/elec/propeller-clock

/*

 * button.cc

 *

 * Copyright (C) 2011 Tim Marston <tim@ed.am> and Dan Marston.

 *

 * This file is part of propeller-clock (hereafter referred to as "this

 * program"). See http://ed.am/dev/software/arduino/propeller-clock for more

 * information.

 *

 * 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 3 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, see <http://www.gnu.org/licenses/>.

 */

#include <Arduino.h>

#include <button.h>

Button::Button( int pin )

	:

	_pin( pin ),

	_state( false ),

	_millis_state( 0 ),

	_millis_done( 0 ),

	_pending_event( 0 ),

	_last_real_state( false ),

	_millis_real_state( 0 )

{

}

void Button::set_event_times( int event_times[] )

{

	_event_times = event_times;

}

void Button::update()

{

	// get time

	unsigned long millis = ::millis();

	// get button state

	bool real_state = digitalRead( _pin )? false : true;

	// if real state has changed, reset the timer

	if( real_state != _last_real_state ) {

		_last_real_state = real_state;

		_millis_real_state = millis;

	}

	// work out current state; if the real state timer has elapsed, set our

	// state to real state

	bool state = _state;

	if( _last_real_state != state && millis - _millis_real_state > 15 )

		state = _last_real_state;

	// if the button is pressed

	if( state )

	{

		// if it has just been pressed, record the time now and reset how much

		// of the press we have already generated events for

		if( !_state ) {

			_millis_state = millis;

			_millis_done = 0;

		}

		// calculate time that has elapsed in total this press

		unsigned long elapsed = millis - _millis_state;

		// look through the events to see if any need to be triggered

		for( int a = 0; _event_times[ a ]; a++ )

		{

			// if this event is in the future, stop

			if( (unsigned)_event_times[ a ] > elapsed ) break;

			// if this event has already been triggered, skip

			if( (unsigned)_event_times[ a ] <= _millis_done ) continue;

			// trigger event

			_pending_event = a + 1;

		}

		// update the amount of press we have processed

		_millis_done = elapsed;

	}

	// update our state

	_state = state;

}

int Button::get_event()

{

	int event = _pending_event;

	_pending_event = 0;

	return event;

}

bool Button::get_state()

{

	return _state;

}