[nautilus/wip/antoniof/new-list-view-continuation: 7/13] view-model: Use GSortListModel internally

[António Fernandes <antoniof src gnome org>]

commit 4281a41fc74c03cd488e89a068c60af448f2d72f
Author: António Fernandes <antoniof gnome org>
Date:   Wed Apr 6 00:56:57 2022 +0100

    view-model: Use GSortListModel internally
    
    This is a required step in order to use GtkTreeListModel later.
    
    GtkTreeListModel doesn't work well when its internal models get
    resorted: it assumes the items are gone, not reordered, causing
    the row objects to get destroyed and the view to lose track of
    things.
    
    This might not be as efficient, but we've got no other option
    other than implementing a custom tree list model...

 src/nautilus-view-model.c | 90 ++++++++++++++++++++---------------------------
 src/nautilus-view-model.h |  3 +-
 2 files changed, 41 insertions(+), 52 deletions(-)
---
diff --git a/src/nautilus-view-model.c b/src/nautilus-view-model.c
index 72fd8a79e..adff16658 100644
--- a/src/nautilus-view-model.c
+++ b/src/nautilus-view-model.c
@@ -8,9 +8,8 @@ struct _NautilusViewModel
 
     GHashTable *map_files_to_model;
     GListStore *internal_model;
+    GtkSortListModel *sort_model;
     GtkMultiSelection *selection_model;
-    GtkSorter *sorter;
-    gulong sorter_changed_id;
 };
 
 static GType
@@ -38,12 +37,12 @@ nautilus_view_model_get_item (GListModel *list,
 {
     NautilusViewModel *self = NAUTILUS_VIEW_MODEL (list);
 
-    if (self->internal_model == NULL)
+    if (self->sort_model == NULL)
     {
         return NULL;
     }
 
-    return g_list_model_get_item (G_LIST_MODEL (self->internal_model), position);
+    return g_list_model_get_item (G_LIST_MODEL (self->sort_model), position);
 }
 
 static void
@@ -137,16 +136,16 @@ dispose (GObject *object)
         self->selection_model = NULL;
     }
 
-    if (self->internal_model != NULL)
+    if (self->sort_model != NULL)
     {
-        g_signal_handlers_disconnect_by_func (self->internal_model,
+        g_signal_handlers_disconnect_by_func (self->sort_model,
                                               g_list_model_items_changed,
                                               self);
-        g_object_unref (self->internal_model);
-        self->internal_model = NULL;
+        g_object_unref (self->sort_model);
+        self->sort_model = NULL;
     }
 
-    g_clear_signal_handler (&self->sorter_changed_id, self->sorter);
+    g_clear_object (&self->internal_model);
 
     G_OBJECT_CLASS (nautilus_view_model_parent_class)->dispose (object);
 }
@@ -159,7 +158,6 @@ finalize (GObject *object)
     G_OBJECT_CLASS (nautilus_view_model_parent_class)->finalize (object);
 
     g_hash_table_destroy (self->map_files_to_model);
-    g_clear_object (&self->sorter);
 }
 
 static void
@@ -216,10 +214,11 @@ constructed (GObject *object)
     G_OBJECT_CLASS (nautilus_view_model_parent_class)->constructed (object);
 
     self->internal_model = g_list_store_new (NAUTILUS_TYPE_VIEW_ITEM);
-    self->selection_model = gtk_multi_selection_new (g_object_ref (G_LIST_MODEL (self->internal_model)));
+    self->sort_model = gtk_sort_list_model_new (g_object_ref (G_LIST_MODEL (self->internal_model)), NULL);
+    self->selection_model = gtk_multi_selection_new (g_object_ref (G_LIST_MODEL (self->sort_model)));
     self->map_files_to_model = g_hash_table_new (NULL, NULL);
 
-    g_signal_connect_swapped (self->internal_model, "items-changed",
+    g_signal_connect_swapped (self->sort_model, "items-changed",
                               G_CALLBACK (g_list_model_items_changed), self);
     g_signal_connect_swapped (self->selection_model, "selection-changed",
                               G_CALLBACK (gtk_selection_model_selection_changed), self);
@@ -250,28 +249,6 @@ nautilus_view_model_init (NautilusViewModel *self)
 {
 }
 
-static gint
-compare_data_func (gconstpointer a,
-                   gconstpointer b,
-                   gpointer      user_data)
-{
-    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (user_data);
-
-    g_return_val_if_fail (self->sorter != NULL, GTK_ORDERING_EQUAL);
-
-    return gtk_sorter_compare (self->sorter, (gpointer) a, (gpointer) b);
-}
-
-static void
-on_sorter_changed (GtkSorter       *sorter,
-                   GtkSorterChange  change,
-                   gpointer         user_data)
-{
-    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (user_data);
-
-    g_list_store_sort (self->internal_model, compare_data_func, self);
-}
-
 NautilusViewModel *
 nautilus_view_model_new ()
 {
@@ -281,23 +258,24 @@ nautilus_view_model_new ()
 GtkSorter *
 nautilus_view_model_get_sorter (NautilusViewModel *self)
 {
-    return self->sorter;
+    return gtk_sort_list_model_get_sorter (self->sort_model);
 }
 
 void
 nautilus_view_model_set_sorter (NautilusViewModel *self,
                                 GtkSorter         *sorter)
 {
-    if (g_set_object (&self->sorter, sorter))
-    {
-        g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SORTER]);
+    gtk_sort_list_model_set_sorter (self->sort_model, sorter);
 
-        g_clear_signal_handler (&self->sorter_changed_id, self->sorter);
-        self->sorter_changed_id = g_signal_connect (self->sorter, "changed",
-                                                    G_CALLBACK (on_sorter_changed), self);
-    }
+    g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SORTER]);
+}
 
-    g_list_store_sort (self->internal_model, compare_data_func, self);
+void
+nautilus_view_model_sort (NautilusViewModel *self)
+{
+    /* Hack: Reset the sorter to trigger ressorting. */
+    gtk_sort_list_model_set_sorter (self->sort_model,
+                                    gtk_sort_list_model_get_sorter (self->sort_model));
 }
 
 GQueue *
@@ -374,7 +352,7 @@ nautilus_view_model_add_item (NautilusViewModel *self,
     g_hash_table_insert (self->map_files_to_model,
                          nautilus_view_item_get_file (item),
                          item);
-    g_list_store_insert_sorted (self->internal_model, item, compare_data_func, self);
+    g_list_store_append (self->internal_model, item);
 }
 
 void
@@ -400,19 +378,29 @@ nautilus_view_model_add_items (NautilusViewModel *self,
     g_list_store_splice (self->internal_model,
                          g_list_model_get_n_items (G_LIST_MODEL (self->internal_model)),
                          0, array, g_queue_get_length (items));
-
-    g_list_store_sort (self->internal_model, compare_data_func, self);
 }
 
 guint
 nautilus_view_model_get_index (NautilusViewModel *self,
                                NautilusViewItem  *item)
 {
-    guint i = G_MAXUINT;
-    gboolean found;
+    guint n_items;
+    guint i = 0;
+
+    n_items = g_list_model_get_n_items (G_LIST_MODEL (self->sort_model));
+    while (i < n_items)
+    {
+        g_autoptr (NautilusViewItem) item_i = NULL;
+
+        item_i = NAUTILUS_VIEW_ITEM (g_list_model_get_item (G_LIST_MODEL (self->sort_model), i));
+        g_warn_if_fail (item_i != NULL);
 
-    found = g_list_store_find (self->internal_model, item, &i);
-    g_warn_if_fail (found);
+        if (item_i == item)
+        {
+            return i;
+        }
+        i++;
+    }
 
-    return i;
+    return G_MAXUINT;
 }
diff --git a/src/nautilus-view-model.h b/src/nautilus-view-model.h
index 839c6d2c7..00d857b2e 100644
--- a/src/nautilus-view-model.h
+++ b/src/nautilus-view-model.h
@@ -15,8 +15,9 @@ NautilusViewModel * nautilus_view_model_new (void);
 GtkSorter *nautilus_view_model_get_sorter (NautilusViewModel *self);
 void nautilus_view_model_set_sorter (NautilusViewModel *self,
                                      GtkSorter         *sorter);
+void nautilus_view_model_sort (NautilusViewModel *self);
 NautilusViewItem * nautilus_view_model_get_item_from_file (NautilusViewModel *self,
-                                                                NautilusFile      *file);
+                                                           NautilusFile      *file);
 GQueue * nautilus_view_model_get_items_from_files (NautilusViewModel *self,
                                                    GQueue            *files);
 /* Don't use inside a loop, use nautilus_view_model_remove_all_items instead. */