/*
  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 ClConstraint
  {
    public ClConstraint(ClStrength strength, double weight)
    {
      _strength = strength;
      _weight = weight;
    }

    public ClConstraint(ClStrength strength)
    {
      _strength = strength;
      _weight = 1.0;
    }

    public ClConstraint()
    {
      _strength = ClStrength.Required; 
      _weight = 1.0;
    }

    public abstract ClLinearExpression Expression
    {
      get;
    }

    public virtual bool IsEditConstraint
    {
      get { return false; }
    }

    public virtual bool IsInequality
    {
      get { return false; }
    }

    public virtual bool IsRequired
    {
      get { return _strength.IsRequired; } 
    }

    public virtual bool IsStayConstraint
    {
      get { return false; }
    }

    public ClStrength Strength
    {
      get { return _strength; }
      set { _strength = value; }
    }

    public double Weight
    {
      get { return _weight; }
      set { _weight = value; }
    }

    public object AttachedObject
    {
      get { return _attachedObject; }
      set { _attachedObject = value; } 
    }
    
    public override string ToString()
    {
      // two curly brackets escape the format, so use three to surround
      // a format expression in brackets!
      //
      // example output: weak:[0,0,1] {1} (23 + -1*[update.height:23]
      return string.Format("{0} {{{1}}} ({2}", Strength, Weight, Expression);
    }

    private ClStrength _strength;
    private double _weight;

    private object _attachedObject;
  }
}