private void UI_MouseDown(object sender, MouseButtonEventArgs e)
 {
     if (e.ChangedButton == MouseButton.Middle && e.ButtonState == MouseButtonState.Pressed)
     {
         _lastMousePoint = e.GetPosition(this);
         UI_GridElemantsWrapper.CaptureMouse();
     }
 }
        private void UI_MouseUp(object sender, MouseButtonEventArgs e)
        {
            Messenger.Default.Send <MouseLeftPressedMessage>(new MouseLeftPressedMessage()
            {
                Pressed = false
            });
            if (e.ChangedButton == MouseButton.Middle && e.ButtonState == MouseButtonState.Released)
            {
                UI_GridElemantsWrapper.ReleaseMouseCapture();

                //_lastMousePoint = new Point();
                //if (SelectedNode != null)
                //{
                //    PrevSelectedNode = SelectedNode;
                //    PrevSelectedNode.Id = SelectedNode.Id;
                //    SelectedNode = null;
                //}
            }
        }