[nautilus/wip/antoniof/new-list-view-continuation: 5/20] view-model: Use GSortListModel internally

[António Fernandes <antoniof src gnome org>]

commit 3627e13554910a7f2cc4f97863d31b11f2d65eea
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 | 89 ++++++++++++++++++++---------------------------
 src/nautilus-view-model.h |  1 +
 2 files changed, 39 insertions(+), 51 deletions(-)
---
diff --git a/src/nautilus-view-model.c b/src/nautilus-view-model.c
index 54fa70972..22794998c 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_handler_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
@@ -135,16 +134,15 @@ 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_handler_id, self->sorter);
 
     G_OBJECT_CLASS (nautilus_view_model_parent_class)->dispose (object);
 }
@@ -157,7 +155,6 @@ 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
@@ -172,7 +169,7 @@ get_property (GObject    *object,
     {
         case PROP_SORTER:
         {
-            g_value_set_object (value, self->sorter);
+            g_value_set_object (value, gtk_sort_list_model_get_sorter (self->sort_model));
         }
         break;
 
@@ -214,10 +211,11 @@ constructed (GObject *object)
     G_OBJECT_CLASS (nautilus_view_model_parent_class)->constructed (object);
 
     self->internal_model = g_list_store_new (NAUTILUS_TYPE_VIEW_ITEM_MODEL);
-    self->selection_model = gtk_multi_selection_new (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);
@@ -247,28 +245,6 @@ 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 ()
 {
@@ -279,14 +255,15 @@ void
 nautilus_view_model_set_sorter (NautilusViewModel *self,
                                 GtkSorter         *sorter)
 {
-    g_clear_signal_handler (&self->sorter_changed_handler_id, self->sorter);
-    g_set_object (&self->sorter, sorter);
-    self->sorter_changed_handler_id = g_signal_connect (self->sorter,
-                                                        "changed",
-                                                        G_CALLBACK (on_sorter_changed),
-                                                        self);
-
-    g_list_store_sort (self->internal_model, compare_data_func, self);
+    gtk_sort_list_model_set_sorter (self->sort_model, sorter);
+}
+
+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 *
@@ -363,7 +340,7 @@ nautilus_view_model_add_item (NautilusViewModel     *self,
     g_hash_table_insert (self->map_files_to_model,
                          nautilus_view_item_model_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
@@ -389,19 +366,29 @@ 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,
                                NautilusViewItemModel *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 (NautilusViewItemModel) item_i = NULL;
+
+        item_i = NAUTILUS_VIEW_ITEM_MODEL (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 1771cd6e2..2c294eff0 100644
--- a/src/nautilus-view-model.h
+++ b/src/nautilus-view-model.h
@@ -14,6 +14,7 @@ NautilusViewModel * nautilus_view_model_new (void);
 
 void nautilus_view_model_set_sorter (NautilusViewModel *self,
                                      GtkSorter         *sorter);
+void nautilus_view_model_sort (NautilusViewModel *self);
 NautilusViewItemModel * nautilus_view_model_get_item_from_file (NautilusViewModel *self,
                                                                 NautilusFile      *file);
 GQueue * nautilus_view_model_get_items_from_files (NautilusViewModel *self,