[nautilus/wip/antoniof/new-list-view-continuation: 6/19] view-model: Expose row objects to the view

[António Fernandes <antoniof src gnome org>]

commit c45f95d0ea04c561e353541e4bdc102e531a4d80
Author: António Fernandes <antoniof gnome org>
Date:   Wed Apr 6 01:22:53 2022 +0100

    view-model: Expose row objects to the view
    
    This is going to allow us to reuse the model for a GtkColumnView-based
    list view with expanding trees support.
    
    As documented, GtkTreeViewRow:item may be NULL when the item it held
    is destroyed. So, we must take care to handle the NULL case when
    expected and also warn and return when not expected.

 src/nautilus-view-icon-controller.c | 51 +++++++++++++++++++++++++++----------
 src/nautilus-view-model.c           |  6 ++---
 2 files changed, 39 insertions(+), 18 deletions(-)
---
diff --git a/src/nautilus-view-icon-controller.c b/src/nautilus-view-icon-controller.c
index 5b2996454..ea85a225b 100644
--- a/src/nautilus-view-icon-controller.c
+++ b/src/nautilus-view-icon-controller.c
@@ -39,6 +39,25 @@ struct _NautilusViewIconController
 
 G_DEFINE_TYPE (NautilusViewIconController, nautilus_view_icon_controller, NAUTILUS_TYPE_FILES_VIEW)
 
+static inline NautilusViewItemModel *
+model_get_item (GListModel *model,
+                guint       position)
+{
+    g_autoptr (GtkTreeListRow) row = g_list_model_get_item (model, position);
+
+    g_return_val_if_fail (GTK_IS_TREE_LIST_ROW (row), NULL);
+    return NAUTILUS_VIEW_ITEM_MODEL (gtk_tree_list_row_get_item (GTK_TREE_LIST_ROW (row)));
+}
+
+static inline NautilusViewItemModel *
+listitem_get_item (GtkListItem *listitem)
+{
+    GtkTreeListRow *row = gtk_list_item_get_item (listitem);
+
+    g_return_val_if_fail (GTK_IS_TREE_LIST_ROW (row), NULL);
+    return NAUTILUS_VIEW_ITEM_MODEL (gtk_tree_list_row_get_item (GTK_TREE_LIST_ROW (row)));
+}
+
 typedef struct
 {
     const NautilusFileSortType sort_type;
@@ -312,7 +331,7 @@ real_get_selection (NautilusFilesView *files_view)
     {
         g_autoptr (NautilusViewItemModel) item_model = NULL;
 
-        item_model = g_list_model_get_item (G_LIST_MODEL (selection), i);
+        item_model = model_get_item (G_LIST_MODEL (selection), i);
         selected_files = g_list_prepend (selected_files,
                                          g_object_ref (nautilus_view_item_model_get_file (item_model)));
     }
@@ -619,7 +638,7 @@ set_icon_size (NautilusViewIconController *self,
     {
         g_autoptr (NautilusViewItemModel) current_item_model = NULL;
 
-        current_item_model = g_list_model_get_item (G_LIST_MODEL (self->model), i);
+        current_item_model = model_get_item (G_LIST_MODEL (self->model), i);
         nautilus_view_item_model_set_icon_size (current_item_model,
                                                 get_icon_size_for_zoom_level (self->zoom_level));
     }
@@ -710,8 +729,7 @@ real_compute_rename_popover_pointing_to (NautilusFilesView *files_view)
     GtkWidget *item_ui;
 
     /* We only allow one item to be renamed with a popover */
-    item = g_list_model_get_item (G_LIST_MODEL (self->model),
-                                  get_first_selected_item (self));
+    item = model_get_item (G_LIST_MODEL (self->model), get_first_selected_item (self));
     item_ui = nautilus_view_item_model_get_item_ui (item);
     g_return_val_if_fail (item_ui != NULL, NULL);
 
@@ -739,7 +757,7 @@ real_reveal_for_selection_context_menu (NautilusFilesView *files_view)
     {
         g_autoptr (NautilusViewItemModel) item = NULL;
 
-        item = g_list_model_get_item (G_LIST_MODEL (selection), i);
+        item = model_get_item (G_LIST_MODEL (selection), i);
         item_ui = nautilus_view_item_model_get_item_ui (item);
         if (item_ui != NULL && gtk_widget_get_parent (item_ui) == focus_child)
         {
@@ -1031,7 +1049,7 @@ get_first_visible_item (NautilusViewIconController *self)
         g_autoptr (NautilusViewItemModel) item = NULL;
         GtkWidget *item_ui;
 
-        item = g_list_model_get_item (G_LIST_MODEL (self->model), i);
+        item = model_get_item (G_LIST_MODEL (self->model), i);
         item_ui = nautilus_view_item_model_get_item_ui (item);
         if (item_ui != NULL)
         {
@@ -1060,7 +1078,7 @@ real_get_first_visible_file (NautilusFilesView *files_view)
     i = get_first_visible_item (self);
     if (i < G_MAXUINT)
     {
-        item = g_list_model_get_item (G_LIST_MODEL (self->model), i);
+        item = model_get_item (G_LIST_MODEL (self->model), i);
         uri = nautilus_file_get_uri (nautilus_view_item_model_get_file (item));
     }
     return uri;
@@ -1213,7 +1231,7 @@ real_select_first (NautilusFilesView *files_view)
     NautilusFile *file;
     g_autoptr (GList) selection = NULL;
 
-    item = NAUTILUS_VIEW_ITEM_MODEL (g_list_model_get_item (G_LIST_MODEL (self->model), 0));
+    item = model_get_item (G_LIST_MODEL (self->model), 0);
     if (item == NULL)
     {
         return;
@@ -1324,7 +1342,7 @@ prioritize_thumbnailing_on_idle (NautilusViewIconController *self)
         return G_SOURCE_REMOVE;
     }
 
-    first_item = g_list_model_get_item (G_LIST_MODEL (self->model), first_index);
+    first_item = model_get_item (G_LIST_MODEL (self->model), first_index);
 
     first_visible_child = nautilus_view_item_model_get_item_ui (first_item);
 
@@ -1332,7 +1350,7 @@ prioritize_thumbnailing_on_idle (NautilusViewIconController *self)
     {
         g_autoptr (NautilusViewItemModel) next_item = NULL;
 
-        next_item = g_list_model_get_item (G_LIST_MODEL (self->model), next_index);
+        next_item = model_get_item (G_LIST_MODEL (self->model), next_index);
         next_child = nautilus_view_item_model_get_item_ui (next_item);
         if (next_child == NULL)
         {
@@ -1354,7 +1372,7 @@ prioritize_thumbnailing_on_idle (NautilusViewIconController *self)
     {
         g_autoptr (NautilusViewItemModel) item = NULL;
 
-        item = g_list_model_get_item (G_LIST_MODEL (self->model), last_index - i);
+        item = model_get_item (G_LIST_MODEL (self->model), last_index - i);
         g_return_val_if_fail (item != NULL, G_SOURCE_REMOVE);
 
         file = nautilus_view_item_model_get_file (NAUTILUS_VIEW_ITEM_MODEL (item));
@@ -1392,7 +1410,8 @@ bind_item_ui (GtkSignalListItemFactory *factory,
     NautilusViewItemModel *item_model;
 
     item_ui = gtk_list_item_get_child (listitem);
-    item_model = NAUTILUS_VIEW_ITEM_MODEL (gtk_list_item_get_item (listitem));
+    item_model = listitem_get_item (listitem);
+    g_return_if_fail (item_model != NULL);
 
     nautilus_view_icon_item_ui_set_model (NAUTILUS_VIEW_ICON_ITEM_UI (item_ui),
                                           item_model);
@@ -1424,10 +1443,14 @@ unbind_item_ui (GtkSignalListItemFactory *factory,
     NautilusViewItemModel *item_model;
 
     item_ui = NAUTILUS_VIEW_ICON_ITEM_UI (gtk_list_item_get_child (listitem));
-    item_model = NAUTILUS_VIEW_ITEM_MODEL (gtk_list_item_get_item (listitem));
+    item_model = listitem_get_item (listitem);
 
     nautilus_view_icon_item_ui_set_model (item_ui, NULL);
-    nautilus_view_item_model_set_item_ui (item_model, NULL);
+    /* item may be NULL when row has just been destroyed. */
+    if (item_model != NULL)
+    {
+        nautilus_view_item_model_set_item_ui (item_model, NULL);
+    }
 }
 
 static void
diff --git a/src/nautilus-view-model.c b/src/nautilus-view-model.c
index 731008b7b..cc7afa9b0 100644
--- a/src/nautilus-view-model.c
+++ b/src/nautilus-view-model.c
@@ -49,7 +49,7 @@ get_child_row (NautilusViewModel *self,
 static GType
 nautilus_view_model_get_item_type (GListModel *list)
 {
-    return NAUTILUS_TYPE_VIEW_ITEM_MODEL;
+    return GTK_TYPE_TREE_LIST_ROW;
 }
 
 static guint
@@ -70,15 +70,13 @@ nautilus_view_model_get_item (GListModel *list,
                               guint       position)
 {
     NautilusViewModel *self = NAUTILUS_VIEW_MODEL (list);
-    g_autoptr (GtkTreeListRow) row = NULL;
 
     if (self->sort_model == NULL)
     {
         return NULL;
     }
 
-    row = g_list_model_get_item (G_LIST_MODEL (self->sort_model), position);
-    return gtk_tree_list_row_get_item (row);
+    return g_list_model_get_item (G_LIST_MODEL (self->sort_model), position);
 }
 
 static void