files-view: Cancel kinetic deceleration on loading

If we change location while the view is still scrolling due to
kinetic deceleration, we get a sudden jump to the same scrolling
position as the previous location, as well as residual scrolling
movement in the new location.

This is both undesirable and unexpected from a user POV.

Workaround that by canceling deceleration when switching locations.

Fixes https://gitlab.gnome.org/GNOME/nautilus/-/issues/1452


(cherry picked from commit a4d7148210970c5eb874df736b900f577684a13b)

1 files changed, 20 insertions, 0 deletions

diff --git a/src/nautilus-files-view.c b/src/nautilus-files-view.c
index 86472df87..dbfb39c34 100644
--- a/src/nautilus-files-view.c
+++ b/src/nautilus-files-view.c
@@ -8516,6 +8516,26 @@ load_directory (NautilusFilesView *view,
 
     setup_loading_floating_bar (view);
 
+    /* HACK: Fix for https://gitlab.gnome.org/GNOME/nautilus/-/issues/1452 */
+    {
+        GtkScrolledWindow *content = GTK_SCROLLED_WINDOW (priv->scrolled_window);
+
+        /* If we load a new location while the view is still scrolling due to
+         * kinetic deceleration, we get a sudden jump to the same scrolling
+         * position as the previous location, as well as residual scrolling
+         * movement in the new location.
+         *
+         * This is both undesirable and unexpected from a user POV, so we want
+         * to abort deceleration when switching locations.
+         *
+         * However, gtk_scrolled_window_cancel_deceleration() is private. So,
+         * we make use of an undocumented behavior of ::set_kinetic_scrolling(),
+         * which calls ::cancel_deceleration() when set to FALSE.
+         */
+        gtk_scrolled_window_set_kinetic_scrolling (content, FALSE);
+        gtk_scrolled_window_set_kinetic_scrolling (content, TRUE);
+    }
+
     /* Update menus when directory is empty, before going to new
      * location, so they won't have any false lingering knowledge
      * of old selection.