yasm.cpp

/* 
				YASM - Yet Another State Machine library

Lightweight library for creating function pointer based state machines

Copyright 2016/2017 bricofoy bricofoy@free.fr


Library provide basic functions for managing state machine execution
and state running timings and counts, and it is intended to be very 
easy to use.

Please see examples and README for documentation.



This library 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 3 of the License, or (at your option) any later version.

This library 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 library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA */

#include "yasm.h"

void YASM::next(void (*pnextstate)(), bool reset/*=false*/)
{
	if ((!reset) && (pnextstate == _pState)) return; //we do nothing if we stay in the same state

	//we change the state so we set the associated values as needed
	_isFirstRun = true; 
	_lastTime = _enterTime = millis();
	_runCount = 0;
	
	//and enventually change exec pointer to the next state
	_pState = pnextstate; 
}

bool YASM::run()
{
	if(_pState==YASM::nop) return false; //check if the machine is currently stopped
										//and just return false if this is the case
	//now machine is running
	_pLastState=_pState; //store the current state
	_pState(); //run the current state
		
	//if pState is the same now than before running it means we did not got state 
	//change request during _pState() execution so next time we again will run the 
	//same state, so we clear the flag and increment runs counter
	if (_pState==_pLastState) {
		_isFirstRun = false; 
		_runCount++; 
	}
	return true; //and eventually report machine was running this time
}

void YASM::stop()
{
	//Same check done at the end of run() for the case when a 
	//state just run once and calls itself for stop().
	//Without doing so here _isFirstRun and _runCount are not updated prior to 
	//stop the machine, and this leads to wrong values used on resume()
	if (_pState==_pLastState) {
		_isFirstRun = false; 
		_runCount++; 
	}
	//Then stop the machine
	_pState = YASM::nop;
}

bool YASM::elapsed(unsigned long durationms)
{
	if (YASM::timeOnState()>durationms) return true;
	return false;
}

bool YASM::periodic(unsigned long durationms, bool first/*=true*/)
{
	unsigned long time = (millis()-_lastTime);
	if( time >= durationms ) 
	{
		_lastTime += time;
		return true;
	}
	if(first) return _isFirstRun;
	return false;
}