* feedback constants (even though it converts in
             * the other direction as well)
             */
            float feedbackFloat = getHeightInItem(event);
            final DragNodeCommand command = new DragNodeCommand(event.item.getData(), feedbackFloat, event.operations, event.detail, selection.toList(), XMLTableTreeViewer.this);
            if (command != null && command.canExecute()) {
              SafeRunnable.run(new SafeRunnable() {
                public void run() throws Exception {
                  command.execute();
                }
              });
            }
          }
        }