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 *
 * CamiTK - Computer Assisted Medical Intervention ToolKit
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#ifndef TOOLS_CHRONO_H
#define TOOLS_CHRONO_H

#include <iostream>
/**
 *
 * @ingroup group_cepmodeling_libraries_mml
 *
 * @brief
 * Elapsed real-time timer.
 * Allows one to measure elapsed real time. You can start, stop, reset
 * and of course get and print the current values of this chronometer.
 */
class Chrono {
public:
    /// default constructor
    Chrono();
    /// new chrono that starts directly at the given time
    Chrono(double);

    ~Chrono() = default;

    /// start at zero
    void start();
    /// start at a given value
    void start(double);
    /// stop chrono
    double stop();

    /// pause the chrono if the parameter is true
    void hold(bool);

    /// reset to zero
    void reset();

    /** if running, get the value (start time - now) without stopping the chrono,
      * else get (start time - stop time) value
      * this method is declared to be const, because we need to call it in <<
      * (and of course, no data member is modified
      */
    double get() const;

    /// print the value of the chrono on the stream
    friend std::ostream& operator << (std::ostream&, const Chrono);

private:
    double startValue;
    double stopValue;
    bool   running;
    double accumulatedTime;

    /// in milliseconds
    double getTimeInMilliseconds() const;
};

#endif // TOOLS_CHRONO_H
