[gtk+] treeview: Avoid usage of gdk_window_get_device_position() during DnD

[Carlos Garnacho <carlosg src gnome org>]

commit b666f14ef826051660241fddfa7c4b5b47cbb197
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu May 21 13:53:43 2015 +0200

    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

 gtk/gtktreeview.c |   20 ++++++++++++++------
 1 files changed, 14 insertions(+), 6 deletions(-)
---
diff --git a/gtk/gtktreeview.c b/gtk/gtktreeview.c
index 5e1f476..27c5a97 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 */