/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( digitalRead( pin )? false : true ),

	_state_millis( ::millis() ),

	_state_duration( 0 )

{

}

void Button::add_event_at( int duration, int event_id )

{

	_press_events[ duration ] = event_id;

}

int Button::update()

{

	// reset event

	_event_id = 0;

	// get time

	unsigned long millis = ::millis();

	// get state and check for change

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

	if( state != _state )

	{

		_state = state;

		_state_millis = millis;

		_state_duration = 0;

	}

	// if button has been pressed for any amount of time

	if( state && _state_millis < millis )

	{

		// calculate new duration for this state

		unsigned long duration = millis - _state_millis;

		// check through events to see if the button has been

		// pressed long enough to trigger one

		for( std::map< int, int >::iterator i = _press_events.begin();

			 i != _press_events.end(); i++ )

		{

			// if this event is in the future, we can stop looking

			if( duration < (unsigned long)i->first )

				break;

			// if this event happened since the previous update, we

			// can trigger it

			if( _state_duration < (unsigned long)i->first )

				_event_id = i->second;

		}

		// update the duration we've accounted for

		_state_duration = duration;

	}

	return _event_id;

}

int Button::get_triggered_event()

{

	return _event_id;

}