@@ -604,6 +623,7 @@ individual_store_contact_update (EmpathyIndividualStore *self,
   gboolean do_set_refresh = FALSE;
   gboolean show_avatar = FALSE;
   GdkPixbuf *pixbuf_status;
+  LoadAvatarData *load_avatar_data;
 
   priv = GET_PRIV (self);
 
@@ -678,8 +698,19 @@ individual_store_contact_update (EmpathyIndividualStore *self,
       show_avatar = TRUE;
     }
 
-  empathy_pixbuf_avatar_from_individual_scaled_async (individual,
-      individual_avatar_pixbuf_received_cb, 32, 32, self);
+  /* Load the avatar asynchronously */
+  load_avatar_data = g_slice_new (LoadAvatarData);
+  load_avatar_data->store = self;
+  g_object_add_weak_pointer (G_OBJECT (self),
+      (gpointer *) &load_avatar_data->store);
+  load_avatar_data->cancellable = g_cancellable_new ();
+
+  priv->avatar_cancellables = g_list_prepend (priv->avatar_cancellables,
+      load_avatar_data->cancellable);
+  empathy_pixbuf_avatar_from_individual_scaled_async (individual, 32, 32,
+      load_avatar_data->cancellable,
+      (GAsyncReadyCallback) individual_avatar_pixbuf_received_cb,
+      load_avatar_data);
 
   pixbuf_status =
       empathy_individual_store_get_individual_status_icon (self, individual);
@@ -957,6 +988,14 @@ individual_store_dispose (GObject *object)
     return;
   priv->dispose_has_run = TRUE;
 
+  /* Cancel any pending avatar load operations */
+  for (l = priv->avatar_cancellables; l != NULL; l = l->next)
+    {
+      /* The cancellables are freed in individual_avatar_pixbuf_received_cb() */
+      g_cancellable_cancel (G_CANCELLABLE (l->data));
+    }
+  g_list_free (priv->avatar_cancellables);
+
   contacts = empathy_individual_manager_get_members (priv->manager);
   for (l = contacts; l; l = l->next)
     {
diff --git a/libempathy-gtk/empathy-ui-utils.c b/libempathy-gtk/empathy-ui-utils.c
index 46a26d8..0a2d4f4 100644
--- a/libempathy-gtk/empathy-ui-utils.c
+++ b/libempathy-gtk/empathy-ui-utils.c
@@ -564,7 +564,7 @@ avatar_file_load_contents_cb (GObject      *object,
 {
 	GFile *file = G_FILE (object);
 	PixbufAvatarFromIndividualClosure *closure = user_data;
-	char *data;
+	char *data = NULL;
 	gsize data_size;
 	struct SizeData size_data;
 	GError *error = NULL;
@@ -617,9 +617,10 @@ out:
 void
 empathy_pixbuf_avatar_from_individual_scaled_async (
 		FolksIndividual     *individual,
-		GAsyncReadyCallback  callback,
 		gint                 width,
 		gint                 height,
+		GCancellable        *cancellable,
+		GAsyncReadyCallback  callback,
 		gpointer             user_data)
 {
 	GFile *avatar_file;
@@ -639,7 +640,7 @@ empathy_pixbuf_avatar_from_individual_scaled_async (
 	if (closure == NULL)
 		goto out;
 
-	g_file_load_contents_async (avatar_file, NULL,
+	g_file_load_contents_async (avatar_file, cancellable,
 			avatar_file_load_contents_cb, closure);
 
 	g_object_unref (result);
diff --git a/libempathy-gtk/empathy-ui-utils.h b/libempathy-gtk/empathy-ui-utils.h
index 9c3ec65..0b76d09 100644
--- a/libempathy-gtk/empathy-ui-utils.h
+++ b/libempathy-gtk/empathy-ui-utils.h
@@ -77,9 +77,10 @@ GdkPixbuf *   empathy_pixbuf_from_data_and_mime         (gchar            *data,
 							 gsize             data_size,
 							 gchar           **mime_type);
 void empathy_pixbuf_avatar_from_individual_scaled_async (FolksIndividual     *individual,
-							 GAsyncReadyCallback  callback,
 							 gint                 width,
 							 gint                 height,
+							 GCancellable        *cancellable,
+							 GAsyncReadyCallback  callback,
 							 gpointer             user_data);
 GdkPixbuf * empathy_pixbuf_avatar_from_individual_scaled_finish (
 							 FolksIndividual  *individual,