old_contents: #------------------------------------------------------------------------------
  #  Copyright (c) 2013, Enthought, Inc.
  #  All rights reserved.
  #------------------------------------------------------------------------------
  
  
  STRENGTHS = set(['required', 'strong', 'medium', 'weak'])
  
  
  def add_symbolic_constraints(namespace):
      """ Add constraints to a namespace that are LinearExpressions of basic
      constraints.
  
      """
      bottom = namespace.bottom
      left = namespace.left
      width = namespace.layout_width
      height = namespace.layout_height
  
      namespace.right = left + width
      namespace.top = bottom + height
      namespace.h_center = left + width / 2.0
      namespace.v_center = bottom + height / 2.0
  
  
  def add_symbolic_contents_constraints(namespace):
      """ Add constraints to a namespace that are LinearExpressions of basic
      constraints.
  
      """
      left = namespace.contents_left
      right = namespace.contents_right
      top = namespace.contents_top
      bottom = namespace.contents_bottom
  
      namespace.contents_width = left - right
      namespace.contents_height = top - bottom
      namespace.contents_v_center = bottom + namespace.contents_height / 2.0
      namespace.contents_h_center = left + namespace.contents_width / 2.0
  
  
new_contents: #------------------------------------------------------------------------------
  #  Copyright (c) 2013, Enthought, Inc.
  #  All rights reserved.
  #------------------------------------------------------------------------------
  
  
  STRENGTHS = set(['required', 'strong', 'medium', 'weak'])
  
  
  def add_symbolic_constraints(namespace):
      """ Add constraints to a namespace that are LinearExpressions of basic
      constraints.
  
      """
      bottom = namespace.bottom
      left = namespace.left
      width = namespace.layout_width
      height = namespace.layout_height
  
      namespace.right = left + width
      namespace.top = bottom + height
      namespace.h_center = left + width / 2.0
      namespace.v_center = bottom + height / 2.0
  
  
  def add_symbolic_contents_constraints(namespace):
      """ Add constraints to a namespace that are LinearExpressions of basic
      constraints.
  
      """
      left = namespace.contents_left
      right = namespace.contents_right
      top = namespace.contents_top
      bottom = namespace.contents_bottom
  
      namespace.contents_width = right - left
      namespace.contents_height = top - bottom
      namespace.contents_v_center = bottom + namespace.contents_height / 2.0
      namespace.contents_h_center = left + namespace.contents_width / 2.0
  
  
subject: Fix a typo in the contents constraints creation.