/// <summary>
/// Process the event in which the user drags the grid splitter between
/// canvas view (that displays the actual shapes) and XML editor.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void GridSplitter_DragDelta(object sender, System.Windows.Controls.Primitives.DragDeltaEventArgs e)
{
if (this.DataContext is DocumentViewModel)
{
DocumentViewModel d = this.DataContext as DocumentViewModel;
d.GridSplitter_DragDelta(e.VerticalChange, _scrollViewer.ActualHeight);
e.Handled = true;
}
}