//--------------------------------------------------------------------------------------------------

        void _Selection_SelectionChanging(SelectionManager selectionManager, SelectionManager.SelectionChangingCancelEventArgs eventArgs)
        {
            if (CurrentTool != null)
            {
                if (CurrentTool.OnEntitySelectionChanging(eventArgs.EntitiesToSelect, eventArgs.EntitiesToUnSelect))
                {
                    eventArgs.Cancel = true;
                    return;
                }
            }
            if (CurrentToolAction != null)
            {
                if (CurrentToolAction.OnEntitySelectionChanging(eventArgs.EntitiesToSelect, eventArgs.EntitiesToUnSelect))
                {
                    eventArgs.Cancel = true;
                    return;
                }
            }
        }