condition.hxx

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#ifndef __SG_CONDITION_HXX
#define __SG_CONDITION_HXX

#include <simgear/debug/logstream.hxx>
#include <simgear/props/props.hxx>
#include <simgear/props/props_io.hxx>


// Conditions.


class SGCondition
{
public:
  SGCondition ();
  virtual ~SGCondition ();
  virtual bool test () const = 0;
};


class SGPropertyCondition : public SGCondition
{
public:
  SGPropertyCondition ( SGPropertyNode *prop_root,
                        const char * propname  );
  virtual ~SGPropertyCondition ();
  virtual bool test () const { return _node->getBoolValue(); }
private:
  SGConstPropertyNode_ptr _node;
};


class SGNotCondition : public SGCondition
{
public:
                                // transfer pointer ownership
  SGNotCondition (SGCondition * condition);
  virtual ~SGNotCondition ();
  virtual bool test () const;
private:
  SGCondition * _condition;
};


class SGAndCondition : public SGCondition
{
public:
  SGAndCondition ();
  virtual ~SGAndCondition ();
  virtual bool test () const;
                                // transfer pointer ownership
  virtual void addCondition (SGCondition * condition);
private:
  vector<SGCondition *> _conditions;
};


class SGOrCondition : public SGCondition
{
public:
  SGOrCondition ();
  virtual ~SGOrCondition ();
  virtual bool test () const;
                                // transfer pointer ownership
  virtual void addCondition (SGCondition * condition);
private:
  vector<SGCondition *> _conditions;
};


class SGComparisonCondition : public SGCondition
{
public:
  enum Type {
    LESS_THAN,
    GREATER_THAN,
    EQUALS
  };
  SGComparisonCondition (Type type, bool reverse = false);
  virtual ~SGComparisonCondition ();
  virtual bool test () const;
  virtual void setLeftProperty( SGPropertyNode *prop_root,
                                const char * propname );
  virtual void setRightProperty( SGPropertyNode *prop_root,
                                 const char * propname );
                                // will make a local copy
  virtual void setRightValue (const SGPropertyNode * value);
private:
  Type _type;
  bool _reverse;
  SGConstPropertyNode_ptr _left_property;
  SGConstPropertyNode_ptr _right_property;
  SGConstPropertyNode_ptr _right_value;
};


class SGConditional
{
public:
  SGConditional ();
  virtual ~SGConditional ();
                                // transfer pointer ownership
  virtual void setCondition (SGCondition * condition);
  virtual const SGCondition * getCondition () const { return _condition; }
  virtual bool test () const;
private:
  SGCondition * _condition;
};


SGCondition *sgReadCondition( SGPropertyNode *prop_root,
                              const SGPropertyNode *node );


#endif // __SG_CONDITION_HXX

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