treeview: Avoid usage of gdk_window_get_device_position() during DnD

Just use the last coordinates given on XdndPosition/drag_motion() in
order to trigger scrolling.

When running on Xwayland, the pointer position is unknown at this
stage on the X11 side, so the coordinates given here are bogus.
This change avoids both roundtrips and this situation.

https://bugzilla.gnome.org/show_bug.cgi?id=749679

1 files changed, 14 insertions, 6 deletions

diff --git a/gtk/gtktreeview.c b/gtk/gtktreeview.c
index 5e1f476cb7..27c5a976cf 100644
--- a/gtk/gtktreeview.c
+++ b/gtk/gtktreeview.c
@@ -4197,11 +4197,8 @@ gtk_tree_view_vertical_autoscroll (GtkTreeView *tree_view)
     }
   else
     {
-      gdk_window_get_device_position (tree_view->priv->bin_window,
-                                      gdk_device_manager_get_client_pointer (
-                                        gdk_display_get_device_manager (
-                                          gtk_widget_get_display (GTK_WIDGET (tree_view)))),
-                                      NULL, &y, NULL);
+      y = tree_view->priv->event_last_y;
+      gtk_tree_view_convert_widget_to_bin_window_coords (tree_view, 0, y, NULL, &y);
     }
 
   y += tree_view->priv->dy;
@@ -7871,7 +7868,10 @@ static void
 gtk_tree_view_drag_end (GtkWidget      *widget,
                         GdkDragContext *context)
 {
-  /* do nothing */
+  GtkTreeView *tree_view = GTK_TREE_VIEW (widget);
+
+  tree_view->priv->event_last_x = -10000;
+  tree_view->priv->event_last_y = -10000;
 }
 
 /* Default signal implementations for the drag signals */
@@ -7966,6 +7966,8 @@ gtk_tree_view_drag_leave (GtkWidget      *widget,
                           GdkDragContext *context,
                           guint             time)
 {
+  GtkTreeView *tree_view = GTK_TREE_VIEW (widget);
+
   /* unset any highlight row */
   gtk_tree_view_set_drag_dest_row (GTK_TREE_VIEW (widget),
                                    NULL,
@@ -7973,6 +7975,9 @@ gtk_tree_view_drag_leave (GtkWidget      *widget,
 
   remove_scroll_timeout (GTK_TREE_VIEW (widget));
   remove_open_timeout (GTK_TREE_VIEW (widget));
+
+  tree_view->priv->event_last_x = -10000;
+  tree_view->priv->event_last_y = -10000;
 }
 
 
@@ -7996,6 +8001,9 @@ gtk_tree_view_drag_motion (GtkWidget        *widget,
   if (!set_destination_row (tree_view, context, x, y, &suggested_action, &target))
     return FALSE;
 
+  tree_view->priv->event_last_x = x;
+  tree_view->priv->event_last_y = y;
+
   gtk_tree_view_get_drag_dest_row (tree_view, &path, &pos);
 
   /* we only know this *after* set_desination_row */