text: //
  // Not used
  //
  #include "window.hpp"
  
  namespace ledhw
  {
    const window_t::column_t window_t::m_empty_column;
    
    window_t::window_t (const libled::matrix_t &matrix)
      : m_position (0),
        m_matrix (matrix)
    {
    }
    window_t::window_t (const libled::matrix_t &matrix,
                        std::size_t start_position)
      : m_position (-static_cast<int>(start_position)),
        m_matrix (matrix)
    {
    }
    
    const window_t::column_t& window_t::get_column (std::size_t position)
    {
      int index = m_position + static_cast<int>(position);
      
      if ((index < 0)
          || (index >= static_cast<int>(m_matrix.size ())))
        return m_empty_column;
  
      return m_matrix.get_column (static_cast<std::size_t>(index));
    }
  
    void window_t::left_shift ()
    {
      ++m_position;
    }
  } // namespace ledhw
  