[nautilus] sidebar: Open folder on DnD hover

[António Fernandes <antoniof src gnome org>]

commit 7f7ced00be0f99c58a1fea0713e067ec7e6b4520
Author: Corey Berla <corey berla me>
Date:   Fri Jul 1 16:11:02 2022 -0700

    sidebar: Open folder on DnD hover
    
    Now that the sidebar is back under control of Nautilus, we
    can handle hovering similar to how it's handled in the view.
    While dragging across the sidebar, set a timeout when hovering over
    a new row that accepts drops and is not the placeholder row
    for new bookmarks.  Use the existing preference
    NAUTILUS_PREFERENCES_OPEN_FOLDER_ON_DND_HOVER
    to determine if folders should be opened on hover.
    
    Fixes: https://gitlab.gnome.org/GNOME/nautilus/-/issues/2056

 src/gtk/nautilusgtkplacessidebar.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
---
diff --git a/src/gtk/nautilusgtkplacessidebar.c b/src/gtk/nautilusgtkplacessidebar.c
index 5a54c2460..d04889f86 100644
--- a/src/gtk/nautilusgtkplacessidebar.c
+++ b/src/gtk/nautilusgtkplacessidebar.c
@@ -35,8 +35,10 @@
 #include "nautilusgtksidebarrowprivate.h"
 #include "gdk/gdkkeysyms.h"
 #include "nautilusgtkbookmarksmanagerprivate.h"
+#include "nautilus-dnd.h"
 #include "nautilus-file.h"
 #include "nautilus-file-operations.h"
+#include "nautilus-global-preferences.h"
 #include "nautilus-properties-window.h"
 #include "nautilus-trash-monitor.h"
 #pragma GCC diagnostic ignored "-Wshadow"
@@ -130,6 +132,8 @@ struct _NautilusGtkPlacesSidebar {
   int drag_row_y;
   GtkWidget *row_placeholder;
   DropState drop_state;
+  guint hover_timer_id;
+  GtkListBoxRow *hover_row;
 
   /* volume mounting - delayed open process */
   NautilusGtkPlacesOpenFlags go_to_after_mount_open_flags;
@@ -1460,6 +1464,28 @@ update_places (NautilusGtkPlacesSidebar *sidebar)
     }
 }
 
+static gboolean
+hover_timer (gpointer user_data)
+{
+  NautilusGtkPlacesSidebar *sidebar = user_data;
+  gboolean open_folder_on_hover;
+  g_autofree gchar *uri = NULL;
+  g_autoptr (GFile) location = NULL;
+
+  open_folder_on_hover = g_settings_get_boolean (nautilus_preferences,
+                                                 NAUTILUS_PREFERENCES_OPEN_FOLDER_ON_DND_HOVER);
+  sidebar->hover_timer_id = 0;
+
+  if (open_folder_on_hover)
+    {
+      g_object_get (sidebar->hover_row, "uri", &uri, NULL);
+      location = g_file_new_for_uri (uri);
+      emit_open_location (sidebar, location, 0);
+    }
+
+  return G_SOURCE_REMOVE;
+}
+
 static gboolean
 check_valid_drop_target (NautilusGtkPlacesSidebar *sidebar,
                          NautilusGtkSidebarRow    *row,
@@ -1645,6 +1671,12 @@ drag_motion_callback (GtkDropTarget    *target,
   action = 0;
   row = gtk_list_box_get_row_at_y (GTK_LIST_BOX (sidebar->list_box), y);
 
+  if (row != sidebar->hover_row)
+    {
+      g_clear_handle_id (&sidebar->hover_timer_id, g_source_remove);
+      sidebar->hover_row = row;
+    }
+
   /* Workaround https://gitlab.gnome.org/GNOME/gtk/-/issues/5023 */
   gtk_list_box_drag_unhighlight_row (GTK_LIST_BOX (sidebar->list_box));
 
@@ -1735,6 +1767,8 @@ drag_motion_callback (GtkDropTarget    *target,
               GFile *dest_file = g_file_new_for_uri (drop_target_uri);
 
               action = emit_drag_action_requested (sidebar, file, g_value_get_boxed (value));
+              if (sidebar->hover_timer_id == 0)
+                sidebar->hover_timer_id = g_timeout_add (HOVER_TIMEOUT, hover_timer, sidebar);
 
               g_object_unref (dest_file);
             }
@@ -1923,6 +1957,7 @@ drag_leave_callback (GtkDropTarget *dest,
       sidebar->drop_state = DROP_STATE_NORMAL;
     }
 
+  g_clear_handle_id (&sidebar->hover_timer_id, g_source_remove);
   sidebar->dragging_over = FALSE;
 }
 
@@ -4122,6 +4157,8 @@ nautilus_gtk_places_sidebar_dispose (GObject *object)
   g_clear_pointer (&sidebar->rename_uri, g_free);
   g_clear_object (&sidebar->shortcuts);
 
+  g_clear_handle_id (&sidebar->hover_timer_id, g_source_remove);
+
 #ifdef HAVE_CLOUDPROVIDERS
   for (l = sidebar->unready_accounts; l != NULL; l = l->next)
     {