unsigned int item_start = wxMax( 0, (update.y / m_lineHeight) );
unsigned int item_count =
wxMin( (int)(((update.y + update.height) / m_lineHeight) - item_start + 1),
unsigned int item_start = wxMax( 0, (update.y / m_lineHeight) );
unsigned int item_count =
wxMin( (int)(((update.y + update.height) / m_lineHeight) - item_start + 1),