[nautilus] window-slot: Instantly apply "Use new views" preference

[Carlos Soriano <csoriano src gnome org>]

commit 9818abb350bb774714788c1a335b4c6f563af0ac
Author: Alexandru Fazakas <alex fazakas97 gmail com>
Date:   Sun Mar 25 16:43:01 2018 +0300

    window-slot: Instantly apply "Use new views" preference
    
    The use new views preference checkbox does not update the view.
    In order for it to take effect, one needs to toggle view.
    
    This behaviour is not intended, and this should work same as
    for other checkbox preferences.
    
    We're fixing this by recreating the view whenever the preference box
    is ticked/unticked.
    
    Closes https://gitlab.gnome.org/GNOME/nautilus/issues/278

 src/nautilus-window-slot.c | 37 +++++++++++++++++++++++++++++++------
 1 file changed, 31 insertions(+), 6 deletions(-)
---
diff --git a/src/nautilus-window-slot.c b/src/nautilus-window-slot.c
index c3260aeb0..2fa9c3339 100644
--- a/src/nautilus-window-slot.c
+++ b/src/nautilus-window-slot.c
@@ -886,7 +886,10 @@ change_files_view_mode (NautilusWindowSlot *self,
 {
     const gchar *preferences_key;
 
-    nautilus_window_slot_set_content_view (self, view_id);
+    if (!nautilus_window_slot_content_view_matches (self, view_id))
+    {
+        nautilus_window_slot_set_content_view (self, view_id);
+    }
     preferences_key = nautilus_view_is_searching (nautilus_window_slot_get_current_view (self)) ?
                       NAUTILUS_PREFERENCES_SEARCH_VIEW :
                       NAUTILUS_PREFERENCES_DEFAULT_FOLDER_VIEWER;
@@ -950,6 +953,24 @@ const GActionEntry slot_entries[] =
     { "search-visible", NULL, NULL, "false", action_search_visible },
 };
 
+static void
+use_experimental_views_changed_callback (GSettings *settings,
+                                         gchar     *key,
+                                         gpointer   callback_data)
+{
+    NautilusWindowSlot *self;
+
+    self = callback_data;
+
+    if (nautilus_window_slot_content_view_matches (self, NAUTILUS_VIEW_GRID_ID))
+    {
+        /* Note that although this call does not change the view id,
+         * it changes the canvas view between new and old.
+         */
+        nautilus_window_slot_set_content_view (self, NAUTILUS_VIEW_GRID_ID);
+    }
+}
+
 static void
 nautilus_window_slot_init (NautilusWindowSlot *self)
 {
@@ -962,6 +983,9 @@ nautilus_window_slot_init (NautilusWindowSlot *self)
     g_signal_connect (nautilus_trash_monitor_get (),
                       "trash-state-changed",
                       G_CALLBACK (trash_state_changed_cb), self);
+    g_signal_connect_object (nautilus_preferences,
+                             "changed::" NAUTILUS_PREFERENCES_USE_EXPERIMENTAL_VIEWS,
+                             G_CALLBACK (use_experimental_views_changed_callback), self, 0);
 
     priv->slot_action_group = G_ACTION_GROUP (g_simple_action_group_new ());
     g_action_map_add_action_entries (G_ACTION_MAP (priv->slot_action_group),
@@ -1942,6 +1966,12 @@ free_location_change (NautilusWindowSlot *self)
     }
 }
 
+/* This sets up a new view, for the current location, with the provided id. Used
+ * whenever the user changes the type of view to use.
+ *
+ * Note that the current view will be thrown away, even if it has the same id.
+ * Callers may first check if !nautilus_window_slot_content_view_matches().
+ */
 static void
 nautilus_window_slot_set_content_view (NautilusWindowSlot *self,
                                        guint               id)
@@ -1958,11 +1988,6 @@ nautilus_window_slot_set_content_view (NautilusWindowSlot *self,
     DEBUG ("Change view of window %s to %d", uri, id);
     g_free (uri);
 
-    if (nautilus_window_slot_content_view_matches (self, id))
-    {
-        return;
-    }
-
     selection = nautilus_view_get_selection (priv->content_view);
     view = nautilus_files_view_new (id, self);