fsfw/timemanager/Countdown.h

#ifndef FSFW_TIMEMANAGER_COUNTDOWN_H_
#define FSFW_TIMEMANAGER_COUNTDOWN_H_

#include "Clock.h"

/**
 *
 * Countdown keeps track of a timespan.
 *
 * Countdown::resetTimer restarts the timer.
 * Countdown::setTimeout sets a new countdown duration and resets.
 *
 * Can be checked with Countdown::hasTimedOut or
 * Countdown::isBusy.
 *
 * Countdown::timeOut will force the timer to time out.
 *
 */
class Countdown {
public:
	/**
	 * Constructor which sets the countdown duration in milliseconds
	 *
	 * It does not start the countdown!
	 * Call resetTimer or setTimeout before usage!
	 * Otherwise a call to hasTimedOut might return True.
	 *
	 * @param initialTimeout Countdown duration in milliseconds
	 */
	Countdown(uint32_t initialTimeout = 0);
	~Countdown();
	/**
	 * Call to set a new countdown duration.
	 *
	 * Resets the countdown!
	 *
	 * @param milliseconds new countdown duration in milliseconds
	 * @return Returnvalue from Clock::getUptime
	 */
	ReturnValue_t setTimeout(uint32_t milliseconds);
	/**
	 * Returns true if the countdown duration has passed.
	 *
	 * @return True if the countdown has passed
	 * 		   False if it is still running
	 */
	bool hasTimedOut() const;
	/**
	 * Complementary to hasTimedOut.
	 *
	 * @return True if the countdown is till running
	 * 		   False if it is still running
	 */
	bool isBusy() const;
	/**
	 *  Uses last set timeout value and restarts timer.
	 */
	ReturnValue_t resetTimer();
	/**
	 * Returns the remaining milliseconds (0 if timeout)
	 */
	uint32_t getRemainingMillis() const;
	/**
	 * Makes hasTimedOut() return true
	 */
	void timeOut();
	/**
	 * Internal countdown duration in milliseconds
	 */
	uint32_t timeout;
private:
	/**
	 * Last time the timer was started (uptime)
	 */
	uint32_t startTime = 0;

	uint32_t getCurrentTime() const;
};

#endif /* FSFW_TIMEMANAGER_COUNTDOWN_H_ */