private void buttonSave_Click(object sender, RoutedEventArgs e)
        {
            if (selectedTile == TileSelections.Save) {
                // Activate default action
                ActionSave();
            }
            else {
                selectedTile = TileSelections.Save;

                listBoxOptions.Items.Clear();
                listBoxOptions.Visibility = Visibility.Visible;
                listBoxOptions.Items.Add(GetNewOptionsItem("Save current", ActionSave));
                listBoxOptions.SelectedIndex = 0;

                labelSelectedTile.Content = "Save";
                labelSelectedTile.Visibility = Visibility.Visible;

                Image image = new Image();
                image.SetBitmapSource("/Metro%20Tables;component/Images/SaveWork.png");
                ShowTopControl(image);
            }
        }
        private void buttonOpen_Click(object sender, RoutedEventArgs e)
        {
            if (selectedTile == TileSelections.Open) {
                // Activate default action
                ActionOpenFromFile();
            }
            else {
                selectedTile = TileSelections.Open;

                listBoxOptions.Items.Clear();
                listBoxOptions.Visibility = System.Windows.Visibility.Visible;
                listBoxOptions.Items.Add(GetNewOptionsItem("From file...", ActionOpenFromFile));
                listBoxOptions.Items.Add(GetNewOptionsItem("From URL...", ActionOpenFromURL));
                listBoxOptions.Items.Add(GetNewOptionsItem("Recent", ActionOpenFromRecent));
                listBoxOptions.SelectedIndex = 0;

                labelSelectedTile.Content = "Open worksheet";
                labelSelectedTile.Visibility = System.Windows.Visibility.Visible;

                Image image = new Image();
                image.SetBitmapSource("/Metro%20Tables;component/Images/OpenXLSX.png");
                ShowTopControl(image);
            }
        }