private bool _HandlingEditorForegroundPaint;

private DevExpress.CodeRush.UserControls.CodePreviewWindow _PreviewWindow;

private SourceRange _PreviewRange;

private void RefactoringProvider_PreparePreview(object sender, DevExpress.Refactor.Core.PrepareRefactoringPreviewEventArgs ea)

{

  Variable variable = ea.Element as Variable;

  if (variable == null)

    return;

  _PreviewRange = variable.Range.Clone();

  if (!_HandlingEditorForegroundPaint)

  {

    _HandlingEditorForegroundPaint = true;

    EventNexus.EditorPaintForeground += new EditorPaintEventHandler(EventNexus_EditorPaintForeground);

  }

  InvalidatePreviews(ea);

  CreatePreviewWindow(ea, variable);

}

private void RefactoringProvider_HidePreview(object sender, DevExpress.Refactor.Core.HideRefactoringPreviewEventArgs ea)

{

  if (_PreviewWindow != null)

  {

    _PreviewWindow.HidePreview();

    _PreviewWindow = null;

  }

  if (_HandlingEditorForegroundPaint)

  {

    _HandlingEditorForegroundPaint = false;

    EventNexus.EditorPaintForeground -= new EditorPaintEventHandler(EventNexus_EditorPaintForeground);

  }

  InvalidatePreviews(ea);

  _PreviewRange = SourceRange.Empty;

}

private void CreatePreviewWindow(PrepareRefactoringPreviewEventArgs ea, Variable variable)

{

  string varCode = GenerateElement(variable);

  _PreviewWindow = new CodePreviewWindow(ea.TextView, _PreviewRange.Top);

  _PreviewWindow.AddCode(varCode);

  _PreviewWindow.ShowPreview();

}

private void InvalidatePreviews(RefactoringPreviewEventArgs ea)

{

  if (_PreviewRange.IsEmpty)

    return;

  int doubleSpaceWidth = ea.TextView.SpaceWidth * 2;

  int textViewLineHeight = ea.TextView.LineHeight;

  Rectangle previewRect = ea.TextView.GetRectangleFromRange(_PreviewRange);

  previewRect.Inflate(doubleSpaceWidth, textViewLineHeight);

  ea.TextView.Invalidate(previewRect);

}

private void EventNexus_EditorPaintForeground(EditorPaintEventArgs ea)

{

  if (_PreviewRange.IsEmpty)

    return;

  using (StrikeThrough strikeThrough = new StrikeThrough())

  {

    strikeThrough.TextView = ea.TextView;

    strikeThrough.FillColor = RefactorColors.StrikeThrough;

    strikeThrough.Range = _PreviewRange;

    strikeThrough.Paint(ea.Graphics);

  }

}