[easytag/easytag-2-2] Fix delays when clearing the CDDB models

[David King <davidk src gnome org>]

commit 930158e964b57e123fedb8fe37fc8a1f4eb56250
Author: David King <amigadave amigadave com>
Date:   Wed Jul 30 14:41:49 2014 +0200

    Fix delays when clearing the CDDB models
    
    Avoid accessing deleted rows in the tree view selection changed
    handlers, by blocking the handlers when clearing the models. Otherwise,
    each release in the list of search results being deleted would be
    fetched from the server and then immediately discarded.

 src/cddb.c |   82 +++++++++++++++++++++++++++++++++++++++++++++++++-----------
 1 files changed, 67 insertions(+), 15 deletions(-)
---
diff --git a/src/cddb.c b/src/cddb.c
index e90daa7..3751250 100644
--- a/src/cddb.c
+++ b/src/cddb.c
@@ -2026,7 +2026,55 @@ Cddb_Free_Track_Album_List (GList *track_list)
     return TRUE;
 }
 
+/*
+ * Clear the album model, blocking the tree view selection changed handlers
+ * during the process, to prevent the handlers being called on removed rows.
+ */
+static void
+cddb_album_model_clear (void)
+{
+    GtkTreeSelection *selection;
+
+    selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (CddbAlbumListView));
+
+    g_signal_handlers_block_by_func (selection,
+                                     G_CALLBACK (Cddb_Get_Album_Tracks_List_CB),
+                                     NULL);
+    g_signal_handlers_block_by_func (selection,
+                                     G_CALLBACK (Cddb_Show_Album_Info),
+                                     NULL);
+
+    gtk_list_store_clear (CddbAlbumListModel);
+
+    g_signal_handlers_unblock_by_func (selection,
+                                       G_CALLBACK (Cddb_Show_Album_Info),
+                                       NULL);
+    g_signal_handlers_unblock_by_func (selection,
+                                       G_CALLBACK (Cddb_Get_Album_Tracks_List_CB),
+                                       NULL);
+}
+
+/*
+ * Clear the album model, blocking the tree view selection changed handlers
+ * during the process, to prevent the handlers being called on removed rows.
+ */
+static void
+cddb_track_model_clear (void)
+{
+    GtkTreeSelection *selection;
+
+    selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (CddbTrackListView));
+
+    g_signal_handlers_block_by_func (selection,
+                                     G_CALLBACK (Cddb_Track_List_Row_Selected),
+                                     NULL);
 
+    gtk_list_store_clear (CddbTrackListModel);
+
+    g_signal_handlers_unblock_by_func (selection,
+                                       G_CALLBACK (Cddb_Track_List_Row_Selected),
+                                       NULL);
+}
 
 /*
  * Load the CddbAlbumList into the corresponding List
@@ -2054,8 +2102,8 @@ Cddb_Load_Album_List (gboolean only_red_lines)
                                    CDDB_ALBUM_LIST_DATA, &cddbalbumSelected, -1);
         }
 
-        // Remove lines
-        gtk_list_store_clear(CddbAlbumListModel);
+        /* Remove lines. */
+        cddb_album_model_clear ();
 
         // Reload list following parameter 'only_red_lines'
         for (l = g_list_first (CddbAlbumList); l != NULL; l = g_list_next (l))
@@ -2097,8 +2145,8 @@ Cddb_Load_Track_Album_List (GList *track_list)
     {
         GList *l;
 
-        // Must block the select signal of the target to avoid looping
-        gtk_list_store_clear(CddbTrackListModel);
+        /* Must block the select signal of the target to avoid looping. */
+        cddb_track_model_clear ();
 
         for (l = g_list_first (track_list); l != NULL; l = g_list_next (l))
         {
@@ -2326,9 +2374,10 @@ Cddb_Search_Album_List_From_String_Freedb (void)
     g_free(cddb_in);
 
 
-    // Delete previous album list
-    gtk_list_store_clear(CddbAlbumListModel);
-    gtk_list_store_clear(CddbTrackListModel);
+    /* Delete previous album list. */
+    cddb_album_model_clear ();
+    cddb_track_model_clear ();
+
     if (CddbAlbumList)
     {
         Cddb_Free_Album_List();
@@ -2586,9 +2635,10 @@ Cddb_Search_Album_List_From_String_Gnudb (void)
         *tmp = '+';
 
 
-    // Delete previous album list
-    gtk_list_store_clear(CddbAlbumListModel);
-    gtk_list_store_clear(CddbTrackListModel);
+    /* Delete previous album list. */
+    cddb_album_model_clear ();
+    cddb_track_model_clear ();
+
     if (CddbAlbumList)
     {
         Cddb_Free_Album_List();
@@ -3012,9 +3062,10 @@ Cddb_Search_Album_From_Selected_Files (void)
                                          (disc_length << 8) | num_tracks));
 
 
-    // Delete previous album list
-    gtk_list_store_clear(CddbAlbumListModel);
-    gtk_list_store_clear(CddbTrackListModel);
+    /* Delete previous album list. */
+    cddb_album_model_clear ();
+    cddb_track_model_clear ();
+
     if (CddbAlbumList)
     {
         Cddb_Free_Album_List();
@@ -3431,8 +3482,9 @@ Cddb_Get_Album_Tracks_List (GtkTreeSelection* selection)
 
     g_return_val_if_fail (CddbWindow != NULL, FALSE);
 
-    gtk_list_store_clear(CddbTrackListModel);
-    Cddb_Set_Apply_Button_Sensitivity();
+    cddb_track_model_clear ();
+    Cddb_Set_Apply_Button_Sensitivity ();
+
     if (gtk_tree_selection_get_selected(selection, NULL, &row))
     {
         gtk_tree_model_get(GTK_TREE_MODEL(CddbAlbumListModel), &row, CDDB_ALBUM_LIST_DATA, &cddbalbum, -1);