iconview: 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

diff --git a/gtk/gtkiconview.c b/gtk/gtkiconview.c
index f11fed149b9d27fcf27f21ac06cdcfa075a85afc..705356d02c8e09933a1a6a0e19c51239e763d022 100644 (file)
--- a/gtk/gtkiconview.c
+++ b/gtk/gtkiconview.c
@@ -6208,8 +6208,7 @@ remove_scroll_timeout (GtkIconView *icon_view)
 }
 
 static void
-gtk_icon_view_autoscroll (GtkIconView *icon_view,
-                          GdkDevice   *device)
+gtk_icon_view_autoscroll (GtkIconView *icon_view)
 {
   GdkWindow *window;
   gint px, py, width, height;
@@ -6217,7 +6216,8 @@ gtk_icon_view_autoscroll (GtkIconView *icon_view,
 
   window = gtk_widget_get_window (GTK_WIDGET (icon_view));
 
-  gdk_window_get_device_position (window, device, &px, &py, NULL);
+  px = icon_view->priv->event_last_x;
+  py = icon_view->priv->event_last_y;
   gdk_window_get_geometry (window, NULL, NULL, &width, &height);
 
   /* see if we are near the edge. */
@@ -6238,27 +6238,14 @@ gtk_icon_view_autoscroll (GtkIconView *icon_view,
                               gtk_adjustment_get_value (icon_view->priv->hadjustment) + hoffset);
 }
 
-typedef struct {
-  GtkIconView *icon_view;
-  GdkDevice   *device;
-} DragScrollData;
-
 static gboolean
-drag_scroll_timeout (gpointer datap)
+drag_scroll_timeout (gpointer data)
 {
-  DragScrollData *data = datap;
-
-  gtk_icon_view_autoscroll (data->icon_view, data->device);
+  gtk_icon_view_autoscroll (data);
 
   return TRUE;
 }
 
-static void
-drag_scroll_data_free (DragScrollData *data)
-{
-  g_slice_free (DragScrollData, data);
-}
-
 static gboolean
 set_destination (GtkIconView    *icon_view,
                 GdkDragContext *context,
@@ -6638,6 +6625,9 @@ gtk_icon_view_drag_motion (GtkWidget      *widget,
   if (!set_destination (icon_view, context, x, y, &suggested_action, &target))
     return FALSE;
 
+  icon_view->priv->event_last_x = x;
+  icon_view->priv->event_last_y = y;
+
   gtk_icon_view_get_drag_dest_item (icon_view, &path, &pos);
 
   /* we only know this *after* set_desination_row */
@@ -6652,12 +6642,8 @@ gtk_icon_view_drag_motion (GtkWidget      *widget,
     {
       if (icon_view->priv->scroll_timeout_id == 0)
        {
-          DragScrollData *data = g_slice_new (DragScrollData);
-          data->icon_view = icon_view;
-          data->device = gdk_drag_context_get_device (context);
-
          icon_view->priv->scroll_timeout_id =
-           gdk_threads_add_timeout_full (G_PRIORITY_DEFAULT, 50, drag_scroll_timeout, data, (GDestroyNotify) drag_scroll_data_free);
+           gdk_threads_add_timeout (50, drag_scroll_timeout, icon_view);
          g_source_set_name_by_id (icon_view->priv->scroll_timeout_id, "[gtk+] drag_scroll_timeout");
        }