/*
  Cassowary.net: an incremental constraint solver for .NET
  (http://lumumba.uhasselt.be/jo/projects/cassowary.net/)
    
  Copyright (C) 2005  Jo Vermeulen (jo.vermeulen@uhasselt.be)
    
  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public License
  as published by the Free Software Foundation; either version 2.1
  of  the License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

using System;

namespace Cassowary
{
  public abstract class ClEditOrStayConstraint : ClConstraint
  {
    public ClEditOrStayConstraint(ClVariable var, 
                                  ClStrength strength, 
                                  double weight) : base(strength, weight)
    {
      _variable = var;
      _expression = new ClLinearExpression(_variable, -1.0, _variable.Value);
    }

    public ClEditOrStayConstraint(ClVariable var, 
                                  ClStrength strength) : this(var, strength, 1.0)
    {}

    public ClEditOrStayConstraint(ClVariable var) : this(var, ClStrength.Required, 1.0)
    {
      _variable = var;
    }

    public override string ToString()
    {
      // add missing bracket -> see ClConstraint#ToString(...)
      return base.ToString() + ")";
    }
    
    public ClVariable Variable
    {
      get { return _variable; }
    }

    public override ClLinearExpression Expression
    {
      get { return _expression; }
    }
    
    protected ClVariable _variable;
    // cache the expression
    private ClLinearExpression _expression;
  }
}