content: 
  ' The MIT License (MIT)
  
  ' Copyright (c) 2015 Karim Kawambwa
  
  ' Permission is hereby granted, free of charge, to any person obtaining a copy
  ' of this software and associated documentation files (the "Software"), to deal
  ' in the Software without restriction, including without limitation the rights
  ' to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  ' copies of the Software, and to permit persons to whom the Software is
  ' furnished to do so, subject to the following conditions:
  
  ' The above copyright notice and this permission notice shall be included in
  ' all copies or substantial portions of the Software.
  
  ' THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  ' IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  ' FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  ' AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  ' LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  ' OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  ' THE SOFTWARE.
  
  function UIContraint(ref, side, value, priority, flexibility = "==" as String)
      this = {  
          x___pr : { 'don't access directly
              ref      : ref
              side     : side
              value    : value
              priority : priority
              flexibility : flexibility
          }
      }
      
      this.ref = function()
          return m.x___pr.ref
      end function
      
      this.side = function()
          return m.x___pr.side
      end function
      
      this.value = function()
          return m.x___pr.value
      end function
      
      this.priority = function()
          return m.x___pr.priority
      end function
      
      this.flexibility = function()
          return m.x___pr.flexibility
      end function
      
      this.setValue = function(value, refresh = true as Boolean, easing = linear as Function)
          m.x___pr.value = value
          'TODO: Easing
          if refresh then RefreshScreen()
      end function
      
      this.setPriority = function(value, refresh = true as Boolean, easing = linear as Function)
          m.x___pr.value = value
          'TODO: Easing
          if refresh then RefreshScreen()
      end function
      
      this.setFlexibility = function(value, refresh = true as Boolean, easing = linear as Function)
          m.x___pr.value = value
          'TODO: Easing
          if refresh then RefreshScreen()
      end function
      
      return this
  end function
  
  function UIConstraintFlexibility()
      return {
          GREATER_THAN_OR_EQUAL : ">="
          LESS_THAN_OR_EQUAL : "<="
          EXACT : "=="
      }
  end function